News and Events
From Wednesday, August 5th through Friday, August 7th, AOS Program will be hosting the "Challenges in Using Current Atmospheric Models to Study Extreme Climate Scenarios" Workshop. Invited Speakers include: Natalie Burls (George Mason University), Matthew Huber (University of New Hampshire), and Robin Wordsworth (Harvard University). The workshop will take place in GFDL's Smagorinsky Room. All in the AOS/GFDL community are invited to attend. Please RSVP by Friday, July 31, 2015.
After Extreme Drought, Forests Take Years to Rebuild CO2 Storage Capacity
An analysis of drought impacts at forest sites worldwide found that living trees took an average of two to four years to resume normal growth rates — and thus carbon-dioxide absorption — after a drought ended, according to a Princeton-based study published this week in the journal Science.
The research team included William Anderegg, a visiting associate research scholar in the Princeton Environmental Institute, and Princeton colleagues Steve Pacala, an AOS associated faculty member; Adam Wolf, an associate research scholar in ecology and evolutionary biology; and CICS Scientist Elena Shevliakova, a senior climate modeler in ecology and evolutionary biology and at GFDL.
Climate Change and Decadal Shifts in the Phenology of Larval Fishes in the California Currents
Climate change has prompted an earlier arrival of spring in numerous ecosystems. It is uncertain whether such changes are occurring in Eastern Boundary Current Upwelling ecosystems, because these regions are subject to natural decadal climate variability, and regional climate models predict seasonal delays in upwelling. To answer this question, a new study published in PNAS, by AOS Postdoctoral Research Associate Rebecca Asch, investigated the phenology of 43 species of larval fishes between 1951 and 2008 off southern California. Ordination of the fish community showed earlier phenological progression in more recent years, with faster changes than many terrestrial ecosystems.
A report entitled “Predicting Future Oceans: Climate Change, Oceans & Fisheries” newly released by the Nereus program, an international interdisciplinary research program aimed at predicting future oceans, suggests that future seafood supply in the world will be substantially altered by climate change, overfishing and habitat destruction if we do not take actions. The report notes that continued CO2 emissions are leading to changes in ocean temperature, acidity and oxygen levels that have been unprecedented over the last several thousands of years. These changes in ocean conditions will affect biological productivity in the ocean, impacting organisms ranging from plankton to fishes. An improved framework for global ocean governance will be needed to ensure sustainable fisheries in the future.
Baldwin Awarded 2015 PEI-STEP Environmental Policy Fellowship
AOS Graduate Student Jane Baldwin has been awarded a 2015 PEI-STEP Environmental Policy Fellowship by the Princeton Environmental Institute (PEI). Baldwin will join fellow 2015 Awardees Ryan Edwards from Civil and Environmental Engineering, Jack Hoang Lu from Chemical and Biological Engineering, and Andrew Tilman and Timothy Treuer from Ecology and Evolutionary Biology in addressing the environmental policy implications of their thesis research.
Congratulations to former AOS Postdoctoral Research Fellow Sarah Kapnick, a GFDL physical research scientist, who was recently awarded a Cryosphere Early Career Award from the American Geophysical Union (AGU). Sarah’s research focuses on the mechanisms controlling extreme storms and mountain snowpack
A Daily Global Mesoscale Ocean Eddy Dataset from Satellite Altimetry
Eddies play a significant role in the mixing and transport of heat, salt, and biogeochemical tracers across the global oceans,and eddies have been shown to influence near-surface winds, clouds, and rainfall within their vicinity as well as marine ecosystems. A new paper coauthored by AOS Postdoctoral Research Fellow Ivy Frenger presents a dataset of ocean mesoscale eddies detected and tracked globally based on daily sea level height anomaly observations over two decades. The dataset can be used to investigate ocean eddy characteristics and effects, and the software used to create the eddy dataset is published in a repository. The paper was published June 9 in Scientific Data.
The Southeast Atmosphere Studies Workshop will be held at GFDL (Smagorinsky Room) Monday to Wednesday (June 8-10). The workshop will focus on a few research topics over the Southeast US, including ozone photochemistry, the formation of organic aerosols, chemistry-climate interactions ("warming hole over eastern US" in particular) and anthropogenic/biogenic emissions. Agenda
Marine ecosystems are increasingly stressed by human-induced changes. Marine ecosystem drivers that contribute to stressing ecosystems – including warming, acidification, deoxygenation and perturbations to biological productivity– can co-occur in space and time, but detecting their trends is complicated by the presence of noise associated with natural variability in the climate system. A new paper led by AOS Research Scholar Keith Rodgers considers emergence characteristics for the four individual and combined drivers. The results underscore the importance of sustained multi-decadal observing systems for monitoring multiple ecosystem drivers. The study was recently published in Biogeosciences.
