Ändra sökning
Avgränsa sökresultatet
1234567 101 - 150 av 493
RefereraExporteraLänk till träfflistan
Permanent länk
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Träffar per sida
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sortering
  • Standard (Relevans)
  • Författare A-Ö
  • Författare Ö-A
  • Titel A-Ö
  • Titel Ö-A
  • Publikationstyp A-Ö
  • Publikationstyp Ö-A
  • Äldst först
  • Nyast först
  • Skapad (Äldst först)
  • Skapad (Nyast först)
  • Senast uppdaterad (Äldst först)
  • Senast uppdaterad (Nyast först)
  • Disputationsdatum (tidigaste först)
  • Disputationsdatum (senaste först)
  • Standard (Relevans)
  • Författare A-Ö
  • Författare Ö-A
  • Titel A-Ö
  • Titel Ö-A
  • Publikationstyp A-Ö
  • Publikationstyp Ö-A
  • Äldst först
  • Nyast först
  • Skapad (Äldst först)
  • Skapad (Nyast först)
  • Senast uppdaterad (Äldst först)
  • Senast uppdaterad (Nyast först)
  • Disputationsdatum (tidigaste först)
  • Disputationsdatum (senaste först)
Markera
Maxantalet träffar du kan exportera från sökgränssnittet är 250. Vid större uttag använd dig av utsökningar.
  • 101. Endris, Hussen Seid
    et al.
    Omondi, Philip
    Jain, Suman
    Lennard, Christopher
    Hewitson, Bruce
    Chang'a, Ladislaus
    Awange, J. L.
    Dosio, Alessandro
    Ketiem, Patrick
    Nikulin, Grigory
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Panitz, Hans-Juergen
    Buechner, Matthias
    Stordal, Frode
    Tazalika, Lukiya
    Assessment of the Performance of CORDEX Regional Climate Models in Simulating East African Rainfall2013Ingår i: Journal of Climate, ISSN 0894-8755, E-ISSN 1520-0442, Vol. 26, nr 21, s. 8453-8475Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    This study evaluates the ability of 10 regional climate models (RCMs) from the Coordinated Regional Climate Downscaling Experiment (CORDEX) in simulating the characteristics of rainfall patterns over eastern Africa. The seasonal climatology, annual rainfall cycles, and interannual variability of RCM output have been assessed over three homogeneous subregions against a number of observational datasets. The ability of the RCMs in simulating large-scale global climate forcing signals is further assessed by compositing the El Nino-Southern Oscillation (ENSO) and Indian Ocean dipole (IOD) events. It is found that most RCMs reasonably simulate the main features of the rainfall climatology over the three subregions and also reproduce the majority of the documented regional responses to ENSO and IOD forcings. At the same time the analysis shows significant biases in individual models depending on subregion and season; however, the ensemble mean has better agreement with observation than individual models. In general, the analysis herein demonstrates that the multimodel ensemble mean simulates eastern Africa rainfall adequately and can therefore be used for the assessment of future climate projections for the region.

  • 102. Eneroth, K
    et al.
    Kjellström, Erik
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Holmen, K
    A trajectory climatology for Svalbard; investigating how atmospheric flow patterns influence observed tracer concentrations2003Ingår i: Physics and Chemistry of the Earth, ISSN 1474-7065, E-ISSN 1873-5193, Vol. 28, nr 28-32, s. 1191-1203Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A 10-year climatology of long-range atmospheric transport to Ny-(A) over circle lesund, Svalbard (78.9degreesN, 11.9degreesE) is developed using three-dimensional 5-day back-trajectories. We calculate trajectories arriving twice daily at 950, 850 and 750 hPa during 1992-2001, using European Centre for Medium-Range Weather Forecasts (ECMWF) analyzed wind, fields. Cluster analysis is used to classify the trajectories into distinct transport patterns. The clustering procedure is performed on the whole 10-year set of trajectories, to study both year-to-year and mouth-to-mouth variability in the synoptic-scale atmospheric circulation. We identify eight major transport patterns to Ny-(A) over circle lesund, which we find to be consistent with mean-pressure charts of the Arctic region. The distribution of trajectories between these flows is similar for all years during the 10-year period. However, there are seasonal differences in when different clusters are most prevalent. The calculated clusters provide an indication of source regions and transport pathways influencing Svalbard at different times of the year. Such information is valuable for interpreting measured time-series of trace gases and aerosols and could serve as guidance for formulating sampling strategies. We compare the trajectory clusters to CO2 measurements to study to what degree different atmospheric flow patterns influence the variability of the atmospheric CO2. Overall we see a linkage between CO2 concentration and the large-scale circulation. For instance, in connection with transport over Europe and Siberia during winter, high CO2 mixing ratios are observed, whereas trajectories originating from the Atlantic are associated with low CO2 concentrations. However, during some periods and for some individual trajectories we see no conclusive linkage between variability in atmospheric CO2 and transport. This can be due to a combination of the complex structure Of CO2 sources and sinks and its relatively long atmospheric turn-over time. CO2 and Rn-222 mixing ratios are calculated using the three-dimensional transport model MATCH to further illustrate these characteristics of CO2. (C) 2003 Elsevier Ltd. All rights reserved.

  • 103. Eyring, Veronika
    et al.
    Righi, Mattia
    Lauer, Axel
    Evaldsson, Martin
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Wenzel, Sabrina
    Jones, Colin
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Anav, Alessandro
    Andrews, Oliver
    Cionni, Irene
    Davin, Edouard L.
    Deser, Clara
    Ehbrecht, Carsten
    Friedlingstein, Pierre
    Gleckler, Peter
    Gottschaldt, Klaus-Dirk
    Hagemann, Stefan
    Juckes, Martin
    Kindermann, Stephan
    Krasting, John
    Kunert, Dominik
    Levine, Richard
    Loew, Alexander
    Maekelae, Jarmo
    Martin, Gill
    Mason, Erik
    Phillips, Adam S.
    Read, Simon
    Rio, Catherine
    Roehrig, Romain
    Senftleben, Daniel
    Sterl, Andreas
    van Ulft, Lambertus H.
    Walton, Jeremy
    Wang, Shiyu
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Williams, Keith D.
    ESMValTool (v1.0) - a community diagnostic and performance metrics tool for routine evaluation of Earth system models in CMIP2016Ingår i: Geoscientific Model Development, ISSN 1991-959X, E-ISSN 1991-9603, Vol. 9, nr 5, s. 1747-1802Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A community diagnostics and performance metrics tool for the evaluation of Earth system models (ESMs) has been developed that allows for routine comparison of single or multiple models, either against predecessor versions or against observations. The priority of the effort so far has been to target specific scientific themes focusing on selected essential climate variables (ECVs), a range of known systematic biases common to ESMs, such as coupled tropical climate variability, monsoons, Southern Ocean processes, continental dry biases, and soil hydrology-climate interactions, as well as atmospheric CO2 budgets, tropospheric and stratospheric ozone, and tropospheric aerosols. The tool is being developed in such a way that additional analyses can easily be added. A set of standard namelists for each scientific topic reproduces specific sets of diagnostics or performance metrics that have demonstrated their importance in ESM evaluation in the peer-reviewed literature. The Earth System Model Evaluation Tool (ESMValTool) is a community effort open to both users and developers encouraging open exchange of diagnostic source code and evaluation results from the Coupled Model Intercomparison Project (CMIP) ensemble. This will facilitate and improve ESM evaluation beyond the state-of-the-art and aims at supporting such activities within CMIP and at individual modelling centres. Ultimately, we envisage running the ESMValTool alongside the Earth System Grid Federation (ESGF) as part of a more routine evaluation of CMIP model simulations while utilizing observations available in standard formats (obs4MIPs) or provided by the user.

