Effects of Irrigation on Summer Precipitation over the United States
| Autor: | David W. Hyndman, Lisi Pei, Anthony D. Kendall, Shiyuan Zhong, Nathan Moore, Zhiqiu Gao |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
Hydrology
Atmospheric Science Irrigation 010504 meteorology & atmospheric sciences Land use 0208 environmental biotechnology 02 engineering and technology 01 natural sciences Irrigation water 020801 environmental engineering High pressure Climatology Weather Research and Forecasting Model Environmental science Climate model Precipitation 0105 earth and related environmental sciences |
| Zdroj: | Journal of Climate. 29:3541-3558 |
| ISSN: | 1520-0442 0894-8755 |
| DOI: | 10.1175/jcli-d-15-0337.1 |
| Popis: | Irrigation’s effects on precipitation during an exceptionally dry summer (June–August 2012) in the United States were quantified by incorporating a novel dynamic irrigation scheme into the Weather Research and Forecasting (WRF) Model. The scheme is designed to represent a typical application strategy for farmlands across the conterminous United States (CONUS) and a satellite-derived irrigation map was incorporated into the WRF-Noah-Mosaic module to realistically trigger the irrigation. Results show that this new irrigation approach can dynamically generate irrigation water amounts that are in close agreement with the actual irrigation water amounts across the high plains (HP), where the prescribed scheme best matches real-world irrigation practices. Surface energy and water budgets have been substantially altered by irrigation, leading to modified large-scale atmospheric circulations. In the studied dry summer, irrigation was found to strengthen the dominant interior high pressure system over the southern and central United States and deepen the trough over the upper Midwest. For the HP and central United States, the rainfall amount is slightly reduced over irrigated areas, likely as a result of a reduction in both local convection and large-scale moisture convergence resulting from interactions and feedbacks between the land surface and atmosphere. In areas downwind of heavily irrigated regions, precipitation is enhanced, resulting in a 20%–100% reduction in the dry biases (relative to the observations) simulated over a large portion of the downwind areas without irrigation in the model. The introduction of irrigation reduces the overall mean biases and root-mean-square errors in the simulated daily precipitation over the CONUS. |
| Databáze: | OpenAIRE |
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