New Research will Help Forecast Bad Ozone Days over the Western U.S.
A new study led by AOS Associate Research Scholar Meiyun Lin uses observations and numerical simulations to demonstrate a strong connection between high ozone days in the western U.S. during late spring and La Niña, an ocean-atmosphere phenomenon that affects global weather patterns. This linkage is important for developing seasonal forecasts with a few months of lead time to aid in western U.S. air quality planning and for effective implementation of U.S. ozone standards. AOS Faculty Member Larry Horowitz is a coauthor of the study recently published in Nature Communications. GFDL Research Highlights
AOS Program Biogeochemistry Seminar Friday, May 29th at 10:30am -- Anand Gnanadesikan (Johns Hopkins), "Implications of the isopycnal mixing paradox for climate and biogeochemical cycling" Sayre Hall Conference Room
Ice Core Atmospheric Bubbles from a Million Years Ago give Climate Change Understanding
A team of researchers with members from Princeton University, the University of Maine and Oregon State University has found that greenhouse gasses a million years ago, were only slightly higher than they were between 450,000 and 800,000 years ago. In their paper published in Proceedings of the National Academy of Sciences, the team describes their study of the newly retrieved ice cores and how it is helping to better understand the changes to the Earth's ice ages. AOS Associated Faculty Member Michael Bender is a coauthor of the study.
Dissecting the Ocean's Unseen Waves to Learn Where the Heat, Energy and Nutrients Go
CICS Associate Director Sonya Legg, an AOS senior research oceanographer, and colleagues from collaborating institutions (including Maarten Buijsman, a former AOS postdoc and now an assistant professor of physical oceanography at the University of Southern Mississippi) created the first “cradle to grave” model of the world’s most powerful internal ocean waves. The study was published late last week in Nature.
Washington Post article
EOS Spotlight: Could Amazonian Deforestation Increase Cloudiness and Rain?
A recent AGU-EOS Research Spotlight highlights the work of AOS Graduate Student Jaya Khanna and David Medvigy, Assistant Professor of Geosciences. The researchers investigated the atmospheric effect of deforestation in Rondônia, a state in west central Brazil, using the recently developed Ocean-Land-Atmosphere Model. (Journal of Geophysical Research: Atmospheres, doi:10.1002/2014JD022278, 2014)
Water Forms Common Thread in Diverse Rainforest Ecosystems
A new study coauthored by AOS Faculty Member David Medvigy determined the minimum amount of rainfall needed to sustain rainforests. The researchers also found surprisingly large differences in the amount of water available to rainforests in different parts of the world. The study was published in Nature Geoscience.
EOS Spotlight by Eric Betz: Investigating Uncertainties in Tropical Climate Forecasts
Observation and numerical climate model prediction do not always match when it comes to atmospheric temperature trends in Earth's tropics. Some skeptics have focused on the mismatch, and the question of a systematic problem in the models has been raised. Recently, former AOS Senior Research Assistant Thomas Flannaghan, The Fueglistaler Group, and AOS Faculty Member Isaac Held et al. set out to find the source of the problem.
AOS Program Biogeochemistry Seminar Friday, May 1st at 3pm -- Desiree Tommasi (AOS), "Incorporating seasonal climate forecasts into a harvest guideline control rule for Pacific sardine" Sayre Hall Conference Room
Congratulations to Rebecca Asch, a postdoc in the Sarmiento Group, who was awarded the best early career scientist presentation for her talk titled "Projected Mismatches Between the Phenology of Phytoplankton Blooms and Fish Spawning Based on the GFDL Earth System Model (ESM2M)" at the Third International Symposium on the Effects of Climate Change on the World's Oceans. The conference took place in late March in Santos, Brazil.
New Study Examines Mechanisms for Low-Frequency Variability of Summer Arctic Sea Ice Extent
The observed decline in summer Arctic sea ice has often been attributed, in large part, to the increase in greenhouse gases. However, the contributions from internal low-frequency variability in the climate system are not well understood. In a new study by AOS Faculty Member Rong Zhang, a multiple regression model is developed for the first time, to the author’s knowledge, to quantify the contributions of three key predictors on the internal low-frequency variability of summer Arctic sea ice extent. The study was published in the Proceedings of the National Academy of Sciences (PNAS).