  • 104. Favre, Alice
    et al.
    Philippon, Nathalie
    Pohl, Benjamin
    Kalognomou, Evangelia-Anna
    Lennard, Christopher
    Hewitson, Bruce
    Nikulin, Grigory
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Dosio, Alessandro
    Panitz, Hans-Juergen
    Cerezo-Mota, Ruth
    Spatial distribution of precipitation annual cycles over South Africa in 10 CORDEX regional climate model present-day simulations2016Ingår i: Climate Dynamics, ISSN 0930-7575, E-ISSN 1432-0894, Vol. 46, nr 5-6, s. 1799-1818Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This study presents an evaluation of the ability of 10 regional climate models (RCMs) participating in the COordinated Regional climate Downscaling Experiment-Africa to reproduce the present-day spatial distribution of annual cycles of precipitation over the South African region and its borders. As found in previous studies, annual mean precipitation is quasi-systematically overestimated by the RCMs over a large part of southern Africa south of about 20A degrees S and more strongly over South Africa. The spatial analysis of precipitation over the studied region shows that in most models the distribution of biases appears to be linked to orography. Wet biases are quasi-systematic in regions with higher elevation with inversely neutral to dry biases particularly in the coastal fringes. This spatial pattern of biases is particularly obvious during summer and specifically at the beginning of the rainy season (November and December) when the wet biases are found to be the strongest across all models. Applying a k-means algorithm, a classification of annual cycles is performed using observed precipitation data, and is compared with those derived from modeled data. It is found that the in-homogeneity of the spatial and temporal distribution of biases tends to impact the modeled seasonality of precipitation. Generally, the pattern of rainfall seasonality in the ensemble mean of the 10 RCMs tends to be shifted to the southwest. This spatial shift is mainly linked to a strong overestimation of convective precipitation at the beginning of the rainy season over the plateau inducing an early annual peak and to an underestimation of stratiform rainfall in winter and spring over southwestern South Africa.

  • 105.
    Fitch, Anna
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Climate Impacts of Large-Scale Wind Farms as Parameterized in a Global Climate Model2015Ingår i: Journal of Climate, ISSN 0894-8755, E-ISSN 1520-0442, Vol. 28, nr 15, s. 6160-6180Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The local, regional, and global climate impacts of a large-scale global deployment of wind power in regionally high densities over land are investigated for a 60-yr period. Wind farms are represented as elevated momentum sinks as well as enhanced turbulence to represent turbine blade mixing in the Community Atmosphere Model, version 5 (CAM5), a global climate model. For a total installed capacity of 2.5 TW, to provide 16% of the world's projected electricity demand in 2050, minimal impacts are found both regionally and globally on temperature, sensible and latent heat fluxes, cloud, and precipitation. A mean near-surface warming of 0.12 +/- 0.07 K is seen within the wind farms, with a global-mean temperature change of -0.013 +/- 0.015 K. Impacts on wind speed and turbulence are more pronounced but largely confined within the wind farm areas. Increasing the wind farm areas to provide an installed capacity of 10 TW, or 65% of the 2050 electricity demand, causes further impacts; however, they remain slight overall. Maximum temperature changes are less than 0.5 K in the wind farm areas. To provide 20 TW of installed capacity, or 130% of the 2050 electricity demand, impacts both within the wind farms and beyond become more pronounced, with a doubling in turbine density. However, maximum temperature changes remain less than 0.7 K. Representing wind farms instead as an increase in surface roughness generally produces similar mean results; however, maximum changes increase, and influences on wind and turbulence are exaggerated. Overall, wind farm impacts are much weaker than those expected from greenhouse gas emissions, with very slight global-mean climate impacts.

  • 106.
    Fitch, Anna
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Notes on using the mesoscale wind farm parameterization of Fitch et al. (2012) in WRF2016Ingår i: Wind Energy, ISSN 1095-4244, E-ISSN 1099-1824, Vol. 19, nr 9, s. 1757-1758Artikel i tidskrift (Refereegranskat)
  • 107.
    Fladrich, Uwe
    et al.
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Stiller, Joerg
    Nagel, Wolfgang E.
    IMPROVED PERFORMANCE FOR NODAL SPECTRAL ELEMENT OPERATORS2008Ingår i: The international journal of high performance computing applications, ISSN 1094-3420, E-ISSN 1741-2846, Vol. 22, nr 4, s. 450-459Artikel i tidskrift (Refereegranskat)
  • 108. Friman, Mathias
    et al.
    Strandberg, Gustav
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Historical responsibility for climate change: science and the science-policy interface2014Ingår i: Wiley Interdisciplinary Reviews: Climate Change, ISSN 1757-7780, E-ISSN 1757-7799, Vol. 5, nr 3, s. 297-316Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    Since 1990, the academic literature on historical responsibility (HR) for climate change has grown considerably. Over these years, the approaches to defining this responsibility have varied considerably. This article demonstrates how this variation can be explained by combining various defining aspects of historical contribution and responsibility. Scientific knowledge that takes for granted choices among defining aspects will likely become a basis for distrust within science, among negotiators under the United Nations Framework Convention on Climate Change (UNFCCC), and elsewhere. On the other hand, for various reasons, not all choices can be explicated at all times. In this article, we examine the full breadth of complexities involved in scientifically defining HR and discuss how these complexities have consequences for the science-policy interface concerning HR. To this end, we review and classify the academic literature on historical contributions to and responsibility for climate change into categories of defining aspects. One immediately policy-relevant conclusion emerges from this exercise: Coupled with negotiators' highly divergent understandings of historical responsibility, the sheer number of defining aspects makes it virtually impossible to offer scientific advice without creating distrust in certain parts of the policy circle. This conclusion suggests that scientific attempts to narrow the options for policymakers will have little chance of succeeding unless policymakers first negotiate a clearer framework for historical responsibility. For further resources related to this article, please visit the . Conflict of interest: The authors have declared no conflicts of interest for this article.

  • 109.
    Fuentes Franco, Ramon
    et al.
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Giorgi, Filippo
    Pavia, Edgar G.
    Graef, Federico
    Coppola, Erika
    Seasonal precipitation forecast over Mexico based on a hybrid statistical-dynamical approach2018Ingår i: International Journal of Climatology, ISSN 0899-8418, E-ISSN 1097-0088, Vol. 38, nr 11, s. 4051-4065Artikel i tidskrift (Refereegranskat)
  • 110.
    Fuentes Franco, Ramon
    et al.
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Koenigk, Torben
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Sensitivity of the Arctic freshwater content and transport to model resolution2019Ingår i: Climate Dynamics, ISSN 0930-7575, E-ISSN 1432-0894, Vol. 53, nr 3-4, s. 1765-1781Artikel i tidskrift (Refereegranskat)
  • 111. Gaillard, M. -J
    et al.
    Sugita, S.
    Mazier, F.
    Trondman, A. -K
    Brostrom, A.
    Hickler, T.
    Kaplan, J. O.
    Kjellström, Erik
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Kokfelt, U.
    Kunes, P.
    Lemmen, C.
    Miller, P.
    Olofsson, J.
    Poska, A.
    Rundgren, M.
    Smith, B.
    Strandberg, Gustav
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Fyfe, R.
    Nielsen, A. B.
    Alenius, T.
    Balakauskas, L.
    Barnekow, L.
    Birks, H. J. B.
    Bjune, A.
    Bjorkman, L.
    Giesecke, T.
    Hjelle, K.
    Kalnina, L.
    Kangur, M.
    van der Knaap, W. O.
    Koff, T.
    Lageras, P.
    Latalowa, M.
    Leydet, M.
    Lechterbeck, J.
    Lindbladh, M.
    Odgaard, B.
    Peglar, S.
    Segerstrom, U.
    von Stedingk, H.
    Seppa, H.
    Holocene land-cover reconstructions for studies on land cover-climate feedbacks2010Ingår i: Climate of the Past, ISSN 1814-9324, E-ISSN 1814-9332, Vol. 6, nr 4, s. 483-499Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The major objectives of this paper are: (1) to review the pros and cons of the scenarios of past anthropogenic land cover change (ALCC) developed during the last ten years, (2) to discuss issues related to pollen-based reconstruction of the past land-cover and introduce a new method, REVEALS (Regional Estimates of VEgetation Abundance from Large Sites), to infer long-term records of past land-cover from pollen data, (3) to present a new project (LANDCLIM: LAND cover - CLIMate interactions in NW Europe during the Holocene) currently underway, and show preliminary results of REVEALS reconstructions of the regional land-cover in the Czech Republic for five selected time windows of the Holocene, and (4) to discuss the implications and future directions in climate and vegetation/land-cover modeling, and in the assessment of the effects of human-induced changes in land-cover on the regional climate through altered feedbacks. The existing ALCC scenarios show large discrepancies between them, and few cover time periods older than AD 800. When these scenarios are used to assess the impact of human land-use on climate, contrasting results are obtained. It emphasizes the need for methods such as the REVEALS model-based land-cover reconstructions. They might help to fine-tune descriptions of past land-cover and lead to a better understanding of how long-term changes in ALCC might have influenced climate. The REVEALS model is demonstrated to provide better estimates of the regional vegetation/land-cover changes than the traditional use of pollen percentages. This will achieve a robust assessment of land cover at regional- to continental-spatial scale throughout the Holocene. We present maps of REVEALS estimates for the percentage cover of 10 plant functional types (PFTs) at 200 BP and 6000 BP, and of the two open-land PFTs 'grassland' and 'agricultural land' at five time-windows from 6000 BP to recent time. The LANDCLIM results are expected to provide crucial data to reassess ALCC estimates for a better understanding of the land suface-atmosphere interactions.

