ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
Filter
  • Articles  (67)
  • Physics  (67)
Collection
  • Articles  (67)
Source
Publisher
Years
Journal
Topic
  • 1
    Electronic Resource
    Electronic Resource
    Simulation of modern and glacial climates with a coupled global model of intermediate complexity (1998)
    [s.l.] : Macmillan Magazines Ltd.
    Nature 391 (1998), S. 351-356 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] A global coupled ocean–atmosphere model of intermediate complexity is used to simulate the equilibrium climate of both today and the Last Glacial Maximum, around 21,000 years ago. The model successfully predicts the atmospheric and oceanic circulations, temperature distribution, hydrological ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/34839
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    On the momentum forcing of a large-scale sea-ice model (1993)
    Springer
    Climate dynamics 9 (1993), S. 71-80 
    Details
    ISSN: 1432-0894
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract A large-scale sea-ice - oceanic mixed-layer model for the Southern Ocean is forced with daily atmospheric fields from operational numerical weather prediction analyses. The strength of the atmospheric forcing is modified considering atmospheric surface-layer physics, which is itself directly dependent on the instantaneous sea-ice condition provided by the sea-ice model. In earlier applications, the atmospheric drag on sea ice was computed from the local momentum transfer over ice. In the present study, this is replaced by a large-scale momentum flux, which is characterized by a large-scale stability function and a large-scale roughness length. The large-scale roughness length depends on the local skin drags and on the form drag, where the latter is given as a function of the ice-plus-snow freeboard and the ice concentration, both provided by the sea-ice model. The thermodynamic part of the calculation is given by the local fluxes, which depend on the local stability of the atmospheric surface layer. This, physically more reasonable, description of the largescale dynamic forcing generally leads to an increase of the momentum transfer via an increase of the roughness length and a decrease of the stability in the atmospheric surface layer. Finally, this yields improved model results, especially in terms of a more dynamic pattern of the ice-thickness distribution.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00210010
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Biomes computed from simulated climatologies (1994)
    Springer
    Climate dynamics 9 (1994), S. 235-243 
    Details
    ISSN: 1432-0894
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract. The biome model of Prentice et al. (1992a) is used to predict global patterns of potential natural plant formations, or biomes, from climatologies simulated by ECHAM, a model used for climate simulations at the Max-Planck-Institut für Meteorologie. This study is undertaken in order to show the advantage of this biome model in diagnosing the performance of a climate model and assessing effects of past and future climate changes predicted by a climate model. Good overall agreement is found between global patterns of biomes computed from observed and simulated data of present climate. But there are also major discrepancies indicated by a difference in biomes in Australia, in the Kalahari Desert, and in the Middle West of North America. These discrepancies can be traced back to failures in simulated rainfall as well as summer or winter temperatures. Global patterns of biomes computed from an ice age simulation reveal that North America, Europe, and Siberia should have been covered largely by tundra and taiga, whereas only small differences are seen for the tropical rain forests. A potential north-east shift of biomes is expected from a simulation with enhanced CO2 concentration according to the IPCC Scenario A. Little change is seen in the tropical rain forest and the Sahara. Since the biome model used is not capable of predicting changes in vegetation patterns due to a rapid climate change, the latter simulation has to be taken as a prediction of changes in conditions favourable for the existence of certain biomes, not as a prediction of a future distribution of biomes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003820050022
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Variability of global biome patterns as a function of initial and boundary conditions in a climate model (1996)
    Springer
    Climate dynamics 12 (1996), S. 371-379 
    Details
    ISSN: 1432-0894
