Lamont Weekly Report, January 25, 2019

    This week included the first classes for the spring semester, a celebration of the life of Martin Luther King Jr. and his lifelong contributions to racial equality in the U.S., and the reality show ( that is our current national government as we near the five-week point for the shutdown of nine Cabinet-level departments – including Commerce (NOAA) and Interior (USGS) – and many independent federal agencies – including NSF, NASA, and EPA.

    Most campus activities, even notable ones, seemed normal in contrast.

    The Geochemistry Division last week welcomed Naomi Saunders as a new Postdoctoral Research Scientist. Naomi recently received her Ph.D. from the University of Oxford, where her research on nickel isotope fractionation in planetary materials was supervised by Alex Halliday and Jane Barling. Naomi is one of the earliest arrivals to Alex’s research group at Lamont.

    Also this week, Visiting Senior Research Scientist Al Hofmann arrived for his annual spring visit to Lamont. A geochemist who has made broad contributions to our understanding of Earth’s mantle and crust, Al is an Emeritus Director at the Max Planck Institute for Chemistry in Mainz, a Foreign Associate of the U.S. National Academy of Sciences, a Foreign Member of the Royal Society, and a recipient of the Goldschmidt Medal from the Geochemical Society, the Urey Award from the European Association of Geochemistry, and the Hess Medal from the American Geophysical Union. While at Lamont, Al will once again teach Advanced Geochemistry and co-lead the “Hot Topics” Seminar in Geochemistry.

    On Monday, Nature Climate Change published a 21-author Perspective piece led by Yochanan Kushnir on the challenges of and opportunities presented by climate forecasting on annual to decadal timescales. The importance of an ability to make accurate predictions on such near-term timescales for climate adaptation and resilience is clear. The team argued that such predictions are possible if initialized from the current climate state, particularly the state of the oceans, but they cautioned that gaps remain in our understanding and ability to model the physical mechanisms of key aspects of governing processes. The article described steps needed to meet these challenges and bring near-term climate predictions to an operational state similar to that for seasonal forecasts. The paper’s findings were summarized in a UPI story on Tuesday (  

    Also on Monday, Nature Geoscience published a paper coauthored by Lorenzo Polvani reporting a new assessment of the relation between the solar cycle and the North Atlantic Oscillation (NAO), which exerts a strong control on the pattern of winter storms in the northern hemisphere and is characterized by sea-level pressure patterns displaying an anomaly of one sign centered near Iceland and an anomaly of the other sign centered over the subtropical North Atlantic. Several previous studies led to the conclusion that the wintertime NAO is influenced by the solar cycle, the variation in sunspot strength over an 11-year period. (The solar cycle has a 22-year period if reversals in the Sun’s dipolar magnetic field are included.) In contrast, Lorenzo and his coauthors, led by Gabriel Chiodo of Columbia’s Department of Applied Physics and Applied Mathematics, showed that there is no solar signal in the instrumental record of the NAO prior to the mid-1960s, and the signal thereafter is only marginally significant. Further, on the basis of global chemistry–climate models forced with the sequence of solar irradiance since the mid-1960s, Lorenzo and his colleagues argued that the solar signal over this interval might have been a chance occurrence resulting from natural variability. Their work implies that knowledge of the solar cycle does not improve the long-range forecasting of wintertime atmospheric circulation in the northern hemisphere. A Marie Aronsohn story on the paper’s findings ( was posted to our web site on Tuesday.

    A Rebecca Fowler interview with Jörg Schaefer and Gisela Winckler on the pair’s use of cosmogenic nuclides to date rock surface exposure intervals as an aid to understanding the history of glaciation in Greenland ( was also posted on Tuesday. A portion of the work by Jörg and Gisela on this topic, which has great relevance to future mass loss by the Greenland ice sheet and its contribution to global sea-level rise, is supported by a joint Fellowship from the Center for Climate and Life.

    On Wednesday, Science Advances published a paper by Julius Busecke and Ryan Abernathey on the relation of mesoscale mixing in the oceans to climate variability. Their paper includes the first time-resolved global dataset of lateral mesoscale eddy diffusivities at the ocean surface, which they obtained by applying suppressed-mixing-length theory to satellite-measured velocities. They found interannual variability throughout the global ocean, and regional correlations of such variability with such climate indices as El Niño–Southern Oscillation, the NAO, the Dipole Mode Index, and the Pacific Decadal Oscillation. Further, they observed that changes in mixing length, driven by variations in the large-scale flow, often exceed the effect of variations in local eddy kinetic energy. The evidence they’ve uncovered for coupling between large-scale climate variability and eddy mixing rates have important consequences for the distribution of heat, salt, and carbon in the global ocean, as well as for marine ecosystem dynamics.

    On Wednesday and Thursday, Róisín Commane hosted a workshop at Lamont on greenhouse gas fluxes in urban areas. Róisín wrote, “It was a workshop focusing on integrating urban carbon and air-quality measurements in the New York metropolitan area, through high-density, low-cost tall-tower, remote sensing, and aircraft observations. We had participants from Lamont and Columbia, CUNY, Stonybrook, Rutgers, U.C. Berkeley, University of Utah, Boston University, and Harvard. [Workshop participants] plan to prepare targeted proposals for submission this spring. The workshop was supported by funds Róisín received with her Lenfest Junior Faculty Development Award.

    Yesterday, Kevin Krajick posted his annual summary of fieldwork by Earth Institute scientists later this calendar year and beyond ( As usual, most of the fieldwork will be led by Observatory scientists, and every continent will receive a share of our attention (although the scrollable version of the map is required to  view fieldwork sites in Antarctica).

    Posted today on our web site was the third in the Earth Institute’s “Tools of the Trade” series of web stories “that bring you inside the labs of Earth Institute scientists,” this one on some of the tools used in Lamont’s Core Repository ( Nichole Anest and Claire Jasper are featured in the Phebe Pierson story.

    Also posted today is a story on the first set of year-long oceanographic observations taken under an Antarctic ice shelf ( by Pierre Dutrieux and collaborators from the University of Washington and the Korean Polar Research Institute. The measurements, key to understanding the vulnerability of ice sheets to warming by the underlying ocean, were made from Seagliders deployed from the Korean icebreaker R/V Araon.

    The start of classes means that the launch of the new Earth Science Colloquium season is not far behind. The inaugural colloquium for the spring series will take place one week from today and will feature our own Terry Plank. I hope to see you there.