  • 112. Gaillard, Marie-Jose
    et al.
    Kleinen, Thomas
    Samuelsson, Patrick
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Nielsen, Anne Birgitte
    Bergh, Johan
    Kaplan, Jed
    Poska, Anneli
    Sandstrom, Camilla
    Strandberg, Gustav
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Trondman, Anna-Kari
    Wramneby, Anna
    Causes of Regional Change-Land Cover2015Kapitel i bok, del av antologi (Övrigt vetenskapligt)
    Abstract [en]

    Anthropogenic land-cover change (ALCC) is one of the few climate forcings for which the net direction of the climate response over the last two centuries is still not known. The uncertainty is due to the often counteracting temperature responses to the many biogeophysical effects and to the biogeochemical versus biogeophysical effects. Palaeoecological studies show that the major transformation of the landscape by anthropogenic activities in the southern zone of the Baltic Sea basin occurred between 6000 and 3000/2500 cal year BP. The only modelling study of the biogeophysical effects of past ALCCs on regional climate in north-western Europe suggests that deforestation between 6000 and 200 cal year BP may have caused significant change in winter and summer temperature. There is no indication that deforestation in the Baltic Sea area since AD 1850 would have been a major cause of the recent climate warming in the region through a positive biogeochemical feedback. Several model studies suggest that boreal reforestation might not be an effective climate warming mitigation tool as it might lead to increased warming through biogeophysical processes.

  • 113. Galmarini, S
    et al.
    Bianconi, R
    Klug, W
    Mikkelsen, T
    Addis, R
    Androllopoulos, S
    Astrup, P
    Baklanov, A
    Bartniki, J
    Bartzis, J C
    Bellasio, R
    Bompay, F
    Buckley, R
    Bouzom, M
    Champion, H
    D'Amours, R
    Davakis, E
    Eleveld, H
    Geertsema, G T
    Glaab, H
    Kolax, Michael
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Ilvonen, M
    Manning, A
    Pechinger, U
    Persson, C
    Polreich, E
    Potemski, S
    Prodanova, M
    Saltbones, J
    Slaper, H
    Sofiev, M A
    Syrakov, D
    Sorensen, J H
    Van der Auwera, L
    Valkama, I
    Zelazny, R
    Can the confidence in long range atmospheric transport models be increased?: The Pan-European experience of ENSEMBLE2004Ingår i: Radiation Protection Dosimetry, ISSN 0144-8420, E-ISSN 1742-3406, Vol. 109, nr 1-2, s. 19-24Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Is atmospheric dispersion forecasting an important asset of the early-phase nuclear emergency response management? Is there a 'perfect atmospheric dispersion model'? Is there a way to make the results of dispersion models more reliable and trustworthy? While seeking to answer these questions the multi-model ensemble dispersion forecast system ENSEMBLE will be presented.

  • 114. Galmarini, S
    et al.
    Bianconi, R
    Klug, W
    Mikkelsen, T
    Addis, R
    Andronopoulos, S
    Astrup, P
    Baklanov, A
    Bartniki, J
    Bartzis, J C
    Bellasio, R
    Bompay, F
    Buckley, R
    Bouzom, M
    Champion, H
    D'Amours, R
    Davakis, E
    Eleveld, H
    Geertsema, G T
    Glaab, H
    Kolax, Michael
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Ilvonen, M
    Manning, A
    Pechinger, U
    Persson, Christer
    SMHI, Forskningsavdelningen, Luftmiljö.
    Polreich, E
    Potemski, S
    Prodanova, M
    Saltbones, J
    Slaper, H
    Sofiev, M A
    Syrakov, D
    Sorensen, J H
    Van der Auwera, L
    Valkama, I
    Zelazny, R
    Ensemble dispersion forecasting - Part I: concept, approach and indicators2004Ingår i: Atmospheric Environment, ISSN 1352-2310, E-ISSN 1873-2844, Vol. 38, nr 28, s. 4607-4617Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The paper presents an approach to the treatment and analysis of long-range transport and dispersion model forecasts. Long-range is intended here as the space scale of the order of few thousands of kilometers known also as continental scale. The method is called multi-model ensemble dispersion and is based on the simultaneous analysis of several model simulations by means of ad-hoc statistical treatments and parameters. The models considered in this study are operational long-range transport and dispersion models used to support decision making in various countries in case of accidental releases of harmful volatile substances, in particular radionuclides to the atmosphere. The ensemble dispersion approach and indicators provide a way to reduce several model results to few concise representations that include an estimate of the models' agreement in predicting a specific scenario. The parameters proposed are particularly suited for long-range transport and dispersion models although they can also be applied to short-range dispersion and weather fields. (C) 2004 Elsevier Ltd. All rights reserved.

  • 115. Gampe, David
    et al.
    Nikulin, Grigory
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Ludwig, Ralf
    Using an ensemble of regional climate models to assess climate change impacts on water scarcity in European river basins2016Ingår i: SCIENCE OF THE TOTAL ENVIRONMENT, ISSN 0048-9697, Vol. 573, s. 1503-1518Artikel i tidskrift (Refereegranskat)
  • 116. Gascard, J. -C
    et al.
    Vihma, T.
    Doescher, Ralf
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    General introduction to the DAMOCLES special issue2015Ingår i: Atmospheric Chemistry And Physics, ISSN 1680-7316, E-ISSN 1680-7324, Vol. 15, nr 10, s. 5377-5379Artikel i tidskrift (Refereegranskat)
  • 117.
    Gbobaniyi, Bode
    et al.
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Sarr, Abdoulaye
    Sylla, Mouhamadou Bamba
    Diallo, Ismaila
    Lennard, Chris
    Dosio, Alessandro
    Dhiediou, Arona
    Kamga, Andre
    Klutse, Nana Ama Browne
    Hewitson, Bruce
    Nikulin, Grigory
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Lamptey, Benjamin
    Climatology, annual cycle and interannual variability of precipitation and temperature in CORDEX simulations over West Africa2014Ingår i: International Journal of Climatology, ISSN 0899-8418, E-ISSN 1097-0088, Vol. 34, nr 7, s. 2241-2257Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    We examine the ability of an ensemble of 10 Regional Climate Models (RCMs), driven by ERA-Interim reanalysis, in skillfully reproducing key features of present-day precipitation and temperature (1990-2008) over West Africa. We explore a wide range of time scales spanning seasonal climatologies, annual cycles and interannual variability, and a number of spatial scales covering the Sahel, the Gulf of Guinea and the entire West Africa. We find that the RCMs show acceptable performance in simulating the spatial distribution of the main precipitation and temperature features. The occurrence of the West African Monsoon jump, the intensification and northward shift of the Saharan Heat Low (SHL), during the course of the year, are shown to be realistic in most RCMs. They also capture the mean annual cycle of precipitation and temperature, including, single and double-peaked rainy seasons, in terms of timing and amplitude over the homogeneous sub-regions. However, we should emphasize that the RCMs exhibit some biases, which vary considerably in both magnitude and spatial extent from model to model. The interannual variability of seasonal anomalies is best reproduced in temperature rather than precipitation. The ensemble mean considerably improves the skill of most of the individual RCMs. This highlights the importance of performing multi-model assessment in properly estimating the response of the West African climate to global warming at seasonal, annual and interannual time scales.

