Sea level is rising and this trend is projected to increase over the next century. The water budget over the global land surface plays an important part in altering the rate of this change. Several…

This federal contract award, valued at $677,726.00, was granted by the National Aeronautics and Space Administration (NASA) to the University System of New Hampshire (UNH), through its University of New Hampshire division operating as the Office of Sponsored Research. The contract is for a research grant to provide land surface hydrological cycle change projections, estimates of uncertainty, and trends in over-land total water storage pertinent to sea level rise.

The research will utilize a water balance model to account for major natural and anthropogenic hydrologic cycle processes, and will evaluate the model against data from the Gravity Recovery and Climate Experiment (GRACE) mission, in situ discharge observations, and new products based on the NASA Surface Water and Ocean Topography (SWOT) mission. Future projections will generate a suite of model runs using climate driver data from the Coupled Model Intercomparison Project (CMIP) to characterize the uncertainty of the land water flux to the ocean. This work is intended to support understanding of how changes in the global water cycle are contributing to sea level rise. The contract does not have a set-aside designation and runs through October 2028.

Sea level is rising and this trend is projected to increase over the next century. The water budget over the global land surface plays an important part in altering the rate of this change. Several over-land water cycle storages contribute to this change: pumping of groundwater, glacier melt, endorheic drainage basins, permafrost thaw and draining of thermokarst lakes. There is significant regional and temporal variability often masking the long-term trend in water storage change that can be a significant contributor to sea level over long time scales. The overall goal of this proposed work is to provide land surface hydrological cycle change projections along with estimates of uncertainty and trends in terms of over-land total water storage pertinent to sea level rise. We will use a water balance model (WBM) to account for major natural and anthropogenic hydrologic cycle processes. Historical runs will be used to evaluate the model compared to grace total water storage. Discharge data from in situ observations as well as data from remotely sensed arctic discharge reanalysis (radr) and new products based on the NASA swot mission will also be applied for model evaluation. Future projections will generate a large suite of WBM runs using a large set of climate drivers from CMIP5/6/7 and downscaled products. A diverse set of runs is important to capture the range of variability and will be used to characterize the uncertainty of the land water flux to the ocean.