THE decade-long “dust bowl” drought that devastated the central US during the great depression of the 1930s can be traced back to changes in tropical ocean temperatures.
Earlier studies linked cool Pacific temperatures to brief dry spells in the Great Plains, but that wasn’t enough to explain the dust bowl. Now a computer model developed by Siegfried Schubert of the NASA Goddard Space Flight Center in Greenbelt, Maryland, pins the blame on an unusually cool Pacific combined with an unusually warm Atlantic (Science, vol 303, p 1855).
Schubert’s group averaged sea-surface temperatures recorded by ships during the 1930s for their model. Adding a warm tropical…
