Klaus Wolter
Biographical Sketch

After coming to the U.S. in 1982, I studied at the University of Wisconsin in Madison where I received my Ph.D. in 1987. Title of my dissertation: Modes of surface circulation and climate over the tropical Atlantic, Eastern Pacific, and Indian Oceans. After a one-year stint at NOAA’s National Meteorological Center in Washington, DC, I transferred to the University of Colorado in late 1988, where I have been affiliated with the Cooperative Institute for Research in the Environmental Sciences (CIRES) ever since.
 
My main research interests lie in empirical climate research, in particular the application of statistical methods to climate problems, such as the impact of ENSO (El Niño/Southern Oscllation) on world-wide climate. I have developed and refined a “Multivariate ENSO Index” (MEI) based on tropical Pacific ship-based observations of sea level pressure, near-surface wind fields, sea – and air surface temperatures, as well as total cloudiness. The MEI is more robust than conventional indices in monitoring the ENSO phenomenon.  Monthly updates and discussions of the MEI can be found under http://www.cdc.noaa.gov/people/klaus.wolter/MEI/
 
In the last decade, I have been able to devote more attention to the analysis and understanding of western U.S. climate, being involved in the Western Water Assessment (WWA) project at CU.  In the context of widespread drought conditions over Colorado and surrounding states, and prompted by repeated requests, I have developed statistical tools that allow me to make seasonal precipitation predictions. Originally, these forecasts leaned heavily on statistical associations with ENSO, but became based on a much wider variety of influences on our climate since late 2001. Monthly updated discussions and forecasts are posted under http://www.cdc.noaa.gov/people/klaus.wolter/SWcasts/
 
Under the WWA umbrella, I have also engaged in climate studies with the Colorado State Climatologist, focusing on assessments of drought and temperature trends in Colorado in the context of ‘Global Change’ (see references below, and: http://wwa.colorado.edu/resources/klaus.wolter.Colorado.temps%20v2.pdf ).
 
RELEVANT PUBLICATIONS:
 
Wolter, K., and M.S. Timlin, 1998: Measuring the strength of ENSO events: How does 1997/98 rank? 
            Weather, 53, 315-324.
 
Wolter, K., R.M. Dole, and C.A. Smith, 1999: Short-term climate extremes over the continental U.S. and ENSO. 
            Part I: Seasonal temperatures. J. Climate, 12, 3255-3272.
 
Pielke Sr., R.A., N. Doesken, O. Bliss, T. Green, C. Chaffin, J.D. Salas, C. Woodhouse, J.L. Lukas, and K. Wolter, 2005: Drought 2002 in Colorado - An unprecedented drought or a routine drought? Pure Appl. Geophys., Special Issue in honor of Prof. Singh, 162, 1455-1479.
 
Chase, T. N., K. Wolter, R. A. Pielke, Sr., and I. Rasool, 2006: Was the 2003 European summer heat wave unusual in a global context?  Geophys. Res. Lett., 33, L23709, doi:10.1029/2006GL027470.