The static stability of the extratropical troposphere is examined in two atmospheric general circulation models (GCM’s) over idealized boundary conditions, with emphasis on the role of moisture in determining the midlatitude stability. The determination of the static stability is compared within two models: an idealized moist model with simplified representations of radiative transfer and other...

[1] The secondary meridional circulation induced by convective momentum transport (CMT) within the ascending branch of the Hadley circulation is a missing dynamical mechanism that can cause common failure of general circulation models (GCMs) in simulating seasonal migration of the intertropical convergence zone (ITCZ) precipitation maximum across the equator. This failure is manifested by the m...

Variations in zonal surface temperature gradients and zonally asymmetric tropical overturning circulations (Walker circulations) are examined over a wide range of climates simulated with an idealized atmospheric general circulation model (GCM). The asymmetry in the tropical climate is generated by an imposed ocean energy flux, which does not vary with climate. The range of climates is simulated...

the effects of climate change, especially due to the increase of greenhouse gasses, have caused lots of problems that have affected different sections of society. one of the most important effects is the increase of natural disasters such as flood, drought, tropical cyclones, raising sea level, dust storm, etc. drought and flood are the most prevalent of these disasters in iran. because of the ...

This project was a continuation of previous work under DOE CCPP funding in which we developed a twin approach of non-homogeneous hidden Markov models (NHMMs) and coupled ocean-atmosphere (O-A) intermediate-complexity models (ICMs) to identify the potentially predictable modes of climate variability, and to investigate their impacts on the regional-scale. We have developed a family of latent-var...

The detection of anthropogenic climate change in observations and the validation of climate models both rely on understanding natural climate variability. To evaluate internal climate variability, we apply spectral analysis to time series of surface air temperature (SAT) from nine coupled general circulation model (GCM) simulations, three recent global paleotemperature reconstructions, and Nort...

Effective radiative forcing (ERF) is evaluated in a General Circulation Model (GCM) with fixed land and sea-surface-temperatures as well sea-ice. The 4xCO2 ERF 8.0 Wm-2. In contrast, typica...