Temat: regional model - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Quality assessment of atmospheric surface fields over the Baltic Sea from an ensemble of regional climate model simulations with respect to ocean dynamics
Autorzy:: Meier, H.E.M.
Hoglund, A.
Doscher, R.
Andersson, H.
Loptien, U.
Kjellstrom, E.
Powiązania:: https://bibliotekanauki.pl/articles/48250.pdf
Data publikacji:: 2011
Wydawca:: Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:: atmosphere-ocean coupling
Baltic region
climate change
climate model
ecosystem
global warming
hydrographic change
regional climate
regional climate modelling
sea ice
temperature
water temperature
Opis:: Climate model results for the Baltic Sea region from an ensemble of eight simulations using the Rossby Centre Atmosphere model version 3 (RCA3) driven with lateral boundary data from global climate models (GCMs) are compared with results from a downscaled ERA40 simulation and gridded observations from 1980 –2006. The results showed that data from RCA3 scenario simulations should not be used as forcing for Baltic Sea models in climate change impact studies because biases of the control climate significantly affect the simulated changes of future projections. For instance, biases of the sea ice cover in RCA3 in the present climate affect the sensitivity of the model’s response to changing climate due to the ice-albedo feedback. From the large ensemble of available RCA3 scenario simulations two GCMs with good performance in downscaling experiments during the control period 1980–2006 were selected. In this study, only the quality of atmospheric surface fields over the Baltic Sea was chosen as a selection criterion. For the greenhouse gas emission scenario A1B two transient simulations for 1961 –2100 driven by these two GCMs were performed using the regional, fully coupled atmosphere-ice-ocean model RCAO. It was shown that RCAO has the potential to improve the results in downscaling experiments driven by GCMs considerably, because sea surface temperatures and sea ice concentrations are calculated more realistically with RCAO than when RCA3 has been forced with surface boundary data from GCMs. For instance, the seasonal 2 m air temperature cycle is closer to observations in RCAO than in RCA3 downscaling simulations. However, the parameterizations of air-sea fluxes in RCAO need to be improved.
Źródło:: Oceanologia; 2011, 53, (1-TI)
0078-3234
Pojawia się w:: Oceanologia
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 2.

Tytuł:: Modelling of the Svalbard fjord Hornsund
Autorzy:: Jakacki, J.
Przyborska, A.
Kosecki, S.
Sundfjord, A.
Albretsen, J.
Powiązania:: https://bibliotekanauki.pl/articles/48674.pdf
Data publikacji:: 2017
Wydawca:: Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:: hydrodynamic model
regional variability
oceanographic condition
salt content
heat content
anomaly
Hornsund Region
Svalbard Fjord
Opis:: The Arctic Ocean is currently in transition towards a new, warmer state. Understanding the regional variability of oceanographic conditions is important, since they have a direct impact on local ecosystems. This work discusses the implementation of a hydrodynamic model for Hornsund, the southernmost fjord of western Svalbard. Despite its location, Hornsund has a stronger Arctic signature than other Svalbard fjords. The model was validated against available data, and the seasonal mean circulation was obtained from numerical simulations. Two main general circulation regimes have been detected in the fjord. The winter circulation represents a typical closed fjord system, while in summer the fresh water discharge from the catchment area generates a surface layer with a net flow out of Hornsund. Also described are the local hydrographic front and its seasonal variability, as well as the heat and salt content in Hornsund. The integration of salt and heat anomalies provides additional information about the salt flux into the innermost basin of the fjord - Brepollen during the summer. Extensive in situ observations have been collected in Hornsund for the last two decades but our hydrodynamic model is the first ever implemented for this area. While at the moment in situ observations better represent the state of this fjord's environment and the location of measurements, a numerical model, despite its flaws, can provide a more comprehensive image of the entire fjord's physical state. In situ observations and numerical simulations should therefore be regarded as complementary tools, with models enabling a better interpretation and understanding of experimental data.
Źródło:: Oceanologia; 2017, 59, 4
0078-3234
Pojawia się w:: Oceanologia
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 3.

Tytuł:: Temporal variation of extreme precipitation events in Lithuania
Autorzy:: Rimkus, E.
Kazys, J.
Bukantis, A.
Krotovas, A.
Powiązania:: https://bibliotekanauki.pl/articles/48347.pdf
Data publikacji:: 2011
Wydawca:: Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:: atmospheric circulation
CCLM model
climate condition
dynamics
heavy rain
Lithuania
negative change
precipitation
regional modelling
spatial distribution
Opis:: Heavy precipitation events in Lithuania for the period 1961–2008 were analysed. The spatial distribution and dynamics of precipitation extremes were investigated. Positive tendencies and in some cases statistically significant trends were deter- mined for the whole of Lithuania. Atmospheric circulation processes were derived using Hess & Brezowski’s classification of macrocirculation forms. More than one third of heavy precipitation events (37%) were observed when the atmospheric circulation was zonal. The location of the central part of a cyclone (WZ weather condition subtype) over Lithuania is the most common synoptic situation (27%) during heavy precipitation events. Climatic projections according to outputs of the CCLM model are also presented in this research. The analysis shows that the recurrence of heavy precipitation events in the 21st century will increase significantly (by up to 22%) in Lithuania.
Źródło:: Oceanologia; 2011, 53, (1-TI)
0078-3234
Pojawia się w:: Oceanologia
Dostawca treści:: Biblioteka Nauki