Past Research

During my graduate studies at the University of Wyoming (UW) and the University of Tennessee (UT) and now as a Post-Doctoral Research Associate at Oak Ridge National Laboratory (ORNL), I have participated in numerous interdisciplinary research activities including:


  • Identification of climate signals and their use in long lead-time (3 to 9 months) forecasting of streamflow and snowpack. This was the core of my thesis and dissertation research and resulted in three(1,2,3) lead authored and two(4,5) co-authored Web of Science publications. I developed MATLAB code and applied multivariate statistical technique to large, spatial, temporal datasets (e.g., gridded Sea Surface Temperatures and 500mb pressures). This resulted in the identification of climatic regions that are teleconnected with hydrologic (e.g., streamflow, snowpack) response. Indices are developed for the regions and then used in a non-parametric forecasting model. When utilizing these “tailored” indices over traditional indices (ENSO, PDO), forecast skill was greatly improved.
  • Evaluation of PRISM precipitation datasets in the Wind River Range and Teton Range (Wyoming) in which remote sensed data was examined to determine glacier change and meltwater contributions to streamflow. I accessed gridded monthly precipitation data to show similarities between summer precipitation patterns in glaciated and non-glaciated watersheds. I also assisted in evaluating and comparing remote sensed snowpack datasets from satellites and in-situ sources(6).
  • Weather Modification (cloud seeding) impacts on streamflow in the North Platte River Basin (Wyoming), and the impacts of climate change and land use change (due to beetle kill) on streamflow. I assisted in the development of a hydrologic model (Variable Infiltration Capacity – VIC) for use in these studies and we currently have one paper in preparation.
  • Paleo reconstructions of streamflow, snowpack and soil moisture, using tree-ring datasets and climate, in the Upper Colorado River Basin. This research is funded by the National Science Foundation, Paleo Perspectives for Climate Change (P2C2) program. I assisted in identifying climatic drivers for use in regression based reconstruction models. We currently have one paper in 2nd review and one paper in preparation.
  • Building of a physical hydrologic model for the entire USA, consisting of more than 2000 USGS HUC 8 basins.  This model will serve as the basis for a climate change impact study conducted by the Environmental Sciences Division and the Climate Sciences Institute at ORNL and other collaborators outside the lab.



(1)Oubeidillah, A. A., G.A. Tootle, C. Moser, T. Piechota, K. Lamb, 2011. Upper Colorado River and Gread basin streamflow and snowpack forecasting using Pacific oceanic-atmospheric variability. Journal of Hydrology, DOI : 10.1016/j.jhydrol.2011.09.030

(2)Oubeidillah, A. A., Glenn Tootle & Sally-Rose Anderson (2012): Atlantic Ocean sea-surface temperatures and regional streamflow variability in the Adour-Garonne basin, France, Hydrological Sciences Journal,DOI:10.1080/02626667.2012.659250


(4)Lamb, K., T. Piechota, O.A. Aziz, G. Tootle, 2011. Establishing A Basis For Extending Long-Term Streamflow Forecasts In The Colorado River Basin. Journal of Hydrologic Engineering, DOI: 10.1061/(ASCE)HE.1943-5584.0000153.

(6)Moser, C., O.A. Aziz G. Tootle, and V. Lakshmi, 2011. A comparison of SNOTEL and AMSR-E snow water equivalent datasets in western U.S. watersheds. International Journal of Remote Sensing, DOI:10.1080/01431161.2010.512936

(3)Aziz, O.A., G.A. Tootle, S.T. Gray and T.C. Piechota, 2010. Identification of Pacific Ocean  Sea Surface Temperatures influences of Upper Colorado River Basin Snowpack. Water Resources Research, 46, W07536.

(5)Soukup, T., O.A. Aziz, G.A. Tootle, S. Wulff and T. Piechota, 2009. Incorporating Climate into a Long Lead-Time Non-parametric Streamflow Forecast. Journal of Hydrology, 368(2009), 131-142.