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Sample records for aerosol campaign isdac

  1. Science Overview Document Indirect and Semi-Direct Aerosol Campaign (ISDAC) April 2008

    SciTech Connect

    SJ Ghan; B Schmid; JM Hubbe; CJ Flynn; A Laskin; AA Zelenyuk; DJ Czizco; CN Long; G McFarquhar; J Verlinde; J Harrington; JW Strapp; P Liu; A Korolev; A McDonald; M Wolde; A Fridlind; T Garrett; G Mace; G Kok; S Brooks; D Collins; D Lubin; P Lawson; M Dubey; C Mazzoleni; M Shupe; S Xie; DD Turner; Q Min; EJ Mlawer; D Mitchell

    2007-11-01

    The ARM Climate Research Facility’s (ACRF) Aerial Vehicle Program (AVP) will deploy an intensive cloud and aerosol observing system to the ARM North Slope of Alaska (NSA) locale for a five week Indirect and Semi-Direct Aerosol Campaign (ISDAC) during period 29 March through 30 April 2008. The deployment period is within the International Polar Year, thus contributing to and benefiting from the many ancillary observing systems collecting data synergistically. We will deploy the Canadian National Research Council Convair 580 aircraft to measure temperature, humidity, total particle number, aerosol size distribution, single particle composition, concentrations of cloud condensation nuclei and ice nuclei, optical scattering and absorption, updraft velocity, cloud liquid water and ice contents, cloud droplet and crystal size distributions, cloud particle shape, and cloud extinction. In addition to these aircraft measurements, ISDAC will deploy two instruments at the ARM site in Barrow: a spectroradiometer to retrieve cloud optical depth and effective radius, and a tandem differential mobility analyzer to measure the aerosol size distribution and hygroscopicity. By using many of the same instruments used during Mixed-Phase Arctic Cloud Experiment (M-PACE), conducted in October 2004, we will be able to contrast the arctic aerosol and cloud properties during the fall and spring transitions. The aerosol measurements can be used in cloud models driven by objectively analyzed boundary conditions to test whether the cloud models can simulate the aerosol influence on the clouds. The influence of aerosol and boundary conditions on the simulated clouds can be separated by running the cloud models with all four combinations of M-PACE and ISDAC aerosol and boundary conditions: M-PACE aerosol and boundary conditions, M-PACE aerosol and ISDAC boundary conditions, ISDAC aerosol and M-PACE boundary conditions, and ISDAC aerosol and boundary conditions. ISDAC and M-PACE boundary

  2. The dependence of ice microphysics on aerosol concentration in arctic mixed-phase stratus clouds during ISDAC and M-PACE

    SciTech Connect

    Jackson, Robert C.; McFarquhar, Greg; Korolev, Alexei; Earle, Michael; Liu, Peter S.; Lawson, R. P.; Brooks, Sarah D.; Wolde, Mengistu; Laskin, Alexander; Freer, Matthew

    2012-08-14

    Cloud and aerosol data acquired by the National Research Council of Canada (NRC) Convair-580 aircraft in, above, and below single-layer arctic stratocumulus cloud during the Indirect and Semi-Direct Aerosol Campaign (ISDAC) in April 2008 were used to test three aerosol indirect effects hypothesized to act in mixed-phase clouds: the riming indirect effect, the glaciation indirect effect, and the cold second indirect effect. The data showed a correlation of R= 0.75 between liquid drop number concentration, Nliq, inside cloud and ambient aerosol number concentration NPCASP below cloud. This, combined with increasing liquid water content LWC with height above cloud base and the nearly constant profile of Nliq, suggested that liquid drops were nucleated from aerosol at cloud base. No strong evidence of a riming indirect effect was observed, but a strong correlation of R = 0.69 between ice crystal number concentration Ni and NPCASP above cloud was noted. Increases in ice nuclei (IN) concentration with NPCASP above cloud combined with the subadiabatic LWC profiles suggest possible mixing of IN from cloud top consistent with the glaciation indirect effect. The higher Nice and lower effective radius rel for the more polluted ISDAC cases compared to data collected in cleaner single-layer stratocumulus conditions during the Mixed-Phase Arctic Cloud Experiment is consistent with the operation of the cold second indirect effect. However, more data in a wider variety of meteorological and surface conditions, with greater variations in aerosol forcing, are required to identify the dominant aerosol forcing mechanisms in mixed-phase arctic clouds.

  3. Indirect and semi-direct aerosol campaign: The impact of Arctic aerosols on clouds

    DOE PAGES

    McFarquhar, Greg M.; Ghan, Steven; Verlinde, Johannes; ...

    2011-02-01

    A comprehensive dataset of microphysical and radiative properties of aerosols and clouds in the boundary layer in the vicinity of Barrow, Alaska, was collected in April 2008 during the Indirect and Semi-Direct Aerosol Campaign (ISDAC). ISDAC's primary aim was to examine the effects of aerosols, including those generated by Asian wildfires, on clouds that contain both liquid and ice. ISDAC utilized the Atmospheric Radiation Measurement Pro- gram's permanent observational facilities at Barrow and specially deployed instruments measuring aerosol, ice fog, precipitation, and radiation. The National Research Council of Canada Convair-580 flew 27 sorties and collected data using an unprecedented 41more » stateof- the-art cloud and aerosol instruments for more than 100 h on 12 different days. Aerosol compositions, including fresh and processed sea salt, biomassburning particles, organics, and sulfates mixed with organics, varied between flights. Observations in a dense arctic haze on 19 April and above, within, and below the single-layer stratocumulus on 8 and 26 April are enabling a process-oriented understanding of how aerosols affect arctic clouds. Inhomogeneities in reflectivity, a close coupling of upward and downward Doppler motion, and a nearly constant ice profile in the single-layer stratocumulus suggests that vertical mixing is responsible for its longevity observed during ISDAC. Data acquired in cirrus on flights between Barrow and Fairbanks, Alaska, are improving the understanding of the performance of cloud probes in ice. Furthermore, ISDAC data will improve the representation of cloud and aerosol processes in models covering a variety of spatial and temporal scales, and determine the extent to which surface measurements can provide retrievals of aerosols, clouds, precipitation, and radiative heating.« less

  4. Indirect and semi-direct aerosol campaign: The impact of Arctic aerosols on clouds

    SciTech Connect

    McFarquhar, Greg M.; Ghan, Steven; Verlinde, Johannes; Korolev, Alexei; Strapp, J. Walter; Schmid, Beat; Tomlinson, Jason M.; Wolde, Menqistu; Brooks, Sarah D.; Cziczo, Dan; Dubey, Manvendra K.; Fan, Jiwen; Flynn, Connor; Gultepe, Ismail; Hubbe, John; Gilles, Mary K.; Laskin, Alexander; Lawson, Paul; Leaitch, W. Richard; Liu, Peter; Liu, Xiaohong; Lubin, Dan; Mazzoleni, Claudio; Macdonald, Ann -Marie; Moffet, Ryan C.; Morrison, Hugh; Ovchinnikov, Mikhail; Ronfeld, Debbie; Shupe, Matthew D.; Xie, Shaocheng; Zelenyuk, Alla; Bae, Kenny; Freer, Matt; Glen, Andrew

    2011-02-01

    A comprehensive dataset of microphysical and radiative properties of aerosols and clouds in the boundary layer in the vicinity of Barrow, Alaska, was collected in April 2008 during the Indirect and Semi-Direct Aerosol Campaign (ISDAC). ISDAC's primary aim was to examine the effects of aerosols, including those generated by Asian wildfires, on clouds that contain both liquid and ice. ISDAC utilized the Atmospheric Radiation Measurement Pro- gram's permanent observational facilities at Barrow and specially deployed instruments measuring aerosol, ice fog, precipitation, and radiation. The National Research Council of Canada Convair-580 flew 27 sorties and collected data using an unprecedented 41 stateof- the-art cloud and aerosol instruments for more than 100 h on 12 different days. Aerosol compositions, including fresh and processed sea salt, biomassburning particles, organics, and sulfates mixed with organics, varied between flights. Observations in a dense arctic haze on 19 April and above, within, and below the single-layer stratocumulus on 8 and 26 April are enabling a process-oriented understanding of how aerosols affect arctic clouds. Inhomogeneities in reflectivity, a close coupling of upward and downward Doppler motion, and a nearly constant ice profile in the single-layer stratocumulus suggests that vertical mixing is responsible for its longevity observed during ISDAC. Data acquired in cirrus on flights between Barrow and Fairbanks, Alaska, are improving the understanding of the performance of cloud probes in ice. Furthermore, ISDAC data will improve the representation of cloud and aerosol processes in models covering a variety of spatial and temporal scales, and determine the extent to which surface measurements can provide retrievals of aerosols, clouds, precipitation, and radiative heating.

  5. Indirect and Semi-Direct Aerosol Campaign: The Impact of Arctic Aerosols on Clouds

    SciTech Connect

    McFarquhar, Greg; Ghan, Steven J.; Verlinde, J.; Korolev, Alexei; Strapp, J. Walter; Schmid, Beat; Tomlinson, Jason M.; Wolde, Mengistu; Brooks, Sarah D.; Cziczo, Daniel J.; Dubey, Manvendra K.; Fan, Jiwen; Flynn, Connor J.; Gultepe, Ismail; Hubbe, John M.; Gilles, Mary K.; Laskin, Alexander; Lawson, Paul; Leaitch, W. R.; Liu, Peter S.; Liu, Xiaohong; Lubin, Dan; Mazzoleni, Claudio; Macdonald, A. M.; Moffet, Ryan C.; Morrison, H.; Ovchinnikov, Mikhail; Shupe, Matthew D.; Turner, David D.; Xie, Shaocheng; Zelenyuk, Alla; Bae, Kenny; Freer, Matthew; Glen, Andrew

    2011-02-01

    A comprehensive dataset of microphysical and radiative properties of aerosols and clouds in the arctic boundary layer in the vicinity of Barrow, Alaska was collected in April 2008 during the Indirect and Semi-Direct Aerosol Campaign (ISDAC) sponsored by the Department of Energy Atmospheric Radiation Measurement (ARM) and Atmospheric Science Programs. The primary aim of ISDAC was to examine indirect effects of aerosols on clouds that contain both liquid and ice water. The experiment utilized the ARM permanent observational facilities at the North Slope of Alaska (NSA) in Barrow. These include a cloud radar, a polarized micropulse lidar, and an atmospheric emitted radiance interferometer as well as instruments specially deployed for ISDAC measuring aerosol, ice fog, precipitation and spectral shortwave radiation. The National Research Council of Canada Convair-580 flew 27 sorties during ISDAC, collecting data using an unprecedented 42 cloud and aerosol instruments for more than 100 hours on 12 different days. Data were obtained above, below and within single-layer stratus on 8 April and 26 April 2008. These data enable a process-oriented understanding of how aerosols affect the microphysical and radiative properties of arctic clouds influenced by different surface conditions. Observations acquired on a heavily polluted day, 19 April 2008, are enhancing this understanding. Data acquired in cirrus on transit flights between Fairbanks and Barrow are improving our understanding of the performance of cloud probes in ice. Ultimately the ISDAC data will be used to improve the representation of cloud and aerosol processes in models covering a variety of spatial and temporal scales, and to determine the extent to which long-term surface-based measurements can provide retrievals of aerosols, clouds, precipitation and radiative heating in the Arctic.

  6. Factors influencing the microphysics and radiative properties of liquid-dominated Arctic clouds: insight from observations of aerosol and clouds during ISDAC

    SciTech Connect

    Earle, Michael; Liu, Peter S.; Strapp, J. Walter; Zelenyuk, Alla; Imre, D.; McFarquhar, Greg; Shantz, Nicole C.; Leaitch, W. R.

    2011-11-04

    Aircraft measurements during the Indirect and Semi-Direct Aerosol Campaign (ISDAC) in April 2008 are used to investigate aerosol indirect effects in Arctic clouds. Two aerosol-cloud regimes are considered in this analysis: single-layer stratocumulus cloud with below-cloud aerosol concentrations (N{sub a}) below 300 cm{sup -3} on April 8 and April 26-27 (clean cases); and inhomogeneous layered cloud with N{sub a} > 500 cm{sup -3} below cloud base on April 19-20, concurrent with a biomass burning episode (polluted cases). Vertical profiles through cloud in each regime are used to determine average cloud microphysical and optical properties. Positive correlations between the cloud droplet effective radius (Re) and cloud optical depth ({tau}) are observed for both clean and polluted cases, which are characteristic of optically-thin, non-precipitating clouds. Average Re values for each case are {approx} 6.2 {mu}m, despite significantly higher droplet number concentrations (Nd) in the polluted cases. The apparent independence of Re and Nd simplifies the description of indirect effects, such that {tau} and the cloud albedo (A) can be described by relatively simple functions of the cloud liquid water path. Adiabatic cloud parcel model simulations show that the marked differences in Na between the regimes account largely for differences in droplet activation, but that the properties of precursor aerosol also play a role, particularly for polluted cases where competition for vapour amongst the more numerous particles limits activation to larger and/or more hygroscopic particles. The similarity of Re for clean and polluted cases is attributed to compensating droplet growth processes for different initial droplet size distributions.

  7. ISDAC Microphysics

    DOE Data Explorer

    McFarquhar, Greg

    2011-07-25

    Best estimate of cloud microphysical parameters derived using data collected by the cloud microphysical probes installed on the National Research Council (NRC) of Canada Convair-580 during ISDAC. These files contain phase, liquid and ice crystal size distributions (Nw(D) and Ni(D) respectively), liquid water content (LWC), ice water content (IWC), extinction of liquid drops (bw), extinction of ice crystals (bi), effective radius of water drops (rew) and of ice crystals (rei) and median mass diameter of liquid drops (Dmml) and of ice crystals (Dmmi) at 30 second resolution.

  8. Cloud Droplet Number Closure Study based on ISDAC Observational Data

    SciTech Connect

    Liu, Peter S. K.

    2012-12-03

    Aerosol-cloud droplet closure analysis was conducted for five cases from the Indirect and Semi-Direct Aerosol Campaign (ISDAC). All cases corresponded to clouds dominated by liquid droplets, with two in relatively clean conditions, and the remaining three in more polluted conditions. This analysis entailed adiabatic cloud parcel model simulations to link the observed properties of aerosols, cloud droplets, and atmospheric dynamics with theoretical predictions. The extent of agreement between observed and modelled droplet number concentrations allowed for the assessment of representations of the physical and chemical properties of aerosols and of the vertical velocity involved in cloud droplet formation. Finally the list of journal publications and conferences are given which corresponds to the research for this DOE grant.

  9. Assesment of the Indirect and Semi-Direct Aerosol-Effect During ISDAC Through Integrated Observational and Modeling Studies

    SciTech Connect

    Boybeyi, Zafer

    2014-09-29

    The Department of Energy (DOE) awarded George Mason University (GMU) with a research project. This project started on June, 2009 and ended July 2014. Main objectives of this research project are; a) to assess the indirect and semi-direct aerosol effects on microphysical structure and radiative properties of Arctic clouds, b) to assess the impact of feedback between the aerosol-cloud interactions and atmospheric boundary layer (ABL) processes on the surface energy balance, c) to better understand and characterize the important unresolved microphysical processes, aerosol effects, and ABL processes and feedbacks, over meso-γ spatial (~1-2 km) and temporal scales (a few minutes to days), and d) to investigate the scale dependency of microphysical parameterizations and its effect on simulations.

