2012-2013 Report to President

The Department of Earth, Atmospheric, and Planetary Sciences (EAPS) has broad intellectual horizons encompassing the solid Earth, its fluid envelopes, and its diverse neighbors throughout the solar system and beyond. The department seeks to understand fundamental physical, chemical, and biological processes that define the origin, evolution, and current state of these systems and to use this understanding to predict future states. The department comprises 39 faculty (including one with a primary appointment in Civil and Environmental Engineering and one with a primary appointment in Engineering Systems Division), and more than 240 research staff, postdoctoral appointments, and visiting scholars.

EAPS is notable for its emphasis on interdisciplinary problems and is involved in numerous laboratories, centers, and programs that address broad questions in the Earth sciences, including those that are among the most pressing societal issues of our time: change in climate and environment, natural resources and hazards, and the origin and evolution of life on Earth and, perhaps, elsewhere. For example, the Earth Resources Laboratory (under directorship of Prof. Hager) integrates faculty, staff, and students across disciplinary, department, and school boundaries to investigate geophysical and geological problems in energy and resource development. The Center for Global Change Science (under directorship of Prof. Prinn) builds on the programs in meteorology, oceanography, hydrology, chemistry, satellite remote sensing, and policy. EAPS is an active participant in the MIT/Woods Hole Oceanographic Institution (WHOI) Joint Program and supports its mission of graduate education and research in ocean sciences and engineering.

Educational Activities

Graduate Program

EAPS has vigorous graduate educational programs in geology, geochemistry, geobiology, geophysics, atmospheres, oceans, climate, and planetary science. In fall 2012, EAPS had 170 graduate students registered in the department, including 75 students in the MIT/WHOI Joint Program. Women constituted 46.7 percent of the graduate student population, and 7 percent were members of an underrepresented minority group.

In May 2013, at a special faculty meeting, the ad hoc taskforce on the EAPS education program presented its final report and recommended changes to the department’s graduate program. The Committee had sought the opinions and thoughts of EAPS faculty, current students, and alumni on the graduate program structure and academics. As important area of agreement by the members of the faculty concerned moving to a uniform structure for the general exam among the four educational disciplines within our graduate program. The decisions of the faculty will be implemented by the EAPS Graduate Education Committee for the graduate students entering in September, 2013.

The excellence of the EAPS graduate program is built not only on the strength of teaching and supervision by the faculty but also on the involvement of EAPS graduate students in departmental activities. Students develop formal and informal ways to improve educational experience as well as student life. The graduate students continue to take responsibility for an expanded orientation program for the incoming graduate students. They plan a number of social events to introduce the newcomers to the EAPS, MIT, and the Cambridge area. The department graduate students meet regularly, with one of the students presenting his/her research. Undergraduate majors are encouraged to attend these talks. The departmental Graduate Student Mentoring Program continues as a well-received approach to provide peer support for new students.

The Program in Atmospheres, Oceans, and Climate, within EAPS, awards the Carl-Gustaf Rossby Prize to recognize the best Ph.D. thesis in the preceding year. Dr. Malte Jansen and Dr. Laura Meredith were the recipients for this past year. EAPS awards an annual prize for excellence in teaching to highlight the superior work of our teaching assistants. During the 2013 academic year, Ms. Ann Bauer, Mr. Tim Cronin, Ms. Katherine French, Ms. Erin Shea, and Ms. Allison Wing were recognized for their contributions.

Our students were also recognized by their respective professional societies. Mr. Martin Singh received the Best Student Paper Award for his paper "The temperature dependence of rainfall intensity, CAPE, and vertical velocities in radiative-convective equilibrium,” presented at the American Meteorological Society’s 19th Conference on Atmospheric and Oceanic Fluids Dynamics. At the 2012 Annual Meeting of the American Geophysical Union four EAPS students were recognized with Outstanding Student Paper Awards. Mr. Anton Ermakov was recognized by the Planetary Sciences section for his paper “Modeling of Vesta’s Interior Structure Using Gravity and Shape Model from the Dawn Mission and Hydrodynamic Impact Simulations.” Mr. Ben Linhoff was recognized by the Cryosphere section for his paper “Greenland Ice Sheet Hydrology: Insights From an Isotope Mixing Model during the 2011 and 2012 Melt Seasons.” Mr. Ben Mandler was recognized by the Volcanology, Geochemistry, and Petrology section for his paper “Magma Storage Conditions Prior to the Caldera-forming Eruption of Newberry Volcano, Oregon.” Ms. Alejandra Ortiz was recognized by the Earth and Planetary Surface Processes section for her paper “Turbulent and Mean Velocity Near Rigid and Flexible Plants, and Implications for Deposition.” At the 17th Conference on the Middle Atmosphere Mr. Justin Bandoro was awarded the Best Student Oral Presentation for his talk titled “Influence of the Antarctic Ozone Hole on Seasonal Changes in Climate in the Southern Hemisphere.”

Undergraduate Program

In fall 2012, EAPS had 19 undergraduate majors, 90 percent of whom were women and 10 percent of whom were members of an underrepresented minority group. Seven students were awarded the SB degree in Earth, Atmospheric, and Planetary Sciences in AY2013.

The department maintains a strong presence in the undergraduate program at MIT beyond the population of majors so that the general MIT student body has access to the geoscientific aspects of climate and environmental change, natural hazards, and natural energy resources.

The department is committed to supporting the Terrascope program with its problem-based approach to education during the first year at MIT and to offering Freshman Advising Seminars (FAS). In fall of 2012 EAPS offered five FASs. With the combined enrollment of Terrascope and the advising seminars, EAPS taught 10% of the students in the freshman class on a weekly basis. Similarly, EAPS is an active participant in three interdisciplinary minor programs; the broadly-based Energy Minor, the Astronomy Minor, with Physics, and the new Atmospheric Chemistry Minor. Professor Susan Solomon, with the enthusiastic support of the EAPS faculty, was a leader of an interdisciplinary team of interested faculty that organized the Atmospheric Chemistry minor, and which will enroll its first students in AY2014.

At the 2012 Student Awards and Recognition Dinner, the Goetze Prize was awarded to Ms. Shaena Berlin in recognition of her outstanding senior thesis, Mr. Thomas B. Thompson received the W.O. Crosby Award for Sustained Excellence, and Ms. Ann Alampi and Mr. Ryan Keating were the recipients of the Award for Excellence as an Undergraduate Teaching Assistant. Ms. Jessica Fujimori and Ms. Kathryn Materna were the recipients of the EAPS Achievement Award, which recognizes a rising senior from across the EAPS disciplines. The award is presented to a student who has distinguished her or himself through a combination of high GPA, focused course work, and leadership within EAPS.

Community Events

In AY '13, EAPS worked with Resource Development, the School of Science, and the MIT Alumni Association to organize a full calendar of events and programs to engage EAPS alumni and prospective donors. The year kicked off with Professor Susan Solomon presenting the Dean's Colloquium to a full house in MIT's 10-250, followed by a celebratory dinner at Boston's Liberty Hotel. Professors Taylor Perron and Noelle Selin were the featured speakers at the October and April School of Science Breakfasts. These breakfasts, held four times a year at MIT's Faculty Club, give Boston area major gift prospects the opportunity to hear about cutting-edge research in the School of Science. EAPS sponsored four events this year, including the November 1 John Carlson Lecture and Dinner, co-sponsored by the New England Aquarium and featuring Oxford's Tim Palmer, and our annual reception during the American Geophysical Union Fall Meeting, which had a record turnout of more than 350. In addition, EAPS coordinated two "state of EAPS" breakfasts for alumni and friends in Houston and Cambridge and capped off the year with a celebration of the new Earth Resources Laboratory (during the annual consortium for corporate sponsors) at which we dedicated a seminar room in honor of Professor M. Nafi Toksöz and announced the successful completion of the M. Nafi Toksöz Fellowship Fund. In collaboration with the MIT Alumni Association, Professors Kerry Emanuel and Dan Cziczo spoke at all-call alumni events in Austin, Texas and Boulder, CO. Professors Emanuel and Cziczo also participated in two on-line Faculty Forums, which proved an effective way to expose an even larger audience to their work. A very successful reception for members of the William Rogers Barton Society (MIT donors of $1,000 plus) was held at New York City's American Museum of Natural History, with Professor Ben Weiss giving a lecture in the Hayden Planetarium.

