A5058631771- Climate variability and models
- Meteorological Phenomena and Simulations
- Tropical and Extratropical Cyclones Research
- Oceanographic and Atmospheric Processes
- Atmospheric and Environmental Gas Dynamics
- Atmospheric Ozone and Climate
- Hydrology and Drought Analysis
- Atmospheric chemistry and aerosols
- Geophysics and Gravity Measurements
- Arctic and Antarctic ice dynamics
- Ocean Acidification Effects and Responses
- Scientific Measurement and Uncertainty Evaluation
- Marine and coastal ecosystems
- Environmental Changes in China
- Climate Change Policy and Economics
- Climate change impacts on agriculture
- Precipitation Measurement and Analysis
- Plant responses to elevated CO2
- Forecasting Techniques and Applications
- Advanced Data Compression Techniques
- Earthquake and Tsunami Effects
- Modeling, Simulation, and Optimization
- Soil Moisture and Remote Sensing
- Air Quality Monitoring and Forecasting
- Coastal and Marine Management
Lawrence Livermore National Laboratory
2012-2024
Nagoya University
2006
Oak Ridge National Laboratory
1999
State University of New York
1986-1991
Stony Brook University
1986-1990
The Atmospheric Model Intercomparison Project (AMIP), initiated in 1989 under the auspices of World Climate Research Programme, undertook systematic validation, diagnosis, and intercomparison performance atmospheric general circulation models. For this purpose all models were required to simulate evolution climate during decade 1979–88, subject observed monthly average temperature sea ice a common prescribed CO2 concentration solar constant. By 1995, 31 modeling groups, representing...
Abstract This study evaluates the tropical intraseasonal variability, especially fidelity of Madden–Julian oscillation (MJO) simulations, in 14 coupled general circulation models (GCMs) participating Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4). Eight years daily precipitation from each model’s twentieth-century climate simulation are analyzed and compared with satellite-retrieved precipitation. Space–time spectral analysis is used to obtain variance phase...
This paper presents the climatology and interannual variation of East Asian winter monsoon based on 1979–95 National Centers for Environmental Prediction/National Center Atmospheric Research reanalysis. In addition to documenting frequency, intensity, preferred propagation tracks cold surges evolution patterns related fields, authors discuss temporal distribution Siberian high surges. Further, circulation its relationship with ENSO were examined. There are average 13 in each season...
Composites of SST, wind, rainfall, and humidity have been constructed for years high rainfall during September, October, November (SON) in equatorial southern-central East Africa. These show that extreme African short rains are associated with large-scale SST anomalies the Indian Ocean closely resemble those develop dipole or zonal mode (IOZM) events. This is corroborated by observation strong IOZM events produce enhanced rainfall. However, it also shown relationship between nonlinear, only...
The interannual variability of rainfall over the Indian subcontinent, African Sahel, and Nordeste region Brazil have been evaluated in 32 models for period 1979–88 as part Atmospheric Model Intercomparison Project (AMIP). variations are most readily captured, owing to intimate link with Pacific Atlantic sea surface temperatures. precipitation India Sahel less well simulated. Additionally, an monsoon wind shear index was calculated each model. Evaluation a summer indicates that exhibit...
Abstract In this paper the extensive integrations produced for Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4) are used to examine relationship between ENSO and monsoons at interannual decadal time scales. The study begins with an analysis of monsoon simulation in twentieth-century integrations. Six 18 models were found have a reasonably realistic representation precipitation climatology. For each these six SST anomalous evolution along equatorial Pacific...
Abstract The ability of eight climate models to simulate the Madden–Julian oscillation (MJO) is examined using diagnostics developed by U.S. Climate Variability and Predictability (CLIVAR) MJO Working Group. Although signal has been extracted throughout annual cycle, this study focuses on boreal winter (November–April) behavior. Initially, maps mean state variance equatorial space–time spectra 850-hPa zonal wind precipitation are compared with observations. Models best represent...
Abstract We present an analysis of version 5.1 the Community Atmospheric Model (CAM5.1) at a high horizontal resolution. Intercomparison this global model approximately 0.25°, 1°, and 2° is presented for extreme daily precipitation as well suite seasonal mean fields. In general, amounts are larger in resolution than lower‐resolution configurations. many but not all locations and/or seasons, rates high‐resolution configuration higher more realistic. The produces tropical cyclones up to...