  10. Characterization of Arctic ice cloud properties observed during ISDAC

    NASA Astrophysics Data System (ADS)

    Jouan, Caroline; Girard, Eric; Pelon, Jacques; Gultepe, Ismail; Delanoë, Julien; Blanchet, Jean-Pierre

    2012-12-01

    Extensive measurements from ground-based sites and satellite remote sensing (CloudSat and CALIPSO) reveal the existence of two types of ice clouds (TICs) in the Arctic during the polar night and early spring. The first type (TIC-2A), being topped by a cover of nonprecipitating very small (radar unseen) ice crystals (TIC-1), is found more frequently in pristine environment, whereas the second type (TIC-2B), detected by both sensors, is associated preferentially with a high concentration of aerosols. To further investigate the microphysical properties of TIC-1/2A and TIC-2B, airborne in situ and satellite measurements of specific cases observed during Indirect and Semi-Direct Aerosol Campaign (ISDAC) have been analyzed. For the first time, Arctic TIC-1/2A and TIC-2B microstructures are compared using in situ cloud observations. Results show that the differences between them are confined in the upper part of the clouds where ice nucleation occurs. TIC-2B clouds are characterized by fewer (by more than 1 order of magnitude) and larger (by a factor of 2 to 3) ice crystals and a larger ice supersaturation (of 15-20%) compared to TIC-1/2A. Ice crystal growth in TIC-2B clouds seems explosive, whereas it seems more gradual in TIC-1/2A. It is hypothesized that these differences are linked to the number concentration and the chemical composition of aerosols. The ice crystal growth rate in very cold conditions impinges on the precipitation efficiency, dehydration and radiation balance. These results represent an essential and important first step to relate previous modeling, remote sensing and laboratory studies with TICs cloud in situ observations.

  11. Chemical characterization of individual particles and residuals of cloud droplets and ice crystals collected on board research aircraft in the ISDAC 2008 study

    NASA Astrophysics Data System (ADS)

    Hiranuma, N.; Brooks, S. D.; Moffet, R. C.; Glen, A.; Laskin, A.; Gilles, M. K.; Liu, P.; MacDonald, A. M.; Strapp, J. W.; McFarquhar, G. M.

    2013-06-01

    Ambient particles and the dry residuals of mixed-phase cloud droplets and ice crystals were collected during the Indirect and Semi-Direct Aerosol Campaign (ISDAC) near Barrow, Alaska, in spring of 2008. The collected particles were analyzed using Computer Controlled Scanning Electron Microscopy with Energy Dispersive X-ray analysis and Scanning Transmission X-ray Microscopy coupled with Near Edge X-ray Absorption Fine Structure spectroscopy to identify physico-chemical properties that differentiate cloud-nucleating particles from the total aerosol population. A wide range of individually mixed components was identified in the ambient particles and residuals including organic carbon compounds, inorganics, carbonates, and black carbon. Our results show that cloud droplet residuals differ from the ambient particles in both size and composition, suggesting that both properties may impact the cloud-nucleating ability of aerosols in mixed-phase clouds. The percentage of residual particles which contained carbonates (47%) was almost four times higher than those in ambient samples. Residual populations were also enhanced in sea salt and black carbon and reduced in organic compounds relative to the ambient particles. Further, our measurements suggest that chemical processing of aerosols may improve their cloud-nucleating ability. Comparison of results for various time periods within ISDAC suggests that the number and composition of cloud-nucleating particles over Alaska can be influenced by episodic events bringing aerosols from both the local vicinity and as far away as Siberia.

  12. Campaign datasets for ARM Cloud Aerosol Precipitation Experiment (ACAPEX)

    DOE Data Explorer

    Leung, L. Ruby; Mei, Fan; Comstock, Jennifer; DeMott, Paul; Gero, Jonathan; Hubee, John; Matthews, Alyssa; Nalli, Nicholas; Pekour, Mikhail; Prather, Kimberly; Sedlackek, Arthur; Springston, Stephen; Tomlinson, Jason; Chand, Duli

    2015-08-12

    This campaign consisted of the deployment of the DOE ARM Mobile Facility 2 (AMF2) and the ARM Aerial Facility (AAF) G-1 in a field campaign called ARM Cloud Aerosol Precipitation Experiment (ACAPEX), which took place in conjunction with CalWater 2- a NOAA field campaign. The joint CalWater 2/ACAPEX field campaign aimed to improve understanding and modeling of large-scale dynamics and cloud and precipitation processes associated with ARs and aerosol-cloud interactions that influence precipitation variability and extremes in the western U.S. The observational strategy consisted of the use of land and offshore assets to monitor: 1. the evolution and structure of ARs from near their regions of development 2. the long-range transport of aerosols in the eastern North Pacific and potential interactions with ARs 3. how aerosols from long-range transport and local sources influence cloud and precipitation in the U.S. West Coast where ARs make landfall and post-frontal clouds are frequent.

  13. GLOBE Aerosol Field Campaign - U.S. Pilot Study 2016

    NASA Technical Reports Server (NTRS)

    Pippin, Margaret; Marentette, Christina; Bujosa, Robert; Taylor, Jessica; Lewis, Preston

    2016-01-01

    During the spring of 2016, from April 4 - May 27, sixteen GLOBE schools participated in the GLOBE Aerosol Field Campaign - U.S. Pilot Study. Thirteen teachers from these schools had previously participated in the NASA LEARN program (Long-term Experience in Authentic Research with NASA) where they were GLOBE trained in Atmosphere protocols, and engaged in 1-3 years of research under the mentorship of NASA scientists. Each school was loaned two aerosol instruments for the Campaign duration, either 2 GLOBE sun photometers, 2 Calitoo sun photometers, or 1 of each. This allowed for students to make measurements side-by-side and in the case of the Calitoos, to compare AOT results immediately with each other for better consistency in data collection. Additionally, as part of the Field Campaign evaluation, multiple instruments allow for an assessment of the ease of use of each instrument for grade level of students, whether in middle school or high school. Before the Campaign, all GLOBE and Calitoo instruments were 'checked out' against an AERONET, then checked again upon return after the Campaign. By examining all data, before, during and after the Campaign, this gives an indication of instrument performance and proficiency obtained by the students. Support was provided to each teacher and their students at the level requested, via email, phone or video conferencing.

  14. Testing cloud microphysics parameterizations in NCAR CAM5 with ISDAC and M-PACE observations

    SciTech Connect

    Liu X.; Lin W.; Xie, S.; Boyle, J.; Klein, S. A.; Shi, X.; Wang, Z.; Ghan, S. J.; Earle, M.; Liu, P. S. K.; Zelenyuk, A.

    2011-12-24

    Arctic clouds simulated by the National Center for Atmospheric Research (NCAR) Community Atmospheric Model version 5 (CAM5) are evaluated with observations from the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Indirect and Semi-Direct Aerosol Campaign (ISDAC) and Mixed-Phase Arctic Cloud Experiment (M-PACE), which were conducted at its North Slope of Alaska site in April 2008 and October 2004, respectively. Model forecasts for the Arctic spring and fall seasons performed under the Cloud-Associated Parameterizations Testbed framework generally reproduce the spatial distributions of cloud fraction for single-layer boundary-layer mixed-phase stratocumulus and multilayer or deep frontal clouds. However, for low-level stratocumulus, the model significantly underestimates the observed cloud liquid water content in both seasons. As a result, CAM5 significantly underestimates the surface downward longwave radiative fluxes by 20-40 W m{sup -2}. Introducing a new ice nucleation parameterization slightly improves the model performance for low-level mixed-phase clouds by increasing cloud liquid water content through the reduction of the conversion rate from cloud liquid to ice by the Wegener-Bergeron-Findeisen process. The CAM5 single-column model testing shows that changing the instantaneous freezing temperature of rain to form snow from -5 C to -40 C causes a large increase in modeled cloud liquid water content through the slowing down of cloud liquid and rain-related processes (e.g., autoconversion of cloud liquid to rain). The underestimation of aerosol concentrations in CAM5 in the Arctic also plays an important role in the low bias of cloud liquid water in the single-layer mixed-phase clouds. In addition, numerical issues related to the coupling of model physics and time stepping in CAM5 are responsible for the model biases and will be explored in future studies.

  15. ARM Cloud-Aerosol-Precipitation Experiment (ACAPEX) Field Campaign Report

    SciTech Connect

    Leung, L Ruby

    2016-03-01

    The U.S. Department of Energy (DOE)’s Atmospheric Radiation Measurement (ARM) Climate Research Facility’s ARM Cloud-Aerosol-Precipitation Experiment (ACAPEX) field campaign contributes to CalWater 2015, a multi-agency field campaign that aims to improve understanding of atmospheric rivers and aerosol sources and transport that influence cloud and precipitation processes. The ultimate goal is to reduce uncertainties in weather predictions and climate projections of droughts and floods in California. With the DOE G-1 aircraft and ARM Mobile Facility 2 (AMF2) well equipped for making aerosol and cloud measurements, ACAPEX focuses specifically on understanding how aerosols from local pollution and long-range transport affect the amount and phase of precipitation associated with atmospheric rivers. ACAPEX took place between January 12, 2015 and March 8, 2015 as part of CalWater 2015, which included four aircraft (DOE G-1, National Oceanic and Atmospheric Administration [NOAA] G-IV and P-3, and National Aeronautics and Space Administration [NASA] ER-2), the NOAA research ship Ron Brown, carrying onboard the AMF2, National Science Foundation (NSF)-sponsored aerosol and precipitation measurements at Bodega Bay, and the California Department of Water Resources extreme precipitation network.

  16. OMI NO2 and aerosol observations during the DANDELIONS campaign

    NASA Astrophysics Data System (ADS)

    Brinksma, E.; Wagner, T.; Richter, A.; van Roozendael, M.; Swart, D.; de Leeuw, G.; Curier, L.; Berkhout, S.; Veefkind, P.; Levelt, P.

    2005-12-01

    Within the two-year project DANDELIONS (Dutch Aerosol and Nitrogen Dioxide Experiments for vaLIdation of OMI and SCIAMACHY), a 9-week campaign took place. The location was the Cabauw Experimental Site for Atmospheric Research (CESAR, 51N, 5E), which is often subject to considerable tropospheric pollution. The campaign focused on measurements of nitrogen dioxide, atmospheric aerosols, and ozone. Five MAXDOAS instruments and one lidar provided data on the nitrogen dioxide total and tropospheric columns, and profiles (0 - 2.5 km). These were intercompared, and also compared to OMI and SCIAMACHY overpass data. The homogeneity of the tropospheric field was studied. A range of permanent aerosol instrumentation, including sun photometers, an aethalometer, nephelometer, boundary layer lidar and radio sonde profiles and MAX DOASes, was used to provide correlative data for OMI and AATSR aerosol optical depths. Ozone Brewer, ozone sondes, and MAX DOASes provided information on tropospheric and total ozone, to be compared with OMI and SCIAMACHY results. Preliminary results show that satellite and groundbased data compare well. In our presentation, we will show information on the homogeneity of the tropospheric pollution, both in ground based and from satellite data. We will also discuss the quality of the OMI data.

  17. Testing Cloud Microphysics Parameterizations in NCAR CAM5 with ISDAC and M-PACE Observations

    SciTech Connect

    Liu, Xiaohong; Xie, Shaocheng; Boyle, James; Klein, Stephen A.; Shi, Xiangjun; Wang, Zhien; Lin, Wuyin; Ghan, Steven J.; Earle, Michael; Liu, Peter; Zelenyuk, Alla

    2011-12-24

    Arctic clouds simulated by the NCAR Community Atmospheric Model version 5 (CAM5) are evaluated with observations from the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Indirect and Semi-Direct Aerosol Campaign (ISDAC) and Mixed-Phase Arctic Cloud Experiment (M-PACE), which were conducted at its North Slope of Alaska site in April 2008 and October 2004, respectively. Model forecasts for the Arctic Spring and Fall seasons performed under the Cloud- Associated Parameterizations Testbed (CAPT) framework generally reproduce the spatial distributions of cloud fraction for single-layer boundary layer mixed-phase stratocumulus, and multilayer or deep frontal clouds. However, for low-level clouds, the model significantly underestimates the observed cloud liquid water content in both seasons and cloud fraction in the Spring season. As a result, CAM5 significantly underestimates the surface downward longwave (LW) radiative fluxes by 20-40 W m-2. The model with a new ice nucleation parameterization moderately improves the model simulations by increasing cloud liquid water content in mixed-phase clouds through the reduction of the conversion rate from cloud liquid to ice by the Wegener-Bergeron- Findeisen (WBF) process. The CAM5 single column model testing shows that change in the homogeneous freezing temperature of rain to form snow from -5 C to -40 C has a substantial impact on the modeled liquid water content through the slowing-down of liquid and rain-related processes. In contrast, collections of cloud ice by snow and cloud liquid by rain are of minor importance for single-layer boundary layer mixed-phase clouds in the Arctic.

  18. Campaign datasets for Two-Column Aerosol Project (TCAP)

    DOE Data Explorer

    Berg,Larry; Mei,Fan; Cairns,Brian; Chand,Duli; Comstock,Jennifer; Cziczo,Daniel; Hostetler,Chris; Hubbe,John; Long,Chuck; Michalsky,Joseph; Pekour,Mikhail; Russell,Phil; Scott,Herman; Sedlacek,Arthur; Shilling,John; Springston,Stephen; Tomlinson,Jason; Watson,Thomas; Zelenyuk-Imre,Alla

    2013-12-30

    This campaign was designed to provide a detailed set of observations with which to 1) perform radiative and cloud condensation nuclei (CCN) closure studies, 2) evaluate a new retrieval algorithm for aerosol optical depth (AOD) in the presence of clouds using passive remote sensing 3) extend a previously developed technique to investigate aerosol indirect effects, and 4) evaluate the performance of a detailed regional-scale model and a more parameterized global-scale model in simulating particle activation and AOD associated with the aging of anthropogenic aerosols. To meet these science objectives, the ARM Mobile Facility (AMF) and the Mobile Aerosol Observing System (MAOS) was deployed on Cape Cod, Massachusetts for a 12-month period starting in the summer of 2012 in order to quantify aerosol properties, radiation and cloud characteristics at a location subject to both clear- and cloudy- conditions, and clean- and polluted-conditions. These observations were supplemented by two aircraft intensive observation periods (IOPS), one in the summer and a second in the winter. Each IOP required two aircraft.

  19. Distributed Regional Aerosol Gridded Observation Network (DRAGON) - Korea 2012 campaign

    NASA Astrophysics Data System (ADS)

    Kim, J.; Holben, B. N.; Eck, T. F.; Jeong, U.; Kim, W. V.; Choi, M.; Kim, D. S.; Kim, B.; Kim, S.; Ghim, Y.; Kim, Y. J.; Kim, J. H.; Park, R.; Seo, M.; Song, C.; Yum, S.; Woo, J.; Yoon, S.; Lee, K.; Lee, M.; Lim, J.; Chang, I.; Jeong, M. J.; Bae, M.; Sorokin, M.; Giles, D. M.; Schafer, J.; Herman, J. R.

    2013-12-01

    One of the main objectives of Distributed Regional Aerosol Gridded Observation Network (DRAGON) campaign in Deriving Information on Surface conditions from Column and Vertically Resolved Observations Relevant to Air Quality (DISCOVER-AQ) mission is to understand the relationship between the column optical properties of the atmosphere and the surface level air quality in terms of aerosols and gases. Recently, with the cooperative efforts with NASA (National Aeronautics and Space Administration) / GSFC (Goddard Space Flight Center), Korean University research groups, and KME (Korea Ministry of Environment) / NIER (National Institute of Environmental Research), DRAGON-Korea 2012 campaign was successfully performed from March to May 2012. The campaign sites were divided into two groups, the National scale sites and Seoul metropolitan sites. Thirteen Cimel sunphotometers were distributed at National scale sites including two metropolitan cities and several remote sites. Nine Cimel sunphotometers were distributed at Seoul Metropolitan sites including several residential sites and traffic source areas. The measured datasets are being analyzed in diverse fields of air quality communities including in-situ measurement groups, satellite remote sensing groups, chemical modeling groups, and airplane measurement groups. We will introduce several preliminary results of the analysis and discuss the future planes and corporations in Korea.

