Subdecadal changes in Earth's rotation rate, and hence in the length of day (LOD), are largely controlled by variations in atmospheric angular momentum. Results from two oceanic general circulation models (OGCMs), forced by observed wind stress and heat flux for the years 1992 through 1994, show that ocean current and mass distribution changes also induce detectable LOD variations. The close si...

Clouds and their interactions with radiation is recognized by the most recent IPCC (Intergovernmental Panel on Climate Change; 2001) report as the greatest uncertainty in future projections of climate, and, despite the considerable improvement of the physical realism of cloud representation in general circulation models, representation of clouds and their feedbacks is still the weakest componen...

Statistical downscaling methods seek to model the relationship between large scale atmospheric circulation, on say a European scale, and climatic variables, such as temperature and precipitation, on a regional or subregional scale. Downscaling is an important area of research as it bridges the gap between predictions of future circulation generated by General Circulation Models (GCMs) and the e...

The relationship between precipitation and large-scale measures of atmospheric circulation has received much attention in recent years (e.g. Bardossy & Caspary, 1990; Bardossy & Plate, 1992; Hughes et al., 1993; Woolhiser et al., 1993; Katz & Parlange, 1993). Some of the interest relates to quantifying the possible change in atmospheric circulation within the past two decades, with associated c...

We examine the relative roles of direct atmospheric radiative forcing (due to observed changes in well-mixed greenhouse gases, tropospheric and stratospheric ozone, sulfate and volcanic aerosols, and solar output) and observed sea surface temperature (SST) forcing of global atmospheric circulation trends during the second half of the 20 century using atmospheric general circulation modeling exp...

[1] We compare cloud-radiative forcing (CRF) at the top-of-the atmosphere from 19 atmospheric general circulation models, employing simulations with prescribed seasurface temperatures, to observations from the Earth Radiation Budget Experiment (ERBE). With respect to 60 N to 60 S means, a surprising result is that many of the 19 models produce unusually large biases in Net CRF that are all of t...

Adaptive mesh refinement techniques offer a flexible framework for future variable-resolution climate and weather models since they can focus their computational mesh on certain geographical areas or atmospheric events. Adaptive meshes can also be used to coarsen a latitude-longitude grid in polar regions. This allows for the so-called reduced grid setups. A spherical, block-structured adaptive...