  • 118. Gode, Jenny
    et al.
    Axelsson, Johan
    Eriksson,, Sara
    Holmgren, Kristina
    Hovsenius, Gunnar
    Kjellström, Erik
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Larsson, Per
    Lundström, Love
    Persson, Gunn
    SMHI, Affärsverksamhet.
    Tänkbara konsekvenser för energisektorn av klimatförändringar- Effekter, sårbarhet och anpassning2007Rapport (Övrigt vetenskapligt)
  • 119. Good, P.
    et al.
    Bärring, Lars
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Giannakopoulos, C.
    Holt, T.
    Palutikof, J.
    Non-linear regional relationships between climate extremes and annual mean temperatures in model projections for 1961-2099 over Europe2006Ingår i: Climate Research (CR), ISSN 0936-577X, E-ISSN 1616-1572, Vol. 31, nr 1, s. 19-34Artikel i tidskrift (Refereegranskat)
  • 120.
    Graham, Phil
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Climate change effects on river flow to the Baltic Sea2004Ingår i: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 33, nr 4-5, s. 235-241Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    River flow to the Baltic Sea originates under a range of different climate regimes in a drainage basin covering some 1 600 000 km(2). Changes to the climate in the Baltic Basin will not only affect the total amount of freshwater flowing into the sea, but also the distribution of the origin of these flows. Using hydrological modeling, the effects of future climate change on river runoff to the Baltic Sea have been analyzed. Four different climate change scenarios from the Swedish Regional Climate Modelling Programme (SWECLIM) were used. The resulting change to total mean annual river flow to the Baltic Sea ranges from -2% to +15% of present-day flow according to the different climate scenarios. The magnitude of changes within different subregions of the basin varies considerably, with the most severe mean annual changes ranging from -30% to +40%. However, common to all of the scenarios evaluated is a general trend of reduced river flow from the south of the Baltic Basin together with increased river flow from the north.

  • 121.
    Graham, Phil
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Modeling runoff to the Baltic Sea1999Ingår i: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 28, nr 4, s. 328-334Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A large-scale hydrologic model of macroscale dimension for total daily runoff to the Baltic Sea has been developed using 25 subbasins ranging from 21000 to 144000 km(2). Daily synoptic input was calibrated against monthly recorded river flows. Reasonable model results for the water balance were obtained while keeping the level of detail to a minimum with a proven conceptual modeling approach. Important elements of the modeled water balance are presented for the five main Baltic Sea drainage basins. The model is used for cooperative research with both meteorological and oceanographic modeling within the Baltic Sea Experiment (BALTEX) and the Swedish Regional Climate Modelling Programme (SWECLIM). It provides off-line analysis for coupled model development and fills a needed role until truly coupled models become available. Furthermore, the model is suitable for operational applications and will be used to extend runoff records, fill in missing data, and perform quality checks on new observations.

  • 122.
    Graham, Phil
    et al.
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Andersson, Lotta
    SMHI, Samhälle och säkerhet.
    Horan, Mark
    Kunz, Richard
    Lumsden, Trevor
    Schulze, Roland
    Warburton, Michele
    Wilk, Julie
    Yang, Wei
    SMHI, Forskningsavdelningen, Hydrologi.
    Using multiple climate projections for assessing hydrological response to climate change in the Thukela River Basin, South Africa2011Ingår i: Physics and Chemistry of the Earth, ISSN 1474-7065, E-ISSN 1873-5193, Vol. 36, nr 14-15, s. 727-735Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This study used climate change projections from different regional approaches to assess hydrological effects on the Thukela River Basin in KwaZulu-Natal, South Africa. Projecting impacts of future climate change onto hydrological systems can be undertaken in different ways and a variety of effects can be expected. Although simulation results from global climate models (GCMs) are typically used to project future climate, different outcomes from these projections may be obtained depending on the GCMs themselves and how they are applied, including different ways of downscaling from global to regional scales. Projections of climate change from different downscaling methods, different global climate models and different future emissions scenarios were used as input to simulations in a hydrological model to assess climate change impacts on hydrology. A total of 10 hydrological change simulations were made, resulting in a matrix of hydrological response results. This matrix included results from dynamically downscaled climate change projections from the same regional climate model (RCM) using an ensemble of three GCMs and three global emissions scenarios, and from statistically downscaled projections using results from five GCMs with the same emissions scenario. Although the matrix of results does not provide complete and consistent coverage of potential uncertainties from the different methods, some robust results were identified. In some regards, the results were in agreement and consistent for the different simulations. For others, particularly rainfall, the simulations showed divergence. For example, all of the statistically downscaled simulations showed an annual increase in precipitation and corresponding increase in river runoff, while the RCM downscaled simulations showed both increases and decreases in runoff. According to the two projections that best represent runoff for the observed climate, increased runoff would generally be expected for this basin in the future. Dealing with such variability in results is not atypical for assessing climate change impacts in Africa and practitioners are faced with how to interpret them. This work highlights the need for additional, well-coordinated regional climate downscaling for the region to further define the range of uncertainties involved. (C) 2011 Elsevier Ltd. All rights reserved.

  • 123.
    Graham, Phil
    et al.
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Andreasson, Johan
    SMHI, Affärsverksamhet.
    Carlsson, Bengt
    SMHI, Forskningsavdelningen, Hydrologi.
    Assessing climate change impacts on hydrology from an ensemble of regional climate models, model scales and linking methods - a case study on the Lule River basin2007Ingår i: Climatic Change, ISSN 0165-0009, E-ISSN 1573-1480, Vol. 81, s. 293-307Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper investigates how using different regional climate model (RCM) simulations affects climate change impacts on hydrology in northern Europe using an offline hydrological model. Climate change scenarios from an ensemble of seven RCMs, two global climate models (GCMs), two global emissions scenarios and two RCMs of varying resolution were used. A total of 15 climate change simulations were included in studies on the Lule River basin in Northern Sweden. Two different approaches to transfer climate change from the RCMs to hydrological models were tested. A rudimentary estimate of change in laydropower potential on the Lule River due to climate change was also made. The results indicate an overall increase in river flow, earlier spring peak flows and an increase in hydropower potential. The two approaches for transferring the signal of climate change to the hydrological impacts model gave similar mean results, but considerably different seasonal dynamics, a result that is highly relevant for other types of climate change impacts studies.

