The US Department of Energy Atmospheric Radiation Measurement Program (ARM) West Antarctic Radiation Experiment (AWARE) was motivated by the need to improve understanding of the Antarctic atmosphere as it impacts surface melt and ice shelf stability in West Antarctica in response to a steadily warming climate. Global climate model simulations have significant uncertainty in the sensitive surface energy balance over Antarctica, particularly as influenced by the radiative effects of cloud cover. There has been an ongoing need to improve our understanding of cloud and aerosol microphysics specific to Antarctica, and this collaboration between the US Antarctic Program and DOE has made major contributions.

AWARE conducted a full year of meteorological and climatological measurements using the most advanced equipment available, on Ross Island, Antarctica, at a site near McMurdo Station. The ARM Second Mobile Facility (AMF2) comprised research radars, lidars, spectral and broadband radiometers, and aerosol microphysical instrumentation. Ross Island it its synoptic-scale environment is characterized by high mountainous terrain that induces gravity waves, cloud formation above the boundary layer, and relatively high cloud ice water content, which are all significant contrasts from the atmosphere above the Arctic Ocean. Much of the Antarctic content adjacent to vulnerable ice sheets and ice shelves shares these characteristics, and the full seasonal cycle captured by AWARE (late November 2015 through December 2016) offers data that can significantly evaluate and improve climate model parameterizations and simulations. The AWARE team also had an opportunity to deploy additional equipment on the West Antarctic Ice Sheet (WAIS) itself during the austral summer of 2015-16. Measurements at the WAIS Divide Ice Camp used a smaller suite of instruments that was optimized for surface energy budget (SEB) determination. AWARE also launched the first rawinsondes from West Antarctica since the 1960s. The entire AWARE dataset is now permanently curated at the ARM Program data archive.

The AWARE deployment at WAIS Divide had an extraordinarily successful outcome. During early January 2016, when all the SEB instruments were operational, a large-scale surface melt event occurred over most of West Antarctica and much of the Ross Ice Shelf. This melt event was caused by a blocking high pressure ridge that funneled warm and moist marine air southward, first over a sea surface temperature anomaly and then over West Antarctica. WAIS Divide was just at the very edge of this melt event region, but AWARE instruments were able to record the pronounced tropospheric warming and thermal radiation from optically thick cloud cover that provided energy to start melting the ice sheet surface. This work was published in the journal Nature Communications in 2017.

The project element covered by this report, comprising the work done by Dr. Lubin and Prof. Russell, has yielded a wide variety of scientific results spanning twelve additional peer-reviewed publications. Prof. Russell analyzed the AWARE aerosol microphysical and chemical measurements to determine climatological contrasts with the much more studied high Arctic. This included mentoring graduate student researcher Jun Liu whose subtle analysis in his PhD dissertation research revealed contributions to aerosol organic chemistry from large seabird populations on Ross Island. Dr. Lubin mentored graduate student researcher Ryan Scott, who served as the WAIS Divide Site Scientist during the campaign, and who subsequently in his PhD dissertation expanded upon the meteorology and atmospheric physics discovered at WAIS Divide to determine the prevailing Southern Ocean weather patterns and their lower-latitude teleconnections that either drive or inhibit surface melting throughout West Antarctica. Dr. Lubin and Prof. Russell also participated with the other Science Team members, and collaborator Dr. Ann Fridlind at NASA Goddard Institute for Space Studies, to incorporate AWARE data in the evaluation of global climate models and numerical weather forecasting models. A full report on the first scientific outcomes from AWARE was published in 2020 in the Bulletin of the American Meteorological Society.

Broader impacts for this project element include considerable mentoring of young researchers, including completed PhD dissertations by Jun Liu and Ryan Scott, a MS dissertation by Kristopher Scarci, and summer REU fellowships for three talented students, Jeramy Dedrick (Texas A&M University), Alexis Wilson (University of Idaho), and Caitlin Glennon (St Olaf College), whose work contributed to peer-review papers. Jeramy Dedrick has since become a PhD student at SIO. Ryan Scott has obtained a team leadership position at NASA Langley Research Center. Jun Liu has taken a postdoctoral position at the University of Michigan. Dr. Lubin also collaborated with Dr. Cheryl Peach, Director of Scripps Educational Alliances, to develop a climate course for presentation at the December 2018 California Science Teachers Association (CSTA) annual meeting in Pasadena, California. This was a two-day program giving statewide science teachers training on Earth and climate science, and Dr. Lubin participated in the instruction during this CSTA meeting.

Last Modified: 03/26/2020
Modified by: Dan Lubin