Sciences and Exploration Directorate

Yeosang Yoon

(Support Scientist)


Org Code: 617

Mail Code: 617
Greenbelt, MD 20771

Employer: Science Application International Corp.

Research Interests

Understanding how satellite measurements, data assimilation techniques and hydrologic models can be used to quantify the potential impacts of climate and/or land cover change on both local and global hydrology.

Earth Science: Hydrology / Water Cycle


Research Scientist

NASA GSFC/Science Applications International Corporation - Greenbelt, MD

October 2016 - Present

  • Developing capabilities to replace the 577 WW current global snow depth analysis (SNODEP) with Land Information System (LIS).
  • Developing, implementing and testing a data assimilation configuration in LIS using a land surface model (LSM) assimilating the snow observations from the SNODEP environment.
  • Assessing the uncertainty in terrestrial water budgets over High Mountain Asia.
  • Developing spatially and temporally continuous estimates of changes in land surface snow and glaciers over High Mountain Asia and its impact on runoff.
  • Collaborating with UMD team to develop Noah-MP synthetic Tb assimilation.

Postdoctoral Scholar

University of California, Merced - Merced, CA

July 2015 - September 2016

  • Simulated streamflow dynamics for the American River Basin using the PRMS.
  • Estimated the spatiotemporal distribution of snow water equivalent in mountainous terrain.
  • Developed snow data assimilation framework for streamflow forecasting.

Postdoctoral Research Associate

Northeastern University - Boston, MA

October 2013 - June 2015

  • Evaluated peak flow sensitivity to the snowmelt in the Susquehanna River Basin.
  • Developed a statistical downscaling method of TRMM for representation of extreme rainfall events.
  • Developed reservoir storage patterns to estimate streamflow on regulated rivers by analysis combining satellite altimetry, a hydrologic model and satellite data assimilation.
  • Improved the HRR hydrologic model, resulting in better performance.
  • Research resulted in three publications in scientific journals and ten presentations at national and/or international meetings.

Research Assistant

The Ohio State University - Columbus, OH

September 2008 - August 2013

  • Developed and used a Bayesian Markov Chain Monte Carlo algorithm to evaluate the sensitivity of the river discharge algorithm accuracy related to the uncertainty in satellite observations.
  • Developed a data assimilation algorithm coupled with hydraulic modeling to solve the river bathymetry-retrieval problem for satellite altimetry.
  • Designed and studied hydrologic and hydraulic models (e.g., LISFLOOD-FP, HEC-RAS, VIC, and CLM) for the Ohio River Basin and the Sacramento River Basin.
  • Developed an optimal interpolation scheme to enhance temporal coverage of space borne measurements.
  • Collaborated with several interdisciplinary science teams (the OSU, UW-Seattle, Univ. of Bristol (UK), USGS, and NASA JPL) for achieving the goals of the above projects.
  • Research resulted in four publications in scientific journals and nine presentations at national and international meetings.

Research Scientist

Inha University/Land Monitoring Research Center - Incheon, Korea

September 2005 - September 2007

  • Developed a near-real time land monitoring scheme from MODIS imagery to support the government’s policy on land management, including one journal publication.

Research Scientist

Korea Aerospace Research Institute - Daejeon, Korea

September 2005 - September 2007

  • Researched object-based and feature extraction techniques for wildfire monitoring, including two journal publications.
  • Designed and evaluated a Cal/Val algorithm for the KOMPSAT-2 (South Korea multipurpose satellite; 1 m spatial resolution), resulting in improved image quality.
  • Supervised a KARI−UN OOSA cooperative project on natural disaster management.

Research Scientist

E&G Information Technology Co. Ltd. - Daejeon, Korea

February 2001 - September 2005

  • Developed software for the Mobile Multi-Sensor System now used to provide locations and terrestrial images for urban environments, resulting in a staple product to government.
  • Developed land cover/use change maps to manage the natural disaster.
  • Consulted with government personnel for developing a strategy for a periodic update of digital topographic maps from high resolution satellite imagery.
  • Extracted urban building features based on the fusion of aerial photo and LiDAR data.


