Change search
Link to record
Permanent link

Direct link
BETA
Publications (10 of 12) Show all publications
Amorim, J. H., Asker, C., Belusic, D., Carvalho, A., Engardt, M., Gidhagen, L., . . . Baklanov, A. (2018). Integrated Urban Services for European cities: the Stockholm case. WMO Bulletin, 67(2), 33-40
Open this publication in new window or tab >>Integrated Urban Services for European cities: the Stockholm case
Show others...
2018 (English)In: WMO Bulletin, ISSN 0042-9767, Vol. 67, no 2, p. 33-40Article in journal (Refereed) Published
Place, publisher, year, edition, pages
The World Meteorological Organization, 2018
National Category
Environmental Sciences
Research subject
Environment
Identifiers
urn:nbn:se:smhi:diva-5183 (URN)
Available from: 2019-04-15 Created: 2019-04-15 Last updated: 2019-04-15Bibliographically approved
Molinder, J., Körnich, H., Olsson, E., Bergstrom, H. & Sjoblom, A. (2018). Probabilistic forecasting of wind power production losses in cold climates: a case study. Wind Energy Science, 3(2), 667-680
Open this publication in new window or tab >>Probabilistic forecasting of wind power production losses in cold climates: a case study
Show others...
2018 (English)In: Wind Energy Science, ISSN 2213-3968, E-ISSN 2366-7443, Vol. 3, no 2, p. 667-680Article in journal (Refereed) Published
National Category
Meteorology and Atmospheric Sciences
Research subject
Meteorology
Identifiers
urn:nbn:se:smhi:diva-4995 (URN)10.5194/wes-3-667-2018 (DOI)000446813300001 ()
Available from: 2018-10-23 Created: 2018-10-23 Last updated: 2018-10-23Bibliographically approved
Berntell, E., Zhang, Q., Chafik, L. & Körnich, H. (2018). Representation of Multidecadal Sahel Rainfall Variability in 20th Century Reanalyses. Scientific Reports, 8, Article ID 10937.
Open this publication in new window or tab >>Representation of Multidecadal Sahel Rainfall Variability in 20th Century Reanalyses
2018 (English)In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 8, article id 10937Article in journal (Refereed) Published
National Category
Meteorology and Atmospheric Sciences
Research subject
Meteorology
Identifiers
urn:nbn:se:smhi:diva-4797 (URN)10.1038/s41598-018-29217-9 (DOI)000439101600036 ()30026485 (PubMedID)
Available from: 2018-08-07 Created: 2018-08-07 Last updated: 2018-08-07Bibliographically approved
Olsson, J., Pers, C., Bengtsson, L., Pechlivanidis, I., Berg, P. & Körnich, H. (2017). Distance-dependent depth-duration analysis in high-resolution hydro-meteorological ensemble forecasting: A case study in Malmo City, Sweden. Environmental Modelling & Software, 93, 381-397
Open this publication in new window or tab >>Distance-dependent depth-duration analysis in high-resolution hydro-meteorological ensemble forecasting: A case study in Malmo City, Sweden
Show others...
2017 (English)In: Environmental Modelling & Software, ISSN 1364-8152, E-ISSN 1873-6726, Vol. 93, p. 381-397Article in journal (Refereed) Published
National Category
Oceanography, Hydrology and Water Resources
Research subject
Hydrology
Identifiers
urn:nbn:se:smhi:diva-4135 (URN)10.1016/j.envsoft.2017.03.025 (DOI)000403512500026 ()
Available from: 2017-08-08 Created: 2017-08-08 Last updated: 2018-01-13Bibliographically approved
Bengtsson, L. & Körnich, H. (2016). Impact of a stochastic parametrization of cumulus convection, using cellular automata, in a mesoscale ensemble prediction system. Quarterly Journal of the Royal Meteorological Society, 142(695), 1150-1159
Open this publication in new window or tab >>Impact of a stochastic parametrization of cumulus convection, using cellular automata, in a mesoscale ensemble prediction system
2016 (English)In: Quarterly Journal of the Royal Meteorological Society, ISSN 0035-9009, E-ISSN 1477-870X, Vol. 142, no 695, p. 1150-1159Article in journal (Refereed) Published
Abstract [en]