Geared towards graduate students and postdocs the annual Long Pond weekend, coordinated by EGSAC (the EAPS Graduate Student Activities Committee), took place over the weekend of September 21-23. This perennial activity provides a valuable opportunity for community building at the start of each year.

Over the same weekend, Professors Sam Bowring and Tom Herring led a two-day field trip to explore the geology of Central and Western Massachusetts. The trip, another perennial EAPS activity, brought together around 30 participants, among them EAPS graduate students, undergraduate majors, postdocs, staff and researchers as well as undergraduates outside Course XII.

This year saw two author nights, the first featuring S.R.S. Mick Follows (October 26, 2012) and a second featuring Professor Kerry Emanuel (May 3, 2013). Each were attended by over one hundred guests and culminated in book signings and refreshments.

Over the course of the year EAPS hosted over 30 Department Lecture Series lectures, with topics ranging across the full spectrum of the earth and planetary sciences. Adding to these the well-attended January 2013 IAP lectures series “The atmosphere as an intersection with...” provided an introduction to the atmospheric sciences as they intersect the solid earth, its oceans and hydrodynamic cycles, and space.

January also saw residency of the year’s one Houghton Lecturer, alumni Joe LaCasce PhD ‘96 (now a professor at the University of Oslo, Norway), who gave a three lecture course on “Lagrangian Methods and Mixing” (as applied to the ocean and atmosphere) and a fourth lecture “Defending the use of Linear Models to Understand the Ocean.”

On 16 February 2013 the Head of Department made his second annual “State of EAPS” presentation to an audience of around 250 interested department members and friends. This year special emphasis was given to the many new communications initiatives EAPS has undertaken as well as emphasising development and fundraising priorities and educational and faculty recruitment goals.

The year ended with a wonderful evening, for the entire EAPS community, the 6th annual Student Recognition Dinner (May 17), at which alumna (and recent joint-Pulitzer Prize winner) Lisa Song, EAPS (B.S. '08) & Science Writing (M.S. '09) shared her journey from undergraduate major in EAPS to award-winning science journalist and internal student awards were announced and presented.

Faculty

The department continues its efforts to hire and help young faculty members develop careers. Two new assistant professors have joined the department in July of 2013. Dr. Hilke Schlichting, a planetary scientist and Dr. German Prieto, a geophysist. We are excited to have the opportunity to bring such a talented duo into our department. We also are happy to report the appointment of Dr. Michael Follows to the rank of associate professor during the same timeframe. We also extended an offer to Ms. Kristin Bergmann a young geologist currently finishing her PhD at Caltech. She will join our faculty in July of 2015.

Honors and Awards

Associate Professor Tanja Bosak received the Edgerton Award, the junior faculty equivalent of the Killian Award.

Associate Professor Dan Cziczo was awarded a Victor Starr Career Development Chair.

NASA Group Achievement Award, MACPEX Mission

Shaena Berlin (undergraduate thesis and current M.S. student): Christopher Goetze Prize

Professor Raffaele Ferrari’s former graduate student Malte Jansen, has been awarded the MIT Rossby Award for best PhD thesis of 2012 and the NOAA Climate and Global Change Postdoctoral Fellowship. He has now been hired as an assistant professor by the University of Chicago.

Professor Timothy Grove was selected as the next Cecil and Ida Green Professor of Geology.

Assistant Professor Taylor Perron’s Graduate student Kimberly Huppert was awarded a NASA Earth and Space Science Graduate Fellowship.

Professor Paola Rizzoli has been appointed the first Singapore-MIT SMART Program Chair for the year 2013 by the MIT Provost, Prof. Chis Kaiser.

Professor Sara Seager was selected the co-winner of the Sackler Prize in the Physical Sciences.

Professor Susan Solomon received the following awards over the past year: Honorary Member, American Meteorological Society, October, 2012. Vetlesen Prize, Vetlesen Foundation, February, 2013. Honorary Member, American Polar Society, April, 2013. BBVA Frontiers of Knowledge Prize, BBVA Foundation, June, 2013. Honorary doctorate, Leeds University, UK, July, 2013.

Professor Maria Zuber received the James R. Killian, Jr., Faculty Achievement Award, a prize given by MIT’s faculty “to recognize extraordinary professional achievement.”

Research Highlights

Samuel Bowring

Prof. Sam Bowring and his research group have worked on a number of diverse projects during the past year involving high-precision U-Pb geochronology. Their work on mass extinctions and large igneous provinces was featured as an article in the journal Science (Blackburn et al. 2013) in which they showed that the end-Triassic extinction was exactly coincident with the first eruptions associated with the Central Atlantic Magmatic Province or CAMP within ± 30 thousand years 201 million years ago. Other contributions involved using high-precision geochronology combined with astrochronology to determine the duration of the “Messinian gap”, corresponding to the evaporative drawdown of the Mediterranean following the closure of the Mediterranean-Atlantic gateway to be 28 ± 9.6 k.y. consistent with the notion of a fast desiccation and refilling of the Mediterranean ca 5.53 million years ago. His PhD students are working on projects that range from high-precision dating of the largest known volcanic province, the Siberian Traps to the timescales for constructing granitic plutons to Hf isotopic investigations of the 4.0 billion year old Acasta Gneisses. Bowring continues to lead the Terrascope Program, a freshman learning group which uses experiential learning to teach students about problems of sustainability and the environment ( http://web.mit.edu/terrascope/www/ )

Edward Boyle

Prof. Edward Boyle has obtained the most highly resolved sections of anthropogenic lead (Pb), Pb isotopes, and colloidal Fe on the U.S. GEOTRACES North Atlantic Transect (Woods Hole-Bermuda-Cape Verde Islands-Lisbon). This data shows that hydrothermal vents at the mid-Atlantic ridge are scavenging anthropogenic Pb out of the mid-depth waters. It also shows that there is a high-salinity, high-Pb, low 206/207Pb isotope signal in an Atlantic water mass at ~100m depth (Subtropical UnderWater, STUW). He finds that half of the so-called “dissolved” Fe in the Atlantic Oceean is in the form of 0.02-0.2 micrometer colloids. He has also used sediments and annually-banded corals from the northern Persian Gulf to reconstruct the history of anthropogenic Pb pollution in this region, with a rise from the 1950’s until the mid-1980’s, then a decrease when leaded gasoline was phased out in this region.

B. C. Burchfiel

Prof. Clark Burchfiel’s research has been focused in three areas. The primary focus has been on the tectonic development of the Tibetan plateau and a book covering our research effort has been published as a Memoir this year jointly by the Geological Society or America and the Chengdu Institute of Geology and Mineral Resources, China. This work has been on going for 28 years. Research on the tectonic development of the Balkan Peninsula and Greece has been a second area of research and the work here is just now in its concluding phase. The third area of research is on the tectonic evolution of the southeast part of the Cordilleran orogen of the western United States in Southeast California. A book is in progress on this region with several large geologic maps and is scheduled for completion in early 2014.

Daniel Cziczo

Prof. Dan Cziczo is an atmospheric chemist interested in the relationship of the small particles found in the atmosphere and cloud formation. His research combines laboratory and field studies to elucidate how these small particles interact with water vapor to form droplets and ice crystals and how they can impact the Earth’s climate system and water cycle. His group conducts experiments, including using small cloud chambers in the laboratory to mimic atmospheric conditions that lead to cloud formation, as well as conducting field studies, such as observing clouds in situ from remote mountaintop sites or aboard research aircraft. Dan Cziczo and Karin Ardon-Dryer (post doctoral fellow) participate in WGBH / Nova’s Cloud Lab by editing educational video, answering viewer questions, etc.

