Lamont Weekly Report, March 20, 2020

    This week has been a time of extraordinary disruption and uncertainty. The coronavirus pandemic has dominated the news and the actions of governments at national, state, and city levels around the world. At Columbia, all classes are now being taught online, most personnel are working remotely, and domestic and international travel on university business has been suspended. Closures of area schools have added to the responsibilities of parents of schoolchildren, and suspension of in-person dining at restaurants in New York City and shuttering of the city’s theaters, clubs, and bars have encouraged social distancing in the most densely populated large city in the U.S. Financial markets – and university endowments – have taken a drubbing, and many small businesses and workers in the service, manufacturing, and travel sectors are facing sudden challenges.

    In such a context, it is all the more notable that the Lamont community responded in less than one week to a university directive to ramp down on-campus research activities to levels at which only a few essential personnel are needed to maintain key laboratory and infrastructural functions across the campus. The ramp-down was completed yesterday, and the great majority of Lamont campus personnel are now working remotely from homes and other locations. The leadership of the Observatory’s research divisions and of IRI and CIESIN are to be congratulated for organizing their research investigators and lab managers quickly and effectively to design ramp-down plans that preserve critical capabilities and accommodate the imperative to decrease sharply the on-campus population. The cooperation and patience of everyone has made for an efficient transition.

    Even over a week when most at Lamont were learning how to complete their typical daily workload from home, signs of scientific progress continued.

    Xiaomeng Jin learned late last week that she has been awarded a NOAA Postdoctoral Fellowship, which she will take to the University of California, Berkeley, to join the research group of Ronald Cohen, Director of the Berkeley Atmospheric Science Center Kudos to Xiaomeng!

    The R/V Marcus Langseth was in port in Pago Pago, American Samoa, this past weekend. The ship sailed on Sunday morning local time and will be at sea for the coming month.

    On Monday, Nature Geoscience published online a paper by Bar Oryan and Roger Buck on tsunami earthquakes, major subduction zone earthquakes that produce unusually large tsunamis for their seismic moment. Using the 2011 Tohoku earthquake as an example, Bar and Roger showed that the strong normal faulting in the upper plate that accompanied the main megathrust event and contributed to tsunami generation may have been at least partly the result of a reduction in the dip angle of the subducting Pacific plate over the past several million years, an idea supported by evidence for migration of the volcanic arc above the subduction zone and records of uplift of the upper plate from deep-sea sediments. With a numerical model of the subduction dynamics, they demonstrated that slap dip reduction can bend the upper plate to the point that it fails in extension when a megathrust earthquake relieves compressive stress across the plate interface. They suggested that a similar reduction in slab dip angle contributed to tsunami earthquakes at other subduction zones. A Kevin Krajick press release was posted Monday, and the story was carried by Sputnik News.

    The 15 March issue of Earth and Planetary Science Letters includes an article by Mike Kaplan, Joerg Schaefer, Carly Peltier, Gisela Winckler, Rosanne Schwartz, and colleagues from Argentina and Chile on the history of glaciation of the northern Antarctic Peninsula during the Holocene. From about four dozen new cosmic-ray exposure ages, Mike and his coauthors showed that since the last glacial maximum glaciers in the region tend to lessen in size during periods when there is less extensive high-latitude sea ice, the westerly winds expand or focus poleward, and conditions resemble those during a persistent positive Southern Annular Mode (SAM) at the century scale. Conversely, glaciers in the area tend to expand when sea ice is more extensive, the westerlies expand or focus equatorward, and conditions resemble those during a persistent negative SAM. Mike and his colleagues suggest that these patterns may be helpful in predicting the behavior of the region’s glaciers and ice shelves in the future.

    Earth’s Future has published online a paper coauthored by Bob Newton, Stephanie Pfirman, and Bruno Tremblay on the transport of Arctic sea ice between the exclusive economic zones of nations surrounding the Arctic Ocean and its implications for the transnational exchange of ice-borne pollutants. The group combined a sea-ice tracking model with a climate model to study ice transport under different scenarios for future greenhouse gas emissions. They showed that by mid-century transnational ice transport will more than triple over current levels, and transit times will shorten. Over longer timescales the sea-ice models are strongly dependent on emission scenario. A web story on the paper’s findings was posted on Wednesday.

    In today’s issue of Science, as part of a special section on Antarctica, is a review article led by Robin Bell on the “History, mass loss, structure, and dynamic behavior of the Antarctic ice sheet.” Robin’s paper summarizes the differences in size, physiography, internal structure, and stability between the East and West Antarctic Ice Sheet, and it describes portions of the ice sheets where recent rates of mass loss are the highest.

    Lamont scientists in the news this week included Park Williams, quoted in an Eos article Wednesday on the impact of early leafing out of trees over the past several decades on northern hemisphere warming. In a BBC story yesterday on the impact of changes in social behavior since the coronavirus outbreak on the emissions of greenhouse gases and atmospheric pollutants, Róisín Commane commented on reduced carbon monoxide, methane, and carbon dioxide levels measured by her group in the New York City area this past week. Also yesterday, the work of Ethan Coffel and his colleagues on the severe health hazards of coupled extreme heat and extreme humidity in a warming climate was mentioned in a story in The Guardian on the impact of climate change on public health.

    The vernal equinox last night was the earliest arrival of spring in 124 years. May you find reasons to enjoy the first weekend of the season, in a manner that keeps you and your family healthy and contributes to our community’s efforts to mitigate the outbreak that now challenges us.