  20. Aerosol Properties Downwind of Biomass Burns Field Campaign Report

    SciTech Connect

    Buseck, Peter R

    2016-04-01

    We determined the morphological, chemical, and thermal properties of aerosol particles generated by biomass burning during the Biomass Burning Observation Project (BBOP) campaign during the wildland fire season in the Pacific Northwest from July to mid-September, 2013, and in October, 2013 from prescribed agricultural burns in the lower Mississippi River Valley. BBOP was a field campaign of the U.S. Department of Energy (DOE)’s Atmospheric Radiation Measurement (ARM) Climate Research Facility. The morphological information was both two-dimensional, as is typical of most microscopy images and that have many of the characteristic of shadows in that they lack depth data, and three-dimensional (3D). The electron tomographic measurements will provided 3D data, including the presence and nature of pores and interstices, and whether the individual particles are coated by or embedded within other materials. These microphysical properties were determined for particles as a function of time and distance from the respective sources in order to obtain detailed information regarding the time evolution of changes during aging.

  1. Investigation of aerosol optical properties for remote sensing through DRAGON (distributed regional aerosol gridded observation networks) campaign in Korea

    NASA Astrophysics Data System (ADS)

    Lim, Jae-Hyun; Ahn, Joon Young; Park, Jin-Soo; Hong, You-Deok; Han, Jin-Seok; Kim, Jhoon; Kim, Sang-Woo

    2014-11-01

    Aerosols in the atmosphere, including dust and pollutants, scatters/absorbs solar radiation and change the microphysics of clouds, thus influencing the Earth's energy budget, climate, air quality, visibility, agriculture and water circulation. Pollutants have also been reported to threaten the human health. The present research collaborated with the U.S. NASA and the U.S. Aerosol Robotic Network (AERONET) is to study the aerosol characteristics in East Asia and improve the long-distance transportation monitoring technology by analyzing the observations of aerosol characteristics in East Asia during Distributed Regional Aerosol Gridded Observation Networks (DRAGON) Campaign (March 2012-May 2012). The sun photometers that measure the aerosol optical characteristics were placed evenly throughout the Korean Peninsula and concentrated in Seoul and the metropolitan area. Observation data are obtained from the DRAGON campaign and the first year (2012) observation data (aerosol optical depth and aerosol spatial distribution) are analyzed. Sun photometer observations, including aerosol optical depth (AOD), are utilized to validate satellite observations from Geostationary Ocean Color Imager (GOCI) and Moderate Resolution Imaging Spectroradiometer (MODIS). Additional analysis is performed associated with the Northeast Asia, the Korean Peninsula in particular, to determine the spatial distribution of the aerosol.

  2. Evaluation of High-Resolution MAIAC Aerosol Retrievals Using DRAGON Field Campaign Data

    NASA Astrophysics Data System (ADS)

    Lyapustin, A.; Wang, Y.; Korkin, S.

    2013-12-01

    Multi-Angle Implementation of Atmospheric Correction (MAIAC) is a new generation algorithm which uses time series analysis and processing of groups of pixels for advanced cloud masking and retrieval of aerosol and surface reflectance properties. MAIAC makes aerosol retrievals from MODIS data at high 1km resolution providing information about the fine scale aerosol variability. This information is required in different applications such as urban air quality analysis, aerosol source identification etc. The DRAGON field campaign data present a unique spatially distributed array of in-situ aerosol measurements for a comprehensive assessment and validation of MAIAC aerosol retrievals from MODIS. We will provide spatial/temporal comparison statistics between MAIAC and AERONET DRAGON for several different field campaigns including USA 2011 (Washington-Baltimore) and 2012-2013 (San Joaquin Valley, CA) and 2013 (Houston).

  3. Ozone, Iodine, and MSA - Case studies in Antarctic aerosol composition from the 2ODIAC Campaign

    NASA Astrophysics Data System (ADS)

    Giordano, M.; Kalnajs, L.; Deshler, T.; Davis, S. M.; Johnson, A.; Slater, A. G.; Goetz, J. D.; Mukherjee, A. D.; DeCarlo, P. F.

    2015-12-01

    Aerosol generation and transport over the Polar Regions, and especially Antarctica, remains a source of uncertainty for geophysical scientists. A characterization of aerosol sources, production, and lifecycle processes in the Polar Regions is required to better understand the polar atmosphere. In an attempt to better characterize Antarctic aerosol and trace gas interactions, the Two-Season, Ozone Depletion and Interaction with Aerosols Campaign (2ODIAC) was launched over the Austral Spring/Summer of 2014 and Austral Winter of 2015. One highlight of the campaign is the first ever deployment of a high-resolution aerosol mass spectrometer to Antarctica. In conjunction with trace gas, meteorology, and aerosol sizing measurements, this presentation will focus on case studies from the campaign relevant to the atmospheric science community. Questions about the role of iodine, MSA, and ozone depletion events in regards to aerosol composition will be examined. Specific attention will be paid to aerosol compositional changes before, during, and after particle bursts especially where changes in aerosol sulfate oxidation occurred (SO2 -> SO4)

  4. The Ny-Alesund aerosol and ozone measurements intercomparison campaign 1997/1998 (NAOMI-1998)

    NASA Technical Reports Server (NTRS)

    Neuber, R.; Beyerle, G.; Beninga, I.; VonderGathen, P.; Rairoux, P.; Schrems, O.; Wahl, P.; Gross, M.; McGee, Th.; Iwasaka, Y.; Fujiwara, M.; Shibata, T.; Klein, U.; Steinbrecht, W.

    1998-01-01

    An intercomparison campaign for Lidar measurements of stratospheric ozone and aerosol has been conducted at the Primary Station of the Network for the Detection of Stratospheric Change (NDSC) in Ny-Alesund/Spitsbergen during January-February 1998. In addition to local instrumentation, the NDSC mobile ozone lidar from NASA/GSFC and the mobile aerosol lidar from Alfred Wegener Institute (AWI) participated. The aim is the validation of stratospheric ozone and aerosol profile measurements according to NDSC guidelines. This paper briefly presents the employed instruments and outlines the campaign. Results of the blind intercomparison of ozone profiles are given in a companion paper and temperature measurements are described in this issue.

  5. Chemical Characterization of Individual Particles and Residuals of Cloud Droplets and Ice Crystals Collected On Board Research Aircraft in the ISDAC 2008 Study

    SciTech Connect

    Hiranuma, Naruki; Brooks, Sarah D.; Moffet, Ryan C.; Glen, Andrew; Laskin, Alexander; Gilles, Marry K.; Liu, Peter; MacDonald, A. M.; Strapp, J. Walter; McFarquhar, Greg

    2013-06-24

    Although it has been shown that size of atmospheric particles has a direct correlation with their ability to act as cloud droplet and ice nuclei, the influence of composition of freshly emitted and aged particles in nucleation processes is poorly understood. In this work we combine data from field measurements of ice nucleation with chemical imaging of the sampled particles to link aerosol composition with ice nucleation ability. Field measurements and sampling were conducted during the Indirect and Semidirect Aerosols Campaign (ISDAC) over Barrow, Alaska, in the springtime of 2008. In-situ ice nucleation measurements were conducted using a Continuous Flow Diffusion Chamber (CFDC). Measured number concentrations of ice nuclei (IN) varied from frequent values of 0.01 per liter to more than 10 per liter. Residuals of airborne droplets and ice crystals were collected through a counterflow virtual impactor (CVI). The compositions of individual atmospheric particles and the residuals were studied using Computer Controlled Scanning Electron Microscopy with Energy Dispersive X-ray analysis (CCSEM/EDX) and Scanning Transmission X-ray Microscopy coupled with Near Edge X-ray Absorption Fine Structure spectroscopy (STXM/NEXAFS). Chemical analysis of cloud particle residuals collected during an episode of high ice nucleation suggests that both size and composition may influence aerosol's ability to act as IN. The STXM/NEXAFS chemical composition maps of individual residuals have characteristic structures of either inorganic or black carbon cores coated by organic materials. In a separate flight, particle samples from a biomass burning plume were collected. Although it has previously been suggested that episodes of biomass burning contribute to increased numbers of highly effective ice nuclei, in this episode we observed that only a small fraction were effective ice nuclei. Most of the particles from the biomass plume episode were smaller in size and were composed of

  6. Updated aerosol module and its application to simulate secondary organic aerosols during IMPACT campaign May 2008

    NASA Astrophysics Data System (ADS)

    Li, Y. P.; Elbern, H.; Lu, K. D.; Friese, E.; Kiendler-Scharr, A.; Mentel, Th. F.; Wang, X. S.; Wahner, A.; Zhang, Y. H.

    2013-03-01

    The formation of Secondary organic aerosol (SOA) was simulated with the Secondary ORGanic Aerosol Model (SORGAM) by a classical gas-particle partitioning concept, using the two-product model approach, which is widely used in chemical transport models. In this study, we extensively updated SORGAM including three major modifications: firstly, we derived temperature dependence functions of the SOA yields for aromatics and biogenic VOCs, based on recent chamber studies within a sophisticated mathematic optimization framework; secondly, we implemented the SOA formation pathways from photo oxidation (OH initiated) of isoprene; thirdly, we implemented the SOA formation channel from NO3-initiated oxidation of reactive biogenic hydrocarbons (isoprene and monoterpenes). The temperature dependence functions of the SOA yields were validated against available chamber experiments. Moreover, the whole updated SORGAM module was validated against ambient SOA observations represented by the summed oxygenated organic aerosol (OOA) concentrations abstracted from Aerosol Mass Spectrometer (AMS) measurements at a rural site near Rotterdam, the Netherlands, performed during the IMPACT campaign in May 2008. In this case, we embedded both the original and the updated SORGAM module into the EURopean Air pollution and Dispersion-Inverse Model (EURAD-IM), which showed general good agreements with the observed meteorological parameters and several secondary products such as O3, sulfate and nitrate. With the updated SORGAM module, the EURAD-IM model also captured the observed SOA concentrations reasonably well especially those during nighttime. In contrast, the EURAD-IM model before update underestimated the observations by a factor of up to 5. The large improvements of the modeled SOA concentrations by updated SORGAM were attributed to the mentioned three modifications. Embedding the temperature dependence functions of the SOA yields, including the new pathways from isoprene photo oxidations

  7. Updated aerosol module and its application to simulate secondary organic aerosols during IMPACT campaign May 2008

    NASA Astrophysics Data System (ADS)

    Li, Y. P.; Elbern, H.; Lu, K. D.; Friese, E.; Kiendler-Scharr, A.; Mentel, Th. F.; Wang, X. S.; Wahner, A.; Zhang, Y. H.

    2013-07-01

    The formation of Secondary organic aerosol (SOA) was simulated with the Secondary ORGanic Aerosol Model (SORGAM) by a classical gas-particle partitioning concept, using the two-product model approach, which is widely used in chemical transport models. In this study, we extensively updated SORGAM including three major modifications: firstly, we derived temperature dependence functions of the SOA yields for aromatics and biogenic VOCs (volatile organic compounds), based on recent chamber studies within a sophisticated mathematic optimization framework; secondly, we implemented the SOA formation pathways from photo oxidation (OH initiated) of isoprene; thirdly, we implemented the SOA formation channel from NO3-initiated oxidation of reactive biogenic hydrocarbons (isoprene and monoterpenes). The temperature dependence functions of the SOA yields were validated against available chamber experiments, and the updated SORGAM with temperature dependence functions was evaluated with the chamber data. Good performance was found with the normalized mean error of less than 30%. Moreover, the whole updated SORGAM module was validated against ambient SOA observations represented by the summed oxygenated organic aerosol (OOA) concentrations abstracted from aerosol mass spectrometer (AMS) measurements at a rural site near Rotterdam, the Netherlands, performed during the IMPACT campaign in May 2008. In this case, we embedded both the original and the updated SORGAM module into the EURopean Air pollution and Dispersion-Inverse Model (EURAD-IM), which showed general good agreements with the observed meteorological parameters and several secondary products such as O3, sulfate and nitrate. With the updated SORGAM module, the EURAD-IM model also captured the observed SOA concentrations reasonably well especially those during nighttime. In contrast, the EURAD-IM model before update underestimated the observations by a factor of up to 5. The large improvements of the modeled SOA

  8. Three Campaigns for the New Mobile Aerosol Observing System

    NASA Astrophysics Data System (ADS)

    Springston, S. R.; Sedlacek, A. J.

    2012-12-01

    The Mobile Aerosol Observing System (MAOS) is a platform for Intensive Operation Periods (IOPs) containing instrumentation for in-situ measurements of aerosols and their precursors. As part of the ARM Climate Research Facility (ACRF), MAOS is physically contained in two 20' SeaTainers custom adapted to provide a sheltered laboratory environment for operators and instruments even under harsh conditions. The two structures are designated MAOS A and MAOS C for Aerosol and Chemistry respectively. Although independent, with separate data systems, inlets and power distribution, the two structures are normally deployed as a single operating unit. The two MAOS enclosures are designed for rapid deployment. All components (except for the Radar Wind Profiler) are transported internally in operating configuration. Once on site with power and internet, most operations can commence within 1-2 hours of set up (erection of the sampling towers and roof railings). The structures are suitable for extreme terrestrial conditions while maintaining laboratory conditions inside. MAOS C has converters for labile compounds at the 10-m sampling height, a separate fast flow PFA inlet for trace gases and both A and C have independent, free-standing aerosol sampling inlets based on existing AOS units within ACRF. Inlets are deiced and guyed for winds up to at least ~50 m/s. In case of severe weather forecasts, the inlets can be quickly lowered. The instrument suite includes aerosol and black carbon counters, optical and electro mobility classifiers, three measurements of aerosol absorbance, hygroscopicity measurements of aerosol growth and scattering, cloud condensation nuclei counters, two measurements of aerosol chemical composition and an extensive suite of research-grade instruments for complementary measurements of trace gas aerosol precursors. A local meteorology sensor at the inlet, a SODAR and a Radar Wind Profiler provide context for the measurements. MAOS has been successfully

  9. Aerosol nucleation and growth in the TTL, due to tropical convection, during the ACTIVE campaign

    NASA Astrophysics Data System (ADS)

    Waddicor, D.; Vaughan, G.; Choularton, T.

    2009-04-01

    The Aerosol and Chemical Transport In tropical convection (ACTIVE) campaign took place between October 2005 and February 2006. This investigation involved the sampling of deep convective storms that occur in the Tropics; the campaign was based in Darwin, Northern Territory, Australia - the latter half of the campaign coincided with the monsoon season. A range of scientific equipment was used to sample the inflow and outflow air from these storms; of particular importance were the NERC Dornier (low-level) and ARA Egrett (high-level outflow) aircraft. The Dornier held a range of aerosol, particle and chemical detectors for the purpose of analysing the planetary boundary layer (PBL), in the vicinity of tropical convection. The Egrett contained detection instrumentation for a range of sizes of aerosol and cloud particles (2 Condensation Particle Counters (CPC), CAPS, CIP, CPI) in the storm outflow. This allowed a quantifiable measurement to be made of the effect of deep tropical convection on the aerosol population in the Tropical Tropopause Layer (TTL). The ACTIVE campaign found that there were large numbers of aerosol particles in the 10 - 100 nm (up to 25,000 /cm3 STP) and 100 - 1000 nm (up to 600 /cm3) size ranges. These values, in many instances, surpassed those found in the PBL. The higher levels of aerosol found in the TTL compared to the PBL could indicate that aerosol nucleation was occurring in the TTL as a direct result of convective activity. Furthermore, the Egrett aircraft found distinct boundaries between the high levels of aerosol, which were found in cloud free regions, and very low numbers of aerosol, which were found in the cloudy regions (storm anvil). The air masses were determined, from back trajectories, to have been through convective uplift and were formerly part of the anvil cloud. The cloudy regions would have contained high levels of entrapped precursor gases. Reduced nucleation and cloud particle scavenging of aerosol and gases would give a

  10. Sources and Distributions of Secondary Aerosols over the Northeastern United States during the WINTER Aircraft Campaign.