(figure from paper: Science, 2013)

 

Kerry Emanuel

Prof. Kerry Emanuel expanded his research efforts into two new areas: Self-aggregation of convection, and climate control of severe local storms. Self-aggregation is a phenomenon observed in cloud-resolving models run into states of statistical radiative-convective equilibrium. Normally, such states exhibit moist convective plumes that are nearly randomly distributed in space, and chaotic in time, but if certain conditions are present, the convection spontaneously aggregates into a single large cluster. The atmosphere around it dries dramatically, suggesting that self-aggregation can strongly regulate tropical climate. Working with graduate student Allison Wing, we have uncovered the essential physical mechanisms underlying self-aggregation, and are beginning to understand its role in regulating climate. Graduate student Vince Agard and I are beginning a new project to understand how severe local storms, which produce damaging wind, hail, and tornadoes, respond to climate change. I continue to work with co-PI Peter Molnar and graduate student Tim Cronin on the nonlinear rectification of the diurnal cycle of moist convection over land, and its possible implications for the climate of the Pliocene, and with graduate student Morgan O’Neill on the dynamics of Saturn’s polar vortices.

Raffaele Ferrari

Prof. Raffaele Ferrari's research focused on two main questions. The first question was to quantify the role of oceanic turbulence in driving the meridional circulation in the Southern Ocean. This is a crucial question for climate, because our uncertainty in the ocean uptake of carbon in a warming climate is largely associated with uncertainties in the dynamics of ocean turbulence. Using a combination of observations collected as part of the DIMES project and numerical simulations, we produced the first direct estimates of the rate at which turbulence mixes tracers into the Southern Ocean. We are now using these estimates to improve the representation of ocean turbulence in climate models. A second focus of our research has been the study of biological productivity in the subpolar oceans. We began a large observational program in the Eastern North Atlantic using a combination of traditional ship-based and glider measurements. We have obtained the first detailed record of biological blooms in the subpolar Atlantic for a full year. Contrary to common wisdom, we have found that much growth occurs in winter and is missed by satellite observations. We are now studying the implications of these observations for estimates of oceanic carbon uptake.

Glenn Flierl

Prof. Glenn Flierl and his students are investigating physical and biological dynamics in the ocean and other more general problems in geophysical fluid dynamics. Three students he coadvised finished their PhD research this year. Ru Chen examined the energetics of ocean variability and showed that the transfers from the mean to the eddies was generally not local. She also showed that ``striations'' in ocean currents (long bands of coherent flow appear in the time-averaged fields) contain a significant amounts of the low-frequency energy in the ocean and are greatly altered by the large-scale flows. Nicholas Woods studied physical processes which would lead to aggregation (in the Great South Channel area) of copepods, the primary food
source for right whales. He examined models of the coastal river-fed buoyant plume and showed that, in its progression down the coast, it could build up the concentration of copepods near the nose of the plume by an order of magnitude. The mixing by eddies can break up patches; Nick analyzed this using drifter data from the Gulf of Maine and the U.Mass Dartmouth mode. The
dispersive processes varied significantly in different subregions of the Gulf and the two-particle statistics showed that ``eddy diffusivity'' is not a good measure of the potential for breaking up patches of copepods. Juliana Albertoni (U. Sao Paolo) m=odelled the flow of the Brazil current around coastal protusions and bays. We are also studying the physical and biological
dynamics of spring blooms in collaboration with Prof. Ferrari.

Tim Grove

Prof. Tim Grove and students have developed a model for predicting the major element compositions of melts of garnet lherzolite over the pressure range of 1.9 to 6 GPa. The model estimates the major element compositions of garnet-saturated melts for a range of mantle lherzolite compositions and predicts the conditions of the spinel to garnet lherzolite phase transition for natural peridotite compositions at above-solidus temperatures and pressures. We compare our predicted garnet lherzolite melts to those of pyroxenite and carbonated lherzolite and develop criteria for distinguishing among melts of these different source types. We also use the model in conjunction with a recently published predictive model for plagioclase and spinel lherzolite (Till et al., JGR, 2012) to characterize the differences in major element composition for melts in the plagioclase, spinel and garnet facies and develop tests to distinguish between melts of these three lherzolite facies based on major elements. There has been a continuing debate about the source materials (peridotite vs. pyroxenite) of basaltic melts of the earth’s upper mantle that has been largely based on evidence from trace elements. Our major element based model brings another set of criteria to bear on this long-standing problem.

References –This is a list of papers that have been published papers so far in 2013.

1. Till, C.B., Grove, T.L., Carlson, R.W., Donnelly-Nolan, J.M., Fouch, M.J., Wagner, L.S., Hart, W.K. (2013) Depths and temperatures of asthenospheric melting and the lithosphere-asthenosphere boundary in the southern Cascades arc and back-arc. Geochem. Geophys. Geosystems 14, 863-878. doi:10.1002/ggge.20070.

2. Barr JA, Grove TL (2013) Experimental petrology of the Apollo 15 group A green glasses: Melting primordial lunar mantle and magma ocean cumulate assimilation. Geochim. Cosmochim. Acta, 106, 216-230. doi:10.1016/j.gca.2012.12.035.

3. Charlier, B., Grove, T.L., Zuber, M.T. (2013) Phase equilibria of ultramafic compositions on Mercury and the origin of the compositional dichotomy. Earth and Planetary Science Letters 363, 50-60, doi:10.0106/j.epsl.2012.12.021.

4. Grove, T.L., Holbig, E.S., Barr, J.A., Till, C.B., Krawczynski, M.J. (2013) Mantle melting in the garnet stability field: Experiments and predictive models. Contrib. Mineral. Petrol. (in press).

5. Laubier, M., Grove, T.L., Langmuir, C.H. (2013) Trace element mineral/melt partitioning for basaltic and basaltic andesite melts: An experimental and LA-ICPMS study with application to the oxidation state of mantle source regions. Earth and Planetary Science Letters (submitted).

6. Grove, T.L. Till, C.B. (2013) Melting the Earth’s Upper Mantle: Chapter 1. In Encyclopedia of Volcanoes, 2nd Edition, Sigurdsson, H.R., ed., Elsevier, (submitted).

Honors and Special activities

Teaching activities and institute service:

I taught a graduate class, Thermodynamics for Geoscientists (12.480) in the fall and an undergraduate class, Structure of Earth Materials (12.108) in the spring.

I continued as Associate Dept. Head and completed the task of strengthening the EAPS graduate program. A notable outcome of this reevaluation is significant progress toward a single general exam structure for the entire department and a department-wide thesis defense requirement.

I served for a second and final year as the chair of MIT’s Committee on the Undergraduate Program (CUP). In collaboration with the Faculty Chair, the Dean for Undergraduate Education and the chancellor the CUP brought a resolution to the Faculty calling on MIT’s administrative leaders to partner with the CUP, the five School Deans, and the Deans for Undergraduate Education and Student Life to develop and implement an advising program that moves the Institute towards this end.

Other service and community outreach

My service as chair of AGU’s governance committee and on AGU’s Board of Directors ended on December 31, 2012. As past-past president, I took on the chair of the AGU Ethics Committee.

I continue as Executive Editor for Contributions to Mineralogy and Petrology.

Bradford H. Hager

Prof. Brad Hager became the Director of the Earth Resources Laboratory (ERL) in June, 2012. His research focus relevant to energy includes induced seismicity, developing techniques for monitoring and verification of geologic storage of CO2, and more safe, efficient and effective techniques for extracting shale gas. In addition, Hager is co-lead of a NASA InSAR satellite mission for measuring ground deformation, ice sheet velocities, and the inventory of woody biomass from space.

