AOES Climate Scientists have been busy recently informing the Northern Virginia public about global warming.
Jagadish Shukla and Jim Kinter spoke at Climate 3.0: The Science, the Politics, and the Policy Agenda. The event, moderated by Washington Post columnist and Mason professor Steven Pearlstein, also featured talks by President Cabrera and faculty from the Communications Department, the Mercatus Center, and other departments.
The Washington Post printed Barry Klinger’s letter to the editor on carbon emissions in the US and around the globe.
Jim Kinter gave talks about The New Normal of climate change to audiences at the Metropolitan Washington Council of Governments, the Northern Virginia Regional Council, and elsewhere in Virginia. Dr. Kinter was also a panelist along with two Virginia Assembly Delegates at “The Ice Melts” event at, organized by honors undergraduate students at George Mason University.
Shukla and Klinger also gave short talks on climate at the “Breaching Waterways: Along the Anacostia River”, a performance piece by Mason performance artist Katie Kehoe.
The American Geophysical Union recently shined a research spotlight on AOES affiliate scientist Rocio Caballero Gill. Caballero-Gill and AOES faculty member Linda Hinnov analyze ancient sediments for clues about the evolution of climate in the past. In her paper with colleagues from Brown University and the US Geological Survey, Caballero-Gill found evidence of a 100,000 year cycle during the Pliocene Epoch, the period of geological history that lasted from about 5.3 to 2.6 million years ago. The cycle they document may be an important component in the pacing between ice ages and interglacials during the Pliocene.
Two students successfully defended Climate Dynamics Doctoral Dissertations in Spring 2019. For full abstracts, see AOES Seminar Pages.
Akiko Elders, working with AOES faculty member Kathy Pegion, investigated the relationship between weather and Arctic sea ice decline. The Arctic is warming faster than other regions of Earth, resulting in a dramatic decline in sea ice. Sea ice decline may be linked to extreme winter whether in mid-latitude regions such as the United States. Elders used a state-of-the-art climate model to separate the impacts on mid-latitude weather of global warming and sea ice decline.
Liang Yu, whose advisor was AOES faculty member Bohua Huang, studied components of Atlantic Multidecadal Variability (AMV). AMV is the tendency of the North Atlantic to be colder or warmer than average for decades at a time, causing large-scale changes in climate during these periods. The phenomenon is poorly understood but thought to be related to interactions between ocean currents and the atmosphere. The atmosphere can drive ocean variability through the exchange of momentum (by wind pushing on the sea surface), heat (cooling and heating the sea), and freshwater (evaporation and precipitation). In a coupled atmosphere-ocean climate model, all three exchanges vary simultaneously. Yu studied the separate effect of each influence by conducting experiments with an ocean circulation model in which each forcing (wind, heat, and water) from the coupled model was applied separately.
Twenty seven graduate students from across the US presented their work to over 50 students and faculty. The theme of “Earth Systems Modelling” included talks on climate change on the scale of months and of decades, melting of the Greenland Ice Sheet, predicting drought in east Africa, use of machine learning in subseasonal forecasting, and the influence of the tropical Madden-Julian Oscillation on midlatitude rainfall. Jagadish Shukla (George Mason University) and Ben Zaitchik (Johns Hopkins University) gave Keynote Lectures.
Much of the planning and organization of the symposium was done by Climate Dynamics PhD students Teresa Cicerone, Olivia Gozdz, and Nicholas Lybarger, who were advised by Research Assistant Professor Laurie Trenary. As Dr. Trenary remarked, “It was really great to see that level of student engagement, to hear the discussions and questions. This is a good opportunity for students – I hope we can find a way to keep it going.”
Clustering techniques identify discrete groups of atmospheric and oceanic structures that occur more frequently than would be expected based on a background distribution, such as a multivariate Gaussian distribution. Some of the techniques identify states that are also unusually long-lived (or persistent).
Examples of atmospheric states identified from cluster analysis include seasonal-mean midlatitude response patterns to El Niño events, and the North Atlantic Oscillation and the Pacific–North America patterns. On weather timescales, cluster analysis has been used to objectively identify a number of typical synoptic patterns familiar to forecasters.
Dr. Straus’s research has applied cluster analysis to better understand the effects of sub-seasonal tropical heating on mid-latitude circulation, and to help categorize extreme precipitation events over North America.
AOES and Center for Ocean-Land-Atmosphere Studies (COLA) had a sizeable presence at the April Workshop on Predictability, dynamics, and applications research held at the European Center for Medium-Range Weather Forecasting (ECMWF). Drs. Cristina Stan and Kathy Pegion (pictured above) and Paul Dirmeyer spoke at the conference.
Pegion, AOES professor Tim DelSole, and Climate Dynamics alumnus Rob Burgmann serve on the core team of The Subseasonal Experiment (SubX), a NOAA/Climate Testbed project focussed on subseasonal predicability and predictions. The project aims to improve forecasts of weather several weeks in advance.
Pegion and Dirmeyer are co-leads of the NOAA/MAPP S2S Task Force. The NOAA Oceanic and Atmospheric Research Program’s Modelling, Analysis, Prodictions and Projections (MAPP) Program “organized the Subseasonal to Seasonal (S2S) Prediction Task Force to advance NOAA’s and the Nation’s capability to model and predict sources of S2S predictability.”
Dirmeyer and Stan serve on the S2S WWRP/WCRP Steering Committee and Liaison Group.
Climate Dynamics doctoral student Keri Kodama was awarded a summer internship to work at National Centers for Environmental Prediction (NCEP), the branch of US NOAA that uses computer models to predict weather, climate, and other features of the environment. Her work at NCEP will build on her dissertation research with AOES faculty member Dr. Natalie Burls. Kodama’s research involves linking atmosphere/ocean energy transfer to El Nino. She has been seeking to evaluate the rate at which energy is pumped into the equatorial Pacific Ocean by wind as a precursor to El Nino, the tropical atmosphere-ocean phenomenon that affects weather all over the globe. Kodama’s NCEP project will involve analyzing the intraseasonal variability of tropical Pacific air-sea fluxes and subsurface temperature and salinity in the MOM6 3DVar ocean reanalysis product.[Figure above, from George Mason’s Center for Ocean-Land-Atmosphere Studies (COLA), summarizes predictions from a suite of climate models maintained at various organizations.]
Last summer Chelsea Snide, an undergraduate atmospheric science student from the University of Albany, did an internship with AOES professor David Straus. The American Meteorological Society selected Snide and 3 other students for “Exceptional Undergraduate Presentations” at its 2019 Annual Meeting.
Chelsea’s presentation, based on her internship work, was on “Large Scale Observational and Model Analysis of the Unusual 2015-2016 El Nino Event: Implications for California Precipitation.” The work was a collaboration between her, Straus, and AOES climate scientists Erik Swenson, part of a long-term effort by Straus and others to better understand how El Nino can be used to better predict variations in United States weather.
Alan Alda, star of the iconic ’70s TV series M*A*S*H, has been organizing workshops to help scientists better communicate with non-scientist audiences. AOES Assistant Professor Natalie Burls attended one of the workshops when it was hosted by George Mason University’s Center for Climate Change Communication. Now she and AOES are featured in a video about the workshops. The video also shows her lecturing in CLIM 102 Introduction to Global Climate Change Science.
Other workshop attendees included Climate Dynamics PhD students Rachel Gaal, Keri Kodama, Nick Lybarger and Douglas Nedza, and AOES scientists Ben Cash and Laurie Trenary.