Yeosang Yoon

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.

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.