Selected publications:

D. L. Hartmann, M. R. Abbott, R.A. Anthes, P. E. Ardanay, S. W. Boland, A. J. Busalacchi, Jr., A. Cazenave, R .DeFries, L-L. Fu, B. H. Hager, A. Huang, A. C. Janetos, D. P. Lettenmaier, J. A. Logan, M. K. Macauley, A. W. Nolin, J. E. Penner, M. J. Prather, D. S. Schimel, W. F. Townsend, and T. H. van der Haar (2012), Earth Science and Applications from Space: A Midterm Assessment of NASA's Implementation of the Decadal Survey, National Academies Press.

Juanes, R., B. H. Hager, and H. J. Herzog (2012), No geologic evidence that seismicity causes fault leakage that would render large-scale carbon capture and storage unsuccessful, Proc. Nat. Acad. Sci., www.pnas.org/cgi/doi/10.1073/pnas.1215026109.

Colette Heald

Associate Prof. Colette Heald and her group (http://web.mit.edu/heald/www/, joint CEE and EAPS) work on a range of problems examining the role of atmospheric chemistry and composition in the Earth system. Recent work has focused on the sources, evolution and impacts of aerosol particles in the atmosphere. This includes studies investigating the representation of dust in global models (Ridley et al., 2013), the origins and transport of smoke (Val Martin et al., 2013), the impact of bark beetle infestation in Western North America on aerosol formation and visibility (Berg et al., 2013), and the satellite constraints on aerosol formation in the Southeastern United States (Ford and Heald, 2013). On-going projects include analyzing the impacts of climate and ozone pollution on projections of global crop productivity, investigating the origin of poor particulate air quality in California, assessing the role of aging on the radiative impacts of black carbon, and exploring the drivers of air quality extremes.

Berg, A. R., Heald, C. L., Huff Hartz, K. E., Hallar, A. G., Meddens, A. J. H., Hicke, J. A., Lamarque, J. F., and Tilmes, S.: The impact of bark beetle infestations on monoterpene emissions and secondary organic aerosol formation in western North America, Atmos. Chem. Phys., 13, 3149-3161, 10.5194/acp-13-3149-2013, 2013.

Ford, B., and Heald, C. L.: Aerosol loading in the Southeastern United States: reconciling surface and satellite observations, Atmos. Chem. Phys., in press, 2013.

Ridley, D. A., Heald, C. L., Pierce, J. R., and Evans, M. J.: Towards resolution-indepdent dust emissions in global models, Geophys. Res. Lett., 40, 2873-2877, doi:10.1002/grl.50409, 2013.

Val Martin, M., Heald, C. L., Ford, B., Prenni, A. J., and Wiedinmyer, C.: A decadal satellite analysis of the origins and impacts of smoke in Colorado, Atmos. Chem. Phys. Discuss., 13, 8233-8260, 2013.

Thomas Herring

Prof. Thomas Herring is using global positioning system (GPS) and VLBI data to develop geophysically based models of Earth deformations on global, regional, and local scales and changes in the rotation of the Earth. He is also using interferometric synthetic aperture radar to study small surface deformations and geodetic methods
 to study Earth’s gravity field. His group is using high-precision GPS measurements
in many different study areas, including over much of the southern Eurasian plate boundary and the western United States. They are investigating processes on time scales of years leading up to earthquakes, transient deformation signals lasting days to many weeks, postseismic deformation after earthquakes on time scales of day to decades, and surface wave propagation during earthquakes using high rate GPS data. All of these measurements have sub-millimeter to few millimeter precision. The group is also monitoring and modeling human-induced deformations in oil fields and on tall buildings.

Ji, K. H. and T. A. Herring , A method for detecting transient signals in GPS position time-series: smoothing and principal component analysis, Geophysical Journal International; doi: 10.1093/gji/ggt003, 2013. http://gji.oxfordjournals.org/cgi/content/full/ggt003?
ijkey=YyTqenOJc4uto9p&keytype=ref

Ji, K. H. and T. A. Herring, Testing Kalman Smoothing/PCA Transient Signal Detection Using Synthetic Data, Seismol. Res. Letters, SRL-D-12-00155R1, in press, 2013.

Alison Malcolm

Assistant Prof. Alison Malcolm’s research program has continued to focus on imaging complex structures. She is particularly excited this year, about our work on nonlinear imaging. Over the past year, Prof. Malcolm’s group has gone from very preliminary experiments suggesting that they could sense the passage of one wave with another wave to experiments which demonstrate that the signal is robust, though small and challenging to measure. They are working on applications of this work to hydraulic fracturing, imaging the fracture system and understanding the fluids that may be contained within it. Further, they have a summer student this year (from USTC, through the program Jie Zhang initiated), who will attempt to model an application to steering hydraulic fractures. Over the past year, she has also spent significant time on full-waveform inversion, an imaging technique that is rising in popularity with increasing computer power. Prof. Malcolm and her students are working on three aspects of this technique: (i) estimating the Hessian in a unique way, that she thinks may truly allow its computation, at reasonable cost, for the first time (ii) estimating the initial model in a more efficient manor, (iii) beginning to use the results in a statistical sense to determine where injected CO2 remained in the reservoir or not. In related work, she is continuing to work on microseismic data. First, they are continuing their work on jointly locating different events, to estimate things like fracture extent rather than simply the locations of events individually. They are also extending this work to estimate uncertainties in seismic images. Second, they are working on velocity analysis and imaging using microseismic data as sources. They are in the process now of applying these ideas to a field data set from Iceland to understand the location and extent of a magma chamber.

One of her papers was selected as one of the top 30 papers of last fall’s Society of Exploration Geo­physicists meeting: Poliannikov, O., Prange, M., Malcolm, A., and Djikpesse, H. (2012) Relative event localization in uncertain velocity model. SEG Technical Program Expanded Abstracts 2012: pp. 1-2.

Publications (∗ indicates the corresponding author when not the first author):

• A. Shabelansky, A. Malcolm, M. Fehler, Measuring Seismic Attenuation Changes Using a 4D Relative Spectrum Method: Case Study from a Heavy Oil Reservoir with Implications for Monitoring Viscosity Changes submitted to Geophysical Prospecting.

• O. Poliannikov, M. Prange, A. Malcolm, and H. Djikpesse, A unified framework for relative source localization using correlograms, in press Geophysical Journal International.

• A. Shabelansky, A. Malcolm, and M. Fehler Data-Driven Estimation of the Sensitivity of Target-Oriented Time-Lapse Seismic Imaging to Source Geometry, Geophysics 78, R47-58.

• G. Melo, A. Malcolm, K. van Wijk, and D. Mikesell, Using SVD for improved interferometric Greens function retrieval, in press Geophysical Journal International.

• A. E. Malcolm and D. P. Nicholls, Operator Expansions and Constrained Quadratic Optimization for Interface Reconstruction: Impenetrable Acoustic Media, In press Wave Motion.

• D. Yang, A. Malcolm, M. Fehler, L. Huang, Time-lapse VSP Walkaway Seismic Monitoring of Carbon Sequestration in SACROC: A Case Study (almost) submitted to Geophysics.

Professor Malcolm’s group has had 6 abstracts accepted for presentation/publication with this year’s SEG meeting.

John Marshall

Prof. John Marshall’s research interests are in the role of the ocean in climate and climate variability. A recent focus has been on the dynamics and biogeochemistry of the southern ocean and asymmetries in the response of the two poles to climate perturbations. He has also been studying geometrical constraints on ocean heat transport and the possibility that the climate may possess multiple equilibria. In the past year John has been instrumental in organizing oceans@mit, a cross-disciplinary amalgam of all things related to the Ocean across the Institute.

