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- Keyword
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- Aerosol equilibrium; dust; chemical transport model (1)
- Aerosol transport; aerosol radiative forcing; rural New England (1)
- Aerosols (1)
- Aerosols; PM2.5; MODIS (1)
- Aerosols; TRACE-P; Asia (1)
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- Aerosols; radioisotopes; beryllium; stratosphere-troposphere exchange (1)
- Aerosols; special field campaigns; instrument comparison (1)
- Airborne aerosol sampling; inlet passing efficiency; tropical Pacific; PEM Tropics B (1)
- Airborne aerosol; chemical composition; intercomparison (1)
- Airborne formaldehyde measurements; tunable diode laser measurements; formaldehyde measurements at high latitudes; formaldehyde during TOPSE (1)
- Aircraft measurement intercomparison; chemistry instruments (1)
- Asian outflow; TRACE-P; aerosol-associated soluble ions; beryllium-7; lead-210 (1)
- Atmospheric chemistry; bromine; Arctic (1)
- Atmospheric composition and structure; troposphere; composition and chemistry; constituent transport and chemistry (1)
- Atmospheric mercury (1)
- Beryllium-7; Be-7; 7Be; ozone; stratosphere/troposphere exchange; polar sunrise (1)
- Biomass burning (1)
- Carbonyl sulfide (OCS); carbon disulfide (CS2); Asian emissions; emission inventories (1)
- Carrington event; ice core; nitrate; sep (1)
- Chemical data assimilation; ozone; ozone and reactive nitrogen budget (1)
- Chemical transport model; lateral boundary condition; ICARTT (1)
- Convection; vertical transport; chemical tracers (1)
- Dust (1)
- Firn densification; ice sheet; mass balance; satellite altimetry (1)
- Gaseous elemental mercury (1)
- Gaseous oxidized mercury (1)
- Greenland Ice Sheet; particulate matter organic carbon (1)
- Greenland ice sheet; organic carbon; particulate matter (1)
- Greenland; MODIS; degradation; dust; albedo; black carbon (1)
- Gulf of Mexico (1)
Articles 1 - 30 of 150
Full-Text Articles in Physical Sciences and Mathematics
Spectral Aerosol Extinction (Spex): A New Instrument For In Situ Ambient Aerosol Extinction Measurements Across The Uv/Visible Wavelength Range, C. E. Jordan, B E. Anderson, A J. Beyersdorf, C A. Corr, Jack E. Dibb, Margaret E. Greenslade, R F. Martin, R H. Moore, Eric Scheuer, M A. Shook, Kenn L. Thornhill, D Troop, Luke D. Ziemba, E L. Winstead
Spectral Aerosol Extinction (Spex): A New Instrument For In Situ Ambient Aerosol Extinction Measurements Across The Uv/Visible Wavelength Range, C. E. Jordan, B E. Anderson, A J. Beyersdorf, C A. Corr, Jack E. Dibb, Margaret E. Greenslade, R F. Martin, R H. Moore, Eric Scheuer, M A. Shook, Kenn L. Thornhill, D Troop, Luke D. Ziemba, E L. Winstead
Earth Sciences
We introduce a new instrument for the measurement of in situ ambient aerosol extinction over the 300– 700 nm wavelength range, the spectral aerosol extinction (SpEx) instrument. This measurement capability is envisioned to complement existing in situ instrumentation, allowing for simultaneous measurement of the evolution of aerosol optical, chemical, and physical characteristics in the ambient environment. In this work, a detailed description of the instrument is provided along with characterization tests performed in the laboratory. Measured spectra of NO2 and polystyrene latex spheres (PSLs) agreed well with theoretical calculations. Good agreement was also found with simultaneous aerosol extinction measurements at …
Neither Dust Nor Black Carbon Causing Apparent Albedo Decline In Greenland's Dry Snow Zone: Implications For Modis C5 Surface Reflectance, Chris Polashenski, Jack E. Dibb, Mark G. Flanner, Justin Y. Chen, Zoe R. Courville, Alexandra M. Lai, James J. Schauer, Martin M. Shafer, Mike Bergin
Neither Dust Nor Black Carbon Causing Apparent Albedo Decline In Greenland's Dry Snow Zone: Implications For Modis C5 Surface Reflectance, Chris Polashenski, Jack E. Dibb, Mark G. Flanner, Justin Y. Chen, Zoe R. Courville, Alexandra M. Lai, James J. Schauer, Martin M. Shafer, Mike Bergin
Earth Sciences
Remote sensing observations suggest Greenland ice sheet (GrIS) albedo has declined since 2001, even in the dry snow zone. We seek to explain the apparent dry snow albedo decline. We analyze samples representing 2012–2014 snowfall across NW Greenland for black carbon and dust light-absorbing impurities (LAI) and model their impacts on snow albedo. Albedo reductions due to LAI are small, averaging 0.003, with episodic enhancements resulting in reductions of 0.01–0.02. No significant increase in black carbon or dust concentrations relative to recent decades is found. Enhanced deposition of LAI is not, therefore, causing significant dry snow albedo reduction or driving …
Brown Carbon Aerosol In The North American Continental Troposphere: Sources, Abundance, And Radiative Forcing, J. Liu, Eric Scheuer, Jack E. Dibb, G S. Diskin, L D. Ziemba, K L. Thornhill, B E. Anderson, A Whisthaler, T Mikoviny, J J. Devi, M Bergin, A E. Perring, M Z. Markovic, J P. Schwarz, P Campuzano-Jost, D A. Day, J L. Jimenez, R J. Weber
