About the Atmospheric Chemistry Group

Principal Investigator: 

Dr. Jack Dibb

Research Staff:

Eric Scheuer
Katharine Duderstadt 

Graduate Students:

Eric Heim 
Hannah Munro

Alumni:

James Lazarcik 
Jacqueline M Amante 
Dr. Chelsea Corr
Dr. Luke Ziemba 
Casey Anderson 
Jeffery Luxford

Sunlight Absorption of the Greenland ice sheet Experiment (SAGE)
[NASA Interdisciplinary Science Program]
Our group quantified black carbon (BC) and major soluble ions (including tracers of dust and biomass burning smoke) in ~ 5000 snow samples collected from 65 snow pits in the central and northwestern portions of the Greenland ice sheet. Fieldwork was conducted by collaborators at Dartmouth College and CRREL via surface traverses in the spring of 2013 and 2014. Our results were instrumental in showing that on the high plateau of the ice sheet the abundance of BC and dust is too small to have a significant impact on albedo (hence snow melt) and did not contribute to the record wide spread melt event in summer 2012. We have also shown that the combination of satellite data products and a state of the art regional chemical transport model can connect BC from smoke in the snow in Greenland to specific fires, but the model does not accurately simulate the amount of BC that is deposited to the snow which is critical to estimate the likely impact of increasing wildfires on the contributions of Greenland melt to global sea level. The team is wrapping up several additional papers which will show that: a lot of processes need to combine in a precise way to deposit enough smoke derived BC on Greenland that it could promote melt (many smoke plumes pass over the ice sheet but leave little or no signal in the snow), and that BC in the snow is more significant climatically than BC in the atmosphere. In fact, smoke over the ice sheet tends to cool the surface snow despite warming the layer of the atmosphere containing the smoke and exerting positive forcing at the top of the atmosphere. 

Korean-US Air Quality Mission (KORUS-AQ)
[NASA Tropospheric Chemistry Program]
The KORUS-AQ mission is a collaborative analysis of Korean air quality conducted between NASA and the Korean National institute of Environmental Research (NEIR). The mission field work was completed in spring of 2016 and utilized measurements from several aircraft, marine vessels, and satellites. The combined data set is one of the largest yet compiled by NASA in a single mission of this type. The primary objectives of the mission aim at understanding the dynamic processes affecting the atmosphere of western Asia, and those impacts on the Korean Peninsula. South Korean atmosphere is in constant flux from biogenic and anthropogenic inputs both domestic and from abroad and complex meteorology adds further levels of seasonal variation. The Atmospheric group of the UNH ERSC played a major role in airborne measurements during the mission. Operating several instruments onboard the NASA DC-8 flying laboratory, both gas and particle phase chemistry were measured. Some major constituents measured by the group include the soluble ions (Ca2+, Mg2+, SO42-,NO3-, Cl-,Br-) as well as gas phase HN03. Current research is focused on understanding how Asian dust acts as a transport mechanism for anthropogenic pollution produced in the industrial centers of eastern China to the Korean mainland. Asian dust is quite pervasive in Korea and regularly leads to visibility and health problems; the loading of anthropogenic acids further complicates the negative effects of dust. Current research will be presented at the 2017 American Geophysical Union’s annual meeting in New Orleans. 

Atmospheric Tomography Mission (ATom)
[NASA Earth Venture Suborbital Program]
Between 2016 and 2018, we are participating in a campaign dubbed the Atmospheric Tomography Mission, or “ATom”. With a team of about 25 research groups from around United States in addition to aircraft personnel, we are studying human produced pollution, greenhouse gasses, and how reactive gasses interact in the remote troposphere and lower stratosphere (0.2 – 12 km). Understanding of the production of, lifetime, and impacts on chemistry and radiative forcing of fine particulate (aerosols) is also a very high priority. All of these measurements are used to improve the predictive capability of global climate models while helping validate space based remote sensors. This series of campaigns consists of 4 month-long global scale science campaigns (August, 2016; February and October, 2017; and May 2018) flying the DC-8 mobile laboratory around the world from its home base in Palmdale, California. Destinations along the route include Anchorage, Alaska; Kona, Hawaii; Nadi, Fiji; Christchurch, New Zealand; Punta Arenas, Chile; Ascension Island; Terceira, Azores; and Thule, Greenland. Flights to Alaska and Greenland extend to ~ 80 N and for the last two campaigns we will fly South from Chile to ~ 75 S. Each flight consists of making measurements while continuously profiling from 500 feet above sea level to the maximum altitudes that the plane can safely achieve to get a comprehensive representation of the surrounding environment. A concerted effort is being made to make this data available for public use as soon as possible. Currently, as of August 2017, the data collected during the first campaign (August, 2016) is available at the NASA Earth Science Project Office website. https://espoarchive.nasa.gov/archive/browse/atom with a planned release of the February, 2017 data in December, 2017. 