David McGee

Assistant Prof. David McGee’s research focuses on reconstructing and understanding past changes in Earth’s hydrological cycle. During the past year we have made important contributions to our understanding of the regional expression of global climate changes in the time from the last ice age to the recent past (i.e., the last 25,000 years). First, we have produced unique new records of the drying of the U.S. Great Basin over the last 25,000 years (McGee et al., EPSL 2012). Our results comprise the most precisely dated and highest resolution records from this region covering this important time period. Our work with Great Basin cave deposits continues, and we anticipate more high-impact publications to come based on stalagmite data we have recently collected. Second, we have produced quantitative estimates of windblown dust emissions from the Sahara desert over the last 20,000 years (McGee et al., EPSL 2013). This work provides important documentation of the abrupt impacts of past global climate changes on North Africa and was featured on the MIT homepage (4/5/13). A key contribution of these data is that they will allow us for the first time to be able to estimate the direct role of eolian dust in amplifying past climate changes in the region. Ongoing work seeks to extend these records through the last ice age to provide calibration data for climate models of the last glacial maximum. Finally, in collaboration with John Marshall’s group I have begun investigating the interpretation of paleo-records of tropical rainfall patterns using models and theory. This work has provided novel constraints on the response of tropical hydrology to past climate changes (Donohoe et al., Journal of Climate 2013; McGee et al., in prep.).

I have received two internal MIT awards in the past year: the Ally of Nature Fund award, and a Research Support Committee Fund award. My primary outreach work has been through serving as a freshman advisor, supporting three summer undergraduate research interns, and presenting our research results to a park volunteers, staff, and interested members of the public at Great Basin National Park.

Paul O’Gorman

Associate Prof. Paul O'Gorman’s group has continued to investigate how the atmosphere behaves in different climates. Graduate student Michael Byrne is the lead author on a paper examining the differential surface warming of land and ocean over a wide range of climates. His theoretical results indicate that the greatest contrast in warming should occur for an ocean surface temperature near 290K, although changes in surface relative humidity over land are also an important factor. Graduate student Marty Singh has investigated the reasons for an upward shift of atmospheric fields in comprehensive simulations of warming climates. Recently published results from the group indicate that there is also some observational evidence for an upward shift in the middle and upper troposphere over the period 1960-2005.

Taylor Perron

Assistant Prof. Taylor Perron and his group study the processes that shape landscapes on Earth and other planets. Their efforts are currently focused on understanding widespread patterns in landscapes, climate’s effects on erosion, and the landscapes of Mars and Saturn’s moon Titan. Perron, graduate student Paul Richardson, and postdoctoral researcher Ken Ferrier recently showed how erosional instabilities create the familiar branching pattern of river networks, a common feature of many landscapes that has lacked a theoretical explanation [Perron et al., 2012]. Perron and Prof. Leigh Royden collaborated on a new mathematical approach for inferring a landscape’s tectonic and climatic history from the elevation profiles of rivers [Royden and Perron, 2013; Perron and Royden, 2013]. Ferrier, graduate student Kim Huppert, and Perron measured erosion rates across one of the world’s steepest rainfall gradients on the Hawaiian island of Kaua‘i (Fig. 1) to discover how rainfall controls the rate at which rivers cut valleys into rock, a relationship that has been surprisingly difficult to detect [Ferrier et al., 2013]. MIT-WHOI Joint Program student Michael Toomey, WHOI researcher Andrew Ashton and Perron revisited Charles Darwin’s theory for the development of coral atolls, and found that glacial sea level cycles have left an imprint on coral reefs around the world [Toomey et al., 2013]. Finally, Perron collaborated on two reviews of the surface geology of Titan, where rivers of liquid methane erode into a surface made of ice (Fig. 2) [Burr et al., 2013; Aharonson et al., in press].

Figures:

Fig. 1. Precipitation map of the island of Kaua‘i. Numbered insets show landscapes on the wet and dry sides of the island. Modified from Ferrier et al. [2013].

Fig. 2. False-color mosaic of Cassini synthetic aperture radar images showing river networks draining into liquid hydrocarbon lakes in Titan's north polar region. Width of scene is roughly 600 km. Image: NASA/JPL-Caltech/USGS.

References:

Aharonson, O., A.G. Hayes, R. Lopes, A. Lucas, P. Hayne and J.T. Perron (2013), Titan’s Surface Geology. In Titan: Interior, Surface, Atmosphere and Space Environment, edited by I. Mueller- Wodarg, C. Griffith, E. Lellouch, and T. Cravens, Cambridge University Press, ISBN:9780521199926, in press.

Ferrier, K.L., K.L. Huppert and J.T. Perron (2013), Climatic control of bedrock river incision. Nature, 496, 206–209, doi:10.1038/nature11982.

Royden, L. and J.T. Perron (2013), Solutions of the stream power equation and application to the evolution of river longitudinal profiles. J. Geophys. Res., 118, doi:10.1002/jgrf.20031.

Perron, J.T. and L. Royden (2013), An integral approach to bedrock river profile analysis. Earth Surface Processes and Landforms, 38, 570-576, doi:10.1002/esp.3302.

Perron, J.T., P.W. Richardson, K.L. Ferrier, and M. Lapôtre (2012), The root of branching river networks. Nature, 492, 100–103, doi:10.1038/nature11672.

Toomey, M., A.D. Ashton and J.T. Perron (2013), Profiles of ocean island coral reefs controlled by sea-level history and carbonate accumulation rates. Geology, 41, 731–734, doi:10.1130/G34109.1.

Burr, D.M., J.T. Perron, M.P. Lamb, R.P. Irwin, G.C. Collins, A.D. Howard, L.S. Sklar, J.M. Moore, M. Adamkovics, V.R. Baker, S.A. Drummond and B.A. Black (2013), Fluvial features on Titan: Insights from morphology and modeling. Geological Society of America Bulletin, 125, 299-321, doi:10.1130/B30612.1.

Education and Outreach:

Perron gave a lecture on landscape patterns at the Dean’s School of Science breakfast lecture series on October 15, 2012.

Perron collaborated with MIT’s Office of Educational Innovation and Technology (OEIT) to develop public-domain geology animations. Examples can be viewed at:

http://mit-artemis.org/portfolio/tectonics/

http://mit-artemis.org/portfolio/earthcycles/

Ronald Prinn

Prof. Ronald Prinn’s Atmospheric Chemistry Group published 17 papers in 2012-2013, 5 led by students and another 4 by research scientists, and 8 using AGAGE network greenhouse gas and ozone-depleting gas data. There is international scientific and political interest in the MIT Integrated Global System Model that links sub-models of the human and natural systems (see Prinn, R. G., Development and Application of Earth System Models, Proceedings National Academy of Sciences, online first, doi: 10.1073/pnas.1107470109, 2012), with invited talks by Prinn at the Joint NAS/Royal Society 2012 Sackler Forum in London, and the 2013 100th Raman Indian Science Conference in Kolkata. The AGAGE network, now in its 35 th year, is expanding into Africa with instruments now being installed in Rwanda by Kat Potter (Ph.D., 2011). Research Scientist Eri Saikawa became an Assistant Professor at Emory University. Diane Ivy, Laura Meredith (Rossby Award) and Anita Ganesan all gained their Ph.D. degrees in 2012-2013.

Appendix: Prinn Group Publications in 2012-2013

Belikov, D.A., S. Maksyutov, M. Krol, A. Fraser, M. Rigby, H. Bian, A. Agusti-Panareda, D. Bergmann, P. Bousquet, P. Cameron-Smith, M.P. Chipperfield, A. Fortems-Cheiney, E. Gloor, K. Haynes, P. Hess, S. Houweling, S. R. Kawa, R. M. Law, Z. Loh, L. Meng, P. I. Palmer, P.K. Patra, R.G. Prinn, R. Saito, C. Wilson, Off-line algorithm for calculation of vertical tracer transport in the troposphere due to deep convection, Atmos. Chem. Phys., 13, 1093-1114, 2013, http://www.atmos-chem-phys.net/13/1093/2013/ doi:10.5194/acp-13-1093-2013.

