A5079640235- Climate variability and models
- Atmospheric and Environmental Gas Dynamics
- Oceanographic and Atmospheric Processes
- Arctic and Antarctic ice dynamics
- Meteorological Phenomena and Simulations
- Atmospheric Ozone and Climate
- Geology and Paleoclimatology Research
- Atmospheric chemistry and aerosols
- Cryospheric studies and observations
- Geophysics and Gravity Measurements
- Climate change and permafrost
- Methane Hydrates and Related Phenomena
- Hydrology and Watershed Management Studies
- Groundwater and Isotope Geochemistry
- Consumer Market Behavior and Pricing
- Marine and coastal ecosystems
- Atmospheric aerosols and clouds
- Satellite Image Processing and Photogrammetry
- Tropical and Extratropical Cyclones Research
- Fish Ecology and Management Studies
- Child and Adolescent Health
- Ionosphere and magnetosphere dynamics
- Geological Studies and Exploration
- Plant Water Relations and Carbon Dynamics
- Hydrological Forecasting Using AI
Goddard Institute for Space Studies
2014-2024
Idaho National Laboratory
2024
Goddard Space Flight Center
1990-2016
Columbia University
2005-2014
Harvard University
2013
Massachusetts General Hospital
2013
University of Iowa
1990-2010
Griffith University
2007
Earth Island Institute
2005
Stinger Ghaffarian Technologies (United States)
2005
We use a global climate model to compare the effectiveness of many forcing agents for producing change. find substantial range in “efficacy” different forcings, where efficacy is temperature response per unit relative CO 2 forcing. Anthropogenic CH 4 has ∼110%, which increases ∼145% when its indirect effects on stratospheric H O and tropospheric 3 are included, yielding an effective ∼0.8 W/m period 1750–2000 making largest anthropogenic other than . Black carbon (BC) aerosols from biomass...
A global atmospheric model is developed with a computational efficiency which allows long-range climate experiments. The solves the simultaneous equations for conservation of mass, energy and momentum, equation state on grid. Differencing schemes dynamics are based work Arakawa; do not need any viscosity numerical stability, can thus yield good results coarse resolution. Radiation computed semi-implicit spectral integration, including all significant gases, aerosols cloud particles. Cloud...
The global temperature rose by 0.2 degrees C between the middle 1960's and 1980, yielding a warming of 0.4 in past century. This increase is consistent with calculated greenhouse effect due to measured increases atmospheric carbon dioxide. Variations volcanic aerosols possibly solar luminosity appear be primary causes observed fluctuations about mean trend increasing temperature. It shown that anthropogenic dioxide should emerge from noise level natural climate variability end century, there...
We use a three‐dimensional climate model, the Goddard Institute for Space Studies (GISS) model II with 8° by 10° horizontal resolution, to simulate global effects of time‐dependent variations atmospheric trace gases and aerosols. Horizontal heat transport ocean is fixed at values estimated today's climate, uptake perturbations beneath mixed layer approximated as vertical diffusion. make 100‐year control run perform experiments three scenarios composition. These begin in 1958 include measured...
Abstract A full description of the ModelE version Goddard Institute for Space Studies (GISS) atmospheric general circulation model (GCM) and results are presented present-day climate simulations (ca. 1979). This is a complete rewrite previous models incorporating numerous improvements in basic physics, stratospheric circulation, forcing fields. Notable changes include following: top now above stratopause, number vertical layers has increased, new cloud microphysical scheme used, vegetation...
Our climate model, driven mainly by increasing human-made greenhouse gases and aerosols, among other forcings, calculates that Earth is now absorbing 0.85 +/- 0.15 watts per square meter more energy from the Sun than it emitting to space. This imbalance confirmed precise measurements of ocean heat content over past 10 years. Implications include (i) expectation additional global warming about 0.6 degrees C without further change atmospheric composition; (ii) confirmation system's lag in...
Abstract We present a description of the ModelE2 version Goddard Institute for Space Studies (GISS) General Circulation Model (GCM) and configurations used in simulations performed Coupled Intercomparison Project Phase 5 (CMIP5). use six variations related to treatment atmospheric composition, calculation aerosol indirect effects, ocean model component. Specifically, we test difference between models that have noninteractive where radiatively important aerosols ozone are prescribed from...
Cenozoic temperature, sea level and CO2 covariations provide insights into climate sensitivity to external forcings sea-level change. Climate depends on the initial state, but potentially can be accurately inferred from precise palaeoclimate data. Pleistocene oscillations yield a fast-feedback of 3±1(°)C for 4 W m(-2) forcing if Holocene warming relative Last Glacial Maximum (LGM) is used as calibration, error (uncertainty) substantial partly subjective because poorly defined LGM global...
This paper describes the GISS-E2.1 contribution to Coupled Model Intercomparison Project, Phase 6 (CMIP6). model version differs from predecessor (GISS-E2) chiefly due parameterization improvements atmospheric and ocean components, while keeping resolution same. skill when compared modern era climatologies is significantly higher than in previous versions. Additionally, updates forcings have a material impact on results. In particular, there been specific representations of modes variability...
We use numerical climate simulations, paleoclimate data, and modern observations to study the effect of growing ice melt from Antarctica Greenland. Meltwater tends stabilize ocean column, inducing amplifying feedbacks that increase subsurface warming shelf melting. Cold meltwater induced dynamical effects cause surface cooling in Southern Ocean North Atlantic, thus increasing Earth's energy imbalance heat flux into most global ocean's surface. cooling, while lower latitudes are warming,...
