HIPPO Research Scientists

HIPPO Scientific Team

• Steve Wofsy, Principal Investigator, Harvard University
• Elliot Atlas, Whole Air Sampler instrument, University of Miami
• Eric Kort, QCLS and CO2 instruments, Harvard University
• Bruce Daube, Mission Scientist / Instrumentation Engineer, Harvard University
• Jasna Pittman, Harvard University
• Mark Zondlo, VCSEL instrument, Princeton University
• Bin Xiang, Harvard University
• Roisin Commane, Harvard University
• Britt Stephens, Co-Principal Investigator, Airborne Oxygen and MEDUSA Air Sampler instruments, NCAR
• Teresa Campos, CO instrument, NCAR
• James Elkins, Co-Principal Investigator, NOAA
• Eric Hintsa, UCATS instrument, NOAA/CIRES
• Fred Moore, PANTHER instrument, NOAA/CIRES
• David Nance, NWAS instrument, NOAA/CIRES
• Ben Miller, Whole Air Sampler instrument, NOAA
• Steve Montzka, Whole Air Sampler instrument, NOAA
• David Fahey, Ozone / SP2 instruments, NOAA
• Ru-Shan Gao, Ozone / SP2 instruments, NOAA
• Shuka Schwarz, SP2 instrument, NOAA
• Ryan Spackman, SP2 / O3 instruments, NOAA
• Ralph Keeling, Co-Principal Investigator, MEDUSA Air Sampler instrument, Scripps Research Institute
• Jonathan Bent, MEDUSA and AO2 Instruments, Scripps Institution of Oceanography

Harvard University Scientists

Steve Wofsy, Harvard University

Lead Principal Investigator
Steve began his studies of the atmosphere after finishing his PhD in molecular physics, in 1971. He has long been interested in understanding how the chemical composition of the atmosphere is affected by the biology, chemistry and physics of the earth's soils, oceans, and air. During his career he has made measurements and constructed computer models to help understand many different aspects of this broad problem, including measurements in the stratosphere, across North America, and at forest sites from Manitoba to equatorial Brazil.

In 2004, a group of us came together to plan the program now known as HIPPO. The idea was to acquire detailed cross sections of the atmosphere in order to visualize its chemical structure in fine detail, at all spatial scales from 100m to global. HIPPO is intended to bridge the gap between small-scale aircraft data and satellite data, which has global scale but low resolution (almost no resolution in the lowest altitudes, the most sensitive to image sources of greenhouse gases). We are using the NSF HIAPER aircraft, a modified GV, which has unique capability in the world to construct this very detailed picture. The goal is to define the source regions, and to quantify the input fluxes, for the most important greenhouse gases and for many other trace gases in the atmosphere.

Elliot Atlas, University of Miami

Whole Air Sampler
Dr. Atlas' research interests are in the sources, transport, and transformation of atmospheric trace gases in the global atmosphere. This work has a primary focus on trace gases and aerosols associated with the formation and destruction of ozone in the atmosphere. The research involves development and application of advanced trace gas sampling and measurement techniques. His research group investigates the distributions and trends of a large variety of halocarbons (both natural and man-made), hydrocarbons, and photochemical oxidation products of these species (such as organic nitrates). The research extends from studies of sub-surface distribution of trace gases in the polar firn record to studies of urban and regional chemical distributions of short-lived tropopsheric gases to measurement of halocarbons in the stratosphere up to 32 km altitude. The research platforms include tropospheric and stratospheric aircraft (C-130, P-3B, ER-2, WB-57), high altitude balloons, oceanographic research ships, and land and island-based experiments. New work at RSMAS will develop techniques to examine the organic content of aerosol particles to investigate the formation and chemistry of secondary aerosol products and their impact in the global atmosphere.

Eric Kort, Harvard University

QCLS & CO₂ instruments
Eric is a graduate student in applied physics with Steve Wofsy at Harvard University. His research interests are centered on the study of greenhouse gases, their atmospheric concentrations and distributions, and key processes driving current trends in these trace gases. Eric is engaged in multiple efforts to improve our knowledge of these key atmospheric constituents; including the development of new instrumentation, in-situ atmospheric measurements, and data-model studies. For HIPPO, he works with two instruments onboard the aircraft, the CO2 and QCLS instruments, which measure carbon dioxide (duplicated), methane, nitrous oxide, and carbon monoxide.

Bruce Daube, Harvard University

Mission Scientist / Instrumentation Engineer
Bio coming soon!

