Lamont Weekly Report, July 1, 2016

     This week included the end of an academic and university fiscal year on Thursday, and the beginning of a new year today. A flurry of personnel and budget activities marked the lead-up to the change in the calendar. 

     Noteworthy among them are three promotions on the Lamont research faculty, all effective today. Natalie Boelman and Michael Previdi have been promoted to Lamont Associate Professor, Senior Staff, and Jonathan Nichols has been promoted to Lamont Associate Professor, Junior Staff. To Natalie, Michael, and Jonathan, congratulations! 

     Yesterday was the last day at Lamont for Ginny Tavarone, our Financial Services Coordinator. Ginny leaves after 25 years at the Observatory. In an e-mail message to the campus yesterday, Ginny wrote, “Some of you may not know me and some that do, especially those with p-cards, I'd like to say that it has been a pleasure working with all of you. There has never been a better place to work than right here, especially in the Finance Department. Thank you all for being a part of my journey.” Please join me in thanking Ginny in turn for her quarter century of service to all of us! 

     The American Geophysical Union this week announced the recipients of awards from its Sections and Focus Groups (https://eos.org/agu-news/2016-agu-section-and-focus-group-awardees-and-named-lecturers). Heather Savage will receive the Mineral and Rock Physics Early Career Award (http://honors.agu.org/scientific-contribution/mineral-and-rock-physics/), and Jerry McManus will receive the Dansgaard Award from the Paleoceanography and Paleoclimatology Focus Group (http://honors.agu.org/scientific-contribution/paleoceanography-and-paleoclimatology/). Heather and Jerry will receive their awards at the AGU Fall Meeting in December. Kudos to both! 

     On Monday, Nature Geoscience published online a paper by Ryan Abernathey and colleagues at the Scripps Institution of Oceanography, the University of Washington, and the British Antarctic Survey on the role of sea ice in controlling portions of the overturning circulation in the Southern Ocean. With the use of a data assimilation code and the water-mass transformation framework, the team compared the contributions of atmospheric, sea-ice, and glacial freshwater fluxes, heat fluxes, and upper-ocean mixing to the buoyancy of seawater in the upper branch of the upwelling of Circumpolar Deep Water. They found that the effects of formation, wind-driven transport, and melting of sea ice dominate that branch of overturning circulation. A Stacy Morford story on the paper, with one of Ryan’s visualizations of seasonal variations in the extent and motion of Antarctic sea ice (http://www.ldeo.columbia.edu/news-events/wind-blown-antarctic-sea-ice-helps-drive-ocean-circulation-study-shows), has been posted on Lamont’s web site. 

     Yesterday Science posted online a paper by Gene Henry, Jerry McManus, and coauthors reporting evidence for strong coupling between changes in ocean circulation and abrupt climate change during the last ice age. Gene and his collaborators compared changes in northern hemisphere climate documented from Greenland ice cores and marine sediments with measurements from a deep North Atlantic sediment core of bulk Pa/Th ratios and carbon isotopes in benthic foraminifera, proxies sensitive to changes in North Atlantic Deep Water production and Atlantic Meridional Overturning Circulation transport. They found that reduced Atlantic overturning circulation preceded and accompanied every cool northern stadial, and that reinvigorated overturning preceded sharp northern hemisphere warming. A Stacy Morford release about the paper, along with an audio interview with Gene (http://www.ldeo.columbia.edu/news-events/ocean-circulation-implicated-past-abrupt-climate-changes), has been posted on Lamont’s web site. An Eric Hand news story in Science summarized the paper and its implications (http://www.sciencemag.org/news/2016/06/crippled-atlantic-conveyor-triggered-ice-age-climate-change). 

     We can all look forward a weekend extended because of the Independence Day holiday on Monday. Although no visible fireworks will accompany the event, NASA’s Juno spacecraft is scheduled to be inserted into its initial orbit about Jupiter on July 4 (http://www.nytimes.com/2016/06/28/science/nasa-jupiter-juno.html?_r=0). Juno’s working orbit will carry it within 5000 km of Jupiter’s cloud tops. From that orbit the solar-powered spacecraft will make high-resolution measurements of the gravity and magnetic fields of the gas-giant planet, yielding new information on Jupiter’s bulk composition, internal structure, and magnetic dynamo. I hope that you will note the milestone even as you enjoy terrestrial fireworks. 

       Sean