A5008203511- Climate variability and models
- Meteorological Phenomena and Simulations
- Oceanographic and Atmospheric Processes
- Tropical and Extratropical Cyclones Research
- Atmospheric and Environmental Gas Dynamics
- Ocean Waves and Remote Sensing
- Atmospheric Ozone and Climate
- Geology and Paleoclimatology Research
- Fluid Dynamics and Turbulent Flows
- Geophysics and Gravity Measurements
- Marine and coastal ecosystems
- Astro and Planetary Science
- Atmospheric aerosols and clouds
- Plant Water Relations and Carbon Dynamics
- Advanced Thermodynamics and Statistical Mechanics
- Atmospheric chemistry and aerosols
- Geomagnetism and Paleomagnetism Studies
- Methane Hydrates and Related Phenomena
- Wind and Air Flow Studies
- Geological and Geophysical Studies
- Calibration and Measurement Techniques
- Climate change impacts on agriculture
- Scientific Research and Discoveries
- Solar and Space Plasma Dynamics
- Ionosphere and magnetosphere dynamics
Princeton University
2014-2024
NOAA Geophysical Fluid Dynamics Laboratory
2012-2023
Instituto de Geociencias
2023
Miller College
2023
University of California, Berkeley
2023
National Oceanic and Atmospheric Administration
2006-2019
University of California, Los Angeles
2017
University Corporation for Atmospheric Research
2005-2017
California Institute of Technology
2017
NOAA Oceanic and Atmospheric Research
1982-2009
Abstract Using the climate change experiments generated for Fourth Assessment of Intergovernmental Panel on Climate Change, this study examines some aspects changes in hydrological cycle that are robust across models. These responses include decrease convective mass fluxes, increase horizontal moisture transport, associated enhancement pattern evaporation minus precipitation and its temporal variance, sensible heat transport extratropics. A surprising finding is a extratropical found only...
How anthropogenic climate change will affect hydroclimate in the arid regions of southwestern North America has implications for allocation water resources and course regional development. Here we show that there is a broad consensus among models this region dry 21st century transition to more should already be under way. If these are correct, levels aridity recent multiyear drought or Dust Bowl 1950s droughts become new climatology American Southwest within time frame years decades.
Abstract The formulation and simulation characteristics of two new global coupled climate models developed at NOAA's Geophysical Fluid Dynamics Laboratory (GFDL) are described. were designed to simulate atmospheric oceanic variability from the diurnal time scale through multicentury change, given our computational constraints. In particular, an important goal was use same model for both experimental seasonal interannual forecasting study this has been achieved. Two versions described, called...
▪ Abstract Water vapor is the dominant greenhouse gas, most important gaseous source of infrared opacity in atmosphere. As concentrations other gases, particularly carbon dioxide, increase because human activity, it centrally to predict how water distribution will be affected. To extent that a warmer world, climatic effects gases amplified. Models Earth's climate indicate this an positive feedback increases sensitivity surface temperatures dioxide by nearly factor two when considered...
Stormy Weather One of the most active questions about effects global warming is whether, and how, it might affect frequency strength hurricanes. Some studies have suggested that will bring fewer, less energetic, hurricanes, while others claimed we can expect more intense storms. Bender et al. (p. 454 ; see news story by Kerr ) explore influence on hurricane dynamics over Atlantic Ocean with a state-of-the-art prediction model. The model predicts annual total number hurricanes in 21st century...
Abstract The climate feedbacks in coupled ocean–atmosphere models are compared using a coordinated set of twenty-first-century change experiments. Water vapor is found to provide the largest positive feedback all and its strength consistent with that expected from constant relative humidity changes water mixing ratio. clouds surface albedo also be models, while only stabilizing (negative) comes temperature response. Large intermodel differences lapse rate observed shown associated differing...
Abstract The Geophysical Fluid Dynamics Laboratory (GFDL) has developed a coupled general circulation model (CM3) for the atmosphere, oceans, land, and sea ice. goal of CM3 is to address emerging issues in climate change, including aerosol–cloud interactions, chemistry–climate coupling between troposphere stratosphere. also designed serve as physical system component earth models decadal prediction near-term future—for example, through improved simulations tropical land precipitation...
A benchmark calculation is proposed for evaluating the dynamical cores of atmospheric general circulation models independently physical parameterizations. The test focuses on long-term statistical properties a fully developed circulation; thus, it particularly appropriate intercomparing dynamics used in climate models. To illustrate use this benchmark, two very different cores—one spectral, one finite difference—are compared. It found that statistics produced by are similar. Selected results...
The structure of certain axially symmetric circulations in a stably stratified, differentially heated, rotating Boussinesq fluid on sphere is analyzed. A simple approximate theory [similar to that introduced by Schneider (1977)] developed for the case which sufficiently inviscid poleward flow Hadley cell nearly angular momentum conserving. predicts width cell, total heat flux, latitude upper level jet zonal wind, and distribution surface easterlies westerlies. Fundamental differences between...
