News and Events
In a new study led by former AOS Associate Research Oceanographer Brendan Carter, a research associate with the Joint Institute for the Study of the Atmosphere and Ocean at the University of Washington, Carter and coauthors developed a new way of looking at alkalinity measurements. Their methods allow them to better examine the chemical signatures of river water and of organisms that build their shells out of the mineral calcium carbonate. They use their new methods to determine what controls the chemical saturation of calcium carbonate, which is thought to determine in part how easy it is for organisms to build their shells out of this mineral. The authors find surface calcium carbonate saturation is primarily determined by gas exchange driven by warming and cooling, and secondarily by rain and evaporation. Calcium carbonate cycling as the shells of organisms comes in third place. J.R. Toggweiler, Bob Key and Jorge Sarmiento are coauthors of the study, published in Biogeosciences on December 19.
A new study coauthored by AOS Graduate Student Jaya Khanna and AOS Faculty Member David Medvigy investigates the effects of Amazonian deforestation on regional hydroclimate. This numerical study shows that contemporary scale deforestation in the southern parts of the Brazilian Amazon can result in an increase in convective activity and cloudiness. The authors find that contemporary scales of deforestation can result in increase in humid conditions in the downwind deforested areas, whereas suppression of cloudiness in the upwind deforested areas. Differences in vegetation height between forested and deforested regions are found to rigger this hydroclimatic effect. This unique convective regime can have implications for climate impact studies of near future deforestation in the Amazon. The study was published in the Journal of Geophysical Research - Atmospheres.
GFDL is hosting a Poster Expo on Wednesday, January 28, 2015 from 1pm-4pm. The Winter Expo is an opportunity for GFDL/AOS/CICS scientists to share their research with colleagues. Posters are limited to 30; existing posters are acceptable. Register early, but no later than 5pm on Wednesday, January 7.
A team of Princeton University researchers, including Denise Mauzerall (AOS Associated Faculty) has uncovered a previously unknown, and possibly substantial, source of the greenhouse gas methane to the Earth's atmosphere. After testing a sample of abandoned oil and natural gas wells in northwestern Pennsylvania, the researchers found that many of the old wells leaked substantial quantities of methane. Because there are so many abandoned wells nationwide (a recent study from Stanford University concluded there were roughly 3 million abandoned wells in the United States) the researchers believe the overall contribution of leaking wells could be significant. The paper was published Dec. 8 in the Proceedings of the National Academy of Sciences.
AOS Program Biogeochemistry Seminar -- Wednesday, December 10th at 1pm -- Ben McNeil (University of South Sales) " Future surface ocean hypercapnia: How anthropogenic changes induce non-linear CO2 extremes " Sayre Hall Conference Room
Former AOS Associate Research Scholar Mike Hiscock, an EPA National Center for Environmental Research scientist, will serve as convener for AGU’s largest session in the Global Environmental Change Program at the American Geophysical Union (AGU) Fall meeting scheduled for Dec. 17-18. The technical session, titled Extreme Events and Climate Change: Impacts on Environment and Resources, will consist of a full day of oral presentations and a half day of poster sessions. It will feature 74 presentations from 20 countries, 14 STAR (Science to Achieve Results) Grantees from the RFA Extreme Event Impacts on Air Quality and Water Quality with a Changing Global Climate, and presentations from 4 other EPA scientists and 9 Federal entities.
Congratulations to Erica Staehling who successfully defended her Ph.D. Thesis "The Influence of African Easterly Waves on Atlantic Tropical Cyclone Activity" on December 8, 2014.
Congratulations to Claire Radley who successfully defended her Ph.D. Thesis "Understanding the Dependence of Tropical High Cloud Amount and Radiative Flux on Sea Surface Temperature" on December 3, 2014.
In the News ... Robotic Floats Will Reveal Southern Ocean’s Mysteries
This December, Hannah Zanowski, a graduate student at Princeton University, will travel to Cape Town, South Africa, bundle up in something warm, and board a German research icebreaker called the Polarstern. Over the next eight weeks, the ship will make its way from the southern tip of Africa to the bottom of South America via the Weddell Sea off the coast of Antarctica, stopping every so often along the way, so Zanowski and the scientists she’ll be working with can plop one of 12 yellow, oblong, instrument-laden, robotic floats into the sea.