Jasna Pittman, Harvard University

Jasna Pittman is a research scientist in the Wofsy group at Harvard University. Prior to joining the Wofsy group, she did analysis of aircraft and satellite data in the Atmospheric Chemistry Division at NCAR. She completed her Ph.D. in Atmospheric Sciences under the guidance of Dr. Jim Anderson and Dr. Elliot Weinstock at Harvard University. While in graduate school, she worked with aircraft instruments and participated in several aircraft campaigns that primarily sampled the tropopause region (10-15 km above ground). Understanding the processes that affect the chemical composition of the lower atmosphere is critical for accurately forecasting changes in the climate system. Thus, performing measurements of key gases such as carbon dioxide (CO₂), methane (CH₄), carbon monoxide (CO), and nitrous oxide (N₂O), comparing aircraft to satellite measurements, and modeling aircraft measurements to test our understanding of how the atmosphere works are among her main interests.

Mark Zondlo, Princeton University

VCSEL instrument
Professor Zondlo’s group conducts research in global climate change and air quality by deploying novel optical sensors in the atmosphere and analyzing the data as part of field campaigns on local to global scales. Water vapor and ammonia are examples of two important trace gas species that are critical to aerosol and cloud particle processes. Recent advances in laser-based sensors allow for unprecedented capabilities to observe these and other trace gases in the atmosphere. Instrumentation developed in the laboratory is deployed as part of international field experiments on aircraft-, network-, and ground-based platforms. Specific research areas include cloud and aerosol particle formation, trends and distribution of water vapor in the atmosphere, and emissions of greenhouse gases to the troposphere.

Bin Xiang, Harvard University

Bin obtained her PhD degree in Atmospheric Chemistry this summer from the Dept of Environmental Health Sciences, State University of New York at Albany, under the supervision of Dr. Lei Zhu. Her PhD work is focused on the gas-phase photolysis of secondary organic pollutants, unsaturated dicarbonyls in particular. The major technique used in the lab is Cavity Ring-Down Spectroscopy (CRDS) combined with laser photolysis. Some of our results suggested that atmospheric photolysis competes or supersedes the OH radical reaction in the removal of these pollutants. Bin joined the Wofsy's group in Harvard University this August as a postdoctoral fellow. She is currently involved in the instrument development on laser spectroscopy and field measurements of greenhouse gases.

Roisin Commane, Harvard University

QCLS Instrument
Roisin is one of the new post-docs working with the Harvard QCLS and OMS instruments to measure CO₂, CO, CH₄ and N₂O. She has just finished her PhD at the University of Leeds in the UK, where she was working on radical measurements. Roisin enjoy travelling and exploring new cultures and loves playing Irish music.

NCAR Scientists

Britt Stephens, NCAR

Co-Principal Investigator, AO₂ instrument & MEDUSA Air Sampler
Britt Stephens is a Scientist III in the Earth Observing Laboratory (EOL) of NCAR. Britt received a Bachelor’s degree in Earth and Planetary Sciences from Harvard in 1993 and a Ph.D. in Oceanography from the Scripps Institution of Oceanography in 1999. His research has focused on developing and deploying new instruments for tower, ship, and aircraft-based observations of atmospheric O₂ and CO₂, and on synthesizing data sets and models to elucidate global carbon cycle processes. The motivation for his work lies in our need to better understand how the Earth's biogeochemical systems, such as forests and ocean regions, respond to natural and human-induced perturbations, so that we may more accurately predict and more effectively mitigate future climate change.

Britt recently completed a synthesis of aircraft CO₂ observations and predictions of global atmospheric models, and authored a /Science/ paper on this work. This study implied a major revision to the conventional view of the global carbon cycle, and specifically that the apparent northern terrestrial missing carbon sink may instead be found in the tropics.

Britt is now participating in an ambitious global airborne field campaign, the HIAPER Pole-to-Pole Observations of Carbon Cycle and Greenhouse Gases Study (HIPPO), to further explore the global distribution of carbon sources and sinks. Among the full payload of advanced HIPPO instruments, Britt will operate two systems which he developed at NCAR - the airborne O₂ analyzer (AO₂) and the MEDUSA flask sampler - during 5 missions over the next 3 years, collecting the first comprehensive observations of the vertical and latitudinal distributions of atmospheric O₂, CO₂, and other gases.

Teresa Campos, NCAR

CO instrument
Bio coming soon!

NOAA Scientists

James Elkins, NOAA

Co-Principal Investigator
James W. Elkins was raised in McLean, VA, a suburb of Washington, DC. He attended McLean High School, a public high school specializing in education of the sciences. It was there that he developed his interest in science by participating in science fairs and national science competitions, including receiving Ford Future Scientists of America and the Westinghouse Science Talent Search (honors group) awards. He attended the University of Virginia where Professor Hugh P. Kelly, a leading expert on atomic physics and provost of the University, was his advisor. He received his Bachelor's degree in physics with high distinction in 1974. His interest in the atmospheric sciences increased while working as a summer student in 1974 under Drs. Hans Mayr and Jay Herman at NASA's Goddard Space Flight Center in Greenbelt, MD in the Laboratory of Planetary Atmospheres. He received a research scholarship and attended graduate school in the Division of Applied Physics and Engineering at Harvard University. He studied atmospheric physics under Professor Michael B. McElroy, a pioneer in the studies of global warming and the depletion of stratospheric ozone. After receiving a Master's degree in science in 1975, he worked on the atmospheric source of nitrous oxide from the ocean as his thesis topic. He received his Ph.D. in applied physics in 1978. He was a research fellow in aquatic chemistry from 1978 through 1979 under Professors McElroy and Steven C. Wofsy.

