GFDL Research Highlights
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February 3, 2012 - The Future of Hurricane Activity: Why Models Differ Among Themselves
One aspect of uncertainty in future projections of basin-wide hurricane activities stems from the variety of projections of the spatial pattern of tropical warming. A tropical cyclone permitting high-resolution, global atmospheric model is used to explore hurricane frequency response to sea surface temperature (SST) anomalies generated by coupled models for the late 21st century using the SRES A1B scenario. Read more...
January 24, 2012 - Pathways Between Primary Production and Fisheries Yields of Large Marine Ecosystems
There is considerable uncertainty in projections of the impact of climate on fisheries yields due to uncertainties in climate change impacts on primary production and the processes controlling how much primary production is transferred to fish. Primary production and proxies such as chlorophyll have proven to be useful predictors of fisheries yields at regional scales but show much less skill when applied globally. The marine food web dynamics that control the transfer of energy from phytoplankton to fish are complex and it has been postulated that the relationship between primary production and fisheries production may differ dramatically between ecosystems due to changes in planktonic foodweb structure. Read more...
September 29, 2011 - Anthropogenic Aerosols and the Weakening of the South Asian Summer Monsoon
An important part of the global water cycle, the South Asian summer monsoon provides about 80% of the region’s annual precipitation, and touches the lives of more than 20% of the world’s population. Using the NOAA/GFDL state-of-the-art global climate model that accounts for all the known natural and anthropogenic forcings, we have investigated what caused the observed decrease in the South Asian summer monsoon rainfall over the second half of the 20th century. Was the widespread drying due to natural factors or human activities? Read more...
September 12, 2011 - Climatological characteristics of Arctic and Antarctic surface-based inversions
Surface-based inversions (SBI) are frequent features of the Arctic and Antarctic atmospheric boundary layer and influence important climate processes. However, prior to this study, climatological polar SBI properties had not been fully characterized, nor had climate model simulations of SBIs been compared comprehensively to observations. Read more...
July 3, 2011 - Different magnitudes of projected subsurface ocean warming around Greenland and Antarctica
Recent acceleration of Greenland and Antarctic outlet glaciers and ice flows is closely linked to ocean warming, especially in the subsurface layer. This land ice melt will cause sea level rise. Read more...
July 1, 2011 - Sensitivity of the aerosol indirect effect to subgrid variability in the cloud parame
The recently developed GFDL AM3 model (Donner et. al 2011) incorporates a prognostic treatment of cloud drop number to simulate the aerosol indirect effect. The present work explores formulation sensitivities by constructing three alternate model configurations (S1, S2, S3). These alternate configurations exhibit only small differences in their present day climatology. Read more...
July 1, 2011 - The GFDL CM3 model
Earlier generations of climate models at GFDL have specified cloud properties to be independent of atmospheric aerosol composition, despite fairly well-understood (at least for liquid clouds) dependence of cloud droplet number on aerosol composition and size distribution. Cloud drop number in turn exerts a major control on cloud radiation, notably albedo, and microphysics and macrophysics, notably cloud structure and lifetimes. Aerosol-cloud interactions are likely to be important in anthropogenic climate change. They have been difficult to incorporate in climate models because they occur at scales much smaller than resolved by climate models. CM3 parameterizes these smaller scales using probability distribution functions for motions smaller than those it explicitly resolves. Read more...
June 5, 2011 - Raining from the Ground Up
Though it is obvious that rainfall moistens the land surface, our scientific understanding of how land surface moisture may interact with the atmosphere to encourage or suppress subsequent rainfall is limited. Using data from the North American Regional Reanalysis (NARR, Mesinger et al., 2006), this study shows that the likelihood of afternoon rainfall in the eastern United States and Mexico is strongly linked to evaporation from the land surface earlier in the day. Read more...
April 22, 2011 - Downward shortwave surface flux in the GFDL CM2.1 General Circulation Model
The downward solar flux at the surface is an important component of the earth's climate system, being a major factor governing the surface temperature and hydrologic cycle. The availability of derived flux climatologies from both ground-based measurements and satellite-based estimates provide a reference for properly assessing general circulation model biases, not only in the surface irradiance, but in the atmospheric factors (aerosols, clouds, and water vapor) affecting it. Read more...
February 22, 2011 - North American isoprene influence on intercontinental ozone pollution
Changing land-use and climate may increase biogenic isoprene emissions, which could offset the benefits from North American air pollution controls for both domestic and European air quality (surface ozone). Both anthropogenic and biogenic emission changes are reflected in peroxy acetyl nitrate (PAN), which may serve as a more effective indicator of intercontinental emission changes than ozone itself. Read more...
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