  • 124.
    Graham, Phil
    et al.
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Bergström, Sten
    SMHI, Forskningsavdelningen, Hydrologi.
    Land surface modelling in hydrology and meteorology - lessons learned from the Baltic Basin2000Ingår i: Hydrology and Earth System Sciences, ISSN 1027-5606, E-ISSN 1607-7938, Vol. 4, nr 1, s. 13-22Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    By both tradition and purpose, the land parameterization schemes of hydrological and meteorological models differ greatly. Meteorologists are concerned primarily with solving the energy balance, whereas hydrologists are most interested in the water balance. Meteorological climate models typically have multi-layered soil parameterisation that solves temperature fluxes numerically with diffusive equations. The same approach is carried over to a similar treatment of water transport. Hydrological models are not usually so interested in soil temperatures, but must provide a reasonable representation of soil moisture to get runoff right. To treat the heterogeneity of the soil, many hydrological models use only one laver with a statistical representation of soil variability. Such a hydrological model can be used on large scales while taking subgrid variability into account. Hydrological models also include lateral transport of water - an imperative if river discharge is to be estimated. The concept of a complexity chain for coupled modelling systems is introduced, together with considerations for mixing model components. Under BALTEX (Baltic Sea Experiment) and SWECLIM (Swedish Regional Climate Modelling Programme), a large-scale hydrological model of runoff in the Baltic Basin is used to review atmospheric climate model simulations. This incorporates both the runoff record and hydrological modelling experience into atmospheric model development. Results from two models are shown. A conclusion is that the key to improved models may be less complexity. Perhaps the meteorological models should keep their multi-layered approach for modelling soil temperature, bur add a simpler, yet physically consistent, hydrological approach for modelling snow processes and water transport in the soil.

  • 125.
    Graham, Phil
    et al.
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Bergström, Sten
    SMHI, Forskningsavdelningen, Hydrologi.
    Water balance modelling in the Baltic Sea drainage basin - analysis of meteorological and hydrological approaches2001Ingår i: Meteorology and atmospheric physics (Print), ISSN 0177-7971, E-ISSN 1436-5065, Vol. 77, nr 1-4, s. 45-60Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Efforts to understand and simulate the global climate in numerical models have led to regional studies of the energy and water balance. The Baltic Basin provides a continental scale test basin where meteorology, oceanography and hydrology all can meet. Using a simple conceptual approach, a large-scale hydrological model of the water balance of the total Baltic Sea Drainage Basin (HBV-Baltic) was used to simulate the basinwide water balance components for the present climate and to evaluate the land surface components of atmospheric climate models. It has been used extensively in co-operative BALTEX (The Baltic Sea Experiment) research and within SWECLIM (Swedish Regional Climate Modelling Programme) to support continued regional climate model development. This helps to identify inconsistencies in bath meteorological and hydrological models. One result is that compensating errors are evident in the snow routines of the atmospheric models studied. The use of HBV-Baltic has greatly improved the dialogue between hydrological and meteorological modellers within the Baltic Basin research community. It is concluded that conceptual hydrological models, although far from being complete, play an important role in the realm of continental scale hydrological modelling. Atmospheric models benefit from the experience of hydrological modellers in developing simpler, yet more effective land surface parameterisations. This basic modelling tool for simulating the large-scale water balance of the Baltic Sea drainage basin is the only existing hydrological model that covers the entire basin and will continue to be used until more detailed models can be successfully applied at this scale.

  • 126.
    Graham, Phil
    et al.
    SMHI, Affärsverksamhet.
    Bringfelt, Björn
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Towards improved modelling of runoff in climate models2001Ingår i: Third study conference on BALTEX / [ed] J. Meywerk, 2001, s. 71-72Konferensbidrag (Övrigt vetenskapligt)
  • 127.
    Graham, Phil
    et al.
    SMHI, Affärsverksamhet.
    Chen, Deliang
    Bøssing Christensen, Ole
    Kjellström, Erik
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Krysanova, Valentina
    Meier, Markus
    SMHI, Forskningsavdelningen, Oceanografi.
    Radziejewski, Maciej
    Räisänen, Jouni
    Rockel, Burkhardt
    Ruosteenoja, Kimmo
    Projections of Future Anthropogenic Climate Change2008Ingår i: Assessment of Climate Change for the Baltic Sea Basin / [ed] The BACC Author Team, Springer, Berlin , 2008, s. 133-219Kapitel i bok, del av antologi (Övrigt vetenskapligt)
  • 128.
    Graham, Phil
    et al.
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Hagemann, Stefan
    Jaun, Simon
    Beniston, Martin
    On interpreting hydrological change from regional climate models2007Ingår i: Climatic Change, ISSN 0165-0009, E-ISSN 1573-1480, Vol. 81, s. 97-122Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Although representation of hydrology is included in all regional climate models (RCMs), the utility of hydrological results from RCMs varies considerably from model to model. Studies to evaluate and compare the hydrological components of a suite of RCMs and their use in assessing hydrological impacts from future climate change were carried out over Europe. This included using different methods to transfer RCM runoff directly to river discharge and coupling different RCMs to offline hydrological models using different methods to transfer the climate change signal between models. The work focused on drainage areas to the Baltic Basin, the Botlinian Bay Basin and the Rhine Basin. A total of 20 anthropogenic climate change scenario simulations from 11 different RCMs were used. One conclusion is that choice of GCM (global climate model) has a larger impact on projected hydrological change than either selection of emissions scenario or RCM used for downscaling.

  • 129.
    Graham, Phil
    et al.
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Jacob, D
    Using large-scale hydrologic modeling to review runoff generation processes in GCM climate models2000Ingår i: Meteorologische Zeitschrift, ISSN 0941-2948, E-ISSN 1610-1227, Vol. 9, nr 1, s. 49-57Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A large-scale application of the Swedish HBV hydrologic model was used to model the daily water balance of total runoff to the Baltic Sea. Ten-year present atmospheric climate model simulations from the ECHAM4/T106 global climate model were summarized on a runoff catchment basis. Climate model daily temperature and precipitation for the Baltic region were input to the water balance model for intercomparison runs. Comparison of results from the water balance model - with climate model input - to direct results from the climate model provides critical review of the behavior of the climate model. This: helped pinpoint systematic compensating errors in the land parameterization scheme.

  • 130.
    Graham, Phil
    et al.
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Olsson, Jonas
    SMHI, Forskningsavdelningen, Hydrologi.
    Kjellström, Erik
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Rosberg, Jörgen
    SMHI, Forskningsavdelningen, Hydrologi.
    Hellström, Sara-Sofia
    SMHI, Forskningsavdelningen, Hydrologi.
    Berndtsson, Ronny
    Simulating river flow to the Baltic Sea from climate simulations over the past millennium2009Ingår i: Boreal environment research, ISSN 1239-6095, E-ISSN 1797-2469, Vol. 14, nr 1, s. 173-182Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The aim of this study was to reconstruct river flow to the Baltic Sea using data from different periods during the past thousand years. A hydrological model coupled to simulations from climate models was used to estimate river flow. A "millennium" simulation of past climate from the ECHO-G coupled atmosphere-ocean global climate model provided climatological inputs. Results from this global model were downscaled with the RCA3 regional climate model over northern Europe. Temperature and precipitation from the downscaled simulation results were then used in the HBV hydrological model to simulate river flows to the Baltic Sea for the periods 1000-1199 and 1551-1929. These were compared with observations for the period 1921-2002. A general conclusion from this work is that although climate has varied during the past millennium, variability in annual river flow to the Baltic Sea does not appear more pronounced in recent years than during the previous millennium, or vice versa.