Palaeoclimate data show that the Earth's climate is remarkably sensitive to global forcings. Positive feedbacks predominate. This allows entire planet be whipsawed between states. One feedback, 'albedo flip' property of ice/water, provides a powerful trigger mechanism. A forcing 'flips' albedo sufficient portion an ice sheet can spark cataclysm. Inertia and ocean only moderate delay disintegration burst added warming. Recent greenhouse gas (GHG) emissions place Earth perilously close...
The cycles of the water isotopic species (HDO and H 2 18 O) have been incorporated into NASA Goddard Institute for Space Studies (GISS) atmospheric general circulation model (GCM). results a 3‐year simulation present‐day conditions are discussed, with special emphasis on comparison between predicted observed distributions (well documented mainly through International Atomic Energy Agency/World Meteorological Organization network) both seasonal annual time scales. generally well simulated....
Winds and convective mixing from a general circulation model of the atmosphere have been applied in chemical tracer (CTM) to simulate global distribution temporal variability chlorofluorocarbons (CFCs). The seasonal cycle moist convection, with maximum activity over continents summer, leads an annual surface concentration CFCs. Emissions are retained lowest levels during winter, concentrations peak near sources. In this season, CFCs European sources carried by low‐level winds into Arctic....
Abstract. We investigate the issue of "dangerous human-made interference with climate" using simulations GISS modelE driven by measured or estimated forcings for 1880–2003 and extended to 2100 IPCC greenhouse gas scenarios as well "alternative" scenario Hansen Sato (2004). Identification "dangerous" effects is partly subjective, but we find evidence that added global warming more than 1°C above level in 2000 has may be highly disruptive. The alternative scenario, peak forcing ~1.5 W/m2 2100,...
A new finite-differencing scheme for solving the tracer transport equation given prescribed winds is presented. The prognostic quantities predicted by are mean concentration and its spatial gradients. In one two-dimensional tests using uniform air masses, roughly comparable to a fourth-order differencing in accuracy. When masses not uniform, superior differencing. An application of schemes three-dimensional modeling included.
Abstract Improved knowledge of glacial-to-interglacial global temperature change yields Charney (fast-feedback) equilibrium climate sensitivity 1.2 ± 0.3°C (2σ) per W/m2, which is 4.8°C 1.2°C for doubled CO2. Consistent analysis over the full Cenozoic era—including ‘slow’ feedbacks by ice sheets and trace gases—supports this implies that CO2 was 300–350 ppm in Pliocene about 450 at transition to a nearly ice-free planet, exposing unrealistic lethargy sheet models. Equilibrium warming today’s...
Abstract A new coupled atmosphere‐ocean model has been developed for climate predictions at decade to century scales. The atmospheric is similar that of Hansen et al. (1983) except the dynamic equations mass and momentum are solved using Arakawa Lamb's (1977) C grid scheme advection potential enthalpy water vapour uses linear upstream (Russell Lerner, 1981). global ocean conserves mass, allows divergent flow, a free surface salt. Both models run 4° × 5° resolution, with 9 vertical layers...
The factors that determine climate response times were investigated with simple models and scaling statements. are particularly sensitive to (i) the amount is amplified by feedbacks (ii) representation of ocean mixing. If equilibrium sensitivity 3 degrees C or greater for a doubling carbon dioxide concentration, then most expected warming attributable trace gases added atmosphere man probably has not yet occurred. This be realized calls into question policy "wait see" regarding issue how...
The hydrologic cycle is a major part of the global climate system. There an atmospheric flux water from ocean surface to continents. closed by return flow in rivers. In this paper river routing model developed use with grid box models for whole earth. needs algorithm mass and direction file, which has been compiled 4°×5° 20°×2.5° resolutions. River basins are defined files. leaving each depends on lake mass, downstream distance, effective speed that topography. As input uses monthly land...
The origin of water precipitating in different geographic regions is investigated with the NASA/GISS GCM. Water evaporating from various source "tagged" and then followed as a tracer four model simulations, one for each season. contributions region evaporations to simulated rainfall at specific locations tabulated. results show that summer, vapor midlatitude high latitude precipitation tends be recycled locally, whereas low continental more dependent on oceanic moisture sources.
River runoff from the world's major rivers is an important part of hydrologic cycle. Runoff changes in response to global greenhouse‐induced warming will have impacts many areas, including agriculture, water resources, and land use. A atmospheric model used calculate annual river for 33 present climate a doubled CO 2 climate. The has horizontal resolution 4° × 5°, but each grid box quartered added appropriate drainage basin on 2° 2.5° resolution. computed depends model's precipitation,...
We investigate the roles of climate forcings and chaos (unforced variability) in change via ensembles simulations which we add one by one. The experiments suggest that most interannual variability period 1979–1996 at middle high latitudes is chaotic. But observed SST anomalies, themselves are partly forced chaotic, account for much low a small portion latitudes. Both natural radiative forcing (volcanic aerosols) an anthropogenic (ozone depletion) leave clear signatures simulated identified...
A three‐dimensional tracer transport model is used to investigate the annual cycle of atmospheric CO 2 concentration produced by seasonal exchanges with terrestrial biosphere. The uses winds generated a global general circulation advect and convect ; no explicit diffusion coefficients are employed. biospheric exchange function constructed from map net primary productivity, Azevedo's (1982) seasonality uptake release closely simulates cycles at coastal stations. results show that zonal...