John Michael Wallace
My research and that of my students has been directed at improving our understanding of global climate and its year-to-year and decade-to-decade variations, making use of observational data. We have contributed to the identification and understanding of a number of atmospheric phenomena, including the vertically propagating planetary waves that drive the quasi-biennial oscillation in zonal winds in the equatorial stratosphere, the 4-5-day period easterly waves that modulate daily rainfall over the tropical oceans, and the dominant spatial patterns in month-to-month and year-to-year climate variability, including the one through which the El Nio phenomenon in the tropical Pacific influences climate over North America. We have contributed to documenting the existence of El Nino- like variability on a decade to decade time scale (the so called 'Pacific Decadal Oscillation'). We are currently investigating two analogous patterns of weather and climate variability: the Northern and Southern Hemisphere 'annular modes' (see http://jisao.washington.edu/ao/) which have played a prominent role in the climatic trends of the past 30 years.