    NASA Astrophysics Data System (ADS)

    Shah, V.; Jaegle, L.; Haskins, J.; Campuzano Jost, P.; Schroder, J. C.; Jimenez, J. L.; Sullivan, A.; Weber, R. J.; Dibb, J. E.; Green, J. R.; Fiddler, M. N.; Bililign, S.; Lopez-Hilfiker, F.; Lee, B. H.; Veres, P. R.; Thornton, J. A.

    2015-12-01

    Atmospheric aerosols harm public health, reduce visibility, and alter the Earth's climate. A significant fraction of the aerosol burden is composed of secondary aerosols formed from gas-phase precursors such as SO2, NOx, NH3, and VOC's. The formation and composition of secondary aerosols depends on precursor abundance, oxidant availability, and the thermodynamic properties of the semi-volatile species. The oxidation and thermodynamic processes are strongly dependent on the available sunlight, temperature, and humidity, and produce large seasonal shifts in the aerosol characteristics. While most previous aircraft campaigns have studied these processes during summer, the Wintertime INvestigation of Transport, Emissions, and Reactivity (WINTER) campaign focuses on the wintertime chemical processes over the northeastern United States. A comprehensive dataset of gas- and particle-phase species was collected during the campaign using the NSF/NCAR C-130 aircraft in February-March 2015. We interpret these observations using the GEOS-Chem chemical transport model with a 1/4 degree latitude by 5/16 degree longitude nested-grid over North America. We present a comparison of the model results with the aircraft measurements, and examine the sources of secondary inorganic and organic aerosols observed during the campaign. We use the model results to investigate the consistency between the aircraft, surface and satellite observations of aerosol concentrations and optical depths. Furthermore, we use multi-year model simulations to understand the effect of the unusually cold weather in 2015 over the northeastern United States on the chemical environment observed during the campaign.

  11. Climatology of aerosol optical properties near the New England coast: preparation for the Two Column Aerosol Program (TCAP) field campaign

    NASA Astrophysics Data System (ADS)

    Berkowitz, C. M.; Chand, D.; Berg, L.; Kassianov, E.; Chapman, E.

    2011-12-01

    A key objective of the U.S. Department of Energy's Two Column Aerosol Project (TCAP) is to provide observations with which to evaluate the uncertainty in model simulations of aerosol optical depth (AOD) and their relation to estimates of aerosol radiative forcing and hence, to climate. To meet this objective, detailed ground-based aerosol measurements will be made via deployment of the ARM Mobile Facility (AMF) and the Mobile Aerosol Observing System (MAOS) at Cape Cod, Massachusetts for a 12-month period starting in the summer of 2012. These measurements will be supported by two scheduled aircraft campaigns using the ARM Aerial Facility's (AAF) G-1 aircraft and the NASA B-200 aircraft in July 2012 and again in February 2013. Each campaign will include sampling within two atmospheric columns using the aircrafts; one column will be located directly over, or very close to, Cape Cod, while the second will be over a relatively remote maritime location. This preliminary study presented here is designed to select the optimum location of the second, remote maritime atmospheric column using the mean and standard deviation of previously observed AODs from surface and space. An area with the large variability in AOD will be considered as a potential location for evaluation of the outputs from atmospheric models. In this study, we present regional climatological values of (1) AOD from the Moderate Resolution Imaging Spectrometer (MODIS) on Terra and Aqua satellite platforms; (2) single scattering albedo from the Multi-angle Imaging SpectroRadiometer (MISR) satellite; (3) the vertical distribution of aerosol layers from the Cloud Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) satellite; and (4) the long term aerosol optical properties from the Aerosol Robotic Network (AERONET) surface sunphotometer at Martha's Vineyard, MA. Seasonal and geographical variations in these quantities will be analyzed and possible explanations will be presented based on

  12. Characteristics of Interstitial Aerosol in Cold and Warm Clouds during the Ice-T Campaign

    NASA Astrophysics Data System (ADS)

    Dhaniyala, S.; He, M.; Moharreri, A.; Craig, L.

    2012-12-01

    Accurate calculation of the contribution of aerosols to the radiative forcing budget requires an understanding of the aerosol role in cloud formation. From a global climate perspective, aerosol-cloud processes must be represented by simple parametric models that can relate aerosol properties to the characteristics of the clouds formed. The development and testing of such simple models requires aerosol-cloud data from a large number of clouds systems. While reasonably accurate cloud data is currently available from a large number of well-established cloud probes, information about aerosol particles in clouds is largely unavailable because of the problem of artifacts in aerosol measurements from the shatter of cloud droplets. During the recent ICE-T campaign (Summer 2011), several different interstitial aerosol inlets were deployed and aerosol measurements were made in a variety of tropical convective clouds, focused particularly on conditions that permit the formation of ice within these systems. The flight operations were based in St. Croix, U.S. Virgin Islands and sampling was largely conducted within ~ 600 miles of this location. The use of new samplers that permit shatter-free sampling of aerosol particles in cold and clouds has allowed for the collection of significant data on interstitial aerosol in tropical convective clouds. Of particular interest are measurements of aerosol size distributions inside and outside clouds made with a fast mobility spectrometer. Size distributions were obtained at 20-30 second resolution, permitting direct measurements of the scavenged aerosol population in clouds and the differences in the scavenged fraction as a function of cloud properties. As part of this presentation, the characteristics of interstitial aerosol in various cloud conditions will be presented and the transformation of aerosol population during cloud processing will be discussed.

  13. Two-Column Aerosol Project (TCAP) Field Campaign Report

    SciTech Connect

    Berg, Larry K

    2016-05-01

    This study included the deployment of the Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility’s Mobile Facility (AMF), ARM Mobile Aerosol Observing System (MAOS) and the ARM Aerial Facility (AAF). The study was a collaborative effort involving scientists from DOE national laboratories, NOAA, NASA, and universities. The AAF and MAOS were deployed for two approximately month-long Intensive Operational Periods (IOPs) conducted in June 2012 and February 2013. Seasonal differences in the aerosol chemical and optical properties observed using the AMF, AAF, and MAOS are presented in this report. The total mass loading of aerosol is found to be much greater in the summer than in the winter, with the difference associated with greater amounts of organic aerosol. The mass fraction of organic aerosol is much reduced in the winter, when sulfate is the dominant aerosol type. Surprisingly, very little sea-salt aerosol was observed in the summer. In contrast, much more sea salt aerosol was observed in the winter. The mass loading of black carbon is nearly the same in both seasons. These differences lead to a relative increase in the aerosol light absorption in the winter and an associated decrease in observed single-scattering albedo. Measurements of aerosol mixing state were made using a single-particle mass spectrometer, which showed that the majority of the summertime aerosol consisted of organic compounds mixed with various amounts of sulfate. A number of other findings are also summarized in the report, including: impact of aerosol layers aloft on the column aerosol optical depth; documentation of the aerosol properties at the AMF; differences in the aerosol properties associated with both columns, which are not systematic but reflect the complicated meteorological and chemical processes that impact aerosol as it is advected away from North America; and new instruments and data-processing techniques for measuring both aerosol and

  14. Ganges Valley Aerosol Experiment (GVAX) Final Campaign Report

    SciTech Connect

    Kotamarthi, VR

    2013-12-01

    In general, the Indian Summer Monsoon (ISM) as well as the and the tropical monsoon climate is influenced by a wide range of factors. Under various climate change scenarios, temperatures over land and into the mid troposphere are expected to increase, intensifying the summer pressure gradient differential between land and ocean and thus strengthening the ISM. However, increasing aerosol concentration, air pollution, and deforestation result in changes to surface albedo and insolation, potentially leading to low monsoon rainfall. Clear evidence points to increasing aerosol concentrations over the Indian subcontinent with time, and several hypotheses regarding the effect on monsoons have been offered. The Ganges Valley Aerosol Experiment (GVAX) field study aimed to provide critical data to address these hypotheses and contribute to developing better parameterizations for tropical clouds, convection, and aerosol-cloud interactions. The primary science questions for the mission were as follows:

  15. Biomass burning and biogenic aerosols in northern Australia during the SAFIRED campaign

    NASA Astrophysics Data System (ADS)

    Milic, Andelija; Mallet, Marc D.; Cravigan, Luke T.; Alroe, Joel; Ristovski, Zoran D.; Selleck, Paul; Lawson, Sarah J.; Ward, Jason; Desservettaz, Maximilien J.; Paton-Walsh, Clare; Williams, Leah R.; Keywood, Melita D.; Miljevic, Branka

    2017-03-01

    There is a lack of knowledge of how biomass burning aerosols in the tropics age, including those in the fire-prone Northern Territory in Australia. This paper reports chemical characterization of fresh and aged aerosols monitored during the 1-month-long SAFIRED (Savannah Fires in the Early Dry Season) field study, with an emphasis on the chemical signature and aging of organic aerosols. The campaign took place in June 2014 during the early dry season when the surface measurement site, the Australian Tropical Atmospheric Research Station (ATARS), located in the Northern Territory, was heavily influenced by thousands of wild and prescribed bushfires. ATARS was equipped with a wide suite of instrumentation for gaseous and aerosol characterization. A compact time-of-flight aerosol mass spectrometer was deployed to monitor aerosol chemical composition. Approximately 90 % of submicron non-refractory mass was composed of organic material. Ozone enhancement in biomass burning plumes indicated increased air mass photochemistry. The diversity in biomass burning emissions was illustrated through variability in chemical signature (e.g. wide range in f44, from 0.06 to 0.18) for five intense fire events. The background particulate loading was characterized using positive matrix factorization (PMF). A PMF-resolved BBOA (biomass burning organic aerosol) factor comprised 24 % of the submicron non-refractory organic aerosol mass, confirming the significance of fire sources. A dominant PMF factor, OOA (oxygenated organic aerosol), made up 47 % of the sampled aerosol, illustrating the importance of aerosol aging in the Northern Territory. Biogenic isoprene-derived organic aerosol factor was the third significant fraction of the background aerosol (28 %).

  16. Pajarito Aerosol Couplings to Ecosystems (PACE) Field Campaign Report

    SciTech Connect

    Dubey, M

    2016-03-01

    Laboratory (LANL) worked on the Pajarito Aerosol Couplings to Ecosystems (PACE) intensive operational period (IOP). PACE’s primary goal was to demonstrate routine Mobile Aerosol Observing System (MAOS) field operations and improve instrumental and operational performance. LANL operated the instruments efficiently and effectively with remote guidance by the instrument mentors. This was the first time a complex suite of instruments had been operated under the ARM model and it proved to be a very successful and cost-effective model to build upon.

  17. Distinct Impacts of Aerosols on an Evolving Continental Cloud System during the RACORO Field Campaign

    NASA Astrophysics Data System (ADS)

    Lin, Y.; Wang, Y.; Zhang, R.; Liu, Y.

    2015-12-01

    Aerosol-cloud interactions have been investigated extensively but still remain high uncertainty due to the complexity of cloud microphysical processes under various dynamic and thermodynamic environments. Cloud-resolving Weather Research and Forecast (CR-WRF) model implemented with a two-moment bulk microphysics and a modified Goddard radiation scheme is employed to investigate aerosol effects on different cloud regimes and their transitions associated with a continental cloud system occurring from 25 May to 27 May, 2009 during the Department of Energy Atmospheric Radiation Measurement Routine AAF Clouds with Low Optical Water Depths Optical Radiative Observations (RACORO) field campaign. The simulated cloud properties and precipitation for the three different cloud regimes, including shallow cumuli, a deep convective cloud (DCC), and a stratus exhibit overall agreements with airborne and ground-based observations. Sensitivity studies with different aerosol scenarios reveal that the responses of cloud micro- and macrophysics to aerosol loading depend on the cloud regimes with monotonic or non-monotonic trend. Aerosol radiative effects modify the atmospheric thermodynamic condition and change the atmospheric stability, which induce different response from aerosol indirect effects. Our results also indicate that the overall aerosol effects on a cloud complex are distinct from those of the individual cloud types. The aerosol-cloud interaction for the different cloud regimes should be evaluated to assess the aerosol direct and indirect radiative forcings on regional and global climate.

  18. Project Overview: Cumulus Humilis Aerosol Processing Study (CHAPS): Proposed Summer 2007 ASP Field Campaign

    SciTech Connect

    Berkowitz, Carl M.; Berg, Larry K.; Ogren, J. A.; Hostetler, Chris A.; Ferrare, Richard

    2006-05-18

    This white paper presents the scientific motivation and preliminary logistical plans for a proposed ASP field campaign to be carried out in the summer of 2007. The primary objective of this campaign is to use the DOE Gulfstream-1 aircraft to make measurements characterizing the chemical, physical and optical properties of aerosols below, within and above large fields of fair weather cumulus and to use the NASA Langley Research Center’s High Spectral Resolution Lidar (HSRL) to make independent measurements of aerosol backscatter and extinction profiles in the vicinity of these fields. Separate from the science questions to be addressed by these observations will be information to add in the development of a parameterized cumulus scheme capable of including multiple cloud fields within a regional or global scale model. We will also be able to compare and contrast the cloud and aerosol properties within and outside the Oklahoma City plume to study aerosol processes within individual clouds. Preliminary discussions with the Cloud and Land Surface Interaction Campaign (CLASIC) science team have identified overlap between the science questions posed for the CLASIC Intensive Operation Period (IOP) and the proposed ASP campaign, suggesting collaboration would benefit both teams.

  19. Organic Aerosol Composition and Sources in Pasadena, California during the 2010 CalNex Campaign

    EPA Science Inventory

    Organic aerosols (OA) in Pasadena are characterized using multiple measurements from the California Research at the Nexus of Air Quality and Climate Change (CalNex) campaign. Five OA components are identified using positive matrix factorization including hydrocarbon-like OA (HOA) ...

  20. Organic Aerosol Composition and Sources in Pasadena, California during the 2010 CalNex Campaign

    EPA Science Inventory

    Organic aerosols (OA) in Pasadena are characterized using multiple measurements from the California Research at the Nexus of Air Quality and Climate Change (CalNex) campaign. Five OA components are identified using positive matrix factorization including hydrocarbon-like OA (HOA) ...

  1. Aerosol transport over Siberia: analysis of the summer 2013 YAK-AEROSIB aircraft campaign

    NASA Astrophysics Data System (ADS)

    Ancellet, Gerard; Penner, Johannes; Kokhanenko, Grigorii; Arshinov, Mikhail; Chernov, Dimitry; Kozlov, Valery; Paris, Jean Daniel; Pruvost, Arnaud; Belan, Boris; Nedelec, Philippe; Pelon, Jacques; Law, Kathy

    2014-05-01

    Transport and transformation of aerosols related to forest fires and Eastern Asia anthropogenic emissions have been identified as very important questions to understand the Arctic climate. Two aircraft campaigns have been conducted over Siberia in summer 2012 and 2013 with in-situ measurements by aerosol spectrometers and also by a 532 nm backscatter lidar in 2013. The aerosol data can be also combined with CO measurements measured on-board the aircraft to identify the aerosol pollution sources. The analysis of the transport processes has been performed with the FLEXPART Lagrangian model run either in the forward or backward mode. While the 2012 campaign is characterized by anticyclonic conditions and strong forest fire emissions, the 2013 campaign corresponds to upward lifting of Northern China emissions. Comparisons with satellite data obtained with the CALIPSO mission for the two summer periods will be presented to identify the spatial extent and the temporal evolution of the pollution plumes and also to test the ability of the satellite data to derive the aerosol types. This work was funded by CNRS (France), the French Ministry of Foreign Affairs, CEA (France), Presidium of RAS (Program No. 4), Brunch of Geology, Geophysics and Mining Sciences of RAS (Program No. 5), Interdisciplinary integration projects of Siberian Branch of RAS (No. 35, No. 70, No. 131), Russian Foundation for Basic Research (grants No 14-05-00526, 14-05-00590).