Fraser, A. Palmer, P.I., Feng, L., Boesch H., Cogan, A., Parker, R., Dlugokencky, E. J., Fraser, P.J., Krummel, P.B., Langenfelds, R L., O’Doherty, S., Prinn, R.G., Steele, L.P., van der Schoot, M., Weiss, R.F., Estimating regional methane surface fluxes: the relative importance of surface and GOSAT mole fraction measurements, Atmos. Chem. Phys., 13, 5697-5713, 2013, http://www.atmos-chem-phys.net/13/5697/2013/ doi:10.5194/acpd-13-5697-2013.

Ganesan, A.L., A. Chatterjee, R.G. Prinn, C.M. Harth, P.K. Salameh, A.J. Manning, B.D. Hall, J. Muhle, L.K. Meredith, R.F. Weiss, S. O’Doherty and
D. Young, The variability of methane, nitrous oxide and sulfur hexafluoride in Northeast India, Atmos. Chem. Phys. Discuss. 13, 17053-17085, 2013; www.atmos-chem-phys-discuss.net/13/17053/2013/; doi:10.5194/acpd-13-17053-2013.

Ivy, D.J., T.J. Arnold, C.M. Harth, L.P. Steele, J. Muhle, M. Rigby, P.K. Salameh, M. Leist, P.B. Krummel, P.J. Fraser, R.F. Weiss, R.G. Prinn, Atmospheric histories and growth trends of C4F10, C5F12, C6F14, C7F16 and C8F18, Atmos. Chem. Phys., 12, 4313-4325, 2012, http://www.atmos-chem-phys.net/12/4313/2012/ , doi:10.5194/acp-12-4313-2012.

Ivy, D.J., M. Rigby, M. Baasandorj, J.B. Burkholder, R.G. Prinn, Global emission estimates and radiative impact of C4F10, C5F12, C6F14, C7F16 and C8F18,, Atmos. Chem. Phys. 12, 7635-7645, 2012, www.atmos-chem-phys.net/12/7635/2012/, doi:10.5194/acp-12-7635-2012.

Kirschke, S., Bousquet, P., Ciais, P., Marielle Saunois, M., Canadell, J.G., Dlugokencky, E.J., Bergamaschi, P., Bergmann, D., Blake, D.R., Bruhwiler, L., Cameron-Smith, P., Castaldi, S., Chevallier, F., Feng, L., Fraser, A., Fraser, P.J., Heimann, M., Hodson, E.L., Houweling, S., Josse, B., Krummel, P.B, Lamarque, J.-F., Langenfelds, R.L., Le Quéré, C., Naik V., O’Doherty, S., Palmer, P.I., Pison, I., Plummer, D., Poulter, B., Prinn, R.G., Rigby, M., Ringeval, B., Santini, M., Schmidt, M., Shindell, D.T., Simpson, I.J., Spahni, R., Steele, L.P., Strode, S.A., Sudo, K., Szopa, S., van der Werf, G.R., Voulgarakis, A., van Weele, M., Weiss, R.F., Williams, J.E., and Zeng, G., Three decades of global methane sources and sinks, Nature Climate, in press.

Potter K.E., S. Ono, R.G. Prinn, Fully automated, high-precision instrumentation for the isotopic analysis of tropospheric N2O using continuous flow isotope ratio mass spectrometry, Rapid Communications in Mass Spectrometry 27, 1723-1728, 2013; doi/10.1002 /rcm.662, Article first published online: 20 June 2013.

Prinn, R. G., Development and application of earth system models, Proceedings of the National Academy of Sciences, online first, doi: 10.1073/pnas.1107470109, 2012.

Rigby, M., A.J. Manning, R.G. Prinn, The value of high-frequency, high-precision methane isotopologue measurements for source and sink estimation,J. Geophys. Research 117, D12312, www.agu.org/pubs/crossref/2012/2011JD017384.shtml , doi:10.1029/2011JD017384, 2012.

Rigby, M., Prinn, R.G., O’Doherty, S., Montzka, S.A., McCulloch, A., Harth, C.M., Mühle, J., Salameh, P.K., Weiss, R.F., Young, D., Simmonds, P.G., Hall, B.D., Dutton, G.S., Nance, D., Mondeel, D.J., Elkins, J.W., Krummel, P.B., Steele, L.P., Fraser P.J., of the lifetimes of the major CFCs and CH3 CCl3 using atmospheric trends, Atmos. Chem. Phys., 13, 2691-2702, 2013, http://www.atmos-chem-phys.net/13/2691/2013/ doi:10.5194/acp-13-2691-2013.

Saikawa E., M. Rigby, R.G. Prinn, S.A. Montzka, B.R. Miller, L.J.M. Kuijpers, P.J.B. Fraser, M.K. Vollmer, T. Saito, Y.Yokouchi, C.M. Harth, J. Muhle, R.F. Weiss, P.K. Salameh, J. Kim, S. Li, S. Park, K.-R. Kim, D. Young, S. O’Doherty, P.G. Simmonds, A. McCulloch, P. B. Krummel, L.P. Steele, C. Lunder, O. Hermansen, M. Maione, J. Arduini, B. Yao, L.X. Zhou, H.J. Wang, J.W. Elkins, B. Hall, Global and regional emissions estimates for HCFC-22, Atmos. Chem. Phys., 12, 10033, 2012, http://www.atmos-chem-phys.net/12/10033/2012/ doi:10.5194/acp-12-10033-2012.

Saikawa, E., C.A. Schlosser and R.G. Prinn, Process modeling of global soil nitrous oxide emissions from natural processes, Global Biogeochemical Cycles, in review; MIT Joint Program on the Science and Policy of Global Change (Report 206), 2012.

Saito, R., Patra, P.K , Sweeney, C., Machida, T., Krol, M., Houweling, S., Bousquet, P., Agusti-Panareda, A., Belikov, D., Bergmann, D., Bian, H., Cameron-Smith, P., Chipperfield, M., Fortems-Cheiney, A., Fraser, A., Gatti, L., Gloor, E., Hess, P., Kawa, S., Law, R., Locatelli, R., Loh, Z., Maksyutov, S., Meng, L., Miller, J., Palmer, P., Prinn, R., Rigby, M., Wilson, C. TransCom model simulations of methane: comparison of vertical profiles with aircraft measurements, J. Geophys. Res. Atmos., 118, 3891-3904, first published online: doi/:10.1002/jgrd.50380, 2013.

Sun, L., M. Webster, G. McGaughey, E. C. McDonald-Buller, T. Thompson, R. Prinn, A. D. Ellerman, D. T. Allen, Flexible NOx abatement from power plants in the eastern United States, Environ. Sci. Technol., 2012, 46, 5607-5615, dx.doi.org/10.102/es204290s.

Thompson R.L., E. Dlugokencky, F. Chevallier, P. Ciais, G. Dutton, J.W. Elkins, R.L. Langenfelds, R.G. Prinn, R. F. Weiss, Y. Tohjima, P. B. Krummel, P. Fraser4, and L.P. Steele, Inter-annual variability in tropospheric nitrous oxide, Geophys. Res. Lett., in press, 2013.

Thompson, R.L., F. Chevallier, A. Crotwell, G. Dutton, R.L. Langenfelds, R.G. Prinn, R.F. Weiss, Y. Tohjima7, T. Nakazawa8, P.B. Krummel, L.P. Steele, P. Fraser, K. Ishijima, and S. Aoki, Nitrous oxide emissions 1999 – 2009 from a global atmospheric inversion, Atmos. Chem. Phys. Discuss, 13, 15697-15747, 2013.

