Coupled Water-Cycle Retrieval: Linking Precipitation and Soil Moisture Across NASA Microwave Missions

Organization National Aeronautics and Space Administration (NASA) Reference Code 0348-NPP-NOV26-JPL-EarthSci How To Apply All applications must be submitted in Zintellect Please visit the NASA Postdoctoral Program website for application instructions and requirements: How to Apply | NASA Postdoctoral Program (orau.org) A complete application to the NASA Postdoctoral Program includes: Research proposalThree letters of recommendationOfficial doctoral transcript documents Application Deadline 11/1/2026 6:00:59 PM Eastern Time Zone Description About the NASA Postdoctoral Program The NASA Postdoctoral Program (NPP) offers unique research opportunities to highly-talented scientists to engage in ongoing NASA research projects at a NASA Center, NASA Headquarters, or at a NASA-affiliated research institute. These one- to three-year fellowships are competitive and are designed to advance NASA’s missions in space science, Earth science, aeronautics, space operations, exploration systems, and astrobiology. Description: Soil moisture and precipitation are two views of the same land–atmosphere exchange: rainfall drives soil moisture dynamics, and the land surface retains a measurable memory of precipitation. This research opportunity invites a participant to investigate that coupling in both directions in support of NASA's microwave remote sensing missions. In the forward direction, physically based inversion of soil-water-balance processes turns satellite soil moisture into an independent constraint on precipitation — a "natural rain gauge" complementary to atmospheric retrievals such as GPM, particularly over regions where ground radar and gauge networks are sparse. In the reverse direction, high-resolution precipitation fields (e.g., MRMS) provide spatially distributed validation for fine-scale soil moisture products where consistent in situ networks do not exist — a critical need as NISAR-era products reach resolutions that conventional validation cannot address. The participant may research and analyze one or more of the following topics: physically based retrieval of precipitation from spaceborne soil moisture observations (SMAP and downscaled active–passive products); characterization of soil-system memory and its spatial variability; use of precipitation coherence as a validation and uncertainty-quantification pathway for high-resolution soil moisture from NISAR and future L-band missions (e.g., ROSE-L); and propagation of physics-traceable soil moisture uncertainty into precipitation estimates. Machine learning approaches are welcome as tools within this framework — for example, learning the space–time variability of soil-water-balance parameters — while retrievals remain anchored in governing physics. The participant will collect and analyze data from multiple NASA missions, collaborate with scientists engaged in SMAP algorithm heritage and NISAR-era high-resolution soil moisture development at JPL, and participate in multi-mission integration research spanning SMAP, NISAR, and ROSE-L. This opportunity offers hands-on experience with operational satellite retrieval algorithms, physics-based forward modeling, and mission-scale validation practice, complementing the participant's background and advancing knowledge directly relevant to NASA's Earth science objectives. Relevant missions and datasets: SMAP, NISAR, GPM, MRMS, CYGNSS, ROSE-L. Field of Science: Earth Science Advisors: Xiaolan Xu xiaolan.xu@jpl.nasa.gov (626) 704-0102 Applications with citizens from Designated Countries will not be accepted at this time, unless they are Legal Permanent Residents of the United States. A complete list of Designated Countries can be found at: https://www.nasa.gov/oiir/export-control. Eligibility is currently open to: U.S. Citizens; U.S. Lawful Permanent Residents (LPR); Foreign Nationals eligible for an Exchange Visitor J-1 visa status; and, Applicants for LPR, asylees, or refugees in the U.S. at the time of application with 1) a valid EAD card and 2) I-485 or I-589 forms in pending status Questions about this opportunity? Please email npp@orau.org Qualifications Candidates should hold a Ph.D. (or complete one before the start date) in hydrology, civil or environmental engineering, remote sensing, geophysics, electrical engineering, atmospheric science, or a related field. Training that bridges land-surface hydrology and microwave remote sensing is the strongest preparation. Favorable skills and experience include: spaceborne microwave observations of the land surface (e.g., SMAP, GPM, CYGNSS, NISAR) and their retrieval products; soil-water-balance physics and land-surface hydrologic processes; inverse methods for retrieving geophysical variables from satellite measurements; uncertainty quantification and validation of satellite products; machine learning applied within physically constrained frameworks rather than as black-box prediction; scientific computing (e.g., Python); and peer-reviewed publications. Experience in all areas is not expected; a strong foundation in the underlying physics matters most. Point of Contact Mikeala Eligibility Requirements Degree: Doctoral Degree.