  • 131. Graßl, Hartmut
    et al.
    Gryning, Sven-Erik
    Isemer, Hans-Jörg
    Omstedt, Anders
    Göteborgs Universitet.
    Rosbjerg, Dan
    Rummukainen, Markku
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Science Plan for BALTEX Phase II 2003-20122012Rapport (Refereegranskat)
  • 132. Gregory, P J
    et al.
    Ingram, J S I
    Andersson, R
    Betts, R A
    Brovkin, V
    Chase, T N
    Grace, P R
    Gray, A J
    Hamilton, N
    Hardy, T B
    Howden, S M
    Jenkins, A
    Meybeck, M
    Olsson, M
    Ortiz-Monasterio, I
    Palm, C A
    Payn, T W
    Rummukainen, Markku
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Schulze, R E
    Thiem, M
    Valentin, C
    Wilkinson, M J
    Environmental consequences of alternative practices for intensifying crop production2002Ingår i: Agriculture, Ecosystems & Environment, ISSN 0167-8809, E-ISSN 1873-2305, Vol. 88, nr 3, s. 279-290Artikel i tidskrift (Refereegranskat)
  • 133. Grist, Jeremy P.
    et al.
    Josey, Simon A.
    New, Adrian L.
    Roberts, Malcolm
    Koenigk, Torben
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Iovino, Doroteaciro
    Increasing Atlantic Ocean Heat Transport in the Latest Generation Coupled Ocean-Atmosphere Models: The Role of Air-Sea Interaction2018Ingår i: Journal of Geophysical Research - Oceans, ISSN 2169-9275, E-ISSN 2169-9291, Vol. 123, nr 11, s. 8624-8637Artikel i tidskrift (Refereegranskat)
  • 134. Guemas, Virginie
    et al.
    Blanchard-Wrigglesworth, Edward
    Chevallier, Matthieu
    Day, Jonathan J.
    Deque, Michel
    Doblas-Reyes, Francisco J.
    Fuckar, Neven S.
    Germe, Agathe
    Hawkins, Ed
    Keeley, Sarah
    Koenigk, Torben
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Salas y Melia, David
    Tietsche, Steffen
    A review on Arctic sea-ice predictability and prediction on seasonal to decadal time-scales2016Ingår i: Quarterly Journal of the Royal Meteorological Society, ISSN 0035-9009, E-ISSN 1477-870X, Vol. 142, nr 695, s. 546-561Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Sea ice plays a crucial role in the Earth's energy and water budget and has a substantial impact on local and remote atmospheric and oceanic circulations. Predictions of Arctic sea-ice conditions a few months to a few years in advance could be of interest for stakeholders. This article presents a review of the potential sources of Arctic sea-ice predictability on these time-scales. Predictability mainly originates from persistence or advection of sea-ice anomalies, interactions with the ocean and atmosphere and changes in radiative forcing. After estimating the inherent potential predictability limit with state-of-the-art models, current sea-ice forecast systems are described, together with their performance. Finally, some challenges and issues in sea-ice forecasting are presented, along with suggestions for future research priorities.

  • 135. Guemas, Virginie
    et al.
    Garcia-Serrano, Javier
    Mariotti, Annarita
    Doblas-Reyes, Francisco
    Caron, Louis-Philippe
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Prospects for decadal climate prediction in the Mediterranean region2015Ingår i: Quarterly Journal of the Royal Meteorological Society, ISSN 0035-9009, E-ISSN 1477-870X, Vol. 141, nr 687, s. 580-597Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The Mediterranean region stands as one of the most sensitive to climate change, both in terms of warming and drying. On shorter time-scales, internal variability has substantially affected the observed climate and in the next decade might enhance or compensate long-term trends. Here we compare the multi-model climate predictions produced within the framework of the CMIP5 (Coupled Model Intercomparison Project Phase 5) project with historical simulations to assess the level of multi-year climate prediction skill in the Mediterranean region beyond that originating from the model accumulated response to the external radiative forcings. We obtain a high and significant skill in predicting 4-year averaged annual and summer mean temperature over most of the study domain and in predicting precipitation for the same seasons over northern Europe and sub-Saharan Africa. A lower skill is found during the winter season but still positive for temperature. Although most of this high skill originates from the model response to the external radiative forcings, the initialization contributes to the temperature skill over the Mediterranean Sea and surrounding land areas. The high and significant correlations between the observed Mediterranean temperatures and the observed Atlantic multidecadal oscillation (AMO) in the summer and annual means are captured by the CMIP5 ensemble which suggests that the added skill is related to the ability of the CMIP5 ensemble to predict the AMO. Such a link to the AMO seems restricted to western Africa and summer means only for the precipitation case.

  • 136. Guettler, Ivan
    et al.
    Stepanov, Igor
    Brankovic, Cedo
    Nikulin, Grigory
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Jones, Colin
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Impact of Horizontal Resolution on Precipitation in Complex Orography Simulated by the Regional Climate Model RCA3*2015Ingår i: Monthly Weather Review, ISSN 0027-0644, E-ISSN 1520-0493, Vol. 143, nr 9, s. 3610-3627Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The hydrostatic regional climate model RCA, version 3 (RCA3), of the Swedish Meteorological and Hydrological Institute was used to dynamically downscale ERA-40 and the ECMWF operational analysis over a 22-yr period. Downscaling was performed at four horizontal resolutions-50, 25, 12.5, and 6.25 km-over an identical European domain. The model-simulated precipitation is evaluated against high-resolution gridded observational precipitation datasets over Switzerland and southern Norway, regions that are characterized by complex orography and distinct climate regimes. RCA3 generally overestimates precipitation over high mountains: during winter and summer over Switzerland and during summer over central-southern Norway. In the summer, this is linked with a substantial contribution of convective precipitation to the total precipitation errors, especially at the coarser resolutions (50 and 25 km). A general improvement in spatial correlation coefficients between simulated and observed precipitation is observed when the horizontal resolution is increased from 50 to 6 km. The 95th percentile spatial correlation coefficients during winter are much higher for southern Norway than for Switzerland, indicating that RCA3 is more successful at reproducing a relatively simple west-to-east precipitation gradient over southern Norway than a much more complex and variable precipitation distribution over Switzerland. The 6-km simulation is not always superior to the other simulations, possibly indicating that the model dynamical and physical configuration at this resolution may not have been optimal. However, a general improvement in simulated precipitation with increasing resolution supports further use and application of high spatial resolutions in RCA3.

  • 137. Guichard, F
    et al.
    Petch, J C
    Redelsperger, J L
    Bechtold, P
    Chaboureau, J P
    Cheinet, S
    Grabowski, W
    Grenier, H
    Jones, Colin
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Kohler, M
    Piriou, J M
    Tailleux, R
    Tomasini, M
    Modelling the diurnal cycle of deep precipitating convection over land with cloud-resolving models and single-column models2004Ingår i: Quarterly Journal of the Royal Meteorological Society, ISSN 0035-9009, E-ISSN 1477-870X, Vol. 130, nr 604, s. 3139-3172Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    An idealized case-study has been designed to investigate the modelling of the diurnal cycle of deep precipitating convection over land. A simulation of this case was performed by seven single-column models (SCMs) and three cloud-resolving models (CRMs). Within this framework, a quick onset of convective rainfall is found in most SCMs, consistent with the results from general-circulation models. In contrast, CRMs do not predict rainfall before noon. A joint analysis of the results provided by both types of model indicates that convection occurs too early in most SCMs, due to crude triggering criteria and quick onsets of convective precipitation. In the CRMs, the first clouds appear before noon, but surface rainfall is delayed by a few hours to several hours. This intermediate stage, missing in all SCMs except for one, is characterized by a gradual moistening of the free troposphere and an increase of cloud-top height. Later on, convective downdraughts efficiently cool and dry the boundary layer (BL) in the CRMs. This feature is also absent in most SCMs, which tend to adjust towards more unstable states, with moister (and often more cloudy) low levels and a drier free atmosphere. This common behaviour of most SCMs with respect to deep moist convective processes occurs even though each SCM simulates a different diurnal cycle of the BL and atmospheric stability. The scatter among the SCMs results from the wide variety of representations of BL turbulence and moist convection in these models. Greater consistency is found among the CRMs, despite some differences in their representation of the daytime BL growth, which are linked to their parametrizations of BL turbulence and/or resolution.