Brown Carbon Aerosol In The North American Continental Troposphere: Sources, Abundance, And Radiative Forcing, J. Liu, Eric Scheuer, Jack E. Dibb, G S. Diskin, L D. Ziemba, K L. Thornhill, B E. Anderson, A Whisthaler, T Mikoviny, J J. Devi, M Bergin, A E. Perring, M Z. Markovic, J P. Schwarz, P Campuzano-Jost, D A. Day, J L. Jimenez, R J. Weber
Earth Sciences
Chemical components of organic aerosol (OA) selectively absorb light at short wavelengths. In this study, the prevalence, sources, and optical importance of this so called brown carbon (BrC) aerosol component are investigated throughout the North American continental tropospheric column during a summer of extensive biomass burning. Spectrophotometric absorption measurements on extracts of bulk aerosol samples collected from an aircraft over the central USA were analyzed to directly quantify BrC abundance. BrC was found to be prevalent throughout the 1 to 12 km altitude measurement range, with dramatic enhancements in biomass-burning plumes. BrC to black carbon (BC) ratios, under background tropospheric …
Modeling Impacts Of Changes In Temperature And Water Table On C Gas Fluxes In An Alaskan Peatland, Jia Deng, Changsheng Li, Steve Frolking
Modeling Impacts Of Changes In Temperature And Water Table On C Gas Fluxes In An Alaskan Peatland, Jia Deng, Changsheng Li, Steve Frolking
Earth Sciences
Northern peatlands have accumulated a large amount of organic carbon (C) in their thick peat profile. Climate change and associated variations in soil environments are expected to have significant impacts on the C balance of these ecosystems, but the magnitude is still highly uncertain. Verifying and understanding the influences of changes in environmental factors on C gas fluxes in biogeochemical models are essential for forecasting feedbacks between C gas fluxes and climate change. In this study, we applied a biogeochemical model, DeNitrification-DeComposition (DNDC), to assess impacts of air temperature (TA) and water table (WT) on C gas fluxes …
The Polarcat Model Intercomparison Project (Polmip): Overview And Evaluation With Observations, L K. Emmons, S R. Arnold, S A. Monks, V Huijnen, S Tilmes, K S. Law, J L. Thomas, J C. Raut, I Bouarar, S Turquety, Y Long, B Duncan, S Steenrod, S Strode, J Flemming, J Mao, J Langner, A M. Thompson, D Tarasick, E C. Apel, D R. Blake, Robert C. Cohen, Jack E. Dibb, Glenn Diskin, A Fried, S R. Hall, L Gregory Huey, Andrew Weinheimer, Armin Wisthaler, Tomas Mikoviny, J Nowak, Jeff Peischl, J M. Roberts, Thomas B. Ryerson, C Warneke, D Helmig
The Polarcat Model Intercomparison Project (Polmip): Overview And Evaluation With Observations, L K. Emmons, S R. Arnold, S A. Monks, V Huijnen, S Tilmes, K S. Law, J L. Thomas, J C. Raut, I Bouarar, S Turquety, Y Long, B Duncan, S Steenrod, S Strode, J Flemming, J Mao, J Langner, A M. Thompson, D Tarasick, E C. Apel, D R. Blake, Robert C. Cohen, Jack E. Dibb, Glenn Diskin, A Fried, S R. Hall, L Gregory Huey, Andrew Weinheimer, Armin Wisthaler, Tomas Mikoviny, J Nowak, Jeff Peischl, J M. Roberts, Thomas B. Ryerson, C Warneke, D Helmig
Earth Sciences
A model intercomparison activity was inspired by the large suite of observations of atmospheric composition made during the International Polar Year (2008) in the Arctic. Nine global and two regional chemical transport models participated in this intercomparison and performed simulations for 2008 using a common emissions inventory to assess the differences in model chemistry and transport schemes. This paper summarizes the models and compares their simulations of ozone and its precursors and presents an evaluation of the simulations using a variety of surface, balloon, aircraft and satellite observations. Each type of measurement has some limitations in spatial or temporal coverage …
Revealing Important Nocturnal And Day-To-Day Variations In Fire Smoke Emissions Through A Multiplatform Inversion, Pablo E. Saide, David A. Peterson, Arlindo Da Silva, Bruce Anderson, Luke D. Ziemba, Glenn Diskin, Glen Sachse, Jonathan Hair, Carolyn Butler, Marta Fenn, Jose L. Jimenez, Pedro Campuzano-Jost, Anne E. Perring, Joshua P. Schwarz, Milos Z. Markovic, Phil Russell, Jens Redemann, Yohei Shinozuka, David G. Streets, Fang Yan, Jack E. Dibb, Robert Yokelson, O Brian Toon, Edward Hyer, Gregory R. Carmichael
Revealing Important Nocturnal And Day-To-Day Variations In Fire Smoke Emissions Through A Multiplatform Inversion, Pablo E. Saide, David A. Peterson, Arlindo Da Silva, Bruce Anderson, Luke D. Ziemba, Glenn Diskin, Glen Sachse, Jonathan Hair, Carolyn Butler, Marta Fenn, Jose L. Jimenez, Pedro Campuzano-Jost, Anne E. Perring, Joshua P. Schwarz, Milos Z. Markovic, Phil Russell, Jens Redemann, Yohei Shinozuka, David G. Streets, Fang Yan, Jack E. Dibb, Robert Yokelson, O Brian Toon, Edward Hyer, Gregory R. Carmichael
Earth Sciences
