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1. NO x Lifetime and NO y Partitioning During WINTER

   https://doi.org/10.1029/2018JD028736  

   Kenagy, Hannah S. ; Sparks, Tamara L. ; Ebben, Carlena J. ; Wooldrige, Paul J. ; Lopez-Hilfiker, Felipe D. ; Lee, Ben H. ; Thornton, Joel A. ; McDuffie, Erin E. ; Fibiger, Dorothy L. ; Brown, Steven S. ; et al ( September 2018 , Journal of Geophysical Research: Atmospheres)
2. ClNO 2 Yields From Aircraft Measurements During the 2015 WINTER Campaign and Critical Evaluation of the Current Parameterization

   https://doi.org/10.1029/2018JD029358  

   McDuffie, Erin E. ; Fibiger, Dorothy L. ; Dubé, William P. ; Lopez Hilfiker, Felipe ; Lee, Ben H. ; Jaeglé, Lyatt ; Guo, Hongyu ; Weber, Rodney J. ; Reeves, J. Michael ; Weinheimer, Andrew J. ; et al ( November 2018 , Journal of Geophysical Research: Atmospheres)

   Nitryl chloride (ClNO₂) plays an important role in the budget and distribution of tropospheric oxidants, halogens, and reactive nitrogen species. ClNO₂is formed from the heterogeneous uptake and reaction of dinitrogen pentoxide (N₂O₅) on chloride‐containing aerosol, with a production yield,ϕ(ClNO₂), defined as the moles of ClNO₂produced relative to N₂O₅lost. Theϕ(ClNO₂) has been increasingly incorporated into 3‐D chemical models where it is parameterized based on laboratory‐derived kinetics and currently accepted aqueous‐phase formation mechanism. This parameterization modelsϕ(ClNO₂) as a function of the aerosol chloride to water molar ratio. Box model simulations of night flights during the 2015 Wintertime INvestigation of Transport, Emissions, and Reactivity (WINTER) aircraft campaign derived 3,425 individualϕ(ClNO₂) values with a median of 0.138 and range of 0.003 to 1. Comparison of the box model median to those predicted by two other field‐basedϕ(ClNO₂) derivation methods agreed within a factor of 1.3, within the uncertainties of each method. In contrast, the box model median was 75–84% lower than predictions from the laboratory‐based parameterization (i.e., [parameterization − box model]/parameterization). An evaluation of factors influencing this difference reveals a positive dependence ofϕ(ClNO₂) on aerosol water, opposite to the currently parameterized trend. Additional factors may include aqueous‐phase competition reactions for the nitronium ion intermediate and/or direct ClNO₂loss mechanisms. Further laboratory studies of ClNO₂formation and the impacts of aerosol water, sulfate, organics, and ClNO₂aqueous‐phase reactions are required to elucidate and quantify these processes on ambient aerosol, critical for the development of a robustϕ(ClNO₂) parameterization.

    

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3. Top-Down Estimates of NO x and CO Emissions From Washington, D.C.-Baltimore During the WINTER Campaign

   https://doi.org/10.1029/2018JD028539  

   Salmon, O. E. ; Shepson, P. B. ; Ren, X. ; He, H. ; Hall, D. L. ; Dickerson, R. R. ; Stirm, B. H. ; Brown, S. S. ; Fibiger, D. L. ; McDuffie, E. E. ; et al ( July 2018 , Journal of Geophysical Research: Atmospheres)
4. Extreme wave activity during 2013/2014 winter and morphological impacts along the Atlantic coast of Europe: EXTREME ATLANTIC WAVES DURING 2013/2014

   https://doi.org/10.1002/2015GL067492  

   Masselink, Gerd ; Castelle, Bruno ; Scott, Tim ; Dodet, Guillaume ; Suanez, Serge ; Jackson, Derek ; Floc'h, France ( March 2016 , Geophysical Research Letters)
5. Winter CO 2 Efflux From Sagebrush Shrublands Distributed Across the Rain‐to‐Snow Transition Zone

   https://doi.org/10.1029/2019JG005325  

   Fellows, Aaron W. ; Flerchinger, Gerald N. ; Seyfried, Mark S. ; Biederman, Joel A. ; Lohse, Kathleen A. ( February 2020 , Journal of Geophysical Research: Biogeosciences)

   The projected shifts in winter weather and snowpack conditions are expected to impact carbon storage in western U.S. rangelands. Sagebrush shrublands comprise much of the western United States, yet contribution of winter CO₂efflux to the overall carbon budget of these ecosystems remains uncertain. We explored factors controlling winter CO₂efflux measured using eddy covariance at five sagebrush‐dominated sites along an elevation/climate transect extending from 1,425 to 2,111 m. Results showed that winter CO₂efflux was modest but had important impacts on annual carbon budgets, and its impact increased in high‐elevation, snow‐dominated ecosystems compared to low, rain‐dominated ones. Observed cumulative winter CO₂efflux accounted for 8–30% of annual gross ecosystem production (GEP) and roughly approximated annual net carbon uptake. Omission of winter periods would have increased net uptake by 1.5 to 2.2 times. Within‐site variability in observed 30‐min winter CO₂efflux was related to soil temperature and moisture. Between‐site variability was attributed to available carbon stocks, including soil organic carbon and the previous year's GEP. At low elevations, lack of snow cover to insulate soil from freezing, coupled with lower carbon stocks, limited CO₂efflux. Conversely, large carbon stocks and deep snowpack that prevented soil freezing at high elevation led to increased CO₂efflux. These results show how climate and biota exert strong controls on winter ecosystem respiration and extend our understanding of how state factors influence winter CO₂efflux. Collectively, our findings suggest that an upward climatic shift in the rain‐to‐snow transition elevation may alter the carbon budget of sagebrush shrublands.

    

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