Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    In: Atmosphere, MDPI AG, Vol. 3, No. 3 ( 2012-08-17), p. 419-450
    Type of Medium: Online Resource
    ISSN: 2073-4433
    Language: English
    Publisher: MDPI AG
    Publication Date: 2012
    detail.hit.zdb_id: 2605928-9
    SSG: 23
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    In: Boundary-Layer Meteorology, Springer Science and Business Media LLC, Vol. 117, No. 2 ( 2005-11), p. 337-381
    Type of Medium: Online Resource
    ISSN: 0006-8314 , 1573-1472
    Language: English
    Publisher: Springer Science and Business Media LLC
    Publication Date: 2005
    detail.hit.zdb_id: 242879-9
    detail.hit.zdb_id: 1477639-X
    SSG: 16,13
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Online Resource
    Online Resource
    American Geophysical Union (AGU) ; 2005
    In:  Eos, Transactions American Geophysical Union Vol. 86, No. 49 ( 2005-12-06), p. 509-509
    In: Eos, Transactions American Geophysical Union, American Geophysical Union (AGU), Vol. 86, No. 49 ( 2005-12-06), p. 509-509
    Abstract: The polar regions are experiencing major climate and environmental changes due to the combined effects of natural variability and global warming. To address regional Arctic climate processes and their global feedbacks, 53 experts from the United States, Canada, Europe, and Russia gathered for a recent workshop at the Alfred Wegener Institute for Polar and Marine Research, in Potsdam, Germany. The workshop, which was organized by Klaus Dethloff and Annette Rinke, focused on the use of regional models of the Arctic, global coupled climate models, and Arctic impact studies. This article summarizes the main advances and outstanding issues in Arctic modeling that were presented and discussed during the workshop.
    Type of Medium: Online Resource
    ISSN: 0096-3941 , 2324-9250
    Language: English
    Publisher: American Geophysical Union (AGU)
    Publication Date: 2005
    detail.hit.zdb_id: 24845-9
    detail.hit.zdb_id: 2118760-5
    detail.hit.zdb_id: 240154-X
    SSG: 16,13
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Online Resource
    Online Resource
    American Geophysical Union (AGU) ; 1996
    In:  Journal of Geophysical Research: Atmospheres Vol. 101, No. D18 ( 1996-10-27), p. 23401-23422
    In: Journal of Geophysical Research: Atmospheres, American Geophysical Union (AGU), Vol. 101, No. D18 ( 1996-10-27), p. 23401-23422
    Abstract: A regional climate model of the whole Arctic using the dynamical package of the High‐Resolution Limited Area Model (HIRLAM) and the physical parameterizations of the Hamburg General Circulation Model (ECHAM3) has been applied to simulate the climate of the Arctic north of 65°N at a 50‐km horizontal resolution. The model has been forced by the European Centre for Medium‐Range Weather Forecasts (ECMWF) analyses at the lateral boundaries and with climatological or actual observed sea surface temperatures and sea ice cover at the lower boundary. The results of simulating the Arctic climate of the troposphere and lower stratosphere for January 1991 and July 1990 have been described. In both months the model rather closely reproduces the observed monthly mean circulation. While the general spatial patterns of surface air temperature, mean sea level pressure, and geopotential are consistent with the ECMWF analyses, the model shows biases when the results are examined in detail. The largest biases appear during winter in the planetary boundary layer and at the surface. The underestimated vertical heat and humidity transport in the model indicates the necessity of improvements in the parameterizations of vertical transfer due to boundary layer processes. The tropospheric differences between model simulations and analyses decrease with increasing height. The temperature bias in the planetary boundary layer can be reduced by increasing the model sea ice thickness. The use of actual observed sea surface temperatures and sea ice cover leads only to small improvements of the model bias in comparison with climatological sea surface temperatures and sea ice cover. The validation of model computed geopotential, radiative fluxes, surface sensible and latent heat fluxes and clouds against selected station data shows deviations between model simulations and observations due to shortcomings of the model. This first validation indicates that improvements in the physical parameterization packages of radiation and in the description of sea ice thickness and sea ice fraction are necessary to reduce the model bias.
