Abstract
In order to understand the impact of irrigation on weather and climate, the 2018 Great Plains Irrigation Experiment collected comprehensive observations straddling irrigated and non-irrigated regions in southeast Nebraska. Using these observations, we examine how irrigation affects diurnal terrain-generated slope circulations, specifically the slope wind. We find that irrigation applied to upslope regions of gently sloping terrain reduces terrain-induced baroclinicity and the associated pressure gradient force by up to two-thirds. This leads to the reduction in the afternoon and evening upslope wind and is supported through comparisons to the High-Resolution Rapid Refresh operational model, which does not explicitly account for irrigation. Additionally, the presence of irrigation decreases daytime sensible heat flux (Bowen ratio reduced 40% compared to non-irrigated regions), weakening turbulent transport of momentum. Modifications to the terrain-forced circulation by irrigation has the potential to affect moisture transport and thus cloud and precipitation formation over the Great Plains.
Original language | English (US) |
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Article number | e2021GL096822 |
Journal | Geophysical Research Letters |
Volume | 49 |
Issue number | 7 |
DOIs | |
State | Published - Apr 16 2022 |
Externally published | Yes |
Keywords
- GRAINEX
- Great Plains
- boundary layer
- irrigation
- mesoscale circulation
- slope wind
ASJC Scopus subject areas
- Geophysics
- General Earth and Planetary Sciences