NOAA 2000-311
Contact: Pat Viets


A new Web site on drought history is available from NOAA's National Geophysical Data Center in Boulder, Colo. The Web site, entitled "North American Drought: A Paleo Perspective," explains how data from sources such as tree rings, lake sediments, and archeological remains can provide insight about past droughts.

Just how unusual was the Dust Bowl drought? Was this a rare event or should we expect drought of similar magnitude to occur in the future? Rainfall records used to evaluate drought extend back just over 100 years, and are too short to answer these questions. Data from the natural archive are used to answer these questions and to evaluate 20th century North American droughts in the context of hundreds to thousands of years in the field of paleoclimatology.

Paleoclimatology is the study of past climate. The word is derived from the Greek root paleo-, which means ancient, and the term "climate" meaning the weather conditions over an interval of time, usually several decades. Paleoclimate is climate that existed before humans began collecting instrumental measurements of weather such as temperature from a thermometer, precipitation from a rain gauge, sea level pressure from a barometer, and wind speed and direction from an anemometer. Instead of instrumental measurements of weather and climate, paleoclimatologists use natural environmental records to infer past climate conditions. Paleoclimatology includes the collection of evidence of past climate conditions, and the investigation of the climate processes underlying these conditions.

The new Web site is the second in NGDC's Paleo Perspectives series and follows the highly successful "A Paleo Perspective on Global Warming."