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 Terrestrial Hydrology (329F): People
JT  Reager's Picture
Jet Propulsion Laboratory
M/S 300-323
4800 Oak Grove Drive
Pasadena, CA 91109
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Curriculum Vitae:

JT Reager

JT Reager is a Research Scientist in the Surface Hydrology group, in the Earth Sciences Section. He studies the Earth's water cycle with a particular focus on hydrologic extremes, sea level rise and water resources. He joined JPL in 2014.

  • Postdoctoral Researcher, UC Center for Hydrological Modeling (2014)
  • PhD in Earth System Science, University of California, Irvine, Irvine, CA (2012)
  • M.S. in Physical Ocean Science and Engineering, University of Delaware, College of Marine Studies, Newark, DE (2004)
  • B.S. in Aerospace Engineering, B.S. in Ocean Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA (2001)

Research Interests
  • Application of satellite gravimetry for terrestrial hydrology
  • Influence of sub-surface water storage on hydrologic extremes
  • Global water cycle variability and sea level rise
  • Land surface modeling and data assimilation
  • Coupled land-ocean mass fluxes
  • Hydrologic predictors of fire season severity


GRACE, the Gravity Recovery and Climate Experiment, provide measurements of the Earth’s gravity field, including the variability of ocean mass.

NASA Sea Level Change Icon NASA Sea Level Change
NASA’s Sea Level Change team was selected in 2014, 2017, and 2020, to focus on advancing NASA sea level science and forming new collaborations to tackle the interdisciplinary challenges in sea level research.

Professional Experience
  • Jet Propulsion Laboratory, Pasadena, CA
    • Scientist (2014-present)
  • University of California, Los Angeles, CA
    • Visiting Researcher, JIFRESSE (2014-present)

Community Service
  • GRACE Deputy Project Applications Lead
  • Lead organizer and presenter, NASA Applied Sciences/CUAHSI workshop on 'Methods and tools in satellite hydrology'. CUAHSI HQ, Boston, April 2017.
  • Presenter, IPCC Conference of the Parties (COP-22), NASA Earth Sciences, Marrakech, Morrocco, November 2016.
  • Lead organizer: Workshop on hydrologic applications of GNSS-reflectometry, NASA Jet Propulsion Laboratory, June 2016.
  • Lead author, National Academies Decadal Survey, RFI2: Water beneath the land surface. Submitted May 15, 2016.
  • Lead organizer and presenter, CUAHSI workshop on 'Methods and tools in satellite hydrology'. Biosphere 2, Tuscon, March 2016.
  • Group leader, Hyper-resolution land surface modeling collaborative, Working Group I: Test case creation. [2014-present]
  • NASA DEVELOP Science Advisor

Selected Awards
  • NOAA David Johnson Award (2016) for innovative Application Of Earth Observation Satellite Data For Operational Purposes.
  • Newkirk Center for Science and Society Fellowship (2012)
  • ARCS Foundation Scholar Achievement Award  (2011)
  • NASA Earth and Space Science Fellowship  (2010)