The Ohio State University Columbus, OH
Ph.D. in Civil Engineering, Aug 2013

Inha University Incheon, Korea
M.E. in Geographic Information Engineering, Feb 2001
B.S. in Computer Science & Engineering, Feb 1999
B.S.E. in Geoinformatic Engineering, Feb 1999

Selected Publications


Yoon, Y., E. M. Kemp, S. V. Kumar, et al. J. W. Wegiel, C. M. Vuyovich, and C. Peters-Lidard. 2022. Development of a global operational snow analysis: The US Air Force Snow and Ice Analysis Remote Sensing of Environment 278 113080 [10.1016/j.rse.2022.113080]

Xue, Y., P. R. Houser, V. Maggioni, et al. Y. Mei, S. V. Kumar, and Y. Yoon. 2022. Evaluation of High Mountain Asia‐Land Data Assimilation System (Version 1) From 2003 to 2016: 2. The Impact of Assimilating Satellite‐Based Snow Cover and Freeze/Thaw Observations Into a Land Surface Model Journal of Geophysical Research: Atmospheres 127 (7): [10.1029/2021jd035992]

Kwon, Y., Y. Yoon, B. A. Forman, S. V. Kumar, and L. Wang. 2021. Quantifying the observational requirements of a space-borne LiDAR snow mission Journal of Hydrology 601 126709 [10.1016/j.jhydrol.2021.126709]

Chul Jung, H., D.-H. Kang, E. Kim, et al. A. Getirana, Y. Yoon, S. Kumar, C. D. Peters-lidard, and E. Hwang. 2020. Towards a Soil Moisture Drought Monitoring System for South Korea Journal of Hydrology 125176 [10.1016/j.jhydrol.2020.125176]

Kwon, Y., B. A. Forman, J. A. Ahmad, S. V. Kumar, and Y. Yoon. 2019. Exploring the Utility of Machine Learning-Based Passive Microwave Brightness Temperature Data Assimilation over Terrestrial Snow in High Mountain Asia Remote Sensing 11 (19): 2265 [10.3390/rs11192265]

Yoon, Y., S. V. Kumar, B. A. Forman, et al. B. F. Zaitchik, Y. Kwon, Y. Qian, S. Rupper, V. Maggioni, P. Houser, D. Kirschbaum, A. Richey, A. Arendt, D. M. Mocko, J. Jacob, S. Bhanja, and A. Mukherjee. 2019. Evaluating the uncertainty of terrestrial water budget components over High Mountain Asia Frontiers in Earth Science 7 [10.3389/feart.2019.00120]

Xue, Y., P. R. Houser, V. Maggioni, et al. Y. Mei, S. V. Kumar, and Y. Yoon. 2019. Assimilation of Satellite-Based Snow Cover and Freeze/Thaw Observations Over High Mountain Asia Frontiers in Earth Science 7 [10.3389/feart.2019.00115]

Ray, R. L., R. E. Beighley, and Y. Yoon. 2016. Integrating Runoff Generation and Flow Routing in Susquehanna River Basin to Characterize Key Hydrologic Processes Contributing to Maximum Annual Flood Events Journal of Hydrologic Engineering 21 (9): 04016026 [10.1061/(asce)he.1943-5584.0001389]

Yoon, Y., E. Beighley, H. Lee, T. Pavelsky, and G. Allen. 2016. Estimating Flood Discharges in Reservoir-Regulated River Basins by Integrating Synthetic SWOT Satellite Observations and Hydrologic Modeling Journal of Hydrologic Engineering 21 (4): 05015030 [10.1061/(asce)he.1943-5584.0001320]

Yoon, Y., P.-A. Garambois, R. C. Paiva, et al. M. Durand, H. Roux, and E. Beighley. 2016. Improved error estimates of a discharge algorithm for remotely sensed river measurements: Test cases on Sacramento and Garonne Rivers Water Resources Research 52 (1): 278-294 [10.1002/2015wr017319]

Yoon, Y., and E. Beighley. 2014. Simulating streamflow on regulated rivers using characteristic reservoir storage patterns derived from synthetic remote sensing data Hydrological Processes 29 (8): 2014-2026 [10.1002/hyp.10342]

Durand, M., J. Neal, E. Rodríguez, et al. K. M. Andreadis, L. C. Smith, and Y. Yoon. 2014. Estimating reach-averaged discharge for the River Severn from measurements of river water surface elevation and slope Journal of Hydrology 511 92-104 [10.1016/j.jhydrol.2013.12.050]

Yoon, Y., M. Durand, C. J. Merry, and E. Rodriguez. 2013. Improving Temporal Coverage of the SWOT Mission Using Spatiotemporal Kriging IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing 6 (3): 1719-1729 [10.1109/jstars.2013.2257697]

Yoon, Y., M. Durand, C. J. Merry, et al. E. A. Clark, K. M. Andreadis, and D. E. Alsdorf. 2012. Estimating river bathymetry from data assimilation of synthetic SWOT measurements Journal of Hydrology 464-465 363-375 [10.1016/j.jhydrol.2012.07.028]