Fire Influence on Regional and global environments Experiment (FIREX)
[NOAA Climate Program]
FIREX is a study on “The Impact of Biomass Burning on Climate and Air Quality: An Intensive Study of Western North America Fires”. Our contributions will be collaborative studies with researchers from Brown University; 1) at the Forest Service firelab in Missoula, some of which have already been conducted, and 2) sampling wildfire smoke plumes from a mobile lab over the summers of 2018 and 2019. Our sampling is focused on nitrogen oxide compounds, with measurements designed to determine both concentration and isotopic composition of NOx (= NO + NO2), HNO3, HONO and aerosol nitrate in wildfire smoke in the Western United States. There will be focus on taking measurements at night, as well as during the day, to potentially fill in gaps in current scientific knowledge especially by sampling closer to fires and much closer to the ground than the NOAA, NASA and NSF aircraft also participating in the study will be able to. NOx compounds play an important role in the oxidation capacity of the atmosphere, and are the primary source of HNO3 and particulate nitrate; two major contributors to acid rain and nitrogen deposition. Nitrogen oxide compounds found in wildfire smoke can be transported long distances and have far reaching impacts on air quality, climate and ecosystem health. NOx contributions from wildfires have seasonal impacts on pristine regions that are particularly sensitive to regional haze and nitrogen deposition. Isotopic composition tracking has the potential to enhance understanding of the transformation and fate of NOx compounds as they move further from the fire source.

Atmospheric Impacts of Energetic Particles (Sun-to-Ice)
[NSF Frontiers in Earth System Dynamics]
Simulations using the Whole Atmosphere Community Climate Model (WACCM-CESM) from the National Center for Atmospheric Research (NCAR) combined with observations from spacecraft and ground-based monitors allow us to quantify atmospheric impacts of energetic particles from the Earth’s magnetosphere, the Sun, and our galaxy. These high-energy electrons, protons, and ions can enhance hydrogen oxides radicals (HOx) and total reactive odd nitrogen (NOy) in the upper atmosphere, leading to the destruction of stratospheric ozone (O3) and potentially influencing global climate. Members of the Atmospheric Chemistry Group have been working with researchers in the Space Science Center to quantify these atmospheric impacts, using space-based data from instruments developed at UNH (e.g., on board the NSF FIREBIRD CubeSats and NASA Van Allen Probes spacecraft) as input to atmospheric model simulations. Solar and galactic cosmic rays that fluctuate with solar activity also produce radioactive isotopes such as 14C, 10Be, and 36Cl in the atmosphere that are eventually sequestered at the surface in paleoclimate archives such as ice cores and tree rings. Our hope is to combine satellite and ground-based measurements of cosmic rays, global climate modeling, and paleoclimate archives to develop reconstructions of historical solar activity. Understanding past solar activity will greatly improve the ability to predict the frequency and strength of future solar storms as well as possible solar influences on global and regional climate. We are also conducting WACCM simulations of 7Be, a relatively short-lived radioisotope produced in the upper atmosphere by cosmic rays, along with 222Rn (and decay product 210Pb), a radioisotope emitted at the Earth’s surface. Comparisons of model results with global observational networks can enhance our understanding not only of energetic particle impacts but also stratosphere-troposphere exchange and aerosol deposition. The plan is to compare these WACCM simulations with similar work being done using the GEOS-Chem model.

• NASA-EPSCOR, 2013-2016
• SEAC4RS, 2013 (NASA DC-8)
• ARCTAS, 2009 (NASA DC-8)
• SHARP, 2009 (Houston, TX)
• TC4, 2007 (NASA DC-8)
• TexAQS-II, 2006 (Houston, TX)
• INTEX-B, 2006 (NASA DC-8)
• PAVE, 2005 (NASA DC-8)
• DICE, 2003 (NASA DC-8)
• TRACE-P, 2001 (NASA DC-8)
• TOPSE (NSF C-130)
• PEM-Tropics B, 1999 (NASA DC-8)
• SONEX, 1997 (NASA DC-8)
• PEM-Tropics A, 1996 (NASA DC-8)
• PEM-West B, 1994 (NASA DC-8) 

2018

Haskins, J. D., L. Jaegle, V. Shah, B. H. Lee, F. D. Lopez-Hilfiker, P. Campuzano-Jost, J. C. Schroder, D. Day, H. Guo, A. Sullivan, R. Wever, J. DIbb T. Campos, J. L. Jimenez, S. S. Brown, and J. A. Thornton (2018), Wintertime gas-particle partitioning and speciation of inorganic chlorine in the lower troposphere over the Northeast United States and coastal ocean, Journal of Geophysical Research, https://doi: 10.1029/2018JD028786.