Selected Publications
  1. Hamlington, B.D., J.T. Reager, B. Leben and K. Karnauskas (2017) Mapping the causes and impacts of decadal sea level variability, Science Advances.
  2. Sinha, D., T.H. Syed, J.S. Famiglietti, J.T. Reager, and R.C. Thomas (2017) Characterizing Drought in India Using GRACE Observations of Terrestrial Water Storage Deficit. J. Hydrometeor., 18, 381-396.
  3. Behrangi, A., Gardner, A. S., Reager, J. T., & Fisher, J. B. (2017). Using GRACE to constrain precipitation amount over cold mountainous basins. Geophysical Research Letters, 44(1), 219-227.
  4. Wada, Y., Reager, J. T., Chao, B. F., Wang, J., Lo, M. H., Song, C., & Gardner, A. S. (2016). Recent Changes in Land Water Storage and its Contribution to Sea Level Variations. Surveys in Geophysics, 1-22.
  5. Fournier, S., J.T. Reager, T. Lee, C.H. David, J. Vazquez and M. Gierach (2016) A Texas flood from land to ocean observed by SMAP, Geophysical Research Letters.
  6. Zuffada, C., Chew, C., Nghiem, S.V., Shah, R., Podest, E., Bloom, A.A., Koning, A., Small, E., Schimel, D., Reager, J.T. and Mannucci, A., (2016). Advancing Wetlands Mapping and Monitoring with GNSS Reflectometry. In Living Planet Symposium, 740, p. 83.
  7. Wada, Y., M.-H. Lo, J.T. Reager et al. (2016) Fate of water pumped from underground and contributions to sea level rise, Nature Climate Change.
  8. Castle, S. S., Reager, J. T., Thomas, B. F., Purdy, A. J., Lo, M. H., Famiglietti, J. S., & Tang, Q. (2016). Remote detection of water management impacts on evapotranspiration in the Colorado River Basin. Geophysical Research Letters, 43(10), 5089-5097.
  9. Richey, A. S., Thomas, B. F., Lo, M. H., Reager, J. T., Famiglietti, J. S., Voss, K., et al.. (2016). Reply to comment by Sahoo et al. on "Quantifying renewable groundwater stress with GRACE". Water Resources Research, 52(5), 4188-4192.
  10. Solander, K. C., J. T. Reager, and J. S. Famiglietti (2016), How well will the Surface Water and Ocean Topography (SWOT) mission observe global reservoirs?, Water Resour. Res., 52, 2123-2140.
  11. Solander, K., J.T. Reager, B.F. Thomas, C.H. David and J.S. Famiglietti (2016) Simulating the human operator: the development of an optimal complexity, climate-adaptive reservoir management model for an LSM. Water Res. Research, accepted.
  12. Reager, J.T., A.S. Gardner, J.S. Famiglietti, D.N. Weiss, A. Eicker and M.H. Lo (2016) A decade of sea level rise slowed by climate-driven hydrology, Science, accepted.
  13. Famiglietti, J.S., A. Cazenave, A. Eicker, J.T. Reager, M. Rodell, and I. Velicogna (2015) Satellites Provide the ‘Big Picture’ for Global Hydrology. Science, 349 (6249).
  14. Sproles, E.A., S.G. Leibowitz, J.T. Reager, P.J. Wigington and S.D. Patil,(2015) GRACE storage-streamflow hystereses reveal the dynamics of regional watersheds. Hydrol. Earth Sys. Science, 19 (7), 3253-3272.
  15. Wu, W.-Y., C.-W. Lan, M.-H. Lo, J.T. Reager, J.S. Famiglietti (2015)  Increases in the Annual Range of Soil Water Storage at Northern Mid- and High-Latitudes under Global Warming. Geophys. Res. Lett.
  16. Richey, A.S., B.F. Thomas, M.-H. Lo, J.S. Famiglietti, J.T. Reager, K.S. Voss, S.C. Swenson and M. Rodell (2015) Uncertainty in Global Groundwater Storage Estimates in a Total Groundwater Stress Framework. Water Res. Research.
  17. Singh, R.S., J.T. Reager and N.L. Miller, J.S. Famiglietti (2015) Towards hyper-resolution land surface modeling: The effects of fine-scale model grid resolution on CLM4.0 simulations in the Southwestern US.  Water Res. Research, 50, doi: 10.1002/2014WR015686.
  18. Billah, M.M., J.L. Goodall, U. Narayand, J.T. Reager, V. Lakshmi, J.S. Famiglietti (2015) Evaluation of regional-scale evapotranspiration estimates using GRACE observations of anomaly in terrestrial water storage: An application to South Carolina, USA. Journal of Hydrology, 523, 574-586.
  19. Bierkens, M.F.P., V.A. Bell, P. Burek, N. Chaney, L. Condon, C.H.
David, A. de Roo, P. Döll, N. Drost, J.S. Famiglietti, M. Flörke, D.J. Gochis, P. Houser, R. Hut, J. Keune, S. Kollet, R. Maxwell, J.T. Reager, L. 
Samaniego, E. Sudicky, E.H. Sutanudjaja, N. van de Giesen, H. Winsemius and E.F. Wood (2015) Hyper-resolution global hydrological modeling: what’s next? Hydrological Processes, 29 (2), 310-320.
  20. Reager, J.T., A.C. Thomas, E.A. Sproles, M. Rodell, H.K. Beaudoing, B.-L. Li, J.S. Famiglietti (2015) Assimilation of GRACE terrestrial wáter storage observations into a land surface model for the assesment of regional flood potential. Remote Sensing. Accepted.
  21. Castle, S.S., B.F. Thomas, J.T. Reager, M. Rodell, S.C. Swenson and J.S. Famiglietti (2014) Groundwater Depletion During Drought Threatens Future Water Security of the Colorado River Basin. Geophys. Res. Lett., 41, 5904–5911. *Highlighted in Science, Editors’ choice, “Looking beneath the drying surface”, August, 2014, 345, 6198.
  22. Thomas, A.C., J.T. Reager, J.S. Famiglietti and M. Rodell (2014) GRACE-observed water storage deficits for hydrological drought characterization. Geophys. Res. Lett., 41, 1537–1545.
  23. Reager, J.T., B.F. Thomas and J.S. Famiglietti (2014) River basin flood potential inferred using GRACE gravity observations at several months lead-time. Nat. Geosci., 7, 588-592. *Highlighted in Science, “Gravity measurements can predict river flooding”, July, 2014.
  24. Reager, J.T. and J.S. Famiglietti (2013), Characteristic mega-basin water storage behavior from GRACE. Water Res. Research, 49, 3314–3329.
  25. Reager, J.T. (2012), Terrestrial water storage across scales: Applications of the GRACE satellite mission for global hydrology. University of California, dissertation #3540046, 110 pp.
  26. Reager, J.T. and J.S. Famiglietti (2009), Global terrestrial water storage capacity and flood potential using GRACE. Geophys. Res. Lett., 36, L23402.

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