    Type of Medium: Online Resource
    ISSN: 0148-0227
    Language: English
    Publisher: American Geophysical Union (AGU)
    Publication Date: 1996
    detail.hit.zdb_id: 2033040-6
    detail.hit.zdb_id: 3094104-0
    detail.hit.zdb_id: 2130824-X
    detail.hit.zdb_id: 2016813-5
    detail.hit.zdb_id: 2016810-X
    detail.hit.zdb_id: 2403298-0
    detail.hit.zdb_id: 2016800-7
    detail.hit.zdb_id: 161666-3
    detail.hit.zdb_id: 161667-5
    detail.hit.zdb_id: 2969341-X
    detail.hit.zdb_id: 161665-1
    detail.hit.zdb_id: 3094268-8
    detail.hit.zdb_id: 710256-2
    detail.hit.zdb_id: 2016804-4
    detail.hit.zdb_id: 3094181-7
    detail.hit.zdb_id: 3094219-6
    detail.hit.zdb_id: 3094167-2
    detail.hit.zdb_id: 2220777-6
    detail.hit.zdb_id: 3094197-0
    SSG: 16,13
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Online Resource
    Online Resource
    American Geophysical Union (AGU) ; 1999
    In:  Journal of Geophysical Research: Atmospheres Vol. 104, No. D16 ( 1999-08-27), p. 19027-19038
    In: Journal of Geophysical Research: Atmospheres, American Geophysical Union (AGU), Vol. 104, No. D16 ( 1999-08-27), p. 19027-19038
    Abstract: The mean Arctic January climatology and its interannual variation have been examined by simulations with a regional climate model of the Arctic atmosphere. To this end, an ensemble of monthlong simulations (January of the 11 years 1985–1995) has been investigated in which the ensemble is large enough to represent a broad range of climatic conditions. The model produces credible simulations of the meteorological patterns. Only small deviations occur between simulations and European Centre for Medium‐Range Weather Forecasts (ECMWF) analyses; that is, over most of the model area these differences in sea level pressure, 850 hPa temperature, and 500 hPa height are below 3 hPa, 1 K, and 5 m, respectively. Larger deviations (up to 5 hPa in the sea level pressure and 20 m in the 500 hPa height) are found over parts of the Arctic Ocean, which seems to be related to the crude sea ice representation at the lower model boundary and deficiencies in the planetary boundary layer parameterization. It is shown that the dynamical aspects of the interannual variability can be adequately captured by the model simulations; that is, the maximum of the model bias of the dynamical variables is significantly smaller than the interannual variability throughout the entire domain. To gain more insight into the spatial and temporal structures of the model's variability, an empirical orthogonal function (EOF) analysis has been applied to determine the most significant structures in the fluctuations of the monthly mean dynamical fields. EOF 1 of the 500 hPa height field describes a regime with well‐pronounced polar vortex and corresponds to the “Arctic Oscillation”, whereas EOFs 2 and 3 show wave structures. A pronounced interannual variability is noticed in the time series of the amplitudes of the EOFs.
