To enhance our knowledge of the phenomena associated with, and physical processes contributing to, the stationary and time-varying states of the Earth's climate system, through analysis of data collected from various observational platforms, and experimentation with numerical climate models.
El Niño-Southern Oscillation
Investigate the impacts of El Niño-Southern Oscillation (ENSO) on the variability of the coupled atmosphere-ocean system on time scales ranging from subseasonal to interdecadal, with emphasis on:
- Origin of sea surface temperature (SST) signatures throughout the World Oceans during ENSO events
- Relative roles of local air-sea coupling and remote oceanic influences in generating ENSO-related atmospheric anomalies in various geographical regions
- Linkages to climates in North America, North Atlantic/Europe and East Asia
- Effects of ENSO variability on regional climates under various scenarios of secular change in the global SST forcing
Study the spatio-temporal climatological evolution of the principal monsoon systems of the World, and the variability of these features on various time scales. Phenomena of interest include:
- Synoptic weather disturbances
- Intraseasonal oscillations
- Interannual changes
- Secular trends
Analyze the output from various experiments based on the current generation of climate models developed at GFDL, with focus on:
- Simulation of synoptic and subsynoptic scale features appearing in integrations with high-resolution (50 km or less) models
- Characteristics of diurnal cycle in model atmospheres
- Perturbations to regional climates in various global warming scenarios projected for the 21st century
Satellite Temperature Trends
Determine the reliability of air temperature trends based on two leading satellite datasets via comparison with independently measured temperatures derived from radiosondes:
- Search for artificial jumps or drifts in satellite time series that may occur due to changes in the measurement system
- Compare the jumps and drifts in the satellite temperatures with independent measurements from radiosondes
- Explore the range of plausible temperature trends, both globally and in the tropics, for the troposphere and stratosphere
Vertical Structure of Temperature Variations in Models vs. Observations
Compare the details of the vertical variation in temperature trends from climate models with those derived from observed data. Address the following questions with regard to long-term changes:
- How well do trends from various model runs compare with different observed datasets and are they consistent?
- What is the effect of adjusting observed datasets (to try to remove measurement biases) in assessing the agreement between models and observations?
- How well do climate models simulate the impacts of major volcanic eruptions?