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ARS Home » Plains Area » El Reno, Oklahoma » Oklahoma and Central Plains Agricultural Research Center » Agroclimate and Hydraulics Research Unit » Research » Publications at this Location » Publication #426154
Research Project: Impacts of Variable Land Management and Climate on Water and Soil Resources

Location: Agroclimate and Hydraulics Research Unit

Title: Bi-hourly changes in land-atmosphere coupling metrics and convective environments during GRAINEX

Author
item WHITESEL, DANIEL - University Of Nebraska
item MAHMOOD, REZAUL - University Of Nebraska
item Flanagan, Paul
item PHILLIPS, CHRISTOPHER - University Of Alabama
item ROUNDY, JOSHUA - University Of Kansas
item PIELKE SR, ROGER - University Of Colorado
item NAIR, UDAYSANKAR - University Of Alabama
item RAPPIN, ERIC - Western Kentucky University

Submitted to: Journal of Geophysical Research: Atmospheres
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/28/2026
Publication Date: N/A
Citation: N/A

Interpretive Summary: Changes in land use and land cover impact the environment, including weather and climate. However, a lack of data makes it difficult to accurately monitor the impact of land-use change. This study uses data from a field study to analyze the impact of irrigation levels in an extensively irrigated to non-irrigated transition area in eastern Nebraska. The resulting analysis of the collected daily data shows that increased irrigation water over a particular area provides more favorable conditions for cumulus convection storms, regardless of the background conditions of that period (i. e. sunny versus cloudy days and regardless of which period of the growing season you're in).

Technical Abstract: Land use land cover change and irrigation plays an important role in modulating weather and climate. This research uses data from a field campaign conducted over southeastern Nebraska, named, the Great Plains Irrigation Experiment (GRAINEX) and quantifies the impacts of irrigation on bi-hourly evolution of the convective environment. The study used the Convective Triggering Potential (CTP) and Low-Level Humidity Index (HIlow), and the Lifting Condensation Level (LCL) Deficit for this purpose. The data were analyzed IOP (IOP1 vs IOP2), by cloud cover (clear vs non-clear days), and by both IOP and cloud cover. The study found that daytime evolution started with high CTP in the morning, lower CTP at midday, and higher CTP in the late afternoon and evening hours. During IOP2, regardless of time-of-day CTP was higher over irrigated land use was higher and it coincided with widespread irrigation. CTP was much higher during early morning (0700 LST), late afternoon (1700 LST) and early evenings (1900 LST). Irrigation’s influence on CTP is even more apparent for all times during clear days of IOP2. HIlow values experienced notable decreases as we transition from IOP1 to IOP2, which points toward favorable environment for convective development and precipitation. In addition, regardless of cloudy or non-cloudy conditions, HIlow values over irrigated areas were lower at all hours during IOP2 suggesting influence of irrigation. Average LCL deficit declined for most hours over irrigated land use during IOP2. In combination with higher CTP, lower HIlow and LCL deficit, it is clear that regardless of background condition irrigation provides a favorable condition for convection development and precipitation.