Abstract:
OMG is a five-year NASA’s Earth Venture Suborbital mission to investigate ocean-driven ice loss in Greenland using a variety of instruments and platforms. Each summer since 2016 our ocean campaign has measured the vertical structure of ocean temperature and salinity around nearly all of Greenland’s continental shelf by deploying ~250 airborne eXpendable CTDs (AXCTDs). A complimentary glacier campaign involves annual March surveys of ice elevation changes for ~200 glaciers using a radar (GLISTIN-A) capable of mapping 10km wide swaths at 3m resolution and 1-2m vertical accuracy. To understand how ocean temperature changes affects ice loss in Greenland, year-on-year changes in ocean conditions on the continental shelf are compared with changes in glacier elevation throughout the mission. With all of the radar ice surveys and most ocean surveys completed, OMG is well on its way to accomplishing its planned scientific goals. Fortunately, large ocean temperature and glacier changes occurred during the mission. In particular, OMG radar and other data revealed a slowing, advancement, and thickening of Jakobshavn Isbrae, a major glacier, reversing nearly 20 years of accelerating, retreat, and thinning. Analysis of OMG’s data and the Estimating the Circulation and Climate of the Ocean (ECCO) ocean state estimate revealed that the observed glacier changes coincided with the arrival of an anomalous ocean cooling signal in the region. We hypothesize that these colder ocean waters suppressed submarine ice melting, allowing the glacier to advance. Since the timescales of both ocean anomalies and the glacier responses to these anomalies appear to exceed OMG’s 5-year duration, more remains to be learned before we can predict how Greenland’s glaciers will evolve in a changing climate. As we approach the end of the planned mission, we are now experimenting with ALAMO floats to determine their viability as a component of a future sustained Greenland ocean observing system.
Short biography:
Dr. Ian Fenty received his Ph.D. in Climate Physics and Chemistry from MIT in 2010 and now works as a climate scientist at the NASA’s Jet Propulsion Laboratory. Dr. Fenty's research includes reconstructing the global ocean and sea-ice state over the past 25 years as part of the Estimating the Circulation and Climate of the Ocean (ECCO) project. In addition, Dr. Fenty is a co-investigator of NASA’s “Oceans Melting Greenland” mission.
Arranged date for the seminar talk: Oct 14, 2019 at 14:15
Place: BCCR lecture rom 4020, Jahnebakken 5