    Type of Medium: Online Resource
    ISSN: 0148-0227
    Language: English
    Publisher: American Geophysical Union (AGU)
    Publication Date: 1999
    detail.hit.zdb_id: 2033040-6
    detail.hit.zdb_id: 3094104-0
    detail.hit.zdb_id: 2130824-X
    detail.hit.zdb_id: 2016813-5
    detail.hit.zdb_id: 2016810-X
    detail.hit.zdb_id: 2403298-0
    detail.hit.zdb_id: 2016800-7
    detail.hit.zdb_id: 161666-3
    detail.hit.zdb_id: 161667-5
    detail.hit.zdb_id: 2969341-X
    detail.hit.zdb_id: 161665-1
    detail.hit.zdb_id: 3094268-8
    detail.hit.zdb_id: 710256-2
    detail.hit.zdb_id: 2016804-4
    detail.hit.zdb_id: 3094181-7
    detail.hit.zdb_id: 3094219-6
    detail.hit.zdb_id: 3094167-2
    detail.hit.zdb_id: 2220777-6
    detail.hit.zdb_id: 3094197-0
    SSG: 16,13
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Online Resource
    Online Resource
    American Geophysical Union (AGU) ; 2004
    In:  Eos, Transactions American Geophysical Union Vol. 85, No. 46 ( 2004-11-16), p. 484-484
    In: Eos, Transactions American Geophysical Union, American Geophysical Union (AGU), Vol. 85, No. 46 ( 2004-11-16), p. 484-484
    Abstract: The Arctic Ocean's role in global climate—while now widely appreciated—remains poorly understood. Lack of information about key processes within the oceanic, cryospheric, biologic, atmospheric, and geologic disciplines will continue to impede physical understanding, model validation, and climate prediction until a practical observing system is designed and implemented. A review of recently observed changes in the physical and biological state of the Arctic and a justification for future Arctic observations are contained in the supporting document of the U.S. National Science Foundation's (NSF) “Study of Environmental Arctic Change” program (SEARCH, http://psc.apl.washington.edu/search/). Comparable Arctic study programs have been conceived as an international contribution to the proposed International Polar Year 2007–2008 (http://www.aosb.org/ipyhtml). Future directions in instrument development for Arctic studies were also considered at a workshop at the Monterey Bay Aquarium Research Institute in October 2002 (http://www.mbari.org/rd/ArcticInstrumentationWorkshop).
    Type of Medium: Online Resource
    ISSN: 0096-3941 , 2324-9250
    Language: English
    Publisher: American Geophysical Union (AGU)
    Publication Date: 2004
    detail.hit.zdb_id: 24845-9
    detail.hit.zdb_id: 2118760-5
    detail.hit.zdb_id: 240154-X
    SSG: 16,13
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Online Resource
    Online Resource
    American Geophysical Union (AGU) ; 2008
    In:  Eos, Transactions American Geophysical Union Vol. 89, No. 16 ( 2008-04-15), p. 150-152
    In: Eos, Transactions American Geophysical Union, American Geophysical Union (AGU), Vol. 89, No. 16 ( 2008-04-15), p. 150-152
    Abstract: The coincidence of rapid change in Arctic climate (the extreme 2007 decline in sea ice and recent unprecedented warming) and enhanced observational activities during the International Polar Year (IPY; 2007–2008) offers hope that these changes will be documented in great detail. However, in order to explain changes in the Arctic and predict its future dynamics, models of the Arctic climatic system are needed to reproduce past and present states and to predict future transformations. Results from existing models are not always satisfactory [e.g., Stroeve et al. , 2007] because there are significant uncertainties in model forcing, parameterization of physical processes, and internal model parameters.
    Type of Medium: Online Resource
    ISSN: 0096-3941 , 2324-9250
    Language: English
    Publisher: American Geophysical Union (AGU)
    Publication Date: 2008
    detail.hit.zdb_id: 24845-9
    detail.hit.zdb_id: 2118760-5
    detail.hit.zdb_id: 240154-X
    SSG: 16,13
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Online Resource
    Online Resource
    American Geophysical Union (AGU) ; 2012
    In:  Eos, Transactions American Geophysical Union Vol. 93, No. 4 ( 2012-01-24), p. 41-42
    In: Eos, Transactions American Geophysical Union, American Geophysical Union (AGU), Vol. 93, No. 4 ( 2012-01-24), p. 41-42
    Abstract: The Arctic is undergoing rapid environmental change, manifested most dramatically by reductions in sea ice extent and thickness. The changes are attributed to anthropogenic effects related to greenhouse warming, with secondary contributions from changing ocean and wind currents as well as from pollutants, especially “absorbing” black carbon. The warmer Arctic air temperatures and new patterns of wind and ocean circulation have also contributed to a younger ice cover [ Maslanik et al. , 2011]. Specific factors that determine the temporal distribution of sea ice are poorly understood because few observations of key variables have been made in the central Arctic. For example, the planetary boundary layer (PBL), the lowest part of the atmosphere governed by interaction with Earth's surface, plays a critical role involving the exchange of momentum, heat, water vapor, trace gases, and aerosol particles. Satellites can provide limited observations of sea ice properties, but so far, accurate measurements of ice thickness or boundary layer properties have not been easily obtained. Although satellite retrievals of geophysical variables might be an essential source of information, their reliability remains questionable owing to inadequate spatial and/or temporal resolution and to a need for further validation.