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The use of one-way coupling of an equilibrium-response vegetation, or biome, model with atmospheric circulation models is critically assessed. Global biome patterns from various, equally likely numerical realisations of present-day climate are compared. It has been found that the changes in global biome patterns to be expected from interdecadal variability in the atmosphere affect 9–12% of the continental surface (Antarctica excluded). There is no unique difference pattern, although changes are mainly induced by the variability of annual moisture availability and, to a lesser extent, by winter temperatures. This variability of biome patterns reflects the uncertainty in the estimate of equilibrium vegetation patterns from finite time interval climatologies. Changes in biome distributions between present-day climate and anomaly climate, the latter induced by an increase in sea-surface temperatures and atmospheric CO2, are larger than and different in kind from the changes due to interdecadal variability. Roughly 30% of the land surface is affected by these changes. It appears that the strongest and most significant signal is seen for boreal biomes which can be attributed to an increase in near surface temperatures.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00211683
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Variability of global biome patterns as a function of initial and boundary conditions in a climate model (1996)
    Springer
    Climate dynamics 12 (1996), S. 371-379 
    Details
    ISSN: 1432-0894
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract. The use of one-way coupling of an equilibrium-response vegetation, or biome, model with atmospheric circulation models is critically assessed. Global biome patterns from various, equally likely numerical realisations of present-day climate are compared. It has been found that the changes in global biome patterns to be expected from interdecadal variability in the atmosphere affect 9–12% of the continental surface (Antarctica excluded). There is no unique difference pattern, although changes are mainly induced by the variability of annual moisture availability and, to a lesser extent, by winter temperatures. This variability of biome patterns reflects the uncertainty in the estimate of equilibrium vegetation patterns from finite time interval climatologies. Changes in biome distributions between present-day climate and anomaly climate, the latter induced by an increase in sea-surface temperatures and atmospheric CO2, are larger than and different in kind from the changes due to inderdecadal variability. Roughly 30% of the land surface is affected by these changes. It appears that the strongest and most significant signal is seen for boreal biomes which can be attributed to an increase in near surface temperatures.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003820050114
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Biomes computed from simulated climatologies (1994)
    Springer
    Climate dynamics 9 (1994), S. 235-243 
    Details
    ISSN: 1432-0894
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The biome model of Prentice et al. (1992a) is used to predict global patterns of potential natural plant formations, or biomes, from climatologies simulated by ECHAM, a model used for climate simulations at the Max-Planck-Institut fur Meteorologie. This study is undertaken in order to show the advantage of this biome model in diagnosing the performance of a climate model and assessing effects of past and future climate changes predicted by a climate model. Good overall agreement is found between global patterns of biomes computed from observed and simulated data of present climate. But there are also major discrepancies indicated by a difference in biomes in Australia, in the Kalahari Desert, and in the Middle West of North America. These discrepancies can be traced back to failures in simulated rainfall as well as summer or winter temperatures. Global patterns of biomes computed from an ice age simulation reveal that North America, Europe, and Siberia should have been covered largely by tundra and taiga, whereas only small differences are seen for the tropical rain forests. A potential northeast shift of biomes is expected from a simulation with enhanced C02 concentration according to the IPCC Scenario A. Little change is seen in the tropical rain forest and the Sahara. Since the biome model used is not capable of predicting changes in vegetation patterns due to a rapid climate change, the latter simulation has to be taken as a prediction of changes in conditions favourable for the existence of certain biomes, not as a prediction of a future distribution of biomes.[/ab]
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00208255
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    The impact of sub-grid scale sea-ice inhomogeneities on the performance of the atmospheric general circulation model ECHAM3 (1996)
    Springer
    Climate dynamics 12 (1996), S. 477-496 
    Details
    ISSN: 1432-0894