  2. Simultaneous Retrieval of Aerosol and Cloud Properties During the MILAGRO Field Campaign

    NASA Technical Reports Server (NTRS)

    Knobelspiesse, K.; Cairns, B.; Redemann, J.; Bergstrom, R. W.; Stohl, A.

    2011-01-01

    Estimation of Direct Climate Forcing (DCF) due to aerosols in cloudy areas has historically been a difficult task, mainly because of a lack of appropriate measurements. Recently, passive remote sensing instruments have been developed that have the potential to retrieve both cloud and aerosol properties using polarimetric, multiple view angle, and multi spectral observations, and therefore determine DCF from aerosols above clouds. One such instrument is the Research Scanning Polarimeter (RSP), an airborne prototype of a sensor on the NASA Glory satellite, which unfortunately failed to reach orbit during its launch in March of 2011. In the spring of 2006, the RSP was deployed on an aircraft based in Veracruz, Mexico, as part of the Megacity Initiative: Local and Global Research Observations (MILAGRO) field campaign. On 13 March, the RSP over flew an aerosol layer lofted above a low altitude marine stratocumulus cloud close to shore in the Gulf of Mexico. We investigate the feasibility of retrieving aerosol properties over clouds using these data. Our approach is to first determine cloud droplet size distribution using the angular location of the cloud bow and other features in the polarized reflectance. The selected cloud was then used in a multiple scattering radiative transfer model optimization to determine the aerosol optical properties and fine tune the cloud size distribution. In this scene, we were able to retrieve aerosol optical depth, the fine mode aerosol size distribution parameters and the cloud droplet size distribution parameters to a degree of accuracy required for climate modeling. This required assumptions about the aerosol vertical distribution and the optical properties of the coarse aerosol size mode. A sensitivity study was also performed to place this study in the context of future systematic scanning polarimeter observations, which found that the aerosol complex refractive index can also be observed accurately if the aerosol optical depth is

  3. Insights into Submicron Aerosol Composition and Sources from the WINTER Aircraft Campaign Over the Eastern US.

    NASA Astrophysics Data System (ADS)

    Schroder, J. C.; Campuzano Jost, P.; Day, D. A.; Fibiger, D. L.; McDuffie, E. E.; Blake, N. J.; Hills, A. J.; Hornbrook, R. S.; Apel, E. C.; Weinheimer, A. J.; Campos, T. L.; Brown, S. S.; Jimenez, J. L.

    2015-12-01

    The WINTER aircraft campaign was a recent field experiment to probe the sources and evolution of gas pollutants and aerosols in Northeast US urban and industrial plumes during the winter. A highly customized Aerodyne aerosol mass spectrometer (AMS) was flown on the NCAR C-130 to characterize submicron aerosol composition and evolution. Thirteen research flights were conducted covering a wide range of conditions, including rural, urban, and marine environments during day and night. Organic aerosol (OA) was a large component of the submicron aerosol in the boundary layer. The fraction of OA (fOA) was smaller (35-40%) than in recent US summer campaigns (~60-70%). Biomass burning was observed to be an important source of OA in the boundary layer, which is consistent with recent wintertime studies that show a substantial contribution of residential wood burning to the OA loadings. OA oxygenation (O/C ratio) shows a broad distribution with a substantial fraction of smaller O/C ratios when compared to previous summertime campaigns. Since measurements were rarely made very close to primary sources (i.e. directly above urban areas), this is consistent with oxidative chemistry being slower during winter. SOA formation and aging in the NYC plume was observed during several flights and compared with summertime results from LA (CalNex) and Mexico City (MILAGRO). Additionally, an oxidation flow reactor (OFR) capable of oxidizing ambient air up to several equivalent days of oxidation was deployed for the first time in an aircraft platform. The aerosol outflow of the OFR was sampled with the AMS to provide real-time snapshots of the potential for aerosol formation and aging. For example, a case study of a flight through the Ohio River valley showed evidence of oxidation of SO2 to sulfate. The measured sulfate enhancements were in good agreement with our OFR chemical model. OFR results for SOA will be discussed.

  4. GOCI Yonsei Aerosol Retrieval (YAER) algorithm and validation during the DRAGON-NE Asia 2012 campaign

    NASA Astrophysics Data System (ADS)

    Choi, Myungje; Kim, Jhoon; Lee, Jaehwa; Kim, Mijin; Park, Young-Je; Jeong, Ukkyo; Kim, Woogyung; Hong, Hyunkee; Holben, Brent; Eck, Thomas F.; Song, Chul H.; Lim, Jae-Hyun; Song, Chang-Keun

    2016-04-01

    The Geostationary Ocean Color Imager (GOCI) onboard the Communication, Ocean, and Meteorological Satellite (COMS) is the first multi-channel ocean color imager in geostationary orbit. Hourly GOCI top-of-atmosphere radiance has been available for the retrieval of aerosol optical properties over East Asia since March 2011. This study presents improvements made to the GOCI Yonsei Aerosol Retrieval (YAER) algorithm together with validation results during the Distributed Regional Aerosol Gridded Observation Networks - Northeast Asia 2012 campaign (DRAGON-NE Asia 2012 campaign). The evaluation during the spring season over East Asia is important because of high aerosol concentrations and diverse types of Asian dust and haze. Optical properties of aerosol are retrieved from the GOCI YAER algorithm including aerosol optical depth (AOD) at 550 nm, fine-mode fraction (FMF) at 550 nm, single-scattering albedo (SSA) at 440 nm, Ångström exponent (AE) between 440 and 860 nm, and aerosol type. The aerosol models are created based on a global analysis of the Aerosol Robotic Networks (AERONET) inversion data, and covers a broad range of size distribution and absorptivity, including nonspherical dust properties. The Cox-Munk ocean bidirectional reflectance distribution function (BRDF) model is used over ocean, and an improved minimum reflectance technique is used over land. Because turbid water is persistent over the Yellow Sea, the land algorithm is used for such cases. The aerosol products are evaluated against AERONET observations and MODIS Collection 6 aerosol products retrieved from Dark Target (DT) and Deep Blue (DB) algorithms during the DRAGON-NE Asia 2012 campaign conducted from March to May 2012. Comparison of AOD from GOCI and AERONET resulted in a Pearson correlation coefficient of 0.881 and a linear regression equation with GOCI AOD = 1.083 × AERONET AOD - 0.042. The correlation between GOCI and MODIS AODs is higher over ocean than land. GOCI AOD shows better

  5. GOCI Yonsei Aerosol Retrieval (YAER) Algorithm and Validation During the DRAGON-NE Asia 2012 Campaign

    NASA Technical Reports Server (NTRS)

    Choi, Myungje; Kim, Jhoon; Lee, Jaehwa; Kim, Mijin; Park, Young-Je; Jeong, Ukkyo; Kim, Woogyung; Hong, Hyunkee; Holben, Brent; Eck, Thomas F.; hide

    2016-01-01

    The Geostationary Ocean Color Imager (GOCI) onboard the Communication, Ocean, and Meteorological Satellite (COMS) is the first multi-channel ocean color imager in geostationary orbit. Hourly GOCI top-of-atmosphere radiance has been available for the retrieval of aerosol optical properties over East Asia since March 2011. This study presents improvements made to the GOCI Yonsei Aerosol Retrieval (YAER) algorithm together with validation results during the Distributed Regional Aerosol Gridded Observation Networks - Northeast Asia 2012 campaign (DRAGONNE Asia 2012 campaign). The evaluation during the spring season over East Asia is important because of high aerosol concentrations and diverse types of Asian dust and haze. Optical properties of aerosol are retrieved from the GOCI YAER algorithm including aerosol optical depth (AOD) at 550 nm, fine-mode fraction (FMF) at 550 nm, single-scattering albedo (SSA) at 440 nm, Angstrom exponent (AE) between 440 and 860 nm, and aerosol type. The aerosol models are created based on a global analysis of the Aerosol Robotic Networks (AERONET) inversion data, and covers a broad range of size distribution and absorptivity, including nonspherical dust properties. The Cox-Munk ocean bidirectional reflectance distribution function (BRDF) model is used over ocean, and an improved minimum reflectance technique is used over land. Because turbid water is persistent over the Yellow Sea, the land algorithm is used for such cases. The aerosol products are evaluated against AERONET observations and MODIS Collection 6 aerosol products retrieved from Dark Target (DT) and Deep Blue (DB) algorithms during the DRAGON-NE Asia 2012 campaign conducted from March to May 2012. Comparison of AOD from GOCI and AERONET resulted in a Pearson correlation coefficient of 0.881 and a linear regression equation with GOCI AOD = 1.083 x AERONET AOD - 0.042. The correlation between GOCI and MODIS AODs is higher over ocean than land. GOCI AOD shows better agreement

  6. Relationship between column aerosol optical properties and surface aerosol gravimetric concentrations during the Distributed Regional Aerosol Gridded Observation Network - Northeast ASIA 2012 campaign

    NASA Astrophysics Data System (ADS)

    Jeong, U.; Kim, J.; Seo, S.; Choi, M.; Kim, W. V.; Holben, B. N.; Lee, S.; Kim, J.

    2012-12-01

    One of the main objectives of Distributed Regional Aerosol Gridded Observation Network (DRAGON) campaign in Deriving Information on Surface conditions from Column and Vertically Resolved Observations Relevant to Air Quality (DISCOVER-AQ) mission is to understand the relationship between the column optical properties of the atmosphere and the surface level air quality in terms of aerosols and gases. This study aims to identify the important parameters that affecting the relationship between those variables during the DRAGON - northeast Asia 2012 campaign. Column aerosol optical properties from ten Cimel sun photometers at DRAGON sites in Seoul, MODIS (Moderate Resolution Imaging Spectroradiometer), and GOCI (Geostationary Ocean Color Imager) and particulate matter (PM10) sampling from 40 NIER (National Institute of Environmental Research of South Korea) measurement sites in Seoul during the period of 1st March - 31th May 2012 were employed in this study. The key parameters in relationship between aerosol optical depth (AOD) and PM are reported to be aerosol vertical profile and hygroscopicity of the aerosols. The meteorological conditions including relative humidity, surface temperature, and wind speed that could affect those parameters were investigated.

  7. Water Soluble Ions in Bulk Aerosol During the WINTER 2015 Campaign.

    NASA Astrophysics Data System (ADS)

    Dibb, J. E.; Scheuer, E. M.; Brown, S. S.; Campuzano Jost, P.; Fibiger, D. L.; Guo, H.; Jimenez, J. L.; Lopez-Hilfiker, F.; McDuffie, E. E.; Schroder, J. C.; Sullivan, A.; Thornton, J. A.; Veres, P. R.; Weber, R. J.

    2015-12-01

    Aerosol samples were collected on filters from the NCAR C-130 during the WINTER campaign using an inlet believed to transmit particles up to 4 micron in diameter. Filter integration times were nominally 7 minutes. Aqueous extracts of the filter samples were analyzed by ion chromatography for 5 anions and 5 cations, we focus primarily on chloride and nitrate due to their roles coupling chlorine and nitrogen oxide chemistry. Comparison to measurements of submicron aerosol (by PILS and AMS) indicates that there was significant coarse chloride in the boundary layer on all WINTER flights, including the 7 flights over the continent. Significant super micron chloride at altitudes above 2 km was seen in just 3 of the filter samples from the entire mission, all of these were well inland. During the 6 flights over the Atlantic ocean we observed displacement of chloride from the dominant seasalt aerosol at times, but evidence for coarse mode nitrate or sulfate aerosol to explain this is less clear. While coarse aerosol chloride mixing ratios were sufficient to support observed production of nitryl chloride, no correlations between these compounds were observed on any flights. However, nitrate was positively correlated with nitryl chloride, as expected, on all flights when the latter exceeded several 100's of pptv for extended periods. Aerosol nitrate was also positively correlated with dinitrogen pentoxide when mixing ratios of the latter exceeded ~500 pptv for significant portions of a flight. On the WINTER flights in February aerosol nitrate was often more abundant than nitric acid, this was less often the case for the flights in March. This change in partitioning of nitrate between gas and particle phases reflects an increasing trend of nitric acid and a small decrease in abundance of aerosol nitrate through the campaign.

  8. Solar irradiance and aerosol optical properties during the CARES field campaign

    NASA Astrophysics Data System (ADS)

    Barnard, J.; Kassianov, E.

    2010-12-01

    Measurements of both broadband and spectral solar irradiances were made during the Carbonaceous Aerosols and Radiative Effects Study (CARES) field campaign at the T0 and T1 sites. The broadband irradiances were measured using a typical Eppley Precision Spectral Pyranometer (PSP), while the spectral irradiances were measured by a Multi-Filter Rotating Shadowband Radiometer (MFRSR) at six wavelengths (415, 500, 615, 673, 870, and 940 nm). The aerosol optical depth (AOD), single scattering albedo (SSA), and asymmetry parameter (AP), can be inferred from the MFRSR measurements for the first five of these wavelengths. Analyses of these data show three distinct aerosol regimes. The first period, at the beginning of the field campaign, was extremely clean, with AOD values at 500nm as low as 0.03 (with uncertainty of 0.02). Such clear air rivals that at other pristine locations, such as Barrow, Alaska, in late summer. Next, a brief episode of biomass burning took place on June 16, as indicated by increased AOD. Finally, towards the end of the campaign, progressively deteriorating air quality was observed with a concomitant increase in AOD, with values 0.1 (500 nm) and larger. However, at no time during the campaign did the air quality deteriorate to the extent that might be observed in less clean locations such as Mexico City, or more humid places were significant hydroscopic growth occurs. The broadband irradiances also reflect clean conditions, with midday total, hemispherical irradiances often exceeding 1000 W/m^2. We also show some initial results of columnar SSA and AP values derived during the three aerosol regimes. MFRSR data taken near the T1 site during the summer of 2009 also indicate generally clear skies, except during episodes of biomass burning when the AOD approaches 1.0 at 500 nm. Such dirty air was never observed during the CARES campaign.

  9. Aerosol optical hygroscopicity measurements during the 2010 CARES campaign

    DOE PAGES

    Atkinson, D. B.; Radney, J. G.; Lum, J.; ...

    2015-04-17

    Measurements of the effect of water uptake on particulate light extinction or scattering made at two locations during the 2010 Carbonaceous Aerosols and Radiative Effects Study (CARES) study around Sacramento, CA are reported. The observed influence of water uptake, characterized through the dimensionless optical hygroscopicity parameter γ, is compared with calculations constrained by observed particle size distributions and size-dependent particle composition. A closure assessment has been carried out that allowed for determination of the average hygroscopic growth factors (GFs) at 85% relative humidity and the dimensionless hygroscopicity parameter κ for oxygenated organic aerosol (OA) and for supermicron particles (defined heremore » as particles with aerodynamic diameters between 1 and 2.5 microns), yielding κ = 0.1–0.15 and 0.9–1.0, respectively. The derived range of oxygenated OA κ values are in line with previous observations. The relatively large values for supermicron particles is consistent with substantial contributions of sea-salt-containing particles in this size range. Analysis of time-dependent variations in the supermicron particle hygroscopicity suggest that atmospheric processing, specifically chloride displacement by nitrate and the accumulation of secondary organics on supermicron particles, can lead to substantial depression of the observed GF.« less

  10. GOCI Yonsei Aerosol Retrieval (YAER) algorithm and validation during DRAGON-NE Asia 2012 campaign

    NASA Astrophysics Data System (ADS)

    Choi, M.; Kim, J.; Lee, J.; Kim, M.; Park, Y. Je; Jeong, U.; Kim, W.; Holben, B.; Eck, T. F.; Lim, J. H.; Song, C. K.