AOS Program Biogeochemistry Seminar -- Friday, December 5th at 3pm -- Daniele Bianchi (University of Washington) "Oxygen minimum zones in CM2.6: Mean state, variability, and o2her o2dities" Sayre Hall Conference Room
Congratulations to Amanda O'Rourke who successfully defended her Ph.D. Thesis "Influence of Long and Short Planetary Waves on the Separation of the Eddy-Driven and Subtropical Jets" on November 24, 2014.
Southern Ocean Plays Dominant Role in Anthropogenic Carbon and Heat Uptake in CMIP5 Models
A new study led by AOS Collaborator Thomas Frölicher (ETH Zurich) assesses the uptake, transport and storage of anthropogenic carbon and heat in the Southern Ocean in a new set of couple carbon-climate Earth System Models conducted for the fifth Coupled Model Intercomparison Project (CMIP5). The study shows that the Southern Ocean accounts for 43% of anthropogenic CO2 and 75% of heat uptake by the ocean over the historical period, underscoring the significant role the Southern Ocean plays in global climate. AOS Director Jorge Sarmiento is a coauthor of the study along with GFDL Scientists, David Paynter, John Dunne, John Krasting and Mike Winton. The study was recently published in the Journal of Climate.
AOS Program Biogeochemistry Seminar -- Friday, Nov. 21st at 3pm -- Adele Morrison, "Dynamics of the Weddell Polynya in CM2.6" Sayre Hall Conference Room
On Monday November 17th, Dr. Beth Orcutt (Bigelow Laboratory for Ocean Sciences in East Boothbay Maine) will be giving the departmental seminar in Geosciences at 12:30 pm in Guyot 10. In addition to her seminar, Dr. Orcutt will be participating in an informal work-life and professional development dinner with early career scientists in Geosciences and AOS.
Where: Campus Club (5 Prospect Ave)
When: Monday November 17th from 6:00 to 8:00 PM
Dinner and drinks will be served
Past discussions topics include: work-life balance, career choice, and identifying mentors. A more detailed summary can be found here.
** RSVP to Darcy McRose (email@example.com) by Tuesday November 11th.
AOS Program Biogeochemistry Seminar -- Friday, Nov. 14th at 3pm -- Ivy Frenger, AOS, "Southern Ocean water mass structure in CM-1deg, CM2.5 and CM2.6 " Sayre Hall Conference Room
Congratulations to AOS Senior Meteorologist Suki Manabe on being awarded the 2015 Benjamin Franklin Medal in Earth and Environmental Science by The Franklin Institute. The award recognizes Suki "for his pioneering research on the sensitivity of Earth’s climate to increasing carbon dioxide in the atmosphere and his development of global climate models, which have led to fundamental advances in the understanding of climate variability and to methods for predicting future climate change."
New Study Examines the Influence of Asia’s High-Mountain Seasonal Cycle on Regional Differences in Climate Change
A new study led by AOS Postdoctoral Research Fellow Sarah Kapnick compares a set of high-resolution models simulations with the latest available observations to focus on the distinct seasonal cycles and resulting climate change signatures of Asia’s high-mountain ranges. The findings, published in Nature Geoscience, suggest a meteorological mechanism for regional differences in the glacier response to climate warming.
GFDL Research Highlights
AOS Program Biogeochemistry Seminar -- Friday, Nov. 7th at 3pm -- John Dunne, GFDL, "Publication planning for CM2.6-miniBLING" Sayre Hall Conference Room
Congratulations to former AOS Faculty Member Ngar-Cheung (Gabriel) Lau on being the selected as the AMS Bernhard Haurwitz Memorial Lecturer for 2015, for “pioneering work on atmospheric circulation systems, from oceanic storm tracks to atmospheric ‘bridges’ connecting ocean anomalies in different basins, using observations and global models.”