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract. Leads and polynyas have a great impact on the energy budget of the polar ocean and atmosphere. Since atmospheric general circulation models are not able to resolve the spatial scales of these inhomogeneities, it is necessary to include the effect of fractional sub-grid scale sea-ice inhomogeneities on climate by a suitable parametrization. In order to do this we have divided each model grid-cell into an ice-covered and an ice-free part. Nevertheless, a numerical model requires effective transports representative for the whole grid-box. A simple procedure would be to use grid averages of the surface parameters for the calculation of the surface fluxes. However, as the surface fluxes are non-linearly dependent on the surface properties, the fluxes over ice and open water should be calculated separately according to the individual surface-layer structure of each surface type. Then these local fluxes should be averaged to obtain representative fluxes. Sensitivity experiments with the Hamburg atmospheric general circulation model ECHAM3 clearly show that a subgrid scale distribution of sea ice is a dominant factor controlling the exchange processes between ocean and atmosphere in the Arctic. The heat and water vapour transports are strongly enhanced leading to a significant warming and moistening of the polar troposphere. This affects the atmospheric circulation in high- and mid-latitudes; e.g. the stationary lows are modified and the transient cyclonic activity over the subpolar oceans is reduced. A pronounced impact of sub-grid scale sea-ice distribution on the model climate can only be obtained when the non-linear behaviour of the surface exchange processes is considered by a proper, physically based, averaging of the surface fluxes. A simple linear averaging of surface parameters is not sufficient.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003820050122
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    On extension of Malkus' theory of turbulence to stably stratified shear flow (1983)
    Springer
    Boundary layer meteorology 27 (1983), S. 209-215 
    Details
    ISSN: 1573-1472
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Malkus' theory of turbulent shear flow and turbulent convection is extended to stably stratified shear flow. The local Richardson number is found to be close to its critical value throughout the turbulent flow. Assuming a strong interaction between velocity and density fields requires that their profiles depend linearly on height. From this, for stratified shear flow at sufficiently high Reynolds numbers, a combination of logarithmic and linear profiles is expected. The purely linear and the log-linear profile are both observed in laboratory channel flow and in atmospheric boundary layer flow.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00124998
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    The flow in a turbulent boundary layer upstream of a change in surface roughness (1987)
    Springer
    Boundary layer meteorology 40 (1987), S. 31-86 
    Details
    ISSN: 1573-1472
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Modification of a turbulent flow upstream of a change in surface roughness has been studied by means of a stream function-vorticity model. A flow reduction is found upstream of a step change in surface roughness when a fluid flows from a smooth onto a rough surface. Above that layer and above the region of flow reduction downstream of a smooth-rough transition, a flow acceleration is observed. Similar flow modification can be seen at a rough-smooth transition with the exception that flow reduction and flow acceleration are reversed. Within a fetch of −500 〈 x/z 0〈 + 500 (z 0 is the maximum roughness length, the roughness transition is located at x/z 0 = 0), flow reduction (flow acceleration) upstream of a roughness transition is one order of magnitude smaller than the flow reduction (flow acceleration) downstream of a smooth-rough (rough-smooth) transition. The flow acceleration (flow reduction) above that layer is two orders of magnitude. The internal boundary layer (IBL) for horizontal mean velocity extends to roughly 300z 0 upstream of a roughness transition, whereas the IBL for turbulent shear stress as well as the distortion of flow equilibrium extend almost twice as far. For the friction velocity, an undershooting (overshooting) with respect to upstream equilibrium is predicted which precedes overshooting (undershooting) over new equilibrium just behind a roughness transition. The flow modification over a finite fetch of modified roughness is weaker than over a corresponding fetch downstream of a single step change in roughness and the flow stays closer to upstream equilibrium. Even in front of the first roughness change of a finite fetch of modified roughness, a distortion of flow equilibrium due to the second, downwind roughness change can be observed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00140068
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    On the inner-layer scale height of boundary-layer flow over low hills (1988)
    Springer
    Boundary layer meteorology 44 (1988), S. 411-413 
    Details
    ISSN: 1573-1472
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Jackson and Hunt's (1975) equation for the depth of the inner layer of flows over low hills does not depend on any closure assumption as contrarily supposed in literature. This equation contains a constant which can arbitrarily be specified. It is suggested that this ‘inner-layer constant’ should be determined from experimental data. A preliminary check with some data from the Askervein experiment suggests that Jackson and Hunt's equation fits these data almost as well as Jensen's equation provided that fitted ‘inner-layer constants’ are used.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00123025
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...