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Berkeley-RWAWC: a new CYGNSS-based watermask unveils unique observations of seasonal dynamics in the Tropics
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  • Tianjiao Pu,
  • Cynthia Gerlein-Safdi,
  • Ying Xiong,
  • Mengze Li,
  • Eric A. Kort,
  • A. Anthony Bloom
Tianjiao Pu
University of California, Berkeley

Corresponding Author:[email protected]

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Cynthia Gerlein-Safdi
UC Berkeley
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Ying Xiong
University of Michigan-Ann Arbor
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Mengze Li
Stanford University
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Eric A. Kort
University of Michigan-Ann Arbor
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A. Anthony Bloom
Jet Propulsion Laboratory, California Institute of Technology
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The UC Berkeley Random Walk Algorithm WaterMask from CYGNSS (Berkeley-RWAWC) is a new data product designed to address the challenges of monitoring inundation in regions hindered by dense vegetation and cloud cover as is the case in most of the Tropics. The Cyclone Global Navigation Satellite System (CYGNSS) constellation provides data with a higher temporal repeat frequency compared to single-satellite systems, offering the potential for generating moderate spatial resolution inundation maps with improved temporal resolution while having the capability to penetrate clouds and vegetation. This paper details the development of a computer vision algorithm for inundation mapping over the entire CYGNSS domain (37.4°N to 37.4°S). The unique reliance on CYGNSS data sets our method apart in the field, highlighting CYGNSS’s indication of water existence. Berkeley-RWAWC provides monthly, near-real-time inundation maps starting in August 2018 and across the CYGNSS latitude range, with a spatial resolution of 0.01° × 0.01°. Here we present our workflow and parameterization strategy, alongside a comparative analysis with established surface water datasets (SWAMPS, WAD2M) in four regions: the Amazon Basin, the Pantanal, the Sudd, and the Indo-Gangetic Plain. The comparisons reveal Berkeley-RWAWC’s enhanced capability to detect seasonal variations, demonstrating its usefulness in studying tropical wetland hydrology. We also discuss potential sources of uncertainty and reasons for variations in inundation retrievals. Berkeley-RWAWC represents a valuable addition to environmental science, offering new insights into tropical wetland dynamics.
13 Jan 2024Submitted to ESS Open Archive
02 Feb 2024Published in ESS Open Archive