The Amazon Water Cycle: Perspectives from Water Budget Closure and Ocean Salinity
- Univ. of Arizona, Tucson, AZ (United States). Dept. of Hydrology and Atmospheric Sciences; Univ. of Arizona, Tucson, AZ (United States)
- Univ. of Arizona, Tucson, AZ (United States). Dept. of Hydrology and Atmospheric Sciences
Global and regional water cycle includes precipitation, water vapor divergence, and change of column water vapor in the atmosphere, and land surface evapotranspiration, terrestrial water storage change, and river discharge, which is linked to ocean salinity near the river mouth. The water cycle is a crucial component of the Earth system, and numerous studies have addressed its individual components (e.g., precipitation). Here we assess, for the first time, if remote sensing and reanalysis datasets can accurately and self-consistently portray the Amazon water cycle. This is further assisted with satellite ocean salinity measurements near the mouth of the Amazon River. The widely used practice of taking the mean of an ensemble of datasets to represent water cycle components (e.g., precipitation) can produce large biases in water cycle closure. Additionally, closure is achieved with only a small subset of data combinations (e.g., ERA5 precipitation and evapotranspiration plus GRACE satellite terrestrial water storage), which rules out the lower precipitation and higher evapotranspiration estimates, providing valuable constraints on assessments of precipitation, evapotranspiration, and their ratio. The common approach of using the Óbidos stream gauge (located hundreds of kilometers from the river mouth) multiplied by a constant (1.25) to represent the entire Amazon discharge is found to misrepresent the seasonal cycle, and this can affect the apparent influence of Amazon discharge on tropical Atlantic salinity.
- Research Organization:
- Univ. of Arizona, Tucson, AZ (United States); Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC); National Aeronautic and Space Administration (NASA)
- Grant/Contract Number:
- SC0016533; AC52-07NA27344
- OSTI ID:
- 1852278
- Journal Information:
- Journal of Climate, Journal Name: Journal of Climate Journal Issue: 4 Vol. 34; ISSN 0894-8755
- Publisher:
- American Meteorological SocietyCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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