We couple airborne, ground-based, and satellite observations; conduct regional simulations; and develop and apply an inversion technique to constrain hourly smoke emissions from the Rim Fire, the third largest observed in California, USA. Emissions constrained with multiplatform data show notable nocturnal enhancements (sometimes over a factor of 20), correlate better with daily burned area data, and are a factor of 2-4 higher than a priori estimates, highlighting the need for improved characterization of diurnal profiles and day-to-day variability when modeling extreme fires. Constraining only with satellite data results in smaller enhancements mainly due to missing retrievals near the emissions source, …
Evolution Of Brown Carbon In Wildfire Plumes, Haviland Forrister, Jiumeng Liu, Jack E. Dibb, Eric Scheuer, Luke D. Ziemba, Kenn L. Thornhill, Bruce Anderson, Glenn Diskin, Anne E. Perring, Joshua P. Schwarz, Pedro Campuzano-Jost, Douglas A. Day, Brett B. Palm, Jose L. Jimenez, Athanasios Nenes, Rodney J. Weber
Evolution Of Brown Carbon In Wildfire Plumes, Haviland Forrister, Jiumeng Liu, Jack E. Dibb, Eric Scheuer, Luke D. Ziemba, Kenn L. Thornhill, Bruce Anderson, Glenn Diskin, Anne E. Perring, Joshua P. Schwarz, Pedro Campuzano-Jost, Douglas A. Day, Brett B. Palm, Jose L. Jimenez, Athanasios Nenes, Rodney J. Weber
Earth Sciences
Particulate brown carbon (BrC) in the atmosphere absorbs light at subvisible wavelengths and has poorly constrained but potentially large climate forcing impacts. BrC from biomass burning has virtually unknown lifecycle and atmospheric stability. Here, BrC emitted from intense wildfires was measured in plumes transported over 2 days from two main fires, during the 2013 NASA SEAC4RS mission. Concurrent measurements of organic aerosol (OA) and black carbon (BC) mass concentration, BC coating thickness, absorption Ångström exponent, and OA oxidation state reveal that the initial BrC emitted from the fires was largely unstable. Using back trajectories to estimate the transport time indicates …
Simulating Ice Core 10be On The Glacial–Interglacial Timescale, C Elsasser, D Wagenbach, I Levin, A Stanzick, Mark J. Christl, A Wallner, S Kipfstuhl, I K. Seietstad, H Wershofen, Jack E. Dibb
Simulating Ice Core 10be On The Glacial–Interglacial Timescale, C Elsasser, D Wagenbach, I Levin, A Stanzick, Mark J. Christl, A Wallner, S Kipfstuhl, I K. Seietstad, H Wershofen, Jack E. Dibb
Earth Sciences
10Be ice core measurements are an important tool for paleoclimate research, e.g., allowing for the reconstruction of past solar activity or changes in the geomagnetic dipole field. However, especially on multi-millennial timescales, the share of production and climate-induced variations of respective 10Be ice core records is still up for debate. Here we present the first quantitative climatological model of the 10Be ice concentration up to the glacial–interglacial timescale. The model approach is composed of (i) a coarse resolution global atmospheric transport model and (ii) a local 10Be air–firn transfer model. Extensive global-scale observational data of short-lived …
Arctic Air Pollution: New Insights From Polarcat-Ipy, Katherine S. Law, Andreas Stohl, Patricia K. Quinn, Charles A. Brock, John F. Burkhart, Jean-Daniel Paris, Gerard Ancellet, Hanwant B. Singh, Anke Roiger, Hans Schlager, Jack E. Dibb, Daniel J. Jacob, S R. Arnold, Jacques Pelon, Jennie L. Thomas
Arctic Air Pollution: New Insights From Polarcat-Ipy, Katherine S. Law, Andreas Stohl, Patricia K. Quinn, Charles A. Brock, John F. Burkhart, Jean-Daniel Paris, Gerard Ancellet, Hanwant B. Singh, Anke Roiger, Hans Schlager, Jack E. Dibb, Daniel J. Jacob, S R. Arnold, Jacques Pelon, Jennie L. Thomas
Earth Sciences
Given the rapid nature of climate change occurring in the Arctic and the difficulty climate models have in quantitatively reproducing observed changes such as sea ice loss, it is important to improve understanding of the processes leading to climate change in this region, including the role of short-lived climate pollutants such as aerosols and ozone. It has long been known that pollution produced from emissions at midlatitudes can be transported to the Arctic, resulting in a winter/spring aerosol maximum known as Arctic haze. However, many uncertainties remain about the composition and origin of Arctic pollution throughout the troposphere; for example, …
Assessing Effects Of Permafrost Thaw On C Fluxes Based On Multiyear Modeling Across A Permafrost Thaw Gradient At Stordalen, Sweden, Jia Deng, C Li, Steve Frolking, Y Zhang, K Backstrand, P Crill
Assessing Effects Of Permafrost Thaw On C Fluxes Based On Multiyear Modeling Across A Permafrost Thaw Gradient At Stordalen, Sweden, Jia Deng, C Li, Steve Frolking, Y Zhang, K Backstrand, P Crill
Earth Sciences
