Gilbert Walker

Sir Gilbert Thomas Walker was an English physicist and statistician who provided the first scientific description of a major pattern of global climate variability. Walker described what he called the Southern Oscillation, a seesawing pattern of atmospheric pressure between the Indian and Pacific Oceans, and showed that it correlated with temperature and rainfall patterns across tropical regions around the world; the associated atmospheric circulation pattern is now called the Walker circulation in his honor, and the phenomenon as a whole is understood today as part of the El Nino-Southern Oscillation. In developing these findings, Walker created statistical time-series analysis techniques, now called the Yule-Walker equations, which he applied in an effort to predict the strength of the Indian monsoon. Walker is also noted for having been instrumental in supporting the early career of the self-taught Indian mathematician Srinivasa Ramanujan. Walker's identification of large-scale, ocean-linked climate oscillations helped move meteorology beyond local weather observation and forecasting toward the study of comprehensive, worldwide climate patterns.