    Type of Medium: Online Resource
    ISSN: 0096-3941 , 2324-9250
    Language: English
    Publisher: American Geophysical Union (AGU)
    Publication Date: 2012
    detail.hit.zdb_id: 24845-9
    detail.hit.zdb_id: 2118760-5
    detail.hit.zdb_id: 240154-X
    SSG: 16,13
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Online Resource
    Online Resource
    Bentham Science Publishers Ltd. ; 2010
    In:  The Open Atmospheric Science Journal Vol. 4, No. 1 ( 2010-6-3), p. 126-136
    In: The Open Atmospheric Science Journal, Bentham Science Publishers Ltd., Vol. 4, No. 1 ( 2010-6-3), p. 126-136
    Abstract: This paper discusses results of a simulation with the regional climate model HIRHAM for 1958-2001, driven by the ECMWF reanalysis (ERA40) data over the Arctic domain. The aim is to analyze the ability of the model to capture certain features of climate extremes derived from daily mean, maximum and minimum temperatures. For this purpose, a range of climate indices (frost days, cold and warm spell days, growing degree days and growing season length) was calculated from the model output as well as from ERA40 data and region-specific station data for Eastern and Western Russian Arctic for comparison. It is demonstrated that the model captures the main features in the spatial distribution and temporal development of most indices well. Though systematic deviations in the seasonal means occur in various indices (frost days, growing degree days), variability and trends are well reproduced. Seasonal mean patterns in frost days are reproduced best, though the model persistently calculates too many frost days. Seasonal means of cold and warm spell days are reproduced without systematic biases, though deviations occur in summer for cold spells and in spring and summer for warm spells due to an early spring warming in the regional climate model and a low variability of the daily maximum temperature over sea ice.
    Type of Medium: Online Resource
    ISSN: 1874-2823
    Language: English
    Publisher: Bentham Science Publishers Ltd.
    Publication Date: 2010
    detail.hit.zdb_id: 2396662-2
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Online Resource
    Online Resource
    Bentham Science Publishers Ltd. ; 2012
    In:  The Open Atmospheric Science Journal Vol. 6, No. 1 ( 2012-3-02), p. 42-48
    In: The Open Atmospheric Science Journal, Bentham Science Publishers Ltd., Vol. 6, No. 1 ( 2012-3-02), p. 42-48
    Abstract: The regional climate model HIRHAM has been applied over the Asian continent from 0°N to 50°N and 42°E to 110°E to simulate the Indian monsoon circulation under past and present-day conditions. The model is driven at the lateral and lower boundaries by the atmospheric output fields of the global coupled Earth system model ECHAM5- JSBACH/MPIOM for 44-years-long time slices during the mid-Holocene and the preindustrial present-day climate. Simulations with a horizontal resolution of 50 km are carried out to analyze the regional monsoon patterns under different external solar forcing and climatic conditions. The focus is on the investigation of the HIRHAM simulated summer monsoon circulation and the comparison of the regional atmospheric circulation and precipitation patterns between the paleo- and the preindustrial climate. Due to mid-Holocene changes in the atmospheric circulation with a reduced and southward shifted monsoonal flow across Arabian Sea and Bay of Bengal, an increase of summer rainfall at the windward slopes of western and southern Himalayas as well as over southern India and decreased rainfall over central India appear which is in agreement with proxy-derived precipitation reconstructions. During the mid-Holocene as well as for the present-day climate the same driving mechanisms for the summer monsoon in extreme wet monsoon years related to regional SST anomalies in the Indian Ocean and convective processes can be verified. Positive (negative) SST anomalies in the northern Indian Ocean enhance (inhibit) the local convection associated with a deepening (weakening) of the low pressure and trigger wet (dry) rainfall anomalies.
    Type of Medium: Online Resource
    ISSN: 1874-2823
    Language: English
    Publisher: Bentham Science Publishers Ltd.
    Publication Date: 2012
    detail.hit.zdb_id: 2396662-2
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. Further information can be found on the KOBV privacy pages