Northern peatlands in permafrost regions contain a large amount of organic carbon (C) in the soil. Climate warming and associated permafrost degradation are expected to have significant impacts on the C balance of these ecosystems, but the magnitude is uncertain. We incorporated a permafrost model, Northern Ecosystem Soil Temperature (NEST), into a biogeochemical model, DeNitrificationDeComposition (DNDC), to model C dynamics in highlatitude peatland ecosystems. The enhanced model was applied to assess effects of permafrost thaw on C fluxes of a subarctic peatland at Stordalen, Sweden. DNDC simulated soil freeze–thaw dynamics, net ecosystem exchange of CO2 (NEE), and CH4 fluxes across …
Atmospheric Oxidation Chemistry And Ozone Production: Results From Sharp 2009 In Houston, Texas, Katherine A. Duderstadt, Jack E. Dibb, Charles H. Jackman, Cora E. Randall, Stanley C. Solomon, Michael J. Mills, Nathan A. Schwadron, Harlan E. Spence
Atmospheric Oxidation Chemistry And Ozone Production: Results From Sharp 2009 In Houston, Texas, Katherine A. Duderstadt, Jack E. Dibb, Charles H. Jackman, Cora E. Randall, Stanley C. Solomon, Michael J. Mills, Nathan A. Schwadron, Harlan E. Spence
Earth Sciences
This study considers whether spikes in nitrate in snow sampled at Summit, Greenland, from August 2000 to August 2002 are related to solar proton events. After identifying tropospheric sources of nitrate on the basis of correlations with sulfate, ammonium, sodium, and calcium, we use the three-dimensional global Whole Atmosphere Community Climate Model (WACCM) to examine unaccounted for nitrate spikes. Model calculations confirm that solar proton events significantly impact HOx, NOx, and O3 levels in the mesosphere and stratosphere during the weeks and months following the major 9 November 2000 solar proton event. However, solar proton event (SPE)-enhanced NOy calculated within …
Intercomparison Of Field Measurements Of Nitrous Acid (Hono) During The Sharp Campaign, J R. Pinto, Jack E. Dibb, B H. Lee, B Rappengluck, E C. Wood, M Levy, R Y. Zhang, Barry Lefer, Xinrong Ren, J Stutz, C Tsai, L Ackermann, J Golovko, S C. Herndon, M Oakes, Q Y. Meng, J W. Munger, M Zahniser, J Zheng
Intercomparison Of Field Measurements Of Nitrous Acid (Hono) During The Sharp Campaign, J R. Pinto, Jack E. Dibb, B H. Lee, B Rappengluck, E C. Wood, M Levy, R Y. Zhang, Barry Lefer, Xinrong Ren, J Stutz, C Tsai, L Ackermann, J Golovko, S C. Herndon, M Oakes, Q Y. Meng, J W. Munger, M Zahniser, J Zheng
Earth Sciences
Because of the importance of HONO as a radical reservoir, consistent and accurate measurements of its concentration are needed. As part of SHARP (Study of Houston Atmospheric Radical Precursors), time series of HONO were obtained by six different measurement techniques on the roof of the Moody Tower at the University of Houston. Techniques used were long path differential optical absorption spectroscopy (DOAS), stripping coil-visible absorption photometry (SC-AP), long path absorption photometry (LOPAP® ), mist chamber/ion chromatography (MC-IC), quantum cascade-tunable infrared laser differential absorption spectroscopy (QC-TILDAS), and ion drift-chemical ionization mass spectrometry (ID-CIMS). Various combinations of techniques were in operation from …
Brown Carbon In The Continental Troposphere, Jiumeng Liu, Eric Scheuer, Jack E. Dibb, Luke D. Ziemba, Kenn L. Thornhill, Bruce Anderson, Armin Wisthaler, Tomas Mikoviny, J J. Devi, Mike Bergin, Rodney J. Weber
Brown Carbon In The Continental Troposphere, Jiumeng Liu, Eric Scheuer, Jack E. Dibb, Luke D. Ziemba, Kenn L. Thornhill, Bruce Anderson, Armin Wisthaler, Tomas Mikoviny, J J. Devi, Mike Bergin, Rodney J. Weber
Earth Sciences
No abstract provided.
Mercury Speciation At A Coastal Site In The Northern Gulf Of Mexico: Results From The Grand Bay Intensive Studies In Summer 2010 And Spring 2011, Xinrong Ren, Winston T. Luke, Paul Kelley, Mark Cohen, Fong Ngan, Richard Artz, Jake Walker, Steve Brooks, Christopher Moore, Phil Swartzendruber, Dieter Bauer, James Remeika, Anthony Hynes, Jack E. Dibb, John Rolison, Nishanth Krishnamurthy, William M. Landing, Arsineh Hecobian, Jeffery Shook, L Gregory Huey
Mercury Speciation At A Coastal Site In The Northern Gulf Of Mexico: Results From The Grand Bay Intensive Studies In Summer 2010 And Spring 2011, Xinrong Ren, Winston T. Luke, Paul Kelley, Mark Cohen, Fong Ngan, Richard Artz, Jake Walker, Steve Brooks, Christopher Moore, Phil Swartzendruber, Dieter Bauer, James Remeika, Anthony Hynes, Jack E. Dibb, John Rolison, Nishanth Krishnamurthy, William M. Landing, Arsineh Hecobian, Jeffery Shook, L Gregory Huey
Earth Sciences
During two intensive studies in summer 2010 and spring 2011, measurements of mercury species including gaseous elemental mercury (GEM), gaseous oxidized mercury (GOM), and particulate-bound mercury (PBM), trace chemical species including O3, SO2, CO, NO, NOY, and black carbon, and meteorological parameters were made at an Atmospheric Mercury Network (AMNet) site at the Grand Bay National Estuarine Research Reserve (NERR) in Moss Point, Mississippi. Surface measurements indicate that the mean mercury concentrations were 1.42 ± 0.12 ng∙m−3 for GEM, 5.4 ± 10.2 pg∙m−3 for GOM, and 3.1 ± 1.9 pg∙m−3 for …