    2015-09-01

    The Geostationary Ocean Color Imager (GOCI) onboard the Communication, Ocean, and Meteorology Satellites (COMS) is the first multi-channel ocean color imager in geostationary orbit. Hourly GOCI top-of-atmosphere radiance has been available for the retrieval of aerosol optical properties over East Asia since March 2011. This study presents improvements to the GOCI Yonsei Aerosol Retrieval (YAER) algorithm over ocean and land together with validation results during the DRAGON-NE Asia 2012 campaign. Optical properties of aerosol are retrieved from the GOCI YAER algorithm including aerosol optical depth (AOD) at 550 nm, fine-mode fraction (FMF) at 550 nm, single scattering albedo (SSA) at 440 nm, Angstrom exponent (AE) between 440 and 860 nm, and aerosol type from selected aerosol models in calculating AOD. Assumed aerosol models are compiled from global Aerosol Robotic Networks (AERONET) inversion data, and categorized according to AOD, FMF, and SSA. Nonsphericity is considered, and unified aerosol models are used over land and ocean. Different assumptions for surface reflectance are applied over ocean and land. Surface reflectance over the ocean varies with geometry and wind speed, while surface reflectance over land is obtained from the 1-3 % darkest pixels in a 6 km × 6 km area during 30 days. In the East China Sea and Yellow Sea, significant area is covered persistently by turbid waters, for which the land algorithm is used for aerosol retrieval. To detect turbid water pixels, TOA reflectance difference at 660 nm is used. GOCI YAER products are validated using other aerosol products from AERONET and the MODIS Collection 6 aerosol data from "Dark Target (DT)" and "Deep Blue (DB)" algorithms during the DRAGON-NE Asia 2012 campaign from March to May 2012. Comparison of AOD from GOCI and AERONET gives a Pearson correlation coefficient of 0.885 and a linear regression equation with GOCI AOD =1.086 × AERONET AOD - 0.041. GOCI and MODIS AODs are more highly correlated

  11. Distinct Impacts of Aerosols on an Evolving Continental Cloud Complex during the RACORO Field Campaign

    SciTech Connect

    Lin, Yun; Wang, Yuan; Pan, Bowen; Hu, Jiaxi; Liu, Yangang; Zhang, Renyi

    2016-08-26

    In this study, a continental cloud complex, consisting of shallow cumuli, a deep convective cloud (DCC), and stratus, is simulated by a cloud-resolving Weather Research and Forecasting Model to investigate the aerosol microphysical effect (AME) and aerosol radiative effect (ARE) on the various cloud regimes and their transitions during the Department of Energy Routine Atmospheric Radiation Measurement Aerial Facility Clouds with Low Optical Water Depths Optical Radiative Observations (RACORO) campaign. Under an elevated aerosol loading with AME only, a reduced cloudiness for the shallow cumuli and stratus resulted from more droplet evaporation competing with suppressed precipitation, but an enhanced cloudiness for the DCC is attributed to more condensation. With the inclusion of ARE, the shallow cumuli are suppressed owing to the thermodynamic effects of light-absorbing aerosols. The responses of DCC and stratus to aerosols are monotonic with AME only but nonmonotonic with both AME and ARE. The DCC is invigorated because of favorable convection and moisture conditions at night induced by daytime ARE, via the so-called aerosol-enhanced conditional instability mechanism. Finally, the results reveal that the overall aerosol effects on the cloud complex are distinct from the individual cloud types, highlighting that the aerosol–cloud interactions for diverse cloud regimes and their transitions need to be evaluated to assess the regional and global climatic impacts.

  12. Distinct Impacts of Aerosols on an Evolving Continental Cloud Complex during the RACORO Field Campaign

    DOE PAGES

    Lin, Yun; Wang, Yuan; Pan, Bowen; ...

    2016-08-26

    In this study, a continental cloud complex, consisting of shallow cumuli, a deep convective cloud (DCC), and stratus, is simulated by a cloud-resolving Weather Research and Forecasting Model to investigate the aerosol microphysical effect (AME) and aerosol radiative effect (ARE) on the various cloud regimes and their transitions during the Department of Energy Routine Atmospheric Radiation Measurement Aerial Facility Clouds with Low Optical Water Depths Optical Radiative Observations (RACORO) campaign. Under an elevated aerosol loading with AME only, a reduced cloudiness for the shallow cumuli and stratus resulted from more droplet evaporation competing with suppressed precipitation, but an enhanced cloudinessmore » for the DCC is attributed to more condensation. With the inclusion of ARE, the shallow cumuli are suppressed owing to the thermodynamic effects of light-absorbing aerosols. The responses of DCC and stratus to aerosols are monotonic with AME only but nonmonotonic with both AME and ARE. The DCC is invigorated because of favorable convection and moisture conditions at night induced by daytime ARE, via the so-called aerosol-enhanced conditional instability mechanism. Finally, the results reveal that the overall aerosol effects on the cloud complex are distinct from the individual cloud types, highlighting that the aerosol–cloud interactions for diverse cloud regimes and their transitions need to be evaluated to assess the regional and global climatic impacts.« less

  13. Distinct Impacts of Aerosols on an Evolving Continental Cloud Complex during the RACORO Field Campaign

    SciTech Connect

    Lin, Yun; Wang, Yuan; Pan, Bowen; Hu, Jiaxi; Liu, Yangang; Zhang, Renyi

    2016-08-26

    In this study, a continental cloud complex, consisting of shallow cumuli, a deep convective cloud (DCC), and stratus, is simulated by a cloud-resolving Weather Research and Forecasting Model to investigate the aerosol microphysical effect (AME) and aerosol radiative effect (ARE) on the various cloud regimes and their transitions during the Department of Energy Routine Atmospheric Radiation Measurement Aerial Facility Clouds with Low Optical Water Depths Optical Radiative Observations (RACORO) campaign. Under an elevated aerosol loading with AME only, a reduced cloudiness for the shallow cumuli and stratus resulted from more droplet evaporation competing with suppressed precipitation, but an enhanced cloudiness for the DCC is attributed to more condensation. With the inclusion of ARE, the shallow cumuli are suppressed owing to the thermodynamic effects of light-absorbing aerosols. The responses of DCC and stratus to aerosols are monotonic with AME only but nonmonotonic with both AME and ARE. The DCC is invigorated because of favorable convection and moisture conditions at night induced by daytime ARE, via the so-called aerosol-enhanced conditional instability mechanism. Finally, the results reveal that the overall aerosol effects on the cloud complex are distinct from the individual cloud types, highlighting that the aerosol–cloud interactions for diverse cloud regimes and their transitions need to be evaluated to assess the regional and global climatic impacts.

  14. The radiative effect of aerosols over Europe during the EUCAARI-LONGREX campaign

    NASA Astrophysics Data System (ADS)

    Esteve, Anna R.; Highwood, Ellie; Morgan, William T.; Coe, Hugh; Brown, Phil; Szpek, Kate; Martínez-Lozano, J. Antonio

    2014-05-01

    Atmospheric aerosols affect the Earth's climate both directly, through the scattering and absorption of radiation, and indirectly, via changes to cloud microphysics and properties. The resultant change in net radiation (radiative forcing) is still characterized by a great uncertainty, both at regional and global scales, due to the variability of the optical properties and the spatial - temporal distribution of the aerosols. Here, we calculate the radiative effect of anthropogenic aerosols over Europe using the data collected by the Facility for Airborne Atmospheric Measurements (FAAM) BAe-146 aircraft during the European Integrated Project on Aerosol Cloud Climate and Air Quality Interactions Long Range Experiment (EUCAARI-LONGREX). The EUCAARI-LONGREX campaign consisted of 15 flights over central Europe or off the UK coast (47 - 57° N and 12° W - 22° E) during May 2008, designed to map the aerosol concentrations and properties over Europe, with a particular focus on observing long range transport of aerosol properties, as well as changes in those properties. The instrumentation aboard the FAAM BAe-146 aircraft allowed the measurement of the chemical composition, microphysical, optical and hygroscopic properties of the atmospheric aerosols, as well as the upwelling and downwelling radiation. We have also quantified here the uncertainties in our calculations due to the variability of aerosol concentration and properties and the way in which they are represented in models. For our calculations of the direct aerosol radiative effect, we use the composition and microphysical measurements together with the Edwards and Slingo radiative transfer model to estimate irradiances from 0.2 to 10 μm. Vertical profiles of temperature, aerosol, water vapour and ozone are taken from the aircraft measurements. The modelled irradiances have been compared to the radiation data from flight b374 of the FAAM BAe-146 aircraft in order to evaluate the validity of model assumptions and

  15. Characteristics of aerosol at a lower atmospheric layer in DRAGON field campaign

    NASA Astrophysics Data System (ADS)

    KUJI, M.; Azuma, Y.; Kitakoga, S.; Sano, I.; Holben, B. N.

    2013-12-01

    Air pollution arises severely over East Asia with the rapid economic development nowadays. Monitoring the atmospheric environment, as one of the purposes, an intensive field campaign, Distributed Regional Aerosol Gridded Observation Networks (DRAGON), was carried out in the spring of year 2012, led by National Aeronautics and Space Administration (NASA). At that time, atmospheric phenomena such as Yellow sand and haze events were observed at Nara in the western part of Japan, as one of the DRAGON observation sites. The atmospheric events were characterized with the AErosol RObotic NETwork (AERONET) data. As a result of the data analysis, it was found that more light-absorbing and smaller particles dominated at the lower than upper atmospheric layer for the Kosa event in particular. A backward trajectory analysis suggested that the Yellow sand event traveled over the East Asian industrial cities, which could lead to a mixture of sand and air pollutants with moderate particle size and light-absorptivity. In addition, visibility observation was evaluated quantitatively with AERONET data in the DRAGON campaign since eye observation was inherently semi-quantitative. The extinction coefficient estimated from visibility was compared to that from AERONET. As a result, it was found that the extinction coefficients were generally consistent to each other. But there were some discrepancies, which could be caused with the atmospheric phenomena or aerosol types. It is confirmed that visibility is strongly influenced with aerosols in the case of severe atmospheric phenomena in particular.

  16. Atmospheric boundary layer and ozone-aerosol interactions under Saharan intrusions observed during AMISOC summer campaign

    NASA Astrophysics Data System (ADS)

    Adame, J. A.; Córdoba-Jabonero, C.; Sorribas, M.; Toledo, D.; Gil-Ojeda, M.

    2015-03-01

    A research campaign was performed for the AMISOC (Atmospheric Minor Species relevant to the Ozone Chemistry) project at El Arenosillo observatory (southwest Spain) in May-June 2012. The campaign focused on the impact of Saharan dust intrusions at the atmospheric boundary layer (ABL) and ozone-aerosol interactions. In-situ and remote-sensing techniques for gases and aerosols were used in addition to modelling analyses. Meteorology features, ABL structures and evolution, aerosol profiling distributions and aerosol-ozone interactions on the surface were analysed. Two four-day periods were selected according to non-dusty (clean conditions) and dusty (Saharan dust) situations. In both scenarios, sea-land breezes developed in the lower atmosphere, but differences were found in the upper levels. Results show that surface temperatures were greater than 3 °C and humidity were lower during dusty than non-dusty conditions. Thermal structures on the surface layer (estimated using an instrument on a 100 m tower) show differences, mainly during nocturnal periods with less intense inversions under dusty conditions. The mixing layer during dusty days was 400-800 m thick, less than observed on non-dusty. Dust also disturbed the typical daily ABL evolution. Stable conditions were observed in the early evening during intrusions. Aerosol extinction on dusty days was 2-3 times higher, and the dust was confined between 1500 and 5500 m. Back trajectory analyses confirmed that the dust had an African origin. On surface, the particle concentration was approximately 3.5 times higher during dusty events, but the local ozone did not exhibit any change. The arrival of Saharan dust in the upper levels impacted the meteorological surface, inhibited the daily evolution of the ABL and caused an increase in aerosol loading on the surface and at higher altitudes; however, no dust influence was observed on the surface ozone.

  17. Characterization and source apportionment of submicron aerosol with aerosol mass spectrometer during the PRIDE-PRD 2006 campaign

    NASA Astrophysics Data System (ADS)

    Xiao, R.; Takegawa, N.; Zheng, M.; Kondo, Y.; Miyazaki, Y.; Miyakawa, T.; Hu, M.; Shao, M.; Zeng, L.; Gong, Y.; Lu, K.; Deng, Z.; Zhao, Y.; Zhang, Y. H.

    2011-01-01

    oxygenated aerosol. The origin of HOA and OOA (the sum of LV-OOA and SV-OOA) has been further confirmed by the statistics that primary organic carbon (POC) and secondary organic carbon (SOC), estimated by the EC tracer method, were closely correlated with HOA and OOA, respectively. The results of the EC tracer method and of the PMF model revealed that primary organic aerosol (POA) constituted ~34-47% of OA mass and secondary organic aerosol (SOA) constituted ~53-66% of regional organic aerosol in PRD during summer reason. The presence of abundant SOA was consistent with water soluble organic carbon (WSOC) results (accounting for ~60% of OC on average) by Miyazaki et al. (2009) for the same campaign. OOA correlated well with WSOC at the BG site, indicating that most OOA were water soluble. More specifically, approximately 86% of LV-OOA and 61% of SV-OOA were estimated as water soluble species on the basis of carbon content comparison.

  18. Characterization and source apportionment of submicron aerosol with aerosol mass spectrometer during the PRIDE-PRD 2006 campaign

    NASA Astrophysics Data System (ADS)

    Xiao, R.; Takegawa, N.; Zheng, M.; Kondo, Y.; Miyazaki, Y.; Miyakawa, T.; Hu, M.; Shao, M.; Zeng, L.; Gong, Y.; Lu, K.; Deng, Z.; Zhao, Y.; Zhang, Y. H.

    2011-07-01

    oxygenated aerosol. The origin of HOA and OOA (the sum of LV-OOA and SV-OOA) has been further confirmed by the statistics that primary organic carbon (POC) and secondary organic carbon (SOC), estimated by the EC tracer method, were closely correlated with HOA and OOA, respectively. The results of the EC tracer method and of the PMF model revealed that primary organic aerosol (POA) constituted ~34-47 % of OA mass and secondary organic aerosol (SOA) constituted ~53-66 % of regional organic aerosol in PRD during summer season. The presence of abundant SOA was consistent with water soluble organic carbon (WSOC) results (accounting for ~60 % of OC on average) by Miyazaki et al. (2009) for the same campaign. OOA correlated well with WSOC at the BG site, indicating that most OOA were water soluble. More specifically, approximately 86 % of LV-OOA and 61 % of SV-OOA were estimated as water soluble species on the basis of carbon content comparison.