 Kenagy, H. S., T. L. Sparks, C. J. Ebben, P. J. Wooldridge, F. D. Lopez-Hilfiker, B. H. Lee, J. A. Thornton, E. E. McDuffie, D. L. Fibiger, S. S. Brown, D. D. Montzka, A. J. Weinheimer, J. C. Schroder, P. Campuzano-Jost, D. A. Day, J. L. Jimenez, J. E. Dibb, T. Campos, V. Shah, L. Jaegle, and R. C. Cohen (2018), NO_x lifetime and NO_y partitioning during WINTER, Journal of Geophysical Research: Atmospheres, 123. https://doi.org/10.1029/2018JD028736.

 Li, J., J. Mao, A. M. Fiore, R. C. Cohen, J. D. Crounse, A. P. Teng, P. O. Wennberg, B. H. Lee, F. D. Lopez-Hilfiker, J. A. Thornton, J. Peischl, I. B. Pollack, T. B. Ryerson, P. Veres, J. M. Roberts, J. A. Neuman, J. B. Nowack, G. M. Wolfe, T. F. Hanisco, A. Fried, H. B. Singh, J. Dibb, F. Paulot and L. Horowitz (2018), Decadal changes in summertime reactive oxidized nitrogen and surface ozone over the Southeast United States, Atmospheric Chemistry and Physics, 18, 2341-2361, https://doi.org/10.5194/acp-18-2341-2018.

McDuffie, E. E., D. L. Fibiger, W. P. Dube, F. L. Hilfiker, B. H. Lee, L. Jaegle, H. Guo, R. J. Weber, J. M. Reeves, A. J. Weinheimer, J. C. Schroder, P. Campuzaon-Jost, J. L. Jimenez, J. E. Dibb, P. Veres, C. Ebben, T. L. Sparks, P. J. Wooldridge, R. C. Cohen, T. Campos, S. R. Hall, K. Ullmann, J. M. Roberts, J. A. Thornton, and S. S. Brown (2018), ClNO₂ yields from aircraft measurements during the 2015 WINTER campaign and critical evaluation of the current parameterization, Journal of Geophysical Research, https://doi.org/10.1029/2018JD029358.

McDuffie, E. E., D. L. Fibiger, W. P. Dube, F. Lopez-Hilfiker, B. H. Lee, J. A. Thornton, V. Shah, L. Jaegle, H. Guo, R. J. Weber, J. M. Reeves, A. J. Weinheimer, J. C. Schroder, P. Campuzano-Jost, J. L. Jimenez, J. E. Dibb, P. Veres, C. Ebben, T. L. Sparks, P. J. Woolridge, R. C. Cohen, R. S. Hornbrook, E. C. Apel, T. Campos, S. R. Hall, K. Ullmann, and S. S. Brown (2018), Heterogeneous N₂O₅ uptake during winter: Aircraft measurements during the 2015 WINTER campaign and critical evaluation of current parameterizations, Journal of Geophysical Research: Atmospheres, 123, 4345-4372. https://doi.org/10.1002/2018JD028336.

 Romer, P. S.,  P. J. Wooldridge, J. D. Crounse, M. Kim, P. O. Wennberg, J. E. Dibb, E. Scheuer, D. R. Blake, S. Meinardi, A. L. Brosius, A. B. Thames, D. O. Miller, W. H. Brune, and R. C. Cohen (2018), Constraints on aerosol nitrate photolysis as a potential source of HONO and NO_x, Environmental Science and Technology, Article ASAP (web publication), DOI:10.1021/acs.est.8b03861.

 Schroder, J. C., P. Campuzano-Jost, D. A. Day, V. Shah, K. Larson, J. M. Sommers, A. P.  Sullivan, T. Campos, J. M. Reeves, A. Hills, R. S. Hornbrook, N. J. Blake, E. Scheuer, H. Guo, D. L. Fibiger, E. E. McDuffie, P. L. Hayes, R. J. Weber, J. E. Dibb, E. C. Apel, L. Jaegle, S. S. Brown, J. A. Thornton, and J. L. Jimenez (2018), Sources and secondary production of organic aerosols in the Northeastern US during WINTER, Journal of Geophysical Research: Atmospheres, 123.https://doi.org/10.1029/2018JD028475.

 Ward, J. L., M. G. Flanner, M. Bergin, J. E. Dibb, C. M. Polashenski, A. J. Soja, and J. L. Thomas (2018), Modeled response of Greenland snowmelt to the presence of biomass burning-based absorbing aerosols in the atmosphere and snow, Journal of Geophysical Research: Atmospheres 123, 6122-6141. https://doi.org/10.1029/2017JD027878.