Snow Spectral Albedo At Summit, Greenland: Measurements And Numerical Simulations Based On Physical And Chemical Properties Of The Snowpack, Carlo Carmagnola, Florent Domine, Marie Dumont, Patrick Wright, B Strellis, M Bergin, Jack E. Dibb, G Picard, Q Libois, L Arnaud, S Morin
Snow Spectral Albedo At Summit, Greenland: Measurements And Numerical Simulations Based On Physical And Chemical Properties Of The Snowpack, Carlo Carmagnola, Florent Domine, Marie Dumont, Patrick Wright, B Strellis, M Bergin, Jack E. Dibb, G Picard, Q Libois, L Arnaud, S Morin
Earth Sciences
The broadband albedo of surface snow is determined both by the near-surface profile of the physical and chemical properties of the snowpack and by the spectral and angular characteristics of the incident solar radiation. Simultaneous measurements of the physical and chemical properties of snow were carried out at Summit Camp, Greenland (72°36´ N, 38°25´ W, 3210 m a.s.l.) in May and June 2011, along with spectral albedo measurements. One of the main objectives of the field campaign was to test our ability to predict snow spectral albedo by comparing the measured albedo to the albedo calculated with a radiative transfer …
The Preservation Of Atmospheric Nitrate In Snow At Summit, Greenland, Dorothy L. Fibiger, Meredith G. Hastings, Jack E. Dibb, L Gregory Huey
The Preservation Of Atmospheric Nitrate In Snow At Summit, Greenland, Dorothy L. Fibiger, Meredith G. Hastings, Jack E. Dibb, L Gregory Huey
Earth Sciences
There is great interest in using nitrate NO3 isotopic composition in ice cores to track the history of precursor nitrogen oxides (NOx = NO + NO2) in the atmosphere. Nitrate NO3 however can be lost from the snow by surface processes, such as photolysis back to NOx upon exposure to sunlight, making it difficult to interpret records of NO3 as a tracer of atmospheric NOx loading. In a campaign consisting of two field seasons (May–June) at Summit, Greenland, high temporal frequency surface snow samples were collected and analyzed for the oxygen isotopic composition of NO3. The strong, linear relationship observed …
On The Export Of Reactive Nitrogen From Asia: NoX Partitioning And Effects On Ozone, T H. Bertram, Paul J. Wooldridge, Jack E. Dibb, Robert C. Cohen, A E. Perring
On The Export Of Reactive Nitrogen From Asia: NoX Partitioning And Effects On Ozone, T H. Bertram, Paul J. Wooldridge, Jack E. Dibb, Robert C. Cohen, A E. Perring
Earth Sciences
The partitioning of reactive nitrogen (NOy was measured over the remote North Pacific during spring 2006. Aircraft observations of NO, NO2, total peroxy nitrates (ΣPNs), total alkyl and multi-functional nitrates (ΣANs) and nitric acid (HNO3, made between 25° and 55° N, confirm a controlling role for peroxyacyl nitrates in NOx production in aged Asian outflow. ΣPNs account for more than 60% of NOy above 5 km, while thermal dissociation limits their contribution to less than 10% in the lower troposphere. Using simultaneous observations of NOx, ΣPNs, ΣANs, HNO3 and average …
Overview Of The 2007 And 2008 Campaigns Conducted As Part Of The Greenland Summit Halogen-HoX Experiment (Gshox), J L. Thomas, Jack E. Dibb, J Stutz, R Von Glasow, Steve Brooks, L Gregory Huey, Barry Lefer
Overview Of The 2007 And 2008 Campaigns Conducted As Part Of The Greenland Summit Halogen-HoX Experiment (Gshox), J L. Thomas, Jack E. Dibb, J Stutz, R Von Glasow, Steve Brooks, L Gregory Huey, Barry Lefer
Earth Sciences
From 10 May through 17 June 2007 and 6 June through 9 July 2008 intensive sampling campaigns at Summit, Greenland confirmed that active bromine chemistry is occurring in and above the snow pack at the highest part of the Greenland ice sheet (72°36´ N, 38°25´ W and 3.2 km above sea level). Direct measurements found BrO and soluble gas phase Br− mixing ratios in the low pptv range on many days (maxima < 10 pptv). Conversion of up to 200 pg m−3 of gaseous elemental mercury (GEM) to reactive gaseous mercury (RGM) and enhanced OH relative to HO2 plus RO2 confirm that active bromine chemistry is …
Spectral Absorption Of Biomass Burning Aerosol Determined From Retrieved Single Scattering Albedo During Arctas, C A. Corr, S R. Hall, B E. Anderson, Kirk Ullman, A J. Beyersdorf, Kenn L. Thornhill, Michael J. Cubison, Jose L. Jimenez, Armin Wisthaler, Jack E. Dibb
Spectral Absorption Of Biomass Burning Aerosol Determined From Retrieved Single Scattering Albedo During Arctas, C A. Corr, S R. Hall, B E. Anderson, Kirk Ullman, A J. Beyersdorf, Kenn L. Thornhill, Michael J. Cubison, Jose L. Jimenez, Armin Wisthaler, Jack E. Dibb
Earth Sciences