AOS Program Biogeochemistry Seminar Friday, April 24th at 10am -- Rebecca Asch (AOS), "How will climate change impact fish reproduction? Case Studies examining phenological mismatches in the North Atlantic and North Pacific and spawning aggregations in the Caribbean" Sayre Hall Conference Room
A symposium honoring 2015 Benjamin Franklin Medal Awardee Suki Manabe will be held on Monday, April 20th from 9:00 to 12:30 pm in the Friend Center. In this symposium, talks will examine advances that have been made in understanding climate change and the future challenges that remain in developing a predictive understanding of Earth's climate system. Program Schedule
AOS Program Biogeochemistry Seminar Friday, April 17th at 3pm -- Carolina Dufour (AOS), "Mechanisms governing the uptake of anthropogenic CO2 by the Southern Ocean: Preliminary results from climate models" Sayre Hall Conference Room
AOS Associate Resarch Scholars Fabien Paulot and Jingqiu Mao are coauthors of a new paper that has important implications for the prediction and management of future ozone air quality. The study uses observations and simulations to diagnose the sensitivity of August surface ozone to large-scale temperature variations in the southeast US during 1988–2011. The study was published in Nature Climate Change.
AOS Program Biogeochemistry Seminar Friday, April 10th at 3pm -- Alison Gray, "New observations from biogeochemical floats in the Southeast Pacific" Sayre Hall Conference Room
AOS Faculty Member Tom Delworth is the lead author of a new study that uses three GFDL climate models to study the mechanisms behind the hiatus in global warming over the last decade and their possible relationship to southwestern U.S. drought. This study suggests that a majority of the drought in the southwestern U.S. over the last decade is the result of persistent anomalous wind conditions in the tropical Pacific, and is likely due to natural variability. The study was published in the Journal of Climate. GFDL Research Highlights
Improved Seasonal Prediction of Temperature and Precipitation over Land in a High-resolution GFDL Climate Model
A recent study led by AOS Associate Research Scholar Liwei Jia demonstrates skillful seasonal prediction of near-surface air temperature and precipitation over land using a new high-resolution climate model developed at GFDL, called FLOR. The study further diagnoses the sources of the prediction skill. Skillful seasonal predictions of surface temperature and precipitation over land are needed because of their importance to ecosystems and sectors such as agriculture, energy, and transportation. The research was conducted while Jia was a UCAR and GFDL employee, and was published in the Journal of Climate. GFDL Research Highlights
AOS Program Biogeochemistry Seminar Friday, March 27th at 3pm -- Yavor Kostov (MIT), "Southern Ocean cooling in a warming world: Reassessing the role of westerly winds" Sayre Hall Conference Room
Are you interested in improving your ability to communicate your work to audiences outside of science? Are you curious about how to conduct effective public outreach? Students, postdocs, staff, and faculty, are invited to attend a hands-on science communication workshop, hosted by STEP, on Friday, March 27 in Robertson Hall.
Enrollment is limited; sign up here at your earliest convenience. Have questions? Email Rachel Licker at firstname.lastname@example.org
AOS Program Biogeochemistry Seminar Friday, March 13th at 3pm -- Anna FitzMaurice (AOS), "Investigating the Relationship Between Sea Ice and the Southern Ocean Overturning Circulation" Sayre Hall Conference Room
The Impact of MPOWIR: A Decade of Investing in Mentoring Women in Physical Oceanography
CICS Associate Director Sonya Legg, an AOS faculty member, is coauthor of a new article featured in a special issue of Oceanography "Women in Oceanography: A Decade Later." The article " The Impact of MPOWIR: A Decade of Investing in Mentoring Women in Physical Oceanography" describes the MPOWIR (Mentoring Physical Oceanography Women to Increase Retention) Program, a US community-initiated and community-led mentoring program aimed at improving the retention of women physical oceanographers in academic and/or research positions. It also describes MPOWIR's impact to date and outlines its future directions.
