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Document Type

Research

Keywords

climate change, climate variability, runs of weather

Abstract

Temperature and precipitation during the past decade have exhibited wide variation throughout Iowa. Is this unusual? An attempt was made to answer this question by computing various statistical parameters that characterize variation in Iowa's long term climatic record. Absolute deviations were used to identify the most and least variable months and years since 1900. Overall, 1936 with a very cold winter and very warm summer was the least normal year. Runs of daily weather showed that heat and cold stress could often persist for more than 1 month. Runs of dry days were much longer than runs of wet days. Rank analysis showed that 1993 was indeed unusual relative to excess rainfall and that 1992 summer temperatures were also unusual, even though both events had comparable analogs in the historic weather record. Annual and seasonal 10-year moving means and standard deviations revealed different patterns of interannual variation between seasons. Winter was most variable, while summer, spring, and fall variability increased during the past two decades. Only during the 1940's and 1960's were the seasons similar for this statistical measure.

Publication Date

March 1997

Journal Title

Journal of the Iowa Academy of Science

Volume

104

Issue

1

First Page

21

Last Page

27

Copyright

© Copyright 1997 by the Iowa Academy of Science, Inc.

Language

EN

File Format

application/pdf