Actinic flux, as well as aerosol chemical and optical properties, were measured aboard the NASA DC-8 aircraft during the ARCTAS (Arctic Research of the Composition of the Troposphere from Aircraft and Satellites) mission in Spring and Summer 2008. These measurements were used in a radiative transfer code to retrieve spectral (350-550 nm) aerosol single scattering albedo (SSA) for biomass burning plumes encountered on 17 April and 29 June. Retrieved SSA values were subsequently used to calculate the absorption Angstrom exponent (AAE) over the 350-500 nm range. Both plumes exhibited enhanced spectral absorption with AAE values that exceeded 1 (6.78 ± …
Characteristics Of Tropospheric Ozone Depletion Events In The Arctic Spring: Analysis Of The Arctas, Arcpac, And Arcions Measurements And Satellite Bro Observations, T P. Kurosu, Yuhang Wang, T P. Kurosu, K Chance, A Rozanov, A Richter, S J. Oltmans, A M. Thompson, Jonathan Hair, Marta Fenn, Andrew Weinheimer, Thomas B. Ryerson, S Solberg, L Gregory Huey, J Liao, Jack E. Dibb, J A. Neuman, J Nowak, B Pierce, M Natarajan, J Al-Saadi
Characteristics Of Tropospheric Ozone Depletion Events In The Arctic Spring: Analysis Of The Arctas, Arcpac, And Arcions Measurements And Satellite Bro Observations, T P. Kurosu, Yuhang Wang, T P. Kurosu, K Chance, A Rozanov, A Richter, S J. Oltmans, A M. Thompson, Jonathan Hair, Marta Fenn, Andrew Weinheimer, Thomas B. Ryerson, S Solberg, L Gregory Huey, J Liao, Jack E. Dibb, J A. Neuman, J Nowak, B Pierce, M Natarajan, J Al-Saadi
Earth Sciences
Arctic ozone depletion events (ODEs) are caused by halogen catalyzed ozone loss. In situ chemistry, advection of ozone-poor air mass, and vertical mixing in the lower troposphere are important factors affecting ODEs. To better characterize the ODEs, we analyze the combined set of surface, ozonesonde, and aircraft in situ measurements of ozone and bromine compounds during the Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS), the Aerosol, Radiation, and Cloud Processes affecting Arctic Climate (ARCPAC), and the Arctic Intensive Ozonesonde Network Study (ARCIONS) experiments (April 2008). Tropospheric BrO columns retrieved from satellite measurements and back …
An Analysis Of Fast Photochemistry Over High Northern Latitudes During Spring And Summer Using In-Situ Observations From Arctas And Topse, J R. Olson, J H. Crawford, William H. Brune, J Mao, Xinrong Ren, A Fried, B Anderson, E C. Apel, M Beaver, D R. Blake, G Chen, John D. Crounse, Jack E. Dibb, Glenn Diskin, S R. Hall, L Gregory Huey, D Knapp, D Richter, D Riemer, J St. Clair, Kirk Ullman, J Walega, P Weibring, Andrew Weinheimer, Paul Wennberg, Armin Wisthaler
An Analysis Of Fast Photochemistry Over High Northern Latitudes During Spring And Summer Using In-Situ Observations From Arctas And Topse, J R. Olson, J H. Crawford, William H. Brune, J Mao, Xinrong Ren, A Fried, B Anderson, E C. Apel, M Beaver, D R. Blake, G Chen, John D. Crounse, Jack E. Dibb, Glenn Diskin, S R. Hall, L Gregory Huey, D Knapp, D Richter, D Riemer, J St. Clair, Kirk Ullman, J Walega, P Weibring, Andrew Weinheimer, Paul Wennberg, Armin Wisthaler
Earth Sciences
Observations of chemical constituents and meteorological quantities obtained during the two Arctic phases of the airborne campaign ARCTAS (Arctic Research of the Composition of the Troposphere from Aircraft and Satellites) are analyzed using an observationally constrained steady state box model. Measurements of OH and HO2 from the Penn State ATHOS instrument are compared to model predictions. Forty percent of OH measurements below 2 km are at the limit of detection during the spring phase (ARCTAS-A). While the median observed-to-calculated ratio is near one, both the scatter of observations and the model uncertainty for OH are at the magnitude of …
Modeling Chemistry In And Above Snow At Summit, Greenland – Part 2: Impact Of Snowpack Chemistry On The Oxidation Capacity Of The Boundary Layer, J L. Thomas, Jack E. Dibb, L Gregory Huey, J Liao, D Tanner, Barry Lefer, R Von Glasow, J Stutz
Modeling Chemistry In And Above Snow At Summit, Greenland – Part 2: Impact Of Snowpack Chemistry On The Oxidation Capacity Of The Boundary Layer, J L. Thomas, Jack E. Dibb, L Gregory Huey, J Liao, D Tanner, Barry Lefer, R Von Glasow, J Stutz
Earth Sciences
The chemical composition of the boundary layer in snow covered regions is impacted by chemistry in the snowpack via uptake, processing, and emission of atmospheric trace gases. We use the coupled one-dimensional (1-D) snow chemistry and atmospheric boundary layer model MISTRA-SNOW to study the impact of snowpack chemistry on the oxidation capacity of the boundary layer. The model includes gas phase photochemistry and chemical reactions both in the interstitial air and the atmosphere. While it is acknowledged that the chemistry occurring at ice surfaces may consist of a true quasi-liquid layer and/or a concentrated brine layer, lack of additional knowledge …
The Carrington Event Not Observed In Most Ice Core Nitrate Records, E W. Wolff, M Bigler, M. A. J. Curran, Jack E. Dibb, M M. Frey, M Legrand, J R. Mcconnell