Congratulations to AOS Faculty Member Tom Delworth for being elected an AMS Fellow. Fellows are selected each year for their “outstanding contributions to the atmospheric or related oceanic or hydrologic sciences or their applications during a substantial period of years."
Congratulations to AOS Faculty Member Yi Ming on being awarded the Henry G. Houghton Award by the American Meteorological Society (AMS) "for major advances in the understanding and modeling of the role of atmospheric aerosols in the radiative forcing of regional and global climate."
Fall Foliage Season may be Later, but Longer on Warmer Earth
Climate change could postpone fall leaf peeping in some areas of the United States as summer temperatures linger later into the year, Princeton University researchers report in the journal Global Ecology and Biogeography. Trees need daily temperatures to be low enough and daylight hours to be short enough to produce the vivid vistas of fall, explained senior author David Medvigy, an assistant professor of geosciences. He and first author Su-Jong Jeong, a former AOS postdoctoral associate now at NASA, found that daily temperature and daylight hours can not only be used to predict the timing of leaf coloration, but that the influence of these factors depends on the individual tree species and the specific geographic area. full story
Recent Study Investigates the Role of Aerosol Absorption in Driving Clear-Sky Solar Dimming over East Asia
The amount of solar radiation reaching the surface is a major driver of the surface energy balance and influences regional circulation and precipitation. Over East Asia, observations show a significant reduction in clear-sky surface solar radiation since the 1960s, colloquially referred to as “dimming,” primarily caused by large regional increases in anthropogenic aerosol emissions. A recent paper, led by AOS Graduate Student Geeta Persad, constitutes a novel mechanistic investigation of the drivers of East Asian clear-sky dimming that sheds light both on the nature of the observed dimming trends and on the behavior of the aerosol formulations in GFDL’s models. Yi Ming, an AOS lecturer, and GFDL Director V. Ramaswamy are coauthors of the study published in the Journal of Geophysical Research-Atmospheres.
AOS Graduate Student/Postdoc Retreat - 2014
On Thursday, September 11, 2014 AOS graduate students, postdocs, and faculty gathered for a one-day retreat at Mountain Lakes House in Princeton. This was the third annual retreat organized by AOS students and faculty to promote scientific and social interactions among the AOS community and to welcome incoming students. Photo Album
SOCCOM Program Awarded National Science Foundation Grant to Study the Southern Ocean
Encircling Antarctica and soaking up half of the human-made carbon in the atmosphere and majority of the planet’s excess heat, the vast Southern Ocean has remained relatively mysterious to scientists until now. Thanks to a six-year initiative that will advance understanding of the role of the Southern Ocean in climate change and biogeochemistry, the secrets of the Southern Ocean may finally be revealed. full story
AOS Program Biogeochemistry Seminar Series
On Friday, Sept. 19th @ 9:30am, Zouhair Lachkar (Center for Prototype Climate Modeling (CPCM), NYU, Abu Dhabi) will be presenting a seminar titled "Effects of climate forcing on ocean acidification and de-oxygenation in eastern boundary upwelling systems: Insights from regional eddy-resolving simulations." Please join us in the Sayre Hall Conference Room.
The AOS Program extends a warm welcome to its newest members -- Graduate Students Chiung-Yin Chang, Xin Rong Chua, Spencer Clark, Michelle Frazer, Tsung-Lin Hsieh, Ching Ho Justin Ng, and Sarah Schlunegger!
Tropical cyclones (TCs, which include hurricanes and typhoons) are a major climate hazard across the Northern Hemisphere, and have exhibited variability and change on year-to-year timescales. In a new study led by Gabe Vecchi, a lecturer in the Department of Geosciences and the AOS Program, the authors use a new high-resolution coupled climate model (GFDL-FLOR) to assess predictions of regional seasonal TC activity produced up to three seasons in advance. The paper "On the Seasonal Forecasting of Regional Tropical Cyclone Activity" was recently published in the Journal of Climate and can be found here. GFDL Research Highlights
Congratulations to Sam Potter who successfully defended his Ph.D. Thesis "Superrotation and tropical waves in idealized atmospheric models" on August 15, 2014.