Abstract The extent to which the climate will change due an external forcing depends largely on radiative feedbacks, act amplify or damp surface temperature response. There are a variety of issues that complicate analysis feedbacks in global models, resulting some confusion regarding their strengths and distributions. In this paper, authors present method for quantifying based “radiative kernels” describe differential response top-of-atmosphere fluxes incremental changes feedback variables....
Abstract We describe the baseline coupled model configuration and simulation characteristics of GFDL's Earth System Model Version 4.1 (ESM4.1), which builds on component developments at GFDL over 2013–2018 for carbon‐chemistry‐climate contributing to sixth phase Coupled Intercomparison Project. In contrast with CM4.0 development effort that focuses ocean resolution physical climate, ESM4.1 comprehensiveness system interactions. features doubled horizontal both atmosphere (2° 1°) (1° 0.5°)...
The vertically integrated moist static energy equation provides a convenient starting point for the construction of simple models time-mean low level convergence in tropics. A measure stability, “gross stability,” proves to be central importance. Minima this quantity mark positions tropical zones. We argue that these minima are determined by moisture field, which is, turn, closely tied surface temperature.
Abstract A global atmospheric model with roughly 50-km horizontal grid spacing is used to simulate the interannual variability of tropical cyclones using observed sea surface temperatures (SSTs) as lower boundary condition. The model’s convective parameterization based on a closure for shallow convection, much deep convection allowed occur resolved scales. Four realizations period 1981–2005 are generated. correlation yearly Atlantic hurricane counts observations greater than 0.8 when...
Abstract Using a comprehensive atmospheric GCM coupled to slab mixed layer ocean, experiments are performed study the mechanism by which displacements of intertropical convergence zone (ITCZ) forced from extratropics. The northern extratropics cooled and southern warmed an imposed cross-equatorial flux beneath layer, forcing southward shift in ITCZ. ITCZ displacement can be understood terms degree compensation between oceanic resulting response energy transport tropics. magnitude is very...
The dynamics of quasi-geostrophic flow with uniform potential vorticity reduces to the evolution buoyancy, or temperature, on horizontal boundaries. There is a formal resemblance two-dimensional flow, surface temperature playing role vorticity, but different relationship between and advected scalar creates several distinctive features. A series examples are described which highlight some these features: an elliptical vortex; start-up vortex shed by over mountain; instability filaments; ‘edge...
The problem of creating truly convincing numerical simulations our Earth's climate will remain a challenge for the next generation scientists. Hopefully, ever increasing power computers make this task somewhat less frustrating than it is at present. But, computational also raises issues as to how we would like see modeling and study dynamics evolve in twenty-first century. One key need address widening gap between simulation understanding.
Abstract The fast and slow components of global warming in a comprehensive climate model are isolated by examining the response to an instantaneous return preindustrial forcing. is characterized initial exponential decay with e-folding time smaller than 5 yr, leaving behind remnant that evolves more slowly. component estimated be small at present, as measured mean near-surface air temperature, and, examined, grows 0.4°C 2100 A1B scenario from Special Report on Emissions Scenarios (SRES),...
We describe the Geophysical Fluid Dynamics Laboratory's CM4.0 physical climate model, with emphasis on those aspects that may be of particular importance to users this model and its simulations. The is built AM4.0/LM4.0 atmosphere/land OM4.0 ocean model. Topics include rationale for key choices made in formulation, stability as well drift preindustrial control simulation, comparison historical simulations observations from recent decades. Notable achievements relatively small biases seasonal...
The Sahel, the transition zone between Saharan desert and rainforests of Central Africa Guinean Coast, experienced a severe drying trend from 1950s to 1980s, which there has been partial recovery. Continuation either or more recent ameliorating would have far-ranging implications for economy ecology region. Coupled atmosphere/ocean climate models being used simulate future had difficulty simulating Sahel rainfall variations comparable those observed, thus calling into question their ability...
A mechanism by which feedback between zonal wind perturbations and evaporation can create unstable, low-frequency modes in a simple two-layer model of the tropical troposphere is presented. The resemble 30–50 day oscillation. series general circulation experiments designed to test effect suppressing this on variability tropics described. results suggest that evaporation-wind be important amplitude spectral peak corresponding oscillation model, but existence does not depend it. found have...
The response of the Southern Hemisphere (SH), extratropical, atmospheric general circulation to transient, anthropogenic, greenhouse warming is investigated in a coupled climate model. extratropical consists SH summer half-year poleward shift westerly jet and year-round positive wind anomaly stratosphere tropical upper troposphere. Along with jet, there several related fields, including belt eddy momentum-flux convergence mean meridional overturning atmosphere ocean. tropospheric projects...
A review is provided of stationary wave theory, the theory for deviations from zonal symmetry climate. To help focus discussion authors concentrate exclusively on northern winter. Several theoretical issues, including external Rossby dispersion relation and vertical structure, critical latitude absorption, nonlinear response to orography, interaction forced trains with preexisting asymmetries, are chosen while simultaneously presenting a decomposition wintertime field using steady-state model.