  • 138. Gutierrez, J. M.
    et al.
    Maraun, D.
    Widmann, M.
    Huth, R.
    Hertig, E.
    Benestad, R.
    Roessler, O.
    Wibig, J.
    Wilcke, Renate
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Kotlarski, S.
    San Martin, D.
    Herrera, S.
    Bedia, J.
    Casanueva, A.
    Manzanas, R.
    Iturbide, M.
    Vrac, M.
    Dubrovsky, M.
    Ribalaygua, J.
    Portoles, J.
    Raty, O.
    Raisanen, J.
    Hingray, B.
    Raynaud, D.
    Casado, M. J.
    Ramos, P.
    Zerenner, T.
    Turco, M.
    Bosshard, Thomas
    SMHI, Forskningsavdelningen, Hydrologi.
    Stepanek, P.
    Bartholy, J.
    Pongracz, R.
    Keller, D. E.
    Fischer, A. M.
    Cardoso, R. M.
    Soares, P. M. M.
    Czernecki, B.
    Page, C.
    An intercomparison of a large ensemble of statistical downscaling methods over Europe: Results from the VALUE perfect predictor cross-validation experiment2019Ingår i: International Journal of Climatology, ISSN 0899-8418, E-ISSN 1097-0088, Vol. 39, nr 9, s. 3750-3785Artikel i tidskrift (Refereegranskat)
  • 139. Gutowski, William J., Jr.
    et al.
    Giorgi, Filippo
    Timbal, Bertrand
    Frigon, Anne
    Jacob, Daniela
    Kang, Hyun-Suk
    Raghavan, Krishnan
    Lee, Boram
    Lennard, Christopher
    Nikulin, Grigory
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    O'Rourke, Eleanor
    Rixen, Michel
    Solman, Silvina
    Stephenson, Tannecia
    Tangang, Fredolin
    WCRP COordinated Regional Downscaling EXperiment (CORDEX): a diagnostic MIP for CMIP62016Ingår i: Geoscientific Model Development, ISSN 1991-959X, E-ISSN 1991-9603, Vol. 9, nr 11, s. 4087-4095Artikel i tidskrift (Refereegranskat)
  • 140. Haarsma, Reindert J.
    et al.
    Roberts, Malcolm J.
    Vidale, Pier Luigi
    Senior, Catherine A.
    Bellucci, Alessio
    Bao, Qing
    Chang, Ping
    Corti, Susanna
    Fuckar, Neven S.
    Guemas, Virginie
    von Hardenberg, Jost
    Hazeleger, Wilco
    Kodama, Chihiro
    Koenigk, Torben
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Leung, L. Ruby
    Lu, Jian
    Luo, Jing-Jia
    Mao, Jiafu
    Mizielinski, Matthew S.
    Mizuta, Ryo
    Nobre, Paulo
    Satoh, Masaki
    Scoccimarro, Enrico
    Semmler, Tido
    Small, Justin
    von Storch, Jin-Song
    High Resolution Model Intercomparison Project (HighResMIP v1.0) for CMIP62016Ingår i: Geoscientific Model Development, ISSN 1991-959X, E-ISSN 1991-9603, Vol. 9, nr 11, s. 4185-4208Artikel i tidskrift (Refereegranskat)
  • 141. Hanson, C. E.
    et al.
    Palutikof, J. P.
    Livermore, M. T. J.
    Bärring, Lars
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Bindi, M.
    Corte-Real, J.
    Durao, R.
    Giannakopoulos, C.
    Good, P.
    Holt, T.
    Kundzewicz, Z.
    Leckebusch, G. C.
    Moriondo, M.
    Radziejewski, M.
    Santos, J.
    Schlyter, P.
    Schwarb, M.
    Stjernquist, I.
    Ulbrich, U.
    Modelling the impact of climate extremes: an overview of the MICE project2007Ingår i: Climatic Change, ISSN 0165-0009, E-ISSN 1573-1480, Vol. 81, s. 163-177Artikel i tidskrift (Refereegranskat)
  • 142. Hartung, Kerstin
    et al.
    Svensson, Gunilla
    Kjellström, Erik
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Resolution, physics and atmosphere-ocean interaction - How do they influence climate model representation of Euro-Atlantic atmospheric blocking?2017Ingår i: Tellus. Series A, Dynamic meteorology and oceanography, ISSN 0280-6495, E-ISSN 1600-0870, Vol. 69, artikel-id 1406252Artikel i tidskrift (Refereegranskat)
  • 143. Hazeleger, W.
    et al.
    Guemas, V.
    Wouters, B.
    Corti, S.
    Andreu-Burillo, I.
    Doblas-Reyes, F. J.
    Wyser, Klaus
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Caian, Mihaela
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Multiyear climate predictions using two initialization strategies2013Ingår i: Geophysical Research Letters, ISSN 0094-8276, E-ISSN 1944-8007, Vol. 40, nr 9, s. 1794-1798Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Multiyear climate predictions with two initialization strategies are systematically assessed in the EC-Earth V2.3 climate model. In one ensemble, an estimate of the observed climate state is used to initialize the model. The other uses estimates of observed ocean and sea ice anomalies on top of the model climatology. The ensembles show similar spatial characteristics of drift related to the biases in control simulations. As expected, the drift is less with anomaly initialization. The full field initialization overshoots to a colder state which is related to cold biases in the tropics and North Atlantic, associated with oceanic processes. Despite different amplitude of the drift, both ensembles show similar skill in multiyear global temperature predictions, but regionally differences are found. On multiyear time scales, initialization with observations enhances both deterministic and probabilistic skill scores in the North Atlantic. The probabilistic verification shows skill over the European continent.

  • 144. Hazeleger, W.
    et al.
    Wang, X.
    Severijns, C.
    Stefanescu, S.
    Bintanja, R.
    Sterl, A.
    Wyser, Klaus
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Semmler, T.
    Yang, S.
    van den Hurk, B.
    van Noije, T.
    van der Linden, E.
    van der Wiel, K.
    EC-Earth V2.2: description and validation of a new seamless earth system prediction model2012Ingår i: Climate Dynamics, ISSN 0930-7575, E-ISSN 1432-0894, Vol. 39, nr 11, s. 2611-2629Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    EC-Earth, a new Earth system model based on the operational seasonal forecast system of the European Centre for Medium-Range Weather Forecasts (ECMWF), is presented. The performance of version 2.2 (V2.2) of the model is compared to observations, reanalysis data and other coupled atmosphere-ocean-sea ice models. The large-scale physical characteristics of the atmosphere, ocean and sea ice are well simulated. When compared to other coupled models with similar complexity, the model performs well in simulating tropospheric fields and dynamic variables, and performs less in simulating surface temperature and fluxes. The surface temperatures are too cold, with the exception of the Southern Ocean region and parts of the Northern Hemisphere extratropics. The main patterns of interannual climate variability are well represented. Experiments with enhanced CO2 concentrations show well-known responses of Arctic amplification, land-sea contrasts, tropospheric warming and stratospheric cooling. The global climate sensitivity of the current version of EC-Earth is slightly less than 1 K/(W m(-2)). An intensification of the hydrological cycle is found and strong regional changes in precipitation, affecting monsoon characteristics. The results show that a coupled model based on an operational seasonal prediction system can be used for climate studies, supporting emerging seamless prediction strategies.

  • 145. Hazeleger, Wilco
    et al.
    Severijns, Camiel
    Semmler, Tido
    Stefanescu, Simona
    Yang, Shuting
    Wang, Xueli
    Wyser, Klaus
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Dutra, Emanuel
    Baldasano, Jose M.
    Bintanja, Richard
    Bougeault, Philippe
    Caballero, Rodrigo
    Ekman, Annica M. L.
    Christensen, Jens H.
    van den Hurk, Bart
    Jimenez, Pedro
    Jones, Colin
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Kållberg, Per
    SMHI, Forskningsavdelningen, Meteorologi.
    Koenigk, Torben
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    McGrath, Ray
    Miranda, Pedro
    Van Noije, Twan
    Palmer, Tim
    Parodi, Jose A.
    Schmith, Torben
    Selten, Frank
    Storelvmo, Trude
    Sterl, Andreas
    Tapamo, Honore
    Vancoppenolle, Martin
    Viterbo, Pedro
    Willén, Ulrika
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    EC-Earth A Seamless Earth-System Prediction Approach in Action2010Ingår i: Bulletin of The American Meteorological Society - (BAMS), ISSN 0003-0007, E-ISSN 1520-0477, Vol. 91, nr 10, s. 1357-1363Artikel i tidskrift (Övrigt vetenskapligt)
  • 146. Hell, Benjamin
    et al.
    Broman, Barry
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Jakobsson, Lars
    Jakobsson, Martin
    Magnusson, Ake
    Wiberg, Patrik
    The Use of Bathymetric Data in Society and Science: A Review from the Baltic Sea2012Ingår i: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 41, nr 2, s. 138-150Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    Bathymetry, the underwater topography, is a fundamental property of oceans, seas, and lakes. As such it is important for a wide range of applications, like physical oceanography, marine geology, geophysics and biology or the administration of marine resources. The exact requirements users may have regarding bathymetric data are, however, unclear. Here, the results of a questionnaire survey and a literature review are presented, concerning the use of Baltic Sea bathymetric data in research and for societal needs. It is demonstrated that there is a great need for detailed bathymetric data. Despite the abundance of high-quality bathymetric data that are produced for safety of navigation purposes, the digital bathymetric models publicly available to date cannot satisfy this need. Our study shows that DBMs based on data collected for safety of navigation could substantially improve the base data for administrative decision making as well as the possibilities for marine research in the Baltic Sea.

