부산대학교 도서관

The water cycle is an important component of the earth system and it plays a key role in many facets of society, including energy production, agriculture, and human health and safety. In this study, the Energy Exascale Earth System Model version 1 (E3SMv1) is run with low‐resolution (roughly 110 km) and high‐resolution (roughly 25 km) configurations—as established by the High Resolution Model Intercomparison Project protocol—to evaluate the atmospheric and terrestrial water budgets over the conterminous United States (CONUS) at the large watershed scale. The warm season water cycle slows down in the HR experiment relative to the LR, with decreasing fluxes of precipitation, evapotranspiration, atmospheric moisture convergence, and runoff. The reductions in these terms exacerbate biases for some watersheds, while reducing them in others. For example, precipitation biases are exacerbated at HR over the Eastern and Central CONUS watersheds, while precipitation biases are reduced at HR over the Western CONUS watersheds. The most pronounced changes with resolution to the water cycle come from reductions in precipitation and evapotranspiration. The reduction in evapotranspiration reduces the biases across nearly all of the CONUS. Additional exploratory metrics show improvements to water cycle extremes (both in precipitation and streamflow), fractional contributions of different storm types to total precipitation, and mountain snowpack. Plain Language Summary: This study seeks to better understand how the U.S. DOE's Earth system model, Energy Exascale Earth System Model, simulates the conterminous United States (CONUS) water cycle. To accomplish this goal, we examine the atmosphere and land water budget terms at the watershed and seasonal space and time scales. At higher resolution and during the warm season, all of the terms in the water budget become smaller: precipitation, evapotranspiration, moisture convergence, and runoff. The reductions in evapotranspiration lead to improvements over nearly the entire CONUS, while other terms show mixed results when increasing resolution. We also examine exploratory metrics with expected resolution sensitivity—including precipitation and streamflow extremes, storm events, and snowpack—and find modest improvements. Key Points: The water cycle slows down (decreased fluxes) when grid spacing has a four times refinementHR generally improves evapotranspiration, but precipitation and other terms have mixed resultsHR improves precipitation extremes, storm event precipitation contributions, and mountain snowpack [ABSTRACT FROM AUTHOR]