|dc.contributor.advisor||Famiglietti, James S.||en
|dc.creator||Branstetter, Marcia Lynne, 1963-||en
|dc.description.abstract||The global hydrologic cycle plays a central role in the interactive
functioning of the Earth’s climate system. The theme of this study is land-oceanatmosphere
interaction. Continental runoff has a notable effect on the global
hydrologic cycle, both directly as freshwater forcing on the oceans and indirectly
through effects on global patterns of precipitation and coincident feedbacks to
continental runoff. To demonstrate this, a series of three projects involving both
observations and modeling were completed.
The first phase involved the development of a parallel river transport
model to deliver runoff from the land surface to the oceans at the appropriate
location and time. Within each watershed, the river routing algorithm used cell-to-cell
routing by considering the mass balance of surface inflows and outflows.
This river transport model was then incorporated into a climate system model.
The second and third phases involved the use of a climate system model to
investigate the effect of continental runoff. To test the sensitivity of the oceans to
freshwater input from runoff, in the second phase, a number of 70-year
simulations were conducted, using the ocean and ice components of a highresolution
climate model with observed runoff and modeled atmospheric forcing.
A half-degree observed runoff data set, consisting of both annual and monthly
averages, was used for this forcing. Differences in sea surface temperature and
salinity between simulations with and without the addition of runoff were found
in the Arctic, Tropical Atlantic, and North Atlantic Oceans. The differences were
especially pronounced in the North Atlantic. By affecting sea surface
temperatures and salinity, the addition of freshwater from river runoff led to a
reduction in North Atlantic Deep Water formation and a corresponding slowdown
of heat transport.
The third phase used a fully coupled land-ocean-atmosphere-ice model
plus the river transport model from the first phase. Two 200-year simulations
were conducted, with and without the river component. The simulation with
rivers had reduced oceanic meridional heat transport. Reduced convective rainfall
and runoff during January in the simulation with rivers indicated a feedback from
the continental runoff flux into the oceans back to the land surface.||
|dc.rights||Copyright is held by the author. Presentation of this material on the Libraries' web site by University Libraries, The University of Texas at Austin was made possible under a limited license grant from the author who has retained all copyrights in the works.||en
|dc.title||Development of a parallel river transport algorithm and applications to climate studies||en
|thesis.degree.grantor||The University of Texas at Austin||en
|thesis.degree.name||Doctor of Philosophy||en