The Carrington Event Not Observed In Most Ice Core Nitrate Records, E W. Wolff, M Bigler, M. A. J. Curran, Jack E. Dibb, M M. Frey, M Legrand, J R. Mcconnell
Earth Sciences
The Carrington Event of 1859 is considered to be among the largest space weather events of the last 150 years. We show that only one out of 14 well-resolved ice core records from Greenland and Antarctica has a nitrate spike dated to 1859. No sharp spikes are observed in the Antarctic cores studied here. In Greenland numerous spikes are observed in the 40 years surrounding 1859, but where other chemistry was measured, all large spikes have the unequivocal signal, including co-located spikes in ammonium, formate, black carbon and vanillic acid, of biomass burning plumes. It seems certain that most spikes …
Analysis Of Satellite-Derived Arctic Tropospheric Bro Columns In Conjunction With Aircraft Measurements During Arctas And Arcpac, S Choi, Yuhang Wang, R J. Salawitch, T Canty, J Joiner, T Zeng, T P. Kurosu, K Chance, A Richter, L Gregory Huey, J Liao, J A. Neuman, J Nowak, Jack E. Dibb, Andrew Weinheimer, Glenn Diskin, Thomas B. Ryerson, Arlindo Da Silva, J Curry, D Kinnison, S Tilmes, P F. Levelt
Analysis Of Satellite-Derived Arctic Tropospheric Bro Columns In Conjunction With Aircraft Measurements During Arctas And Arcpac, S Choi, Yuhang Wang, R J. Salawitch, T Canty, J Joiner, T Zeng, T P. Kurosu, K Chance, A Richter, L Gregory Huey, J Liao, J A. Neuman, J Nowak, Jack E. Dibb, Andrew Weinheimer, Glenn Diskin, Thomas B. Ryerson, Arlindo Da Silva, J Curry, D Kinnison, S Tilmes, P F. Levelt
Earth Sciences
We derive tropospheric column BrO during the ARCTAS and ARCPAC field campaigns in spring 2008 using retrievals of total column BrO from the satellite UV nadir sensors OMI and GOME-2 using a radiative transfer model and stratospheric column BrO from a photochemical simulation. We conduct a comprehensive comparison of satellite-derived tropospheric BrO column to aircraft in-situ observations of BrO and related species. The aircraft profiles reveal that tropospheric BrO, when present during April 2008, was distributed over a broad range of altitudes rather than being confined to the planetary boundary layer (PBL). Perturbations to the total column resulting from tropospheric …
Longpath Doas Observations Of Surface Bro At Summit, Greenland, J Stutz, J L. Thomas, S C. Hurlock, M Schneider, R Von Glasow, M Piot, K Gorham, John F. Burkhart, Luke D. Ziemba, Jack E. Dibb, Barry Lefer
Longpath Doas Observations Of Surface Bro At Summit, Greenland, J Stutz, J L. Thomas, S C. Hurlock, M Schneider, R Von Glasow, M Piot, K Gorham, John F. Burkhart, Luke D. Ziemba, Jack E. Dibb, Barry Lefer
Earth Sciences
Reactive halogens, and in particular bromine oxide (BrO), have frequently been observed in regions with large halide reservoirs, for example during bromine catalyzed coastal polar ozone depletion events. Much less is known about the presence and impact of reactive halogens in areas without obvious halide reservoirs, such as the polar ice sheets or continental snow.
We report the first LP-DOAS measurements of BrO at Summit research station in the center of the Greenland ice sheet at an altitude of 3200 m. BrO mixing ratios in May 2007 and June 2008 were typically between 1–3 pmol mol−1, with maxima …
Observations Of Hydroxyl And Peroxy Radicals And The Impact Of Bro At Summit, Greenland In 2007 And 2008, J Liao, L Gregory Huey, D Tanner, N Brough, Steve Brooks, Jack E. Dibb, J Stutz, J L. Thomas, Barry Lefer, C Haman, K Gorham
Observations Of Hydroxyl And Peroxy Radicals And The Impact Of Bro At Summit, Greenland In 2007 And 2008, J Liao, L Gregory Huey, D Tanner, N Brough, Steve Brooks, Jack E. Dibb, J Stutz, J L. Thomas, Barry Lefer, C Haman, K Gorham
Earth Sciences
The Greenland Summit Halogen-HOx (GSHOX) Campaign was performed in spring 2007 and summer 2008 to investigate the impact of halogens on HOx (= OH + HO2) cycling above the Greenland Ice Sheet. Chemical species including hydroxyl and peroxy radicals (OH and HO2+ RO2), ozone (O3), nitrogen oxide (NO), nitric acid (HNO3), nitrous acid (HONO), reactive gaseous mercury (RGM), and bromine oxide (BrO) were measured during the campaign. The median midday values of HO2 + RO2 and OH concentrations observed by chemical ionization mass spectrometry (CIMS) were …
In Situ Measurements Of Tropospheric Volcanic Plumes In Ecuador And Colombia During Tc, S A. Carn, K D. Froyd, B E. Anderson, Paul Wennberg, John D. Crounse, K Spencer, Jack E. Dibb, N A. Krotkov, E V. Browell, Jonathan Hair, Glenn S. Diskin, G W. Sachse
In Situ Measurements Of Tropospheric Volcanic Plumes In Ecuador And Colombia During Tc, S A. Carn, K D. Froyd, B E. Anderson, Paul Wennberg, John D. Crounse, K Spencer, Jack E. Dibb, N A. Krotkov, E V. Browell, Jonathan Hair, Glenn S. Diskin, G W. Sachse
Earth Sciences