A stochastic parametrization for deep convection, based on cellular automata, has been evaluated in the high-resolution (2.5 km) ensemble prediction system Hirlam Aladin Regional Mesoscale Operational NWP Ensemble Prediction System (HarmonEPS). We studied whether such a stochastic physical parametrization, whilst implemented in a deterministic forecast model, can have an impact on the performance of the uncertainty estimates given by an ensemble prediction system. Various feedback mechanisms in the parametrization were studied with respect to ensemble spread and skill, in both subgrid and resolved precipitation fields. It was found that the stochastic parametrization improves the model skill in general, by reducing a positive bias in precipitation. This reduction in bias, however, led to a reduction in ensemble spread of precipitation. Overall, scores that measure the accuracy and reliability of probabilistic predictions indicate that the net impact (improved skill, degraded spread) of the ensemble prediction system is improved for 6 h accumulated precipitation with the stochastic parametrization and is rather neutral for other quantities examined.

National Category
Meteorology and Atmospheric Sciences
Research subject
Meteorology
Identifiers
urn:nbn:se:smhi:diva-2029 (URN)10.1002/qj.2720 (DOI)000372951300051 ()
Available from: 2016-05-03 Created: 2016-05-02 Last updated: 2017-11-30Bibliographically approved
Megner, L., Tan, D. G., Körnich, H., Isaksen, L., Horanyi, A., Stoffelen, A. & Marseille, G.-J. -. (2015). Linearity aspects of the ensemble of data assimilations technique. Quarterly Journal of the Royal Meteorological Society, 141(687), 426-432
Open this publication in new window or tab >>Linearity aspects of the ensemble of data assimilations technique
Show others...
2015 (English)In: Quarterly Journal of the Royal Meteorological Society, ISSN 0035-9009, E-ISSN 1477-870X, Vol. 141, no 687, p. 426-432Article in journal (Refereed) Published
Abstract [en]

We examine the linearity of the Ensemble of Data Assimilations (EDA) technique with respect to the amplitude of the applied observation perturbations. We provide explicit examples to assess the linear relationship between such modifications of the observing system and the resulting changes in the EDA ensemble spread. The results demonstrate that, for a state-of-the-art numerical weather prediction (NWP) system, such linearity between the applied observation perturbations and the EDA ensemble spread holds well for temporal and spatial regimes relevant to global medium-range weather prediction: specifically, for forecast lead-times of up to approximately 5 days, in the vertical throughout the troposphere up to the lower and middle stratosphere and for broad horizontal scales.

National Category
Meteorology and Atmospheric Sciences
Research subject
Meteorology
Identifiers
urn:nbn:se:smhi:diva-1992 (URN)10.1002/qj.2362 (DOI)000353413500007 ()
Available from: 2016-04-25 Created: 2016-03-03 Last updated: 2017-11-30Bibliographically approved
Schlutow, M., Becker, E. & Körnich, H. (2014). Positive definite and mass conserving tracer transport in spectral GCMs. Journal of Geophysical Research - Atmospheres, 119(20), 11562-11577
Open this publication in new window or tab >>Positive definite and mass conserving tracer transport in spectral GCMs
2014 (English)In: Journal of Geophysical Research - Atmospheres, ISSN 2169-897X, E-ISSN 2169-8996, Vol. 119, no 20, p. 11562-11577Article in journal (Refereed) Published
Abstract [en]