Zhuang, Q., K. Xu, J. Tang, M. Chen, E. Saikawa, Y. Lu, J.M. Melillo, R.G. Prinn and A.D. McGuire, Response of global soil consumption of atmospheric methane due to changes in atmospheric climate and nitrogen deposition, Global Biogeochemical Cycles, in press, 2013.

Paola Rizzoli

Prof. Paola Rizzoli and her collaborators, Research Scientists Drs. Jun Wei, Pengfei Xue, Danya Xu and Haoliang Chen, have continued their research on the South China Sea and Indonesian Through Flow reconstructing the climate and circulation of the basin over four decades, 1960-2000, emphasizing local climate changes in the strait and shelf adjacent to Singapore that show considerable warming. Numerical simulations have successfully reproduced this warming which has considerable implications for the local ecosystem and the fisheries of the coastal waters. These results have just been reported in publication 1 below.

The second major focus is in the collaboration of with Prof. Eltahir’s group in the coupling of Rizzoli’s ocean model with Eltahir’s atmospheric model for simulations of the present climate of the South East Maritime Continent. The two-way coupling has been successfully completed and the results reported in publication 2 below. Research has started using the MIT statistical approach for projections of future climate change of the Maritime Continent over the decadal time scale.

Publications

1) D.Xu and P.Malanotte-Rizzoli, “The seasonal variation of the upper layers of the South China Sea (SCS) circulation and the Indonesian Through-Flow (ITF): an ocean model study” , Dyn. Atmos.Oceans, DOI:10.1016/J.dynatmoce.2013.05.05, 63 , 103-130, 2013

2) J.Wei, P.Malanotte-Rizzoli, E.Eltahir and P.Xue, “ Coupling of a regional atmospheric model (RegCM3) and a regional oceanic model (FVCOM) over the Maritime Continent”, in press in Climate Dynamics, 2013

Daniel Rothman

Prof. Daniel Rothman continues to develop a basic understanding of Earth's carbon cycle. In work published in the past year (Forney and Rothman, 2012), Rothman and his graduate student David Forney show, by a combination of empirical analysis and mathematical theory, that the decay of plant matter exhibits a lognormal distribution of degradation rates. This result derives in part from an understanding of the ways in which micro-organisms interact with a fluctuating physical environment. Rothman's current work in this area attempts to develop an understanding of the ways in which such interactions influence the long-term stability of the carbon cycle, including the Precambrian rise of atmospheric oxygen.

Noelle Selin

Assistant Prof. Noelle Selin’s research focuses on linking atmospheric chemistry modeling to decision-making about air pollution, particularly from toxics that can harm health and the environment. I use models to track the transport, chemical transformations, and environmental fate of pollutants such as mercury, persistent organic pollutants (POPs), ozone, and atmospheric particulate matter. In the past year, my group has developed new models of POPs in the atmosphere, a first effort at inverse modeling for mercury, and applied new uncertainty techniques to atmospheric chemical models and projecting pollution health impacts.

Awards: I have been awarded a Leopold Leadership Fellowship: I am one of 20 academics selected for this fellowship based on our work on linking scientific knowledge to action on sustainability challenges. For more info: http://leopoldleadership.stanford.edu/

As of July 2013, I have been selected to be an Esther and Harold E. Edgerton Career Development Professor for a three-year term.

My EAPS PhD student Colin Pike-Thackray has been awarded a Canadian NSERC graduate research fellowship.

Special educational activities: This past IAP, I took a group of 10 graduate students (including EAPS and JP students as well as students from other MIT programs) on a field trip to the final negotiating session for the Minamata Convention on mercury, which is a new global treaty regulating mercury. The students presented scientific information to the treaty negotiators, observed the sessions, and communicated back to MIT and worldwide using blogs and twitter.

I have also participated in the Southeast Atmosphere Study, a major atmospheric chemistry campaign in Summer 2013. My role was to contribute forecast and near-real-time modeling for the distribution of mercury, to help plan and interpret measurements of mercury from an aircraft platform. For more info: http://www.eol.ucar.edu/projects/sas/. EAPS student Shaojie Song and I were both in the field for that effort.

Susan Solomon

Prof. Susan Solomon’s research focuses on atmospheric chemistry and its interactions with climate change. Here a subset of the effort is briefly summarized.

Over about the past year, we have focused on the variability of climate in the context of the past and future character and detection of human-induced changes, not only in atmospheric temperatures (Deser et al., 2012; Mahlstein et al., 2012b; Santer et al., 2013a) but also in precipitation (Mahlstein et al., 2012a) and ecosystem shifts (Mahlstein et al., 2013). For example, in a paper published in Nature Climate Change, Mahlstein et al. (2013) showed that climate change should be expected to result in an increasing pace of shifts of ecosystems as the world warms in the 21st century, implying that species will have less and less time to adapt.

Scientific and public attention worldwide has been directed at the question of the recent rate of global warming, and the processes that are making it occur at a different rate than previous decades. In particular, an important result of our work is that increases in stratospheric aerosol particles have made significant contributions to the recent slowing of the decadal rate of global warming compared to the previous two, an unexpected result. We have shown that these stratospheric aerosols are due to volcanic eruptions previously thought to be of no relevance for climate. Thus, a surprising number of relatively small volcanoes can indeed influence the stratospheric aerosol layer and thereby the total global optical thickness and surface climate. Our recent work has revealed how small volcanoes can overwhelm coal burning sources (Neely et al., 2013a,b) and has also included a new analysis of how volcanic eruptions can be used to infer information about the sensitivity of the Earth’s climate to volcanic eruptions (Santer et al., 2013b).

We also focus on how stratospheric ozone is changing, its chemistry (Wegner et al., 2013) and how it affects changes in temperatures in the stratosphere as well as at the ground. Two important papers published in the past year have shown that the past changes in stratospheric ozone content based on a comprehensive analysis of observations display a greater range than previously thought. This is important because of questions regarding whether the vertical structure of warming agrees with climate model calculations, which is key to detection and attribution of human influences. Our work shows that larger uncertainties need to be applied to the cooling due to stratospheric ozone loss, which in turn has important implications for the range of uncertainty in stratospheric and tropospheric climate responses (Solomon et al., 2012; Hassler et al., 2013).

Several of our most current studies focus on how climate changes in the stratosphere are linked to the troposphere. A new paper in preparation with EAPS graduate student Justin Bandoro as first author probes how the Antarctic ozone hole appears to have much more far-reaching effects on the surface climate of many parts of the southern hemisphere than previously thought (Bandoro et al., in preparation, 2013). Bandoro’s presentation of this work at the recent American Meteorological Society Middle Atmosphere meeting was recognized with an outstanding oral student paper award. Another new paper with EAPS post-doc Diane Ivy is focused on how the Arctic stratosphere is changing, and reveals how changes in the upper stratosphere can propagate to the lower stratosphere and upper troposphere particularly in those winters when sudden stratospheric warmings do not occur (Ivy et al., submitted to J. Climate, 2013).

Publications

Deser, C., R. Knutti, S. Solomon, and A. S. Phillips, Communication of the Role of Natural Variability in Future North American Climate, Nature Climate Change, 2, 775-779, doi: 10.1038/nclimate1562, 2012.

Mahlstein, I., R. W. Portmann, J. S. Daniel, S. Solomon, and R. Knutti, Perceptible changes in regional precipitation in a future climate, Geophys. Res. Lett., 39, L05701, doi:10.1029/2011GL050738, 2012a.

Solomon, S., P. J. Young, and B. Hassler, Uncertainties in the evolution of stratospheric ozone and implications for recent temperature changes in the tropical lower stratosphere, Geophys. Res. Lett., 39, L17706, doi:10.1029/2012GL052723, 2012.