  19. Fast Airborne Aerosol Size and Chemistry Measurements with the High Resolution Aerosol Mass Spectrometer during the MILAGRO Campaign

    NASA Technical Reports Server (NTRS)

    DeCarlo, P. F.; Dunlea, E. J.; Kimmel, J. R.; Aiken, A. C.; Sueper, D.; Crounse, J.; Wennberg, P. O.; Emmons, L.; Shinozuka, Y.; Clarke, A.; hide

    2007-01-01

    The concentration, size, and composition of non-refractory submicron aerosol (NR-PM(sub l)) was measured over Mexico City and central Mexico with a High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) onboard the NSF/NCAR C-130 aircraft as part of the MILAGRO field campaign. This was the first aircraft deployment of the HR-ToF-AMS. During the campaign the instrument performed very well, and provided 12 s data. The aerosol mass from the AMS correlates strongly with other aerosol measurements on board the aircraft. Organic aerosol (OA) species dominate the NR-PM(sub l) mass. OA correlates strongly with CO and HCN indicating that pollution (mostly secondary OA, SOA) and biomass burning (BB) are the main OA sources. The OA to CO ratio indicates a typical value for aged air of around 80 microg/cubic m (STP) ppm(exp -1). This is within the range observed in outflow from the Northeastern US, which could be due to a compensating effect between higher BB but lower biogenic VOC emissions during this study. The O/C atomic ratio for OA is calculated from the HR mass spectra and shows a clear increase with photochemical age, as SOA forms rapidly and quickly overwhelms primary urban OA, consistent with Volkamer et al. (2006) and Kleinman et al. (2008). The stability of the OA/CO while O/C increases with photochemical age implies a net loss of carbon from the OA. BB OA is marked by signals at m/z 60 and 73, and also by a signal enhancement at large m/z indicative of larger molecules or more resistance to fragmentation. The main inorganic components show different spatial patterns and size distributions. Sulfate is regional in nature with clear volcanic and petrochemical/power plant sources, while the urban area is not a major regional source for this species. Nitrate is enhanced significantly in the urban area and immediate outflow, and is strongly correlated with CO indicating a strong urban source. The importance of nitrate decreases with distance from the city

  20. Fast Airborne Aerosol Size and Chemistry Measurements with the High Resolution Aerosol Mass Spectrometer during the MILAGRO Campaign

    NASA Technical Reports Server (NTRS)

    DeCarlo, P. F.; Dunlea, E. J.; Kimmel, J. R.; Aiken, A. C.; Sueper, D.; Crounse, J.; Wennberg, P. O.; Emmons, L.; Shinozuka, Y.; Clarke, A.; Zhou, J.; Tomlinson, J.; Collins,D. R.; Knapp, D.; Weinheimer, A. J.; Montzka,D. D.; Campos,T.; Jimenez, J. L.

    2007-01-01

    The concentration, size, and composition of non-refractory submicron aerosol (NR-PM(sub l)) was measured over Mexico City and central Mexico with a High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) onboard the NSF/NCAR C-130 aircraft as part of the MILAGRO field campaign. This was the first aircraft deployment of the HR-ToF-AMS. During the campaign the instrument performed very well, and provided 12 s data. The aerosol mass from the AMS correlates strongly with other aerosol measurements on board the aircraft. Organic aerosol (OA) species dominate the NR-PM(sub l) mass. OA correlates strongly with CO and HCN indicating that pollution (mostly secondary OA, SOA) and biomass burning (BB) are the main OA sources. The OA to CO ratio indicates a typical value for aged air of around 80 microg/cubic m (STP) ppm(exp -1). This is within the range observed in outflow from the Northeastern US, which could be due to a compensating effect between higher BB but lower biogenic VOC emissions during this study. The O/C atomic ratio for OA is calculated from the HR mass spectra and shows a clear increase with photochemical age, as SOA forms rapidly and quickly overwhelms primary urban OA, consistent with Volkamer et al. (2006) and Kleinman et al. (2008). The stability of the OA/CO while O/C increases with photochemical age implies a net loss of carbon from the OA. BB OA is marked by signals at m/z 60 and 73, and also by a signal enhancement at large m/z indicative of larger molecules or more resistance to fragmentation. The main inorganic components show different spatial patterns and size distributions. Sulfate is regional in nature with clear volcanic and petrochemical/power plant sources, while the urban area is not a major regional source for this species. Nitrate is enhanced significantly in the urban area and immediate outflow, and is strongly correlated with CO indicating a strong urban source. The importance of nitrate decreases with distance from the city

  1. Aerosol data assimilation in the chemical transport model MOCAGE during the TRAQA/ChArMEx campaign: aerosol optical depth

    NASA Astrophysics Data System (ADS)

    Sič, Bojan; El Amraoui, Laaziz; Piacentini, Andrea; Marécal, Virginie; Emili, Emanuele; Cariolle, Daniel; Prather, Michael; Attié, Jean-Luc

    2016-11-01

    In this study, we describe the development of the aerosol optical depth (AOD) assimilation module in the chemistry transport model (CTM) MOCAGE (Modèle de Chimie Atmosphérique à Grande Echelle). Our goal is to assimilate the spatially averaged 2-D column AOD data from the National Aeronautics and Space Administration (NASA) Moderate-resolution Imaging Spectroradiometer (MODIS) instrument, and to estimate improvements in a 3-D CTM assimilation run compared to a direct model run. Our assimilation system uses 3-D-FGAT (first guess at appropriate time) as an assimilation method and the total 3-D aerosol concentration as a control variable. In order to have an extensive validation dataset, we carried out our experiment in the northern summer of 2012 when the pre-ChArMEx (CHemistry and AeRosol MEditerranean EXperiment) field campaign TRAQA (TRAnsport à longue distance et Qualité de l'Air dans le bassin méditerranéen) took place in the western Mediterranean basin. The assimilated model run is evaluated independently against a range of aerosol properties (2-D and 3-D) measured by in situ instruments (the TRAQA size-resolved balloon and aircraft measurements), the satellite Spinning Enhanced Visible and InfraRed Imager (SEVIRI) instrument and ground-based instruments from the Aerosol Robotic Network (AERONET) network. The evaluation demonstrates that the AOD assimilation greatly improves aerosol representation in the model. For example, the comparison of the direct and the assimilated model run with AERONET data shows that the assimilation increased the correlation (from 0.74 to 0.88), and reduced the bias (from 0.050 to 0.006) and the root mean square error in the AOD (from 0.12 to 0.07). When compared to the 3-D concentration data obtained by the in situ aircraft and balloon measurements, the assimilation consistently improves the model output. The best results as expected occur when the shape of the vertical profile is correctly simulated by the direct model. We

  2. Aerosol Composition in Los Angeles During the 2010 CalNex Campaign Studied by High Resolution Aerosol Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Hayes, P. L.; Ortega, A. M.; Cubison, M.; Hu, W.; Toohey, D. W.; Flynn, J. H.; Grossberg, N.; Lefer, B. L.; Alvarez, S.; Rappenglueck, B.; Allan, J. D.; McKeen, S. A.; Holloway, J. S.; Gilman, J. B.; Kuster, W. C.; Graus, M.; Warneke, C.; de Gouw, J. A.; Richter, R.; Hofer, J.; Prevot, A. S.; Jimenez, J. L.

    2010-12-01

    Submicron atmospheric aerosols impact climate and human health, but their sources and composition are poorly understood. To address this knowledge gap, high-resolution time-of-flight aerosol mass spectrometry (AMS) [DeCarlo et al. Anal. Chem. 2006] and other advanced instrumentation were deployed during the CalNex field campaign in May and June 2010 for 4 weeks to characterize the composition of aerosols in the Los Angeles area. Utilizing AMS, the concentrations for both organic and non-refractory inorganic (sulfate, nitrate, ammonium, chloride) submicron aerosols were quantified at the Caltech/Pasadena ground site 15 km NE of downtown Los Angeles. The total submicron mass concentration as well as the species concentrations measured by AMS compare well with other instruments. Nitrate aerosols appear to dominate in the cooler mornings, but their concentration is reduced in the afternoon when organic aerosols (OA) increase and dominate. The diurnal variations in concentration are strongly influenced by vertical dilution from the rising planetary boundary layer in the afternoon. Secondary organic aerosols (SOA) are an important fraction of submicron aerosols. To assess the concentrations of different OA components present at the site, positive matrix factorization (PMF) is used to analyze the field data. The major OA classes are oxygenated OA (OOA, a surrogate for total SOA), and hydrocarbon-like OA (HOA, a surrogate for primary combustion OA). Preliminary PMF analysis finds that OOA is consistently the largest type of OA present (~75% of the total OA concentration). This result suggests that the air mass over the site has undergone substantial chemical aging. The correlations between OOA and Ox (O3 + NO2) concentrations, as well as between HOA, CO and black carbon concentrations are strong and consistent with previous studies. AMS and 14C measurements are combined to determine the fractions of HOA and OOA from non-fossil vs. fossil sources. Using measurements of SOA

  3. The 2005 and 2006 DANDELIONS NO2 and aerosol intercomparison campaigns

    NASA Astrophysics Data System (ADS)

    Brinksma, E. J.; Pinardi, G.; Volten, H.; Braak, R.; Richter, A.; SchöNhardt, A.; van Roozendael, M.; Fayt, C.; Hermans, C.; Dirksen, R. J.; Vlemmix, T.; Berkhout, A. J. C.; Swart, D. P. J.; Oetjen, H.; Wittrock, F.; Wagner, T.; Ibrahim, O. W.; de Leeuw, G.; Moerman, M.; Curier, R. L.; Celarier, E. A.; Cede, A.; Knap, W. H.; Veefkind, J. P.; Eskes, H. J.; Allaart, M.; Rothe, R.; Piters, A. J. M.; Levelt, P. F.

    2008-08-01

    Dutch Aerosol and Nitrogen Dioxide Experiments for Validation of OMI and SCIAMACHY (DANDELIONS) is a project that encompasses validation of spaceborne measurements of NO2 by the Ozone Monitoring Instrument (OMI) and Scanning Imaging Absorption Spectrometer for Atmospheric Cartography (SCIAMACHY), and of aerosol by OMI and Advanced Along-Track Scanning Radiometer (AATSR), using an extensive set of ground-based and balloon measurements over the polluted area of the Netherlands. We present an extensive data set of ground-based, balloon, and satellite data on NO2, aerosols, and ozone obtained from two campaigns within the project, held during May-June 2005 and September 2006. We have used these data for first validation of OMI NO2, and the data are available through the Aura Validation Data Center website for use in other validation efforts. In this paper we describe the available data, and the methods and instruments used, including the National Institute of Public Health and the Environment (RIVM) NO2 lidar. We show that NO2 from Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) compares well with in situ measurements. We show that different MAX-DOAS instruments, operating simultaneously during the campaign, give very similar results. We also provide unique information on the spatial homogeneity and the vertical and temporal variability of NO2, showing that during a number of days, the NO2 columns derived from measurements in different directions varied significantly, which implies that, under polluted conditions, measurements in one single azimuth direction are not always representative for the averaged field that the satellite observes. In addition, we show that there is good agreement between tropospheric NO2 from OMI and MAX-DOAS, and also between total NO2 from OMI and direct-sun observations. Observations of the aerosol optical thickness (AOT) show that values derived with three ground-based instruments correspond well with each other, and with

  4. An Overview of the DAURE Campaign: Aerosols Emissions and Evolution in the Western Mediterranean Basin

    NASA Astrophysics Data System (ADS)

    Pandolfi, Marco; Querol, Xavier; Alastuey, Andrés.; Jimenez, Jose L.

    2010-05-01

    DAURE (Determination of the sources of atmospheric Aerosols in Urban and Rural Environments in the western Mediterranean) is a multidisciplinary international measurement campaign mainly aimed at estimating the sources and origin of atmospheric fine aerosols in the Western Mediterranean Basin (WMB), with particular attention to the carbonaceous fraction. Main focuses of the campaign are the study of the origin of the intense pollution episodes frequently occurring at regional scale in summer and winter in the WMB (Perez et al., 2008) and the emission, formation, transport and transformation of aerosols during these polluted scenarios. The peculiar atmospheric dynamics in the WMB, regulated by complex climatic and orographic effects (Millán et al., 1997), together with the large pollutant emissions from densely populated areas, large industrial areas and ports located along the coastline, give rise to a complex phenomenology for aerosol formation and transformation. In this context, extremely high concentrations of fine particulate matter (mainly PM1, particulate matter with aerodynamic diameter < 1um) are usually registered at regional background stations, with levels even higher than those simultaneously registered at urban stations. DAURE brings together state-of-the-art measurements and modeling techniques from about 20 International and Spanish Institutions. The DAURE campaign took place during winter (February-March 2009) and summer (July 2009) at an urban site (Barcelona, 80 m a.s.l., NE Spain) and a regional background site (Montseny, 720 m a.s.l., NE Spain, a Supersite of the EUSAAR network). Widespread in situ aerosol sampling techniques (such as PM optical counters, PM samplers, MAAP, CPC, SMPS, Rotating Drum Impactor, among others) and remote sensing techniques (LIDAR, sunphotometer) have been applied together with state-of-the-art methods such as 14C (Szidat et al., 2006), Proton-Transfer Reaction Mass Spectrometry (PTRMS) for VOCs, and High

  5. Hygroscopic Measurements of Aerosol Particles in Colorado during the Discover AQ Campaign 2014

    NASA Astrophysics Data System (ADS)

    Orozco, D.; Delgado, R.; Espinosa, R.; Martins, J. V.; Hoff, R. M.

    2014-12-01

    In ambient conditions, aerosol particles experience hygroscopic growth due to the influence of relative humidity (RH), scattering more light than when the particles are dry. The quantitative knowledge of the RH effect and its influence on the light scattering and, in particular, on the phase function and polarization of aerosol particles is of substantial importance when comparing ground observations with other optical aerosol measurements such satellite and sunphotometric retrievals of aerosol optical depth and their inversions. In the summer of 2014, the DISCOVER-AQ campaign was held in Colorado, where systematic and concurrent observations of column- integrated surface, and vertically-resolved distributions of aerosols and trace gases relevant to air quality and their evolution during the day were observed. Aerosol optical properties were measured in the UMBC trailer at the city of Golden using a TSI-3563 nephelometer and an in-situ Polarized Imaging Nephelometer (PI-NEPH) designed and built by the LACO group at UMBC. The PI-NEPH measures aerosol phase matrix components in high angular range between 2 and 178 degrees scattering angle at three wavelengths (λ=473, 532 and 671nm). The two measured elements of the phase matrix, intensity (P11) and linear polarization (P12) provide extensive characterization of the scattering properties of the studied aerosol. The scattering coefficient, P11 and P12 were measured under different humidity conditions to obtain the enhancement factor f(RH) and the dependence of P11 and P12 to RH using a humidifier dryer system covering a RH range from 20 to 90%. The ratio between scattering coefficients at high and low humidity in Golden Colorado showed relatively low hygroscopic growth in the aerosol particles f(RH=80%) was 1.27±0.19 for the first three weeks of sampling. According to speciated measurements performed at the UMBC trailer, the predominance of dust and organic aerosols over more hygroscopic nitrate and sulfate in the

  6. Evaluating Aerosol Process Modules within the Framework of the Aerosol Modeling Testbed

    NASA Astrophysics Data System (ADS)

    Fast, J. D.; Velu, V.; Gustafson, W. I.; Chapman, E.; Easter, R. C.; Shrivastava, M.; Singh, B.

    2012-12-01

    MILAGRO, 2008 ISDAC, 2008 VOCALS, 2010 CARES, and 2010 CalNex campaigns, have been incorporated into the AMT as testbed cases. Data from operational networks (e.g. air quality, meteorology, satellite) are also included in the testbed cases to supplement the field campaign data. The CARES and CalNex testbed cases are used to demonstrate how the AMT can be used to assess the strengths and weaknesses of simple and complex representations of aerosol processes in relation to computational cost. Anticipated enhancements to the AMT and how this type of testbed can be used by the scientific community to foster collaborations and coordinate aerosol modeling research will also be discussed.

  7. Susceptibility of aerosol optical thickness retrievals to thin cirrus contamination during the BASE-ASIA campaign

    NASA Astrophysics Data System (ADS)

    Huang, Jingfeng; Hsu, N. Christina; Tsay, Si-Chee; Jeong, Myeong-Jae; Holben, Brent N.; Berkoff, Timothy A.; Welton, Ellsworth J.