2014 summer intern presentations are scheduled for Friday, August 8 from 2:00 to 4:00 pm in the Sayre Hall Conference Room.
Congratulations to Joe Majkut who successfully defended his Ph.D. Thesis "Variability and Trends in the Carbon Cycle" on August 1, 2014.
The "Art of Science 2014" exhibit showcases 44 images of artistic merit created during the course of scientific research. More than 250 images were submitted by undergraduates, graduate students, faculty, postdocs, staff and alumni representing over 25 departments. This year, for the first time in its seven-year history, the competition also includes video. Twelve videos were chosen from more than 50 submissions. Check out AOS Associate Research Scholar Martin Jucker's Fly Me video (best seen wtih blue-red 3D glasses) in the video gallery. Art of Science 2014 was co-sponsored by the Cooperative Institute for Climate Science (CICS). Related article
A new study coauthored by AOS Faculty Member David Medvigy explains the environmental factors that cause the leaves to change color in autumn. Variations in the timing of leaf coloring throughout the U.S., why the leaves of different species change color at different times, and how the timing of leaf coloring will change over the next 100 years are discussed. The lead author of the paper is Su Jong-Jeong, a former AOS postdoctoral associate presently at NASA/Jet Propulsion Laboratory. The paper, titled "Macroscale prediction of autumn leaf coloration throughout the continental United States," was recently published online in Global Ecology and Biography and can be found here.
Congratulations to AOS Graduate Student Jane Baldwin who was recently selected for the Princeton Energy Scholars (PECS) group. She is among the eight new graduate student members selected for the 2014-2015 academic year.
Understanding the mechanisms by which climate variability affects multiple trophic levels in food webs is essential for determining ecosystem responses to climate change. A new study, coauthored by AOS Visiting Research Collaborator Vincent Saba (NOAA National Marine Fisheries Service), uses over two decades of data collected by the Palmer Long Term Ecological Research program (PAL-LTER) to determine how large-scale climate and local physical forcing affect phytoplankton, zooplankton, and an apex predator along the West Antarctic Peninsula (WAP). The authors show that positive anomalies in chlorophyll-a (chl-a) at Palmer Station, occurring every 4-6 years, are constrained by physical processes in the preceding winter/spring and a negative phase of the Southern Annular Mode (SAM). Years of positive chl-a anomalies are associated with the initiation of a robust krill cohort the following summer, which is evident in Adélie penguin diets, thus demonstrating tight trophic coupling. Projected climate change in this region may have a significant, negative impact on phytoplankton biomass, krill recruitment, and upper trophic level predators in this coastal Antarctic ecosystem. The study, led by Grace Saba (IMCS, Rutgers), was published on July 7 in Nature Communications and is available here. Related article Related article
Regular Weekly Seminars
Throughout the academic year, Geophysical Fluid Dynamics Laboratory (GFDL) hosts seminars every Wednesday at noon - 1:00 p.m. and every Thursday from 2:00 pm - 3:00 p.m. in the Smagorinsky Seminar Room. These events feature internal and external speakers who discuss their research on various aspects of atmosphere, ocean, weather and climate.
Click here for a complete list of GFDL seminars.
Geosciences hosts a number of events including their departmental lecture series on Tuesdays at 12:30 p.m., the Environmental Geology & Geochemistry Seminar (EGGS) Lecture Series on Thursdays at 12:30-1:30 p.m., and the Solid Earth Brown Bag Seminars on Friday at 12 noon in Guyot Hall Room 220. They also regularly host their Junior Colloquium .
Click here for a complete list of Geosciences events.
The David Bradford Seminars in Science, Technology and Environmental Policy, co-sponsored with the Princeton Environmental Institute, are a lunchtime seminar series held at Wallace Hall, Room 300 at noon - 1:00 p.m. Lunch is provided starting at 11:45 a.m.
Click here for a complete list of STEP seminars.