Trends in Precipitation Intensity In The Climate Record
Abstract
We summarize our research which suggests that changes (mostly increases) in precipitation intensity (heavy and very heavy daily precipitation events) have occurred during the past one hundred years in various regions of the world including the contiguous United States. While the United States constitutes a small fraction of the Earth's surface, it is important to note that similar processes (increase in "very heavy" precipitation) have taken place in many extratropical regions. Specifically in addition to the United States, we present our results for Russia, Australia, Nordic countries, South Africa, Brazil, Mexico, and Canada. Summary of results for several other regions will be also shown. There is an ambiguity in impact assessments of heavy precipitation: it can be considered beneficial or harmful. By raising thresholds of definitions and assessing changes in "very heavy" and "extreme" events, we try to remove this ambiguity. The occurrences of the events studied here are likely to be economically disruptive and potentially life threatening. However, very dense networks are required to reveal changes in frequency of these events. This is shown using the estimates of the representativeness of networks that report daily precipitation extreme events in different countries. So far, both the empirical evidence from the period of instrumental observations and model projections of a greenhouse-enriched atmosphere indicate an increasing probability of heavy precipitation events in the extratropics.
- Publication:
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AGU Spring Meeting Abstracts
- Pub Date:
- May 2004
- Bibcode:
- 2004AGUSM.A52A..06G
- Keywords:
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- 1854 Precipitation (3354)