Matthews, H. D., S. Solomon, and R. Pierrehumbert, Cumulative carbon as a policy framework for achieving climate stabilization, Phil. Trans. Roy. Soc., 370, 4365-4379 doi: 10.1098/rsta.2012.0064, 2012.

Solomon, S., R. Pierrehumbert, D. Matthews, J. S. Daniel, and P. Friedlingstein, Atmospheric composition, irreversible climate change, and mitigation policy, in Climate Science for Serving Society: Research, Modelling and Prediction Priorities (J. Hurrell and G. Asrar, eds.), Springer, New York, NY, 2012.

Polvani, L. M., and S. Solomon, The signature of ozone depletion on tropical temperature trends, as revealed by their seasonal cycle in model integrations with single forcings, J. Geophys. Res., 117(D17102), doi:10.1029/2012JD017719, 2012.

Mahlstein, I., G. Hegerl, and S. Solomon, Emerging local warming signals in observational data, Geophys. Res. Lett., 39, L21711, doi:10.1029/2012GL053952, 2012b.

Emanuel, K., S. Solomon, D. Folini, S. Davis, and C. Cagnazzo, Influence of Tropical Tropopause Layer Cooling on Atlantic Hurricane Activity, J. Clim., 26, 2288–2301, 2013.

Matthews, H.D. and S. Solomon, Irreversible Does Not Mean Unavoidable, Science, 340, 438-439, doi:10.1126/science/1236372, 2013.

Shaman, J., S. Solomon, R.R. Colwell, and C.B.Field, Fostering advances in interdisciplinary climate science, From the Academy: Colloquium Introduction, Proc. Nat. Acad. Sci., 110, 3653-3656, 2013.

Santer, B.D., J.F. Painter, C.A. Mears, C. Doutriaux, P. Caldwell, J.M. Arblaster, P.J. Cameron-Smith, N.P. Gillett, P.J. Gleckler, J. Lanzante, J. Perlwitz, S. Solomon, P.A. Stott, K.E. Taylor, L. Terray, P.W. Thorne, M.F. Wehner, F.J. Wentz, T.M.L. Wigley, L.J. Wilcox, and C-Z. Zou, Identifying human influences on atmospheric temperature, Proc. Nat. Acad. Sci., 110, 26-33, 2013a.

Wegner, T., D.E,Kinnison, R.R. Garcia, and S. Solomon, Simulation of Polar Stratospheric Clouds in the Specified Dynamics Version of the Whole Atmosphere Community Climate Model, in press, J. Geophys. Res., doi:10:1029, 2013.

Neely III, R.R., O.B. Toon, S. Solomon, J.-P. Vernier, C. Alvarez, J.M. English, K.H. Rosenlof, M.J. Mills, C.G. Bardeen, J.S. Daniel and J.P. Thayer, Recent anthropogenic increases in SO2 from Asia have minimal impact on stratospheric aerosol, Geophysical Research Letters, 40, doi:10.1002/grl.50263, 2013a.

Mahlstein, I., J.S. Daniel, S. Solomon, Increasing pace of shifts in climate regions with increasing global temperature, in press, Nature Climate Change, 2013

Bandoro, J., S. Solomon, D. W. J. Thompson, A. Donohoe, and B. D. Santer, Influence of the Antarctic ozone hole on seasonal changes in climate in the southern hemisphere, in preparation, 2013.

Ivy, D. J., S. Solomon, and D. W. J. Thompson, On the identification of the downward propagation of Arctic stratospheric climate change over recent decades, submitted to J. Clim, 2013.

Neely, R. R., P. Yu, K. H. Rosenlof, O. B. Toon, J. S. Daniel, and S. Solomon, The contribution of anthropogenic SO2 emissions to the Asian tropical aerosol layer, submitted to Geophys. Res. Lett., 2013b.

Santer, B. D., C. Bonfils, J. Painter, M. Zelinka, C. Mears, S. Solomon, G. A. Schmidt, J. C. Fyfe, J. N. S. Cole, L. Nazarenko, K. E. Taylor , and F. J. Wentz, Volcanic contribution to recent changes in tropospheric warming rate, submitted to Science, 2013b.

Roger Summons

Bontognali T.R.R, Sessions A.L., Allwood A.C., Fischer W.W. Grotzinger J.P. , Summons R.E. Eiler J.M., 2012. Sulfur isotopes of organic matter preserved in 3.45-billion-year-old stromatolites reveal microbial metabolism. Proceedings of the National Academy of Sciences (USA) 109, 15146-15151.

Wakeham S.G., Turich C., Schubotz F., Podlask A., Lic X.N., Varel R., Astor Y., Sáenz J.P., Rush D., Damsté J.S.S., Summons R.E., Mary I. Scranton M.I., Gordon T. Taylor G.T. and Kai-Uwe Hinrichs K.-U., 2012. Biomarkers, Chemistry and Microbiology Show Chemoautotrophy in a Multilayer Chemocline in the Cariaco Basin. Deep Sea Research Part I: Oceanographic Research Papers 63, 133–156.

Edgcomb, V.P., Bernhard J.M., Beaudoin D., Pruss S., Welander P.V., Schubotz F., Mehay S., Gillespie A.L. and Summons R.E. (2013) Molecular indicators of microbial diversity in oolitic sands of Highborne Cay, Bahamas. Geobiology 11, 234–251.

Bernhard J.M., Edgcomb V.P., McIntyre-Wressnig A., Summons R.E. , Visscher P.T., Jeglinski, M., 2013. The potential role of foraminifera in the Neoproterozoic decline of stromatolites. Proceedings of the National Academy of Sciences (USA) www.pnas.org/cgi/doi/10.1073/pnas.1221721110.

Summons R.E., Bird L.R., Gillespie A.L., Pruss S.B., Roberts M. and Sessions A.L., 2013. Lipid biomarkers in ooids from different locations and ages: evidence for a common bacterial flora Geobiology, available online.

Johnson C.M., McLennan S.M., McSween H.Y. and Summons R.E., 2013. Smaller, better, more: Five decades of advances in geochemistry in Celebrating Advances in Geoscience, Book Chapter for 125th Anniversary of the Geological Society of America.

Hallmann C. and Summons R.E., 2013. Paleobiological Clues to Early Atmospheric Evolution Chapter 13.5 in Treatise on Geochemistry, 2nd Edition, In Press.

Summons R.E. and Hallmann C., 2013. Organic Geochemical Signatures of Early Life on Earth. Chapter 10.05 in Treatise on Geochemistry, 2nd Edition, In Press.

Edgcomb V.P., Bernhard J.M., Summons R.E., Orsi W., Beaudoin D. and Visscher P.T., 2013. Active eukaryotes in microbialites from Highborne Cay, Bahamas and Hamelin Pool (Shark Bay), Australia. ISME J, in press.

Lincoln, S. A., Bradley, A. S., Newman, S. A., and Summons, R. E., 2013, Archaeal and bacterial glycerol dialkyl glycerol tetraether lipids in chimneys of the Lost City Hydrothermal Field: Organic Geochemistry 60, 45-53.

Schubotz F., Meyer-Dombard D.R., Bradley A.S., Fredricks H.F., Shock E.L., Hinrichs K.-U., Summons R.E., 2013. The Lipid and Isotopic Compositions of Streamer Biofilm Communities in the Lower Geyser Basin of Yellowstone National Park. Geobiology, In Review.

Jack Wisdom

Professor Jack Wisdom has been studying the early evolution of the Earth-Moon system after the giant impact that is presumed to have formed the Moon. Isotopic similarities of the Earth and Moon suggest that the Moon-forming impact was more severe than previously thought, but this would leave the system with too much angular momentum. It was proposed that a resonance between the Moon and the Earth's motion about the Sun could remove the excess angular momentum. But Professor Wisdom has recently shown that this mechanism does not work, because extreme tidal heating affects the resonance dynamics and insufficient angular momentum is lost. The Moon remains a mystery.