The diurnal cycle of dew point temperature and its seasonal variation can be used to study the interaction of land-atmosphere processes. Oklahoma's winter wheat belt is a 150 km-wide strip of land that extends from north-central into southwestern Oklahoma. Winter wheat is a cold-season crop that normally matures each spring and is harvested during June. It is a near-ideal laboratory setting of vegetation.

Using data collected by the Oklahoma Mesonet during an eight-year period (~2 billion observations), the diurnal cycle of dew point temperature is analyzed across the winter wheat belt and surrounding locations. This cycle and its seasonal variation illustrates the impact on the atmosphere from the wheat belt before and after the harvest, during drought years and years with normal rainfall, and during years when the wheat crop was rated as poor.

For a given location, the diurnal cycle of dew point temperature exhibits distinct patterns that reflect the small-scale influences of the wheat belt. These patterns will be discussed in the manuscript and during the oral presentation.