Professor Steven Sherwood - research

My research group is using a variety of tools to address outstanding questions related to climate change and the behavior of the various forms of water in the climate system. These tools include the analysis of global satellite datasets capable of characterizing cloud properties, including their heights attained, water content, solar reflectance and particle sizes and shapes; the simulations of individual clouds and statistical properties of cloud populations using numerical, cloud-resolving models; careful analysis of large datasets, including temperature and moisture variations in radiosondes as well as satellite radiances, using better statistical techniques (possibly including "machine learning"); simulations of global climate using numerical general circulation models; and the development of more idealized or simple models/theories of climate and climate-relevant processes. Some of the questions we are now studying using the above tools are:

How will atmospheric humidity and surface rainfall change as climate warms? How well can climate models be trusted in simulating these?
What effects will higher humidity have on human heat stress and other impacts of changing climates?
What controls global variations of storm intensity and cloud properties? Why does lightning occur so rarely over oceans even though there are plenty of storms there?
What is the connection between recent droughts and warming? Will these droughts worsen?
Are there ways of observing natural variability in the climate that will reveal its sensitivity to external forcings such as increases in greenhouse gases?
Are prehistoric climate changes suggested by geologic evidence consistent with our current understanding of how the atmosphere and oceans work? Going the other way, can past continental and orographic reconstructions be constrained meteorologically?
How important are tropospheric convection (storms) in modifying the tropical and summer extratropical tropopause temperature and moisture? Which convective systems around the world are most involved? Why is Earth's stratosphere getting colder and moister?

Each of these general questions has many aspects, the investigation of any one of which could consitute a substantial research project. The broad scope of our investigations is aided by collaboration with others in the CCRC and with colleagues at overseas institutions in the United States and Europe.

Last updated 08/04/2009.