The Madden-Julian Oscillation (MJO) simulation diagnostics developed by MJO Working Group and the process-oriented Task Force are applied to 37 Coupled Model Intercomparison Project phase 5 (CMIP5) models in order assess model skill representing amplitude, period, coherent eastward propagation of MJO, establish a link between parameterized physical processes. Process-oriented include Relative Humidity Composite based on Precipitation (RHCP), Normalized Gross Moist Stability (NGMS),...
Abstract Many climate models struggle with a poor simulation of the Madden‐Julian Oscillation (MJO), especially its propagation across Maritime Continent (MC). This study quantitatively evaluates robustness MJO over MC in that participated Coupled Model Intercomparison Project Phase 5 (CMIP5) and 6 (CMIP6) newly developed metric. The results show CMIP6 simulate more realistically than CMIP5 models. Lower free‐tropospheric moisture budget analysis highlights greater horizontal advection is...
Abstract The Madden‐Julian Oscillation (MJO) is the dominant mode of tropical variability at intraseasonal time‐scales. It displays substantial interannual in intensity which may have important implications for predictability coupled system. reasons this are not understood. aim paper to investigate whether behaviour MJO related sea surface temperature (SST) anomalies, particularly El Niño, and hence it predictable. has been diagnosed initially 40‐year National Centers Environmental...
The behavior of the Asian summer monsoon is documented and compared using European Centre for Medium-Range Weather Forecasts (ECMWF) Reanalysis (ERA) National Centers Environmental Prediction–National Center Atmospheric Research (NCEP–NCAR) Reanalysis. In terms seasonal mean climatologies results suggest that, in several respects, ERA superior to NCEP–NCAR overall better simulation precipitation hence diabatic heating field over domain means that analyzed circulation probably nearer reality....
The Madden–Julian oscillation (MJO) dominates tropical variability on time scales of 30–70 days. During the boreal winter–spring it is manifested as an eastward propagating disturbance, with a strong convective signature over Eastern Hemisphere. space–time structure MJO described using National Centers for Environmental Prediction–National Center Atmospheric Research reanalysis, Advanced Very High Resolution Radiometer outgoing longwave radiation, observed sea surface temperature, and...
Abstract The relationship between subseasonal and interannual variability of the Asian summer monsoon has been investigated through analysis dominant modes in 40‐year NCEP/NCAR Re‐analysis, with complementary satellite surface‐based precipitation data. hypothesis that characteristics (i.e. weather regimes) are modulated on time‐scales a systematic therefore predictable manner tested. null is predictability seasonal mean behaviour requires effects slowly varying components climate system be...
Abstract The boreal summer intraseasonal variability (BSISV) associated with the 30–50-day mode is represented by coexistence of three components: poleward propagation convection over Indian and tropical west Pacific longitudes eastward along equator. hypothesis that components influence each other has been investigated using observed outgoing longwave radiation (OLR), NCEP–NCAR reanalysis, solutions from an idealized linear model. null are mutually independent. Cyclostationary EOF (CsEOF)...
The U.S. Climate Variability and Predictability (CLIVAR) MJO Working Group (MJOWG) has taken steps to promote the adoption of a uniform diagnostic set skill metrics for analyzing assessing dynamical forecasts MJO. Here we describe framework initial implementation approach using real-time forecast data from multiple operational numerical weather prediction (NWP) centers. objectives this activity are provide means i) quantitatively compare across centers, ii) measure gains in over time by...
Abstract Process-oriented diagnostics for Madden–Julian oscillation (MJO) simulations are being developed to facilitate improvements in the representation of MJO weather and climate models. These process-oriented intended provide insights into how parameterizations physical processes models should be improved a better simulation. This paper proposes one such diagnostic, which is designed represent sensitivity simulated convection environmental moisture: composites relative humidity (RH)...
Abstract. Systematic, routine, and comprehensive evaluation of Earth system models (ESMs) facilitates benchmarking improvement across model generations identifying the strengths weaknesses different configurations. By gauging consistency between observations, this endeavor is becoming increasingly necessary to objectively synthesize thousands simulations contributed Coupled Model Intercomparison Project (CMIP) date. The Program for Climate Diagnosis (PCMDI) Metrics Package (PMP) an...