Irrigation Impact on Water and Energy Cycle During Dry Years Over the United States Using Convection-Permitting WRF and a Dynamical Recycling Model

Zhao Yang, Yun Qian, Ying Liu, Larry K. Berg, Huancui Hu, Francina Dominguez, Ben Yang, Zhe Feng, William I. Gustafson, Maoyi Huang, Qi Tang

Research output: Contribution to journalArticle

Abstract

An irrigation scheme is implemented in the Weather Research and Forecasting (WRF) model to investigate irrigation impacts over the Continental U.S. (CONUS). Four major irrigated regions and two downwind regions were chosen to understand irrigation impacts over different climate regimes with a focus on irrigation-induced changes on the water and energy cycles. The Dynamic Recycling Model (DRM) is employed to quantify precipitation induced by irrigation and the precipitation recycling ratios over each irrigated region. With the irrigation scheme, WRF improves the simulated precipitation, surface skin temperature, and energy fluxes compared to reference datasets. For the energy cycle, irrigation increases latent heat flux over the irrigated regions along with reduced sensible heat flux. The evaporative cooling effect induced by irrigation leads to a cooler surface and less outgoing longwave radiation at the surface. Irrigation also intensifies the hydrological cycle over the irrigated regions, reflected by the increased precipitation, evapotranspiration, recycling ratio, and moisture export. Downwind regions exhibit increased precipitation and evaporation, decreased moisture flux divergence, and less consistent variations in recycling ratio. The precipitation increases over the irrigated regions can be partly explained by the more unstable low-level conditions, while reduced net moisture export is coincident with the precipitation increases over the downwind regions.

Original languageEnglish (US)
JournalJournal of Geophysical Research: Atmospheres
DOIs
StateAccepted/In press - Jan 1 2019

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Keywords

  • energy budget
  • Irrigation
  • land-atmosphere interaction
  • moisture tracking
  • water recycling

ASJC Scopus subject areas

  • Geophysics
  • Forestry
  • Oceanography
  • Aquatic Science
  • Ecology
  • Water Science and Technology
  • Soil Science
  • Geochemistry and Petrology
  • Earth-Surface Processes
  • Atmospheric Science
  • Earth and Planetary Sciences (miscellaneous)
  • Space and Planetary Science
  • Palaeontology

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