Endre søk
Link to record
Permanent link

Direct link
Ljungemyr, Patrik
Publikasjoner (4 av 4) Visa alla publikasjoner
Hordoir, R., Axell, L., Höglund, A., Dieterich, C., Fransner, F., Groger, M., . . . Haapala, J. (2019). Nemo-Nordic 1.0: a NEMO-based ocean model for the Baltic and North seas - research and operational applications. Geoscientific Model Development, 12(1), 363-386
Åpne denne publikasjonen i ny fane eller vindu >>Nemo-Nordic 1.0: a NEMO-based ocean model for the Baltic and North seas - research and operational applications
Vise andre…
2019 (engelsk)Inngår i: Geoscientific Model Development, ISSN 1991-959X, E-ISSN 1991-9603, Vol. 12, nr 1, s. 363-386Artikkel i tidsskrift (Fagfellevurdert) Published
HSV kategori
urn:nbn:se:smhi:diva-5159 (URN)10.5194/gmd-12-363-2019 (DOI)000456302000003 ()
Tilgjengelig fra: 2019-02-05 Laget: 2019-02-05 Sist oppdatert: 2019-02-05bibliografisk kontrollert
Golbeck, I., Li, X., Janssen, F., Bruening, T., Nielsen, J. W., Huess, V., . . . Axell, L. (2015). Uncertainty estimation for operational ocean forecast products-a multi-model ensemble for the North Sea and the Baltic Sea. Ocean Dynamics, 65(12), 1603-1631
Åpne denne publikasjonen i ny fane eller vindu >>Uncertainty estimation for operational ocean forecast products-a multi-model ensemble for the North Sea and the Baltic Sea
Vise andre…
2015 (engelsk)Inngår i: Ocean Dynamics, ISSN 1616-7341, E-ISSN 1616-7228, Vol. 65, nr 12, s. 1603-1631Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Multi-model ensembles for sea surface temperature (SST), sea surface salinity (SSS), sea surface currents (SSC), and water transports have been developed for the North Sea and the Baltic Sea using outputs from several operational ocean forecasting models provided by different institutes. The individual models differ in model code, resolution, boundary conditions, atmospheric forcing, and data assimilation. The ensembles are produced on a daily basis. Daily statistics are calculated for each parameter giving information about the spread of the forecasts with standard deviation, ensemble mean and median, and coefficient of variation. High forecast uncertainty, i.e., for SSS and SSC, was found in the Skagerrak, Kattegat (Transition Area between North Sea and Baltic Sea), and the Norwegian Channel. Based on the data collected, longer-term statistical analyses have been done, such as a comparison with satellite data for SST and evaluation of the deviation between forecasts in temporal and spatial scale. Regions of high forecast uncertainty for SSS and SSC have been detected in the Transition Area and the Norwegian Channel where a large spread between the models might evolve due to differences in simulating the frontal structures and their movements. A distinct seasonal pattern could be distinguished for SST with high uncertainty between the forecasts during summer. Forecasts with relatively high deviation from the multi-model ensemble (MME) products or the other individual forecasts were detected for each region and each parameter. The comparison with satellite data showed that the error of the MME products is lowest compared to those of the ensemble members.

HSV kategori
urn:nbn:se:smhi:diva-1937 (URN)10.1007/s10236-015-0897-8 (DOI)000365876400002 ()
Tilgjengelig fra: 2016-04-29 Laget: 2016-03-03 Sist oppdatert: 2018-01-10bibliografisk kontrollert
Funquist, L. & Ljungemyr, P. (1997). Validation of HIROMB during 1995-96. SMHI
Åpne denne publikasjonen i ny fane eller vindu >>Validation of HIROMB during 1995-96
1997 (engelsk)Rapport (Annet vitenskapelig)
Abstract [en]

IROMB (High Resolution Operational Model of the Baltic Sea) is the result of a combined effort between BSH (Bundesamt för Seeschiffahrt und Hydrographie) and SMHI (Swedish Meteorological and Hydrological Institute). In its present form, the model is a modified version of the BSH operational model (Kleine, 1994) with identical boundaries to the North Atlantic. The cooperation started in summer 1994 when the model was set up at SMHI. The first operational runs started in the sumrner 1995 and since then the model has been running daily except fora limited number of periods when there were no meteorological input from the HIRLAM (atmospheric) model available because of computer problems. During the first months, some occasions with stability problems occurred, leading toa restart from the climatological fields.