  • 147. Hellstrom, C
    et al.
    Chen, D L
    Achberger, C
    Räisänen, Jouni
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Comparison of climate change scenarios for Sweden based on statistical and dynamical downscaling of monthly precipitation2001Ingår i: Climate Research (CR), ISSN 0936-577X, E-ISSN 1616-1572, Vol. 19, nr 1, s. 45-55Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Two dynamically and statistically downscaled precipitation scenarios for Sweden are compared with respect to changes in the mean, The dynamically downscaled scenarios are generated by a 44 km version of the Rossby Centre regional climate model (RCM). The RCM is driven by data from 2 global greenhouse gas simulations sharing a 2.6degreesC global warming, one made by the HadCM2 and the other by the ECHAM4 general circulation model (GCM). The statistical downscaling model driven by the same GCMs is regression-based and incorporates large-scale circulation indices of the 2 geostrophic wind components (u and v), total vorticity (xi) and large-scale humidity at 850 hPa (q850) as predictors. The precipitation climates of the GCMs, RCMs and statistical models from the control runs are compared with respect to their ability to reproduce the observed seasonal cycle. Great improvements in the simulation of the seasonal cycle by all the downscaling models compared to the GCMs significantly increase the credibility of the downscaling models, The precipitation changes produced by the statistical models result from changes in all predictors, but the change in 4 is the greatest contributor in southern Sweden followed by q850 and u, while changes in q850 have greater effects in the northern parts of the country. The temporal and spatial variability of precipitation changes are higher in the statistically downscaled scenarios than in the dynamically downscaled ones. Comparisons of the 4 scenarios show that the spread of the scenarios created by the statistical model is on average larger than that between the RCM scenarios. The relatively large average spread is mainly due to the large differences found in summer. The seasonally averaged difference of the dynamical and statistical scenarios for the ECHAM4-based downscaled scenarios is 12%, and for the HadCM2 downscaled scenarios 21%. The differences in annual precipitation change are smaller, on average 4.5% among the HadCM2-based downscaled scenarios, and 6.9% among the ECHAM4-based downscaling scenarios.

  • 148. Helmert, Juergen
    et al.
    Lange, Martin
    Dong, Jiarui
    De Rosnay, Patricia
    Gustafsson, David
    SMHI, Forskningsavdelningen, Hydrologi.
    Churulin, Evgeniy
    Kurzeneva, Ekaterina
    Mueller, Richard
    Trentmann, Joerg
    Souverijns, Niels
    Koch, Roland
    Boehm, Uwe
    Bartik, Martin
    Osuch, Marzena
    Rozinkina, Inna
    Bettems, Jean-Marie
    Samuelsson, Patrick
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Marcucci, Francesca
    Milelli, Massimo
    1st Snow Data Assimilation Workshop in the framework of COST HarmoSnow ESSEM 14042018Ingår i: Meteorologische Zeitschrift, ISSN 0941-2948, E-ISSN 1610-1227, Vol. 27, nr 4, s. 325-333Artikel i tidskrift (Refereegranskat)
  • 149. Hennemuth, B
    et al.
    Rutgersson, Anna
    SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Bumke, K
    Clemens, M
    Omstedt, Anders
    Jacob, D
    Smedman, A S
    Net precipitation over the Baltic Sea for one year using models and data-based methods2003Ingår i: Tellus. Series A, Dynamic meteorology and oceanography, ISSN 0280-6495, E-ISSN 1600-0870, Vol. 55, nr 4, s. 352-367Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Precipitation and evaporation over the Baltic Sea are calculated for a one-year period from September 1998 to August 1999 by four different tools, the two atmospheric regional models HIRLAM and REMO, the oceanographic model PROBE-Baltic in combination with the SMHI (1 x 1)degrees database and Interpolated Fields, based essentially on ship measurements. The investigated period is slightly warmer and wetter than the climatological mean. Correlation coefficients of the differently calculated latent heat fluxes vary between 0.81 (HIRLAM and REMO) and 0.56 (SMHI/PROBE-Baltic and Interpolated Fields), while the correlation coefficients between model fluxes and measured fluxes range from 0.61 and 0.78. Deviations of simulated and interpolated monthly precipitation over the Baltic Sea are less than 5 mm in the southern Baltic and up to 20 mm near the Finnish coast for the one-year period. The methods simulate the annual cycle of precipitation and evaporation of the Baltic Proper in a similar manner with a broad maximum of net precipitation in spring and early summer and a minimum in late summer. The annual averages of net precipitation of the Baltic Proper range from 57 mm (REMO) to 262 turn (HIRLAM) and for the Baltic Sea from 96 turn (SMHI/PROBE-Baltic) to 209 rum (HIRLAM). This range is considered to give the uncertainty of present-day determination of the net precipitation over the Baltic Sea.

  • 150.
    Hordoir, Robinson
    et al.
    SMHI, Forskningsavdelningen, Oceanografi.
    Axell, Lars
    SMHI, Forskningsavdelningen, Oceanografi.
    Höglund, Anders
    SMHI, Forskningsavdelningen, Oceanografi.
    Dieterich, Christian
    SMHI, Forskningsavdelningen, Oceanografi.
    Fransner, Filippa
    Groger, Matthias
    SMHI, Forskningsavdelningen, Oceanografi.
    Liu, Ye
    SMHI, Forskningsavdelningen, Oceanografi.
    Pemberton, Per
    SMHI, Forskningsavdelningen, Oceanografi.
    Schimanke, Semjon
    SMHI, Forskningsavdelningen, Oceanografi.
    Andersson, Helén
    SMHI, Forskningsavdelningen, Oceanografi.
    Ljungemyr, Patrik
    SMHI, Samhälle och säkerhet.
    Nygren, Petter
    SMHI, Samhälle och säkerhet.
    Falahat, Saeed
    SMHI, Samhälle och säkerhet.
    Nord, Adam
    SMHI, Samhälle och säkerhet.
    Jönsson, Anette
    SMHI, Samhälle och säkerhet.
    Lake, Irene
    SMHI, Samhälle och säkerhet. SMHI, Forskningsavdelningen, Klimatforskning - Rossby Centre.
    Doos, Kristofer
    Hieronymus, Magnus
    SMHI, Forskningsavdelningen, Oceanografi.
    Dietze, Heiner
    Loeptien, Ulrike
    Kuznetsov, Ivan
    Westerlund, Antti
    Tuomi, Laura
    Haapala, Jari
    Nemo-Nordic 1.0: a NEMO-based ocean model for the Baltic and North seas - research and operational applications2019Ingår i: Geoscientific Model Development, ISSN 1991-959X, E-ISSN 1991-9603, Vol. 12, nr 1, s. 363-386Artikel i tidskrift (Refereegranskat)
1234567 101 - 150 av 493
RefereraExporteraLänk till träfflistan
Permanent länk
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
v. 2.35.8
|