Climate Dynamics 

About: Climate Dynamics is an academic journal published by Springer Science+Business Media. The journal publishes majorly in the area(s): Climate model & Sea surface temperature. It has an ISSN identifier of 0930-7575. Over the lifetime, 7521 publications have been published receiving 351522 citations. The journal is also known as: Climate dynamics (Print).

The simulation of SST, sea ice extents and ocean heat transports in a version of the Hadley Centre coupled model without flux adjustments

Abstract: Results are presented from a new version of the Hadley Centre coupled model (HadCM3) that does not require flux adjustments to prevent large climate drifts in the simulation The model has both an improved atmosphere and ocean component In particular, the ocean has a 125° × 125° degree horizontal resolution and leads to a considerably improved simulation of ocean heat transports compared to earlier versions with a coarser resolution ocean component The model does not have any spin up procedure prior to coupling and the simulation has been run for over 400 years starting from observed initial conditions The sea surface temperature (SST) and sea ice simulation are shown to be stable and realistic The trend in global mean SST is less than 0009 °C per century In part, the improved simulation is a consequence of a greater compatibility of the atmosphere and ocean model heat budgets The atmospheric model surface heat and momentum budget are evaluated by comparing with climatological ship-based estimates Similarly the ocean model simulation of poleward heat transports is compared with direct ship-based observations for a number of sections across the globe Despite the limitations of the observed datasets, it is shown that the coupled model is able to reproduce many aspects of the observed heat budget

Decadal atmosphere-ocean variations in the Pacific

Abstract: Considerable evidence has emerged of a sub- stantial decade-long change in the north Pacific atmo- sphere and ocean lasting from about 1976 to 1988. Ob- served significant changes in the atmospheric circula- tion throughout the troposphere revealed a deeper and eastward shifted Aleutian low pressure system in the winter half year which advected warmer and moister air along the west coast of North America and into Alaska and colder air over the north Pacific. Conse- quently, there were increases in temperatures and sea surface temperatures (SSTs) along the west coast of North America and Alaska but decreases in SSTs over the central north Pacific, as well as changes in coastal rainfall and streamflow, and decreases in sea ice in the Bering Sea. Associated changes occurred in the surface wind stress, and, by inference, in the Sverdrup trans- port in the north Pacific Ocean. Changes in the month- ly mean flow were accompanied by a southward shift in the storm tracks and associated synoptic eddy activi- ty and in the surface ocean sensible and latent heat fluxes. In addition to the changes in the physical envi- ronment, the deeper Aleutian low increased the nu- trient supply as seen through increases in total chloro- phyll in the water column, phytoplankton and zoo- plankton. These changes, along with the altered ocean currents and temperatures, changed the migration pat- terns and increased the stock of many fish species. A north Pacific (NP) index is defined to measure the de- cadal variations, and the temporal variability of the in- dex is explored on daily, annual, interannual and de- cadal time scales. The dominant atmosphere-ocean re- lation in the north Pacific is one where atmospheric changes lead SSTs by one to two months. However, strong ties are revealed with events in the tropical Pa- cific, with changes in tropical Pacific SSTs leading SSTs in the north Pacific by three months. Changes in the storm tracks in the north Pacific help to reinforce and maintain the anomalous circulation in the upper tro-

The impact of new physical parametrizations in the Hadley Centre Climate Model—HADAM3

Abstract: Results are presented from the latest version of the Hadley Centre climate model, HadAM3 (Hadley Centre Atmospheric Model version 3). It represents a significant improvement over the previous version, HadAM2b. This is demonstrated using a series of ten year integrations with AMIP (Atmospheric Model Intercomparison Project) boundary conditions. The work covers three aspects of model performance: (1) it shows the improvements in the mean climate in changing from HadAM2b to HadAM3; (2) it demonstrates that the model now compares well with observations and (3) it isolates the impacts of new physical parametrizations.

Climate change projections using the IPSL-CM5 Earth System Model: From CMIP3 to CMIP5

Abstract: We present the global general circulation model IPSL-CM5 developed to study the long-term response of the climate system to natural and anthropogenic forcings as part of the 5th Phase of the Coupled Model Intercomparison Project (CMIP5). This model includes an interactive carbon cycle, a representation of tropospheric and stratospheric chemistry, and a comprehensive representation of aerosols. As it represents the principal dynamical, physical, and bio-geochemical processes relevant to the climate system, it may be referred to as an Earth System Model. However, the IPSL-CM5 model may be used in a multitude of configurations associated with different boundary conditions and with a range of complexities in terms of processes and interactions. This paper presents an overview of the different model components and explains how they were coupled and used to simulate historical climate changes over the past 150 years and different scenarios of future climate change. A single version of the IPSL-CM5 model (IPSL-CM5A-LR) was used to provide climate projections associated with different socio-economic scenarios, including the different Representative Concentration Pathways considered by CMIP5 and several scenarios from the Special Report on Emission Scenarios considered by CMIP3. Results suggest that the magnitude of global warming projections primarily depends on the socio-economic scenario considered, that there is potential for an aggressive mitigation policy to limit global warming to about two degrees, and that the behavior of some components of the climate system such as the Arctic sea ice and the Atlantic Meridional Overturning Circulation may change drastically by the end of the twenty-first century in the case of a no climate policy scenario. Although the magnitude of regional temperature and precipitation changes depends fairly linearly on the magnitude of the projected global warming (and thus on the scenario considered), the geographical pattern of these changes is strikingly similar for the different scenarios. The representation of atmospheric physical processes in the model is shown to strongly influence the simulated climate variability and both the magnitude and pattern of the projected climate changes.

The global climatology of an interannually varying air–sea flux data set

Abstract: The air–sea fluxes of momentum, heat, freshwater and their components have been computed globally from 1948 at frequencies ranging from 6-hourly to monthly. All fluxes are computed over the 23 years from 1984 to 2006, but radiation prior to 1984 and precipitation before 1979 are given only as climatological mean annual cycles. The input data are based on NCEP reanalysis only for the near surface vector wind, temperature, specific humidity and density, and on a variety of satellite based radiation, sea surface temperature, sea-ice concentration and precipitation products. Some of these data are adjusted to agree in the mean with a variety of more reliable satellite and in situ measurements, that themselves are either too short a duration, or too regional in coverage. The major adjustments are a general increase in wind speed, decrease in humidity and reduction in tropical solar radiation. The climatological global mean air–sea heat and freshwater fluxes (1984–2006) then become 2 W/m2 and −0.1 mg/m2 per second, respectively, down from 30 W/m2 and 3.4 mg/m2 per second for the unaltered data. However, decadal means vary from 7.3 W/m2 (1977–1986) to −0.3 W/m2 (1997–2006). The spatial distributions of climatological fluxes display all the expected features. A comparison of zonally averaged wind stress components across ocean sub-basins reveals large differences between available products due both to winds and to the stress calculation. Regional comparisons of the heat and freshwater fluxes reveal an alarming range among alternatives; typically 40 W/m2 and 10 mg/m2 per second, respectively. The implied ocean heat transports are within the uncertainty of estimates from ocean observations in both the Atlantic and Indo-Pacific basins. They show about 2.4 PW of tropical heating, of which 80% is transported to the north, mostly in the Atlantic. There is similar good agreement in freshwater transport at many latitudes in both basins, but neither in the South Atlantic, nor at 35°N.