2017

Adolph, A. , M. R. Albert, J. Lazarckik, J. E. Dibb, J. M. Amante, A. Price (2017) Dominance of grain size impacts on seasonal snow albedo at deforested sites in New Hampshire, Journal of Geophysical Research, 122, 121-139, doi:10.1002/2016JD025362.

Amaral, T., C. P. Wake, J. E. Dibb, E. A. Burakowski, and M. Stampone (2017), A simple model for predicting snow albedo decay using observations from the Community Collaborative Rain, Hail, and Snow-Albedo (CoCoRAHS-Albedo) Network, Journal of Glaciology, 63, 877-887, https://doi.org/10.1017/jog.2017.54.

Contosta, A. R., A. Adolph, D. Burchsted, E. Burakowski, M. Green, D. Guerra, M. Albert, J. Dibb, M. Martin, W. H. McDowell, M. Routhier, C. Wake, R. Whitaker, and W. Wollheim (2017), A longer vernal window: The role of winter coldness and snowpack in driving spring thresholds and lags, Global Change Biology, 23, 1610-1625, doi: 10.1111/gcb.13517.

Lai, A. M., M. M. Shafer, J. E. Dibb, C. M. Polashenski, and J. J. Schauer (2017), Elements and inorganic ions as source tracers in recent Greenland snow, Atmospheric Environment, 164, 205-215, http://dx.doi.org/10.106/j.atmosenv.2017.05.048.

 Lazarcik, J., J. E. Dibb, A. C. Adolph, J. M. Amante, C. P. Wake, E. Scheuer, M. M. Mineau, and M. R. Albert (2017) Major fraction of black carbon is flushed from the melting New Hampshire snowpack nearly as quickly as soluble impurities, Journal of Geophysical Research, 122, 537-553, doi:10.1002/2016JD025351.

 Lazarcik, J., and J. E. Dibb (2017), Evidence of road salt in New Hampshire’s snowpack hundreds of meters from roadways,Geosciences, 7, 54, doi:10.3390/geosciences7030054.

Nault, B. A., J. L. Laughner, P.J. Wooldridge, J. D. Crounse, J. Dibb, G. Diskin, J. Peischl, J. R. Podolske, I. B. Pollack, T. B. Ryerson, E. Scheuer, P. O. Wennberg, and R. C. Cohen (2017), Lightning NO_x emissions: Reconciling measured and modeled estimates with updated NO_x chemistry, Geophysical Research Letters, 44, 9479-9488, doi:10.1002/2017GL074436.

 Thomas, J. L., C. M. Polashenski, A. J. Soja, L. Marelle, K. Casey, H. D. Choi, J.-C. Raut, C. Wiedinmyer, L. Emmons, J. Fast, J. Pelon, K. S. Law, M. G. Flanner, and J. E. Dibb (2017), Quantifying black carbon deposition over the Greenland ice sheet from forest fires in Canada, Geophysical Research Letters, doi:10.1002/2017GL073701.

 Zhang, Y., H. Forrister, J. Liu, J. Dibb, B. Anderson, J. P. Schwarz, A. E. Perrring, J. L. Jimenez, P. Campuzano-Jost, Y. Wang, A. Nenes, and R. J. Weber (2017), Brown carbon in the upper troposphere affects top of atmosphere radiative forcing, Nature Geoscience, doi:10.1038/NGEO2960.

2016

Duderstadt, K. A, J. E. Dibb, N. A. Schwadron, H. E. Spence, S. C. Solomon, V. A. Yudin, C. H. Jackman, and C. E. Randall (2016), Nitrate ions spikes in ice cores are not suitable proxies for solar proton events, Journal of Geophysical Research, 121, doi:10.1002/2015JD023805.

Duderstadt, K. A., J. E. Dibb, C. H. Jackman, C. E. Randall, N. A. Schwadron, S. C. Solomon, and H. E. Spence (2016), Comment on “Atmospheric ionization by high-fluence, hard spectrum solar proton events and their probable appearance in the ice core archive” by A. L. Melott et al. [2016], Journal of Geophysical Research, 121, doi:10.1002/2016JD025220.

2014

Duderstadt, K. A., J. E. Dibb, C. H. Jackman, C. E. Randall, S. C. Solomon, M. J. Mills, N. A. Schwadron, and H. E. Spence (2014), Nitrate deposition to surface snow at Summit, Greenland following the 9 November 2000 solar proton event, Journal of Geophysical Research 119, 6938-6957, doi:10.1002/2013JD021389.