AOS Program Biogeochemistry Seminar Friday, March 6th at 3pm -- Philip Pika (ETH Zurich), "Determining ocean biomes and Chlorophyll content in a changing climate" Sayre Hall Conference Room
AOS Program Biogeochemistry Seminar Friday, Feb. 27th at 3pm -- Katsuya Toyama (AOS), "Lagrangian analysis of nutrient transport in the Southern Ocean" Sayre Hall Conference Room
New Study Uses GFDL Global Climate Models to Investigate Behavior of Brewer-Dobson Circulation
In a new study led by AOS Postdoctoral Research Associate Pu Lin, GFDL global climate models were used to investigate how the Brewer-Dobson circulation would vary in response to different natural and anthropogenic climate forcings. The authors calculate the strengths of the Brewer-Dobson circulation simulated by GFDL global climate models CM3 and CM2.1, and find that the strengths correlate with the tropical mean surface temperature. This correlation is also supported by observational-based analysis. Yi Ming, a lecturer in Department of Geosciences and the AOS Program, and GFDL Director V. Ramaswamy are coauthors of the study published in Geophysical Research Letters.
Representations of the Nordic Seas Overflows and their Large Scale Climate Impact in Coupled Models
He Wang, a graduate student in the AOS program, is the lead author of a new study published in Ocean Modelling that describes the sensitivity of the North Atlantic climate in GFDL models to the model representation of the Nordic Sea overflows (flows of dense water through gaps in the ridge between Greenland and Scotland). These flows are usually poorly captured in coarse resolution climate models. Wang and coauthors CICS Associate Director Sonya Legg and Robert Hallberg, an AOS faculty member, find that the Meridional overturning circulation, the direction of the warm North Atlantic Current and the temperature and salinity of the northernmost part of the Atlantic can all be affected. This is the first study to carefully compare old and new methods of capturing the overflows in climate models, and to show the importance of representing these flows accurately in order to correctly simulate the climate in the North Atlantic.
Diversity in Science: A Conversation - Wednesday, Feb. 25th 6 - 8 pm
EEB Women in Science Partnership & Princeton Women In Geosciences (PWiGs) invite all members of the AOS community (faculty, postdocs, graduate students, and research staff) to a gathering of GEO, AOS, and EEB to celebrate and discuss the value of diversity in science. The event features dinner (from Chipotle), a faculty panel featuring voices from our department, and group discussions. Be part of the conversation! RSVP by Feb.18th.
Energy Flux into Internal Lee Waves: Sensitivity to Future Climate Changes using Linear Theory and a Climate Model
A recent study led by former AOS Postdoctoral Research Associate Angelique Melet (LEGOS, France), in collaboration with former AOS Associate Research Scholar Max Nikurashin (University of Tasmania), examines how the energy transferred from geostrophic eddies to lee-waves (small-scale underwater waves over bumpy sea-floor topography), can change as climate changes, e.g. due to global warming. This lee-wave energy is important because it can drive mixing in the interior of the Southern Ocean. AOS Faculty Member Robert Hallberg, Alistair Adcroft (GFDL), and CICS Associate Director Sonya Legg, an AOS faculty member, are couathors of the study published in the Journal of Climate.
AOS Program Biogeochemistry Seminar Friday, Feb. 20th at 3pm -- Natasha Henschke (University of New South Wales), "Salp swarms in the Tasman Sea: Are there fisheries and climate implications?" Sayre Hall Conference Room
AOS Program Biogeochemistry Seminar Friday, Feb. 13th at 3pm -- Haidi Chen (University of Wisconsin), "Observed dominance of submesoscale fronts to primary production in the North Atlantic Subtropical Gyre" Sayre Hall Conference Room
AOS Postdoctoral Research Associate Adele Morrison is the lead author of a recent article outlining the mechanisms and impacts of upwelling in the Southern Ocean and the role of the SOCCOM Program in investigating it. AOS DIrector Jorge Sarmiento and Thomas Frölicher (ETH Zurich) are coauthors of the article published in Physics Today.
Study Investigates the Dynamics of Marine Populations at a Global Scale
Modeling the dynamics of marine populations at a global scale - from phytoplankton to fish - is necessary if scientists are to quantify how climate change and other broad-scale anthropogenic actions affect the supply of marine-based food. A recent study led by James Watson, while a postdoc in the AOS Program, investigates the dynamics of marine populations at a global scale using a simple size-based food web model coupled to simulations of global ocean physics and biogeochemistry. GFDL Scientist Charles Stock, an AOS collaborator, and AOS Director Jorge Sarmiento are coauthors of the study published in Progress in Oceanography.
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.