Eric Hintsa, NOAA/CIRES

UCATS instrument
Bio & picture coming soon!

Fred Moore, NOAA/CIRES

PANTHER instrument
Bio coming soon!

David Nance, NOAA/CIRES

NWAS instrument
Bio coming soon!

Ben Miller, NOAA

Whole Air Sampler
Ben joined the HATS group in early 2008, having moved from La Jolla where he had worked for nearly 18 years at the University of California, San Diego, developing in situ GCMS field instruments and primary standard calibration techniques with the Advanced Global Atmospheric Gases Experiment. He now works with Steve Montzka and others in a collaboration with the Carbon Cycle Greenhouse Gases group to study the abundances, trends, sources and sinks of about 40 halocarbons, hydrocarbons and other trace atmospheric compounds by GCMS from automated flask sampling packages acquired at the CCGG aircraft and tower sites. Ben is assisting in the logistics, sampling, analysis and interpretation of the NWAS and AWAS flask packages that are taken aboard HIPPO.

Steve Montzka, NOAA

Whole Air Sampler
Bio & picture coming soon!

David Fahey, NOAA

Ozone & SP2 instruments
In situ measurements of trace gases and aerosols in the upper troposphere and lower stratosphere, the interpretation and modeling of measurements for understanding of atmospheric photochemical and transport processes, the design and construction of aircraft instrumentation for atmospheric measurements, and the evaluation and presentation of scientific results in national and international assessments.

Ru-Shan Gao, NOAA

Ozone & SP2 instruments
Ru-Shan is a research physicist in NOAA's Earth System Research Laboratory in Boulder. Colorado, USA. His principal research interests are 1. The measurement of trace gases and aerosols in the troposphere and lower stratosphere using instruments on board research aircraft, and 2. Interpretive studies addressing stratospheric ozone depletion, the photochemistry of nitrogen oxides, the formation of nitric acid containing aerosols, and the role of black carbon aerosol in climate. Ru-Shan has participated and served as Principal Investigator for a variety of instruments on a number of airborne sampling missions with research aircraft. Ru-Shan is considered by his colleagues to be a Master Craftsman who is outstanding at creating one-of-a-kind scientific devices for laboratory and field instruments.

Shuka Schwarz, NOAA

SP2 instrument
Joshua Schwarz has been working with the Single Particle Soot Photometer (SP2) since 2004. He has played a leading role in characterizing this powerful addition to traditional measurements of aerosol black carbon and applying it to measurements in North America, the Tropics, and China, and from the surface to the lower stratosphere. His publications include technical manuscripts about the SP2 as well as scientific results and implications of these measurements. He led the NOAA SP2 instrument involvement in the first HIPPO campaign -- configuring the instrument for operation in the NSF/NCAR G-V, flying the entire route of the G-V with the instrument to ensure its proper operation and correct calibration, and finalizing and analyzing its data products. Presently he is preparing a manuscript centered around a comparison between black carbon aerosol in Aerocom global models and the SP2 observations during HIPPO I.

Ryan Spackman, NOAA

Ozone & SP2 instruments
Ryan is a research scientist at NOAA in Boulder, Colorado and will be flying on the G-V aircraft for the second phase of the HIPPO mission leading the operation of the Single Particle Soot Photometer (SP2) and NOAA Ozone instruments. Since his first field experience in the Azores in 1995 launching ozonesondes, he continues to follow his interests in conducting atmospheric measurements of trace gases and aerosols, mostly aboard research aircraft. His broader interests include collaborating with scientists who model these species to better understand the coupling between chemistry, dynamics and radiation in the atmosphere. Atmospheric observations are crucial to testing global models that scientists use to predict the evolution of greenhouse gases and aerosols that have impacts on climate.

Scripps Scientists

Ralph Keeling, Scripps Research Institute

Co-Principal Investigator, MEDUSA Air Sampler
Ralph Keeling is the current program director of the Scripps CO₂ Program. He is also a Professor and the Principle Investigator for the Atmospheric Oxygen Research Group at Scripps Institution of Oceanography.

Jonathan Bent, Scripps Institution of Oceanography

AO₂ instrument & MEDUSA Air Sampler
Jonathan Bent is a doctoral student at Scripps Institution of Oceanography in San Diego, CA. He studies atmospheric chemistry under Ralph Keeling. Jonathan has worked on the START08, HIPPO Phase I and HIPPO Phase II campaigns, and operates the AO₂ and MEDUSA instruments.