A new scheme that solves the advection-diffusion equation for tracers in a spectral General Circulation Model (GCM) is presented. The main ideas are (1) using a monotonic and smooth functional of the tracer as prognostic variable to ensure positive definite concentrations and continuity of all derivatives and (2) defining an adjustable tracer-mass correction as a multiplication of the tracer in grid space, giving rise to an efficient correction in spectral space. Common standard benchmark tests for two-dimensional horizontal advection using deformational wind fields show that the new scheme is accurate and essentially not diffusive. A three-dimensional test is proposed in order to validate vertical transport. Additionally to standard error norms and global tracer mass, the entropy of mixing is introduced as another conservation constraint and utilized to determine the strength of the mass correction which is a free parameter. The transport scheme is applied in a mechanistic spectral GCM from the surface to the lower thermosphere. It is extended such that the mass correction takes the diffusion and other nonconservative effects explicitly into account. By this method we estimate the mean age of air along with its dependence on the turbulent horizontal Schmidt number.

Keywords
tracer transport, subgrid-scale diffusion, spectral method
National Category
Meteorology and Atmospheric Sciences
Research subject
Meteorology
Identifiers
urn:nbn:se:smhi:diva-101 (URN)10.1002/2014JD021661 (DOI)000345298100006 ()
Available from: 2015-04-14 Created: 2015-03-26 Last updated: 2017-12-04Bibliographically approved
Chen, H. W., Zhang, Q., Körnich, H. & Chen, D. (2013). A robust mode of climate variability in the Arctic: The Barents Oscillation. Geophysical Research Letters, 40(11), 2856-2861
Open this publication in new window or tab >>A robust mode of climate variability in the Arctic: The Barents Oscillation
2013 (English)In: Geophysical Research Letters, ISSN 0094-8276, E-ISSN 1944-8007, Vol. 40, no 11, p. 2856-2861Article in journal (Refereed) Published
Abstract [en]

The Barents Oscillation (BO) is an anomalous wintertime atmospheric circulation pattern in the Northern Hemisphere that has been linked to the meridional flow over the Nordic Seas. There are speculations that the BO has important implications for the Arctic climate; however, it has also been suggested that the pattern is an artifact of Empirical Orthogonal Function (EOF) analysis due to an eastward shift of the Arctic Oscillation/North Atlantic Oscillation (AO/NAO). In this study, EOF analyses are performed to show that a robust pattern resembling the BO can be found during different time periods, even when the AO/NAO is relatively stationary. This BO has a high and stable temporal correlation with the geostrophic zonal wind over the Barents Sea, while the contribution from the AO/NAO is small. The surface air temperature anomalies over the Barents Sea are closely associated with this mode of climate variability.

Keywords
Barents Oscillation, Arctic Oscillation, North Atlantic Oscillation, Arctic climate variability, Barents Sea, Empirical Orthogonal Function
National Category
Meteorology and Atmospheric Sciences
Research subject
Meteorology
Identifiers
urn:nbn:se:smhi:diva-373 (URN)10.1002/grl.50551 (DOI)000321261600069 ()
Available from: 2015-04-10 Created: 2015-03-31 Last updated: 2017-12-04Bibliographically approved
Sundqvist, H. S., Holmgren, K., Fohlmeister, J., Zhang, Q., Bar Matthews, M., Spoetl, C. & Körnich, H. (2013). Evidence of a large cooling between 1690 and 1740 AD in southern Africa. Scientific Reports, 3, Article ID 1767.
Open this publication in new window or tab >>Evidence of a large cooling between 1690 and 1740 AD in southern Africa
Show others...
2013 (English)In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 3, article id 1767Article in journal (Refereed) Published
Abstract [en]

A 350-year-long, well-dated delta O-18 stalagmite record from the summer rainfall region in South Africa is positively correlated with regional air surface temperatures at interannual time scales. The coldest period documented in this record occurred between 1690 and 1740, slightly lagging the Maunder Minimum (1645-1710). A temperature reconstruction, based on the correlation between regional surface temperatures and the stalagmite delta O-18 variations, indicates that parts of this period could have been as much as 1.4 degrees C colder than today. Significant cycles of 22, 11 and 4.8 years demonstrate that the solar magnetic and the El Nino-Southern Oscillation cycle could be important drivers of multidecadal to interannual climate variability in this region. The observation that the most important driver of stalagmite delta O-18 on interannual time scales from this subtropical region is regional surface temperature cautions against deterministic interpretations of delta O-18 variations in low-latitude stalagmites as mainly driven by the amount of precipitation.

