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Title: DEW DURATION AND AMOUNT ON CORN LEAVES AS DETERMINED FROM SMEX05 MEASUREMENTS AND REANALYSIS USING THE ALEX MODEL

Author
item KABELA, E - IOWA STATE UNIVERSITY
item HORNBUCKLE, B - IOWA STATE UNIVERSITY
item Cosh, Michael
item Anderson, Martha
item GLEASON, M - IOWA STATE UNIVERSITY

Submitted to: American Geophysical Union
Publication Type: Abstract Only
Publication Acceptance Date: 4/1/2006
Publication Date: 5/23/2006
Citation: Kabela, E., Hornbuckle, B., Cosh, M.H., Anderson, M., Gleason, M.L. 2006. Dew duration and amount on corn leaves as determined from SMEX05 measurements and reanalysis using ALEX model [abstract]. 2006 American Geophysical Union Spring Meeting. Abstract H43B-01.

Interpretive Summary:

Technical Abstract: Dew plagues crop producers in many facets of agriculture. Many studies have been done on the effects of dew in terms of pest formation and diseases on crops. Although the formation of dew is significant on a micro-scale, satellite projects such as SMOS aim to measure soil moisture on a meso or synoptic scale. The presence of dew has been found to decrease soil brightness temperature, which in turn effects soil moisture readings. The purpose of the dew collection portion of the Soil Moisture Experiment in 2005 (SMEX05) was to manually measure dew so that the effect could be studied on measurements made by remotely sensed soil moisture readings. The purpose of this paper is to determine if manual dew measurements obtained during SMEX05 are accurately modeled by the atmosphere-land exchange model, ALEX. Dew measurements were taken during SMEX05 from June 16 to July 3, 2005 in corn, soybean, and alfalfa fields south of Ames, Iowa. Collection usually began at approximately 645 CDT and commenced at approximately 900 CDT each morning. My hypothesis for this paper is that dew amount and duration collected from SMEX05 are predicted accurately by the atmosphere-land exchange (ALEX) model. Accuracy for dew amount is defined as an amount within 0.05 to 0.1 mm of manual measurements. Accuracy for dew duration is defined as 0.5 hours within automated observations from leaf wetness sensors deployed in various fields within the Walnut Creek watershed. It was found that dew amount is accurate for light, moderate, and heavy dew events, while dew duration is predicted within 0.5 to 1.0 hours.