Colin Gleason, an Assistant Professor in our Civil and Environmental Engineering Department, was part of a huge, UCLA-led, 23-person team whose 2015 research on the Greenland ice sheet recently graced the front page of the December 5th New York Times and could revolutionize how scientists regard sea-level rise due to climate change.
Each year, Greenland loses 270 billion tons of ice as the planet warms, a rate that would contribute about two inches to sea level rise by the end of the century. This newly released research shows that some of that water might be trapped in the ice sheet, which could change how scientists think about global sea levels.
As Henry Fountain and Derek Watkins write in their New York Times article: “In the summer of 2015, two New York Times journalists joined a team of researchers in Greenland that was conducting a unique experiment: directly measuring a river of meltwater runoff on the top of the ice. Now, the scientists have published the results of that work. A key finding — that not as much meltwater flows immediately through the ice sheet and drains to the ocean as previously estimated — may have implications for sea-level rise, one of the major effects of climate change.”
Fountain and Watkins add that “The scientists say it appears that some of the meltwater is retained in porous ice instead of flowing to the bottom of the ice sheet and out to sea.”
A UCLA press release from December 4 summarizes the work done in Greenland: “The research, published today in the journal Proceedings of the National Academy of Sciences [PNAS], offers new insights about previously unknown factors affecting Greenland’s melting ice sheet, and it could ultimately help scientists more accurately predict how the phenomenon could cause sea levels to rise.”
The journal paper was published on December 4 in the prestigious PNAS, one of the world's most-cited and comprehensive multidisciplinary scientific journals, publishing more than 3,100 research papers annually.
Gleason’s research group concentrates on the role that rivers play in the global water budget, particularly as climate change alters our hydrologic cycle and we venture into an uncertain hydrologic future. This interest manifests primarily in studies related to Arctic hydrology and ungauged river basins. His research employs a diverse range of methodologies, including intensive field work, algorithm development, remote sensing, and hydrologic and hydraulic modelling.
In the case of the 2015 expedition reported in the New York Times, Gleason explains that “I was slated to spend a week atop the Greenland ice sheet for dramatic-sounding work – flown in by helicopter to battle the elements and endless whiteness of the ice sheet while cut off from civilization to make the unprecedented, round-the-clock measurements the article details. However, I was too heavy for the helicopter, and we prioritized a lighter researcher and a key piece of equipment over me!”
Instead, Gleason ended up coordinating reporters, field equipment, project managers, PIs, and helicopter pilots in what was probably “my most demanding field role ever.”
The 2015 research was a continuation of Gleason’s studies on the Greenland ice sheet. He went to Greenland in 2011, 2012, 2013, and 2015 to perform various tasks on several different research teams producing many lasting impacts. For example, in 2012, Gleason was the medical lead for a five-day ice camp as part of a team of four researchers who made supraglacial stream measurements atop the ice from a base camp and from extensive helicopter travel. Additionally, he was part of the team that established a tundra camp for several weeks and make proglacial hydrologic measurements.
In 2013, Gleason led a team of three researchers on a 15-day hydrologic measurement campaign in Greenland. There, he was responsible for the safe travel of his team and for all measurement protocol and research designs in back country without vehicular support. Then, in the winter of 2015, Gleason was part of a two-person Greenland mission in -40C temperatures to drill through ice in proglacial rivers in search of winter discharge.
All of these research activities and more have led Gleason to invent a revolutionary set of geomorphic relationships known as “at-many-stations hydraulic geometry” (AMHG), showing that the empirical parameters of at-a-station hydraulic geometry (AHG) are functionally related along a river. This conclusion seemingly refutes previous decades of research defining AHG as spatially independent and site specific. Furthermore, AMHG was the centerpiece of an unprecedented recent methodology that successfully estimated river discharge solely from satellite imagery.
In that context, Gleason currently serves as a member of the prestigious NASA Surface Water and Ocean Topography Science Team (SWOT). SWOT encompasses a $1-billion mission shared among NASA, the French government space agency, the Centre National D'études Spatiales, and the space agencies of Canada and the United Kingdom. The SWOT mission promises to use revolutionary instrumentation that simultaneously measures water surface height and extent, which translates to river width and river surface elevation.
From these novel measurements from space, the SWOT team expects to measure river discharge in ungauged basins around the world, monitor volume changes in global reservoirs, and improve our understanding of sub-mesoscale ocean processes. (January 2017)