National Category
Meteorology and Atmospheric Sciences
Research subject
Meteorology
Identifiers
urn:nbn:se:smhi:diva-378 (URN)10.1038/srep01767 (DOI)000318334000004 ()
Available from: 2015-04-07 Created: 2015-03-31 Last updated: 2017-12-04Bibliographically approved
Baron, P., Murtagh, D. P., Urban, J., Sagawa, H., Ochiai, S., Kasai, Y., . . . Yasui, M. (2013). Observation of horizontal winds in the middle-atmosphere between 30 degrees S and 55 degrees N during the northern winter 2009-2010. Atmospheric Chemistry And Physics, 13(12), 6049-6064
Open this publication in new window or tab >>Observation of horizontal winds in the middle-atmosphere between 30 degrees S and 55 degrees N during the northern winter 2009-2010
Show others...
2013 (English)In: Atmospheric Chemistry And Physics, ISSN 1680-7316, E-ISSN 1680-7324, Vol. 13, no 12, p. 6049-6064Article in journal (Refereed) Published
Abstract [en]

Although the links between stratospheric dynamics, climate and weather have been demonstrated, direct observations of stratospheric winds are lacking, in particular at altitudes above 30 km. We report observations of winds between 8 and 0.01 hPa (similar to 35-80 km) from October 2009 to April 2010 by the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) on the International Space Station. The altitude range covers the region between 35-60 km where previous space-borne wind instruments show a lack of sensitivity. Both zonal and meridional wind components were obtained, though not simultaneously, in the latitude range from 30 degrees S to 55 degrees N and with a single profile precision of 7-9 ms(-1) between 8 and 0.6 hPa and better than 20 ms(-1) at altitudes above. The vertical resolution is 5-7 km except in the upper part of the retrieval range (10 km at 0.01 hPa). In the region between 1-0.05 hPa, an absolute value of the mean difference <2 ms(-1) is found between SMILES profiles retrieved from different spectroscopic lines and instrumental settings. Good agreement (absolute value of the mean difference of similar to 2 ms(-1)) is also found with the European Centre for Medium-Range Weather Forecasts (ECMWF) analysis in most of the stratosphere except for the zonal winds over the equator (difference >5 ms(-1)). In the mesosphere, SMILES and ECMWF zonal winds exhibit large differences (>20 ms(-1)), especially in the tropics. We illustrate our results by showing daily and monthly zonal wind variations, namely the semi-annual oscillation in the tropics and reversals of the flow direction between 50-55 degrees N during sudden stratospheric warmings. The daily comparison with ECMWF winds reveals that in the beginning of February, a significantly stronger zonal westward flow is measured in the tropics at 2 hPa compared to the flow computed in the analysis (difference of similar to 20 ms(-1)). The results show that the comparison between SMILES and ECMWF winds is not only relevant for the quality assessment of the new SMILES winds, but it also provides insights on the quality of the ECMWF winds themselves. Although the instrument was not specifically designed for measuring winds, the results demonstrate that space-borne sub-mm wave radiometers have the potential to provide good quality data for improving the stratospheric winds in atmospheric models.

National Category
Meteorology and Atmospheric Sciences
Research subject
Meteorology
Identifiers
urn:nbn:se:smhi:diva-405 (URN)10.5194/acp-13-6049-2013 (DOI)000321766300013 ()
Available from: 2015-04-01 Created: 2015-03-31 Last updated: 2017-12-04Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0003-0524-6440

Search in DiVA

Show all publications
v. 2.35.7
|