A NASA DC‐8 research aircraft penetrated tropospheric gas and aerosol plumes sourced from active volcanoes in Ecuador and Colombia during the Tropical Composition, Cloud and Climate Coupling (TC4 ) mission in July–August 2007. The likely source volcanoes were Tungurahua (Ecuador) and Nevado del Huila (Colombia). The TC4 data provide rare insight into the chemistry of volcanic plumes in the tropical troposphere and permit a comparison of SO2 column amounts measured by the Ozone Monitoring Instrument (OMI) on the Aura satellite with in situ SO2 measurements. Elevated concentrations of SO2, sulfate aerosol, and particles were measured by DC‐8 instrumentation in volcanic …
Modeling Chemistry In And Above Snow At Summit, Greenland – Part 1: Model Description And Results, J L. Thomas, J Stutz, Barry Lefer, L Gregory Huey, K Toyota, Jack E. Dibb, R Von Glasow
Modeling Chemistry In And Above Snow At Summit, Greenland – Part 1: Model Description And Results, J L. Thomas, J Stutz, Barry Lefer, L Gregory Huey, K Toyota, Jack E. Dibb, R Von Glasow
Earth Sciences
Sun-lit snow is increasingly recognized as a chemical reactor that plays an active role in uptake, transformation, and release of atmospheric trace gases. Snow is known to influence boundary layer air on a local scale, and given the large global surface coverage of snow may also be significant on regional and global scales. We present a new detailed one-dimensional snow chemistry module that has been coupled to the 1-D atmospheric boundary layer model MISTRA. The new 1-D snow module, which is dynamically coupled to the overlaying atmospheric model, includes heat transport in the snowpack, molecular diffusion, and wind pumping of …
Multi-Scale Modeling Study Of The Source Contributions To Near-Surface Ozone And Sulfur Oxides Levels Over California During The Arctas-Carb Period, M. Huang, Gregory R. Carmichael, S N. Spak, B Adhikary, S Kulkarni, Y Cheng, C Wei, Y Tang, A D'Allura, Paul Wennberg, L Gregory Huey, Jack E. Dibb, Jose L. Jimenez, Michael J. Cubison, Andrew Weinheimer, Ajith P. Kaduwela, Chenxia Cai, M Wong, R Bradley Pierce, J Al-Saadi, David G. Streets, Q Zhang
Multi-Scale Modeling Study Of The Source Contributions To Near-Surface Ozone And Sulfur Oxides Levels Over California During The Arctas-Carb Period, M. Huang, Gregory R. Carmichael, S N. Spak, B Adhikary, S Kulkarni, Y Cheng, C Wei, Y Tang, A D'Allura, Paul Wennberg, L Gregory Huey, Jack E. Dibb, Jose L. Jimenez, Michael J. Cubison, Andrew Weinheimer, Ajith P. Kaduwela, Chenxia Cai, M Wong, R Bradley Pierce, J Al-Saadi, David G. Streets, Q Zhang
Earth Sciences
Chronic high surface ozone (O3) levels and the increasing sulfur oxides (SOx = SO2+SO4) ambient concentrations over South Coast (SC) and other areas of California (CA) are affected by both local emissions and long-range transport. In this paper, multi-scale tracer, full-chemistry and adjoint simulations using the STEM atmospheric chemistry model are conducted to assess the contribution of local emission sourcesto SC O3 and to evaluate the impacts of transported sulfur and local emissions on the SC sulfur budgetduring the ARCTAS-CARB experiment period in 2008. Sensitivity simulations quantify contributions of biogenic and fire …
A New Interpretation Of Total Column Bro During Arctic Spring, R J. Salawitch, T Canty, T P. Kurosu, K Chance, Q Liang, Arlindo Da Silva, S Pawson, J E. Neilsen, J. V. Rodriguez, P K. Bhartia, X Liu, L Gregory Huey, J Liao, R E. Stickel, D Tanner, Jack E. Dibb, W R. Simpson, D Donohue, Andrew Weinheimer, F Flocke, D Knapp, D Montzka, J A. Neuman, J Nowak, Thomas B. Ryerson, S J. Oltmans, D R. Blake, E L. Atlas, D Kinnison, S Tilmes, L L. Pan, F Hendrick, R Bradley Pierce, M Van Roozendael, K Kreher, P V. Johnston, R S. Gao, B Johnson, T P. Bui, G Chen, R B. Pierce, J H. Crawford, D J. Jacob
A New Interpretation Of Total Column Bro During Arctic Spring, R J. Salawitch, T Canty, T P. Kurosu, K Chance, Q Liang, Arlindo Da Silva, S Pawson, J E. Neilsen, J. V. Rodriguez, P K. Bhartia, X Liu, L Gregory Huey, J Liao, R E. Stickel, D Tanner, Jack E. Dibb, W R. Simpson, D Donohue, Andrew Weinheimer, F Flocke, D Knapp, D Montzka, J A. Neuman, J Nowak, Thomas B. Ryerson, S J. Oltmans, D R. Blake, E L. Atlas, D Kinnison, S Tilmes, L L. Pan, F Hendrick, R Bradley Pierce, M Van Roozendael, K Kreher, P V. Johnston, R S. Gao, B Johnson, T P. Bui, G Chen, R B. Pierce, J H. Crawford, D J. Jacob
Earth Sciences
Emission of bromine from sea-salt aerosol, frost flowers, ice leads, and snow results in the nearly complete removal of surface ozone during Arctic spring. Regions of enhanced total column BrO observed by satellites have traditionally been associated with these emissions. However, airborne measurements of BrO and O3 within the convective boundary layer (CBL) during the ARCTAS and ARCPAC field campaigns at times bear little relation to enhanced column BrO. We show that the locations of numerous satellite BrO “hotspots” during Arctic spring are consistent with observations of total column ozone and tropopause height, suggesting a stratospheric origin to these …