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Southeast Nexus: Studying the Interactions Between Natural and Anthropogenic Emissions at the Nexus of Climate Change and Air Quality.  SENEX was a NOAA P-3 aircraft campaign based near Nashville, TN with research flights across the southeast and midwestern US.  The Southeast US has large biogenic emissions, and one goal was to characterize their interactions with anthropogenic emissions of air pollutants. Our group deployed two instruments. The first was the Airborne Cavity Enhanced Spectrometer (ACES), which made its first research flights during this campaign and produced the first high resolution map of glyoxal over the large isoprene emitting regions of the southeast U.S.  The second was the nitrogen oxide cavity ring down spectrometer, with a focus on the nighttime chemistry of NO₃and N₂O₅. Analysis of night flights demonstrated the degree to which NO₃radicals arising from NO_xpollution influences nighttime isoprene oxidation occurring in the residual layer and showed that the southeast is in a transition between NO_xsaturated and NO_xlimited nighttime chemistry.

Selected Papers

Fry, J.L., S.S. Brown, A.M. Middlebrook, P.M. Edwards, P. Campuzano-Jost, D.A. Day, J.L. Jimenez, H.M. Allen, T.B. Ryerson, I. Pollack, M. Graus, C. Warneke, J.A. de Gouw, C.A. Brock, J. Gilman, B.M. Lerner, W.P. Dubé, J. Liao, and A. Welti, Secondary organic aerosol (SOA) yields from NO3 radical + isoprene based on nighttime aircraft power plant plume transects. Atmos. Chem. Phys., 2018. 18(16): p. 11663-11682. 

Edwards, P.M., K.C. Aikin, W.P. Dube, J.L. Fry, J.B. Gilman, J.A. de Gouw, M.G. Graus, T.F. Hanisco, J. Holloway, G. Hubler, J. Kaiser, F.N. Keutsch, B.M. Lerner, J.A. Neuman, D.D. Parrish, J. Peischl, I.B. Pollack, A.R. Ravishankara, J.M. Roberts, T.B. Ryerson, M. Trainer, P.R. Veres, G.M. Wolfe, C. Warneke, and S.S. Brown, Transition from high- to low-NO_x control of night-time oxidation in the southeastern US. Nature Geosci, 2017. 10(7): p. 490-495. 

Li, J., J. Mao, K.-E. Min, R.A. Washenfelder, S.S. Brown, J. Kaiser, F.N. Keutsch, R. Volkamer, G.M. Wolfe, T.F. Hanisco, I.B. Pollack, T.B. Ryerson, M. Graus, J.B. Gilman, B.M. Lerner, C. Warneke, J.A. de Gouw, A.M. Middlebrook, J. Liao, A. Welti, B.H. Henderson, V.F. McNeill, S.R. Hall, K. Ullmann, L.J. Donner, F. Paulot, and L.W. Horowitz, Observational constraints on glyoxal production from isoprene oxidation and its contribution to organic aerosol over the Southeast United States. Journal of Geophysical Research: Atmospheres, 2016. 121(16): p. 9849-9861. 

Kaiser, J., G.M. Wolfe, K.E. Min, S.S. Brown, C.C. Miller, D.J. Jacob, J.A. deGouw, M. Graus, T.F. Hanisco, J. Holloway, J. Peischl, I.B. Pollack, T.B. Ryerson, C. Warneke, R.A. Washenfelder, and F.N. Keutsch, Reassessing the ratio of glyoxal to formaldehyde as an indicator of hydrocarbon precursor speciation. Atmos. Chem. Phys., 2015. 15(13): p. 7571-7583.