This report presents results from a continous verification exercise, where model results are compared to observations of water level, surface temperature, currents, ice thickness and salinity and temperature profiles. The times series data are taken from the period September-November 1996 while the ice thickness data are from November and December 1996 and the sea surface temperature data are taken from August, November and December 1996.

For a detailed description of the model, the reader is referred to a forthcoming report by Funkquist and Kleine.

sted, utgiver, år, opplag, sider
SMHI, 1997. s. 16
Oceanografi, ISSN 0283-7714 ; 67
HSV kategori
urn:nbn:se:smhi:diva-2528 (URN)Oceanografi, Rapporter, Serie Oceanografi (Lokal ID)Oceanografi, Rapporter, Serie Oceanografi (Arkivnummer)Oceanografi, Rapporter, Serie Oceanografi (OAI)
Tilgjengelig fra: 1997-05-15 Laget: 2016-07-08 Sist oppdatert: 2019-11-26bibliografisk kontrollert
Ljungemyr, P., Gustafsson, N. & Omstedt, A. (1996). Parameterization of lake thermodynamics in a high-resolution weather forecasting model. Paper presented at 1st Study Conference on BALTEX, AUG 28-SEP 01, 1995, VISBY, SWEDEN. Tellus. Series A, Dynamic meteorology and oceanography, 48(5), 608-621
Åpne denne publikasjonen i ny fane eller vindu >>Parameterization of lake thermodynamics in a high-resolution weather forecasting model
1996 (engelsk)Inngår i: Tellus. Series A, Dynamic meteorology and oceanography, ISSN 0280-6495, E-ISSN 1600-0870, Vol. 48, nr 5, s. 608-621Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

A model for the parameterization of lake temperatures and lake ice thicknesses in atmospheric models is presented. The model is verified independently, and it is also tested within the framework of the High Resolution Limited Area Model(HIRLAM), applied operationally for short range weather forecasting at the Swedish Meteorological and Hydrological Institute (SMHI). The lake model is a slab model based upon energy conservation and treats the lakes as well mixed boxes with depths represented by the mean depths. The model is forced by near surface fluxes calculated from total cloudiness, air temperature, air humidity and low-level winds. A data base, describing 92000 Swedish lakes. provides the model with lake mean depths, areal sizes and locations. When the model is used for parameterization of lake effects in the atmospheric model, all the smaller lakes and the fractions of larger lakes within each horizontal grid square of the atmospheric model are parameterized by four model lakes, representing the lake size distribution. The verification of the lake model is done by comparing it with a more advanced, vertically resolved model, including parameterization of turbulent mixing processes, as well as by comparison with observations. A sensitivity test shows great interannual variations of the ice-covered season, which implies that lake models should be used instead of climate data. The results from an experiment with two-way coupling of the lake model to the atmospheric model are verified by comparing forecasted weather parameters with routine meteorological observations. These results show that the impact of lake effects can reach several degrees C in air temperatures close to the surface.

HSV kategori
urn:nbn:se:smhi:diva-1629 (URN)10.1034/j.1600-0870.1996.t01-4-00002.x (DOI)A1996VV42600002 ()
1st Study Conference on BALTEX, AUG 28-SEP 01, 1995, VISBY, SWEDEN
Tilgjengelig fra: 2016-01-26 Laget: 2015-12-22 Sist oppdatert: 2018-05-24
v. 2.35.9