    2011-04-01

    We used a combination of ground measurements (Aerosol Robotic Network, AERONET; Micro-Pulse Lidar Network, MPLNET) and satellite data (Moderate Resolution Imaging Spectroradiometer, MODIS; Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation, CALIPSO) to examine the susceptibility of ground and satellite aerosol retrievals to thin cirrus contamination at Phimai, Thailand (102.56°E, 15.18°N, also known as Pimai), during the Biomass-burning Aerosols in South East-Asia: Smoke Impact Assessment (BASE-ASIA) campaign (February-May 2006). Using the strengths of spaceborne or ground lidars to detect cirrus clouds, we conducted statistical analyses for four different scenarios: MPLNET versus AERONET, MPLNET versus MODIS, CALIPSO versus AERONET, and CALIPSO versus MODIS. Cirrus identifications from MPLNET or CALIPSO were paired up with concurrent aerosol optical thickness (AOT) measurements from AERONET or MODIS. Results from the BASE-ASIA campaign suggest that current operational AERONET and MODIS AOT products are influenced by thin cirrus contamination featuring strong seasonality. Concurrent AERONET and MPLNET observations indicate that additional thin cirrus screening changes AOT monthly means by 5%, with 20% of the AERONET aerosol data at Phimai being cirrus contaminated in boreal spring. From noncirrus cases to cirrus-contaminated cases, AERONET AOT increases along with larger particle sizes. We further evaluated the performance of eight MODIS-derived cirrus screening parameters for their effectiveness on thin cirrus screening: apparent reflectance at 1.38 μm (R1.38), cirrus reflectance at 0.66 μm (CR0.66), CR0.66 cirrus flag, reflectance ratio between 1.38 μm and 0.66 μm (RR1.38/0.66), reflectance ratio between 1.38 μm and 1.24 μm (RR1.38/1.24), brightness temperature difference between 8.6 μm and 11 μm (BTD8.6-11), brightness temperature difference between 11 μm and 12 μm (BTD11-12), and cloud phase infrared approach. Correlation analysis

  8. Impact of aerosol direct effect on East Asian air quality during the EAST-AIRE campaign

    NASA Astrophysics Data System (ADS)

    Wang, Jing; Allen, Dale J.; Pickering, Kenneth E.; Li, Zhanqing; He, Hao

    2016-06-01

    WRF-Chem simulations were performed for the March 2005 East Asian Studies of Tropospheric Aerosols: an International Regional Experiment (EAST-AIRE) Intensive Observation Campaign (IOC) to investigate the direct effects of aerosols on surface radiation and air quality. Domain-wide, WRF-Chem showed a decrease of 20 W/m2 in surface shortwave (SW) radiation due to the aerosol direct effect (ADE), consistent with observational studies. The ADE caused 24 h surface PM2.5 (particulate matter with diameter < 2.5 µm) concentrations to increase in eastern China (4.4%), southern China (10%), western China (2.3%), and the Sichuan Basin (9.6%), due to different aerosol compositions in these four regions. Conversely, surface 1 h maximum ozone was reduced by 2.3% domain-wide and up to 12% in eastern China because less radiation reached the surface. We also investigated the impact of reducing SO2 and black carbon (BC) emissions by 80% on aerosol amounts via two sensitivity simulations. Reducing SO2 decreased surface PM2.5 concentrations in the Sichuan Basin and southern China by 5.4% and decreased ozone by up to 6 ppbv in the Sichuan Basin and Southern China. Reducing BC emissions decreased PM2.5 by 3% in eastern China and the Sichuan Basin but increased surface ozone by up to 3.6 ppbv in eastern China and the Sichuan Basin. This study indicates that the benefits of reducing PM2.5 associated with reducing absorbing aerosols may be partially offset by increases in ozone at least for a scenario when NOx and VOC emissions are unchanged.

  9. Two-Column Aerosol Project: Aerosol Light Extinction Measurements Field Campaign Report

    SciTech Connect

    Dubey, Manvendra; Aiken, Allison; Berg, Larry K.; Freedman, Andrew; Gorkowski, Kyle

    2016-09-01

    We deployed Aerodyne Research Inc.’s first Cavity Attenuated Phase Shift extinction (CAPS PMex) monitor (built by Aerodyne) that measures light extinction by using a visible-light-emitting diode (LED) as a light source, a sample cell incorporating two high-reflectivity mirrors centered at the wavelength of the LED, and a vacuum photodiode detector in Cape Cod in 2012/13 for the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility’s Two-Column Aerosol Project (TCAP). The efficacy of this instrument is based on the fact that aerosols are broadband scatterers and absorbers of light. The input LED is square-wave modulated and passed through the sample cell that distorts it due to exponential decay by aerosol light absorption and scattering; this is measured at the detector. The amount of phase shift of the light at the detector is used to determine the light extinction. This extinction measurement provides an absolute value, requiring no calibration. The goal was to compare the CAPS performance with direct measurements of absorption with ARM’s baseline photoacoustic soot spectrometer (PASS-3) and nephelometer instruments to evaluate its performance.

  10. Hygroscopic growth of urban aerosol particles during the 2009 Mirage-Shanghai Campaign

    NASA Astrophysics Data System (ADS)

    Ye, Xingnan; Tang, Chen; Yin, Zi; Chen, Jianmin; Ma, Zhen; Kong, Lingdong; Yang, Xin; Gao, Wei; Geng, Fuhai

    2013-01-01

    The hygroscopic properties of submicrometer urban aerosol particles were studied during the 2009 Mirage-Shanghai Campaign. The urban aerosols were composed of more-hygroscopic and nearly-hydrophobic particles, together with a trace of less-hygroscopic particles. The mean hygroscopicity parameter κ of the more-hygroscopic mode varied in the range of 0.27-0.39 depending on particle size. The relative abundance of the more-hygroscopic particles at any size was ca. 70%, slightly increasing with particle size. The number fraction of the nearly-hydrophobic particles fluctuated between 0.1 and 0.4 daily, in accordance with traffic emissions and atmospheric diffusion. The results from relative humidity dependence on hygroscopic growth and chemical analysis of fine particles indicated that particulate nitrate formation through the homogenous gas-phase reaction was suppressed under ammonia-deficient atmosphere in summer whereas the equilibrium was broken by more available NH3 during adverse meteorological conditions.

  11. Light-absorbing Aerosol Properties in the Kathmandu Valley during SusKat-ABC Field Campaign

    NASA Astrophysics Data System (ADS)

    Kim, S.; Yoon, S.; Kim, J.; Cho, C.; Jung, J.

    2013-12-01

    Light-absorbing aerosols, such as black carbon (BC), are major contributors to the atmospheric heating and the reduction of solar radiation reaching at the earth's surface. In this study, we investigate light-absorption and scattering properties of aerosols (i.e., BC mass concentration, aerosol solar-absorption/scattering efficiency) in the Kathmandu valley during Sustainable atmosphere for the Kathmandu valley (SusKat)-ABC campaign, from December 2012 to February 2013. Kathmandu City is among the most polluted cities in the world. However, there are only few past studies that provide basic understanding of air pollution in the Kathmandu Valley, which is not sufficient for designing effective mitigation measures (e.g., technological, financial, regulatory, legal and political measures, planning strategies). A distinct diurnal variation of BC mass concentration with two high peaks observed during wintertime dry monsoon period. BC mass concentration was found to be maximum around 09:00 and 20:00 local standard time (LST). Increased cars and cooking activities including substantial burning of wood and other biomass in the morning and in the evening contributed to high BC concentration. Low BC concentrations during the daytime can be explain by reduced vehicular movement and cooking activities. Also, the developmements of the boundary layer height and mountain-valley winds in the Kathmandu Valley paly a crucial role in the temproal variation of BC mass concentrations. Detailed radiative effects of light-absorbing aerosols will be presented.

  12. Modeling meteorological and chemical effects of secondary organic aerosol during an EUCAARI campaign

    NASA Astrophysics Data System (ADS)

    Athanasopoulou, E.; Vogel, H.; Vogel, B.; Tsimpidi, A.; Pandis, S. N.; Knote, C.; Fountoukis, C.

    2012-08-01

    A Volatility Basis Set (VBS) approach for Secondary Organic Aerosol (SOA) formation is incorporated in the online coupled atmospheric model system COSMO-ART and applied over Europe during the EUCAARI May 2008 campaign. Organic Aerosol (OA) performance is improved when compared to the default SOA module of COSMO-ART (SORGAM) against high time resolution Aerosol Mass Spectrometer (AMS) ground measurements. This allows the investigation of SOA impact upon the radiative budget. The mean direct surface radiative cooling averaged over Europe is -1.2 W m-2 and contributes by about 20% to the total aerosol effect. Nevertheless, responses are not spatially correlated with the forcing, due to the nonlinear interactions among changes in particle chemical composition, water content, size distribution and cloud cover. These interactions initiated~by~the effect of SOA on radiation result even in a positive forcing over a limited surface and mostly where the net effect of interactions on the cloud cover is negative. Further model experiments showed that nitrogen oxides availability slightly affects SOA production, but the aging rate constant within the VBS approximation and the boundary concentrations assumed in the model should be carefully selected. SOA aging is found to reduce hourly nitrate levels up to 30%, while the condensation upon pre-existing, SOA-rich particles result in a monthly average increase of 5% in sulfate and ammonium formation in the accumulation mode.

  13. Modeling the meteorological and chemical effects of secondary organic aerosols during an EUCAARI campaign

    NASA Astrophysics Data System (ADS)

    Athanasopoulou, E.; Vogel, H.; Vogel, B.; Tsimpidi, A. P.; Pandis, S. N.; Knote, C.; Fountoukis, C.

    2013-01-01

    A volatility basis set (VBS) approach for the simulation of secondary organic aerosol (SOA) formation is incorporated in the online coupled atmospheric model system COSMO-ART and applied over Europe during the EUCAARI May 2008 campaign. Organic aerosol performance is improved when compared to the default SOA module of COSMO-ART (SORGAM) against high temporal resolution aerosol mass spectrometer ground measurements. The impact of SOA on the overall radiative budget was investigated. The mean direct surface radiative cooling averaged over Europe is -1.2 W m-2, representing approximately 20% of the total effect of aerosols on the radiative budget. However, responses are not spatially correlated with the radiative forcing, due to the nonlinear interactions among changes in particle chemical composition, water content, size distribution and cloud cover. These interactions initiated~by the effect of SOA on radiation are found to result even in a positive forcing in specific areas. Further model experiments showed that the availability of nitrogen oxides slightly affects SOA production, but that the aging rate constant used in the VBS approximation and boundary concentrations assumed in the model should be carefully selected. The aging of SOA is found to reduce hourly nitrate levels by up to 30%, while the condensation of inorganic species upon pre-existing, SOA-rich particles results in a monthly average increase of 5% in sulfate and ammonium formation in the accumulation mode.

  14. DRAGON-West Japan campaign in 2012: regional aerosol measurements over Osaka

    NASA Astrophysics Data System (ADS)

    Sano, I.; Mukai, S.; Holben, B. N.; Nakata, M.; Yonemitsu, M.; Sugimoto, N.; Fujito, T.; Hiraki, T.; Iguchi, N.; Kozai, K.; Kuji, M.; Muramatsu, K.; Okada, Y.; Okada, Y.; Sadanaga, Y.; Tohno, S.; Toyazaki, Yasuo; Yamamoto, Kouhei

    2012-11-01

    It is known that the aerosol distribution in Asia is complicated due to the increasing emissions of anthropogenic aerosols in association with economic growth and natural dust significantly varied with the seasons. Therefore it is clear that local spatially and temporally resolved measurements of atmospheric aerosols in Asian urban city are necessary. Since Osaka, Kobe, Kyoto, and Nara are located in very close each others (all cities are included in around 70×70 km2 area). The population of the region is around 13 millions including neighbor prefectures, accordingly air quality in this region is slightly bad in comparison with the remote area. Furthermore, in recent years, Asian dusts and anthropogenic small particles some times transported from China and cover these cities throughout year. DRAGON (Distributed Regional Aerosol Gridded Observation Network) is a project of dense sun/sky radiometer network in the urban area. The DRAGON-West Japan field campaign was performed over Osaka and neighbor cities with 7 AERONET instruments from March to end of May in 2012. As results, DRAGON measurements indicate small differences among the values of AOT over Osaka region.

  15. Daily variation of organic aerosol concentration and composition in Seoul, Korea during KORUS pre-campaign

    NASA Astrophysics Data System (ADS)

    Shin, H. J.; Lee, J.; Choi, A. Y.; Park, S. M.; Park, J. S.; Song, I. H.; Hong, Y. D.

    2015-12-01

    Daily variation of Organic Aerosol (OA) as well as organic tracer compounds have been observed in aerosol samples collected during KORUS-AQ (Korea-US Air Quality Study) pre-campaign (From May 18 to June 12) in Seoul, Korea. NR-PM1 bounded OA was measured by HR-TOF-AMS (Aerodyne) and the temporal variation, composition of OA by family group characterization, and oxidation state of OA was studied. And to distinguish the source characteristics (such as HOA, COA, NOA, SV-OOA, LV-OOA, etc…) of the organic, AMS-PMF model will be used.For the observation of organic tracer compounds, solvent extractable fractions were analyzed by GC-MS. More than 80 organic compounds were detected in the aerosol samples and grouped by source characterized classes, including vehicular emission tracers, biomass burning tracers, coal emission tracers, secondary organic aerosol (SOA) tracers. The main objective of this study is evaluation of the validity of OA fractionation based on the AMS measurement. So, we will compare daily variation of OA composition measured by AMS with daily variation of organic tracer compounds. Further, we will specify source characteristics estimated using AMS-PMF model by comparing the results of source apportionment of OA using PMF of organic tracer compounds.

  16. Lidar Measurements of Stratospheric Ozone, Aerosols and Temperature during the SAUNA Campaign at Sodankyla, Finland

    NASA Technical Reports Server (NTRS)

    McGee, T.; Twigg, L.; Sumnicht, G.; McPeters, R.; Bojkov, B.; Kivi, R.

    2008-01-01

    The Sodankyla Total Column Ozone Intercomparison (SAUNA) campaign took place at the Finnish Meteorological Institute Arctic Research Center (FMI-ARC) at Sodankyla, Finland (67.37 N) in two separate phases during early spring 2006, and winter 2007. These campaigns has several goals: to determine and improve the accuracy of total column ozone measurements during periods of low solar zenith angle and high total column ozone; to determine the effect of ozone profile shape on the total column retrieval; and to make validate satellite ozone measurements under these same conditions. The GSFC Stratospheric Ozone Lidar (STROZ), which makes profile measurements of ozone temperature, aerosols and water vapor participated in both phases of the campaign. During the deployments, more than 30 profile measurements were made by the lidar instrument, along with Dobson, Brewer, DOAS, ozonesonde, and satellite measurements. The presentation will concentrate on STROZ lidar results from the second phase of the campaign and comparisons with other instruments will be discussed. This will include both ground-based and satellite comparisons.

  17. Spatial Variability of AERONET Aerosol Optical Properties and Satellite Data in South Korea during NASA DRAGON-Asia Campaign.

    PubMed

    Lee, Hyung Joo; Son, Youn-Suk

    2016-04-05

    We investigated spatial variability in aerosol optical properties, including aerosol optical depth (AOD), fine-mode fraction (FMF), and single scattering albedo (SSA), observed at 21 Aerosol Robotic Network (AERONET) sites and satellite remote sensing data in South Korea during the spring of 2012. These dense AERONET networks established in a National Aeronautics and Space Administration (NASA) field campaign enabled us to examine the spatially detailed aerosol size distribution and composition as well as aerosol levels. The springtime particle air quality was characterized by high background aerosol levels and high contributions of coarse-mode aerosols to total aerosols. We found that between-site correlations and coefficient of divergence for AOD and FMF strongly relied on the distance between sites, particularly in the south-north direction. Higher AOD was related to higher population density and lower distance from highways, and the aerosol size distribution and composition reflected source-specific characteristics. The ratios of satellite NO2 to AOD, which indicate the relative contributions of local combustion sources to aerosol levels, represented higher local contributions in metropolitan Seoul and Pusan. Our study demonstrates that the aerosol levels were determined by both local and regional pollution and that the relative contributions of these pollutions to aerosols generated spatial heterogeneity in the particle air quality.

  18. Measurements of fluorescent aerosols using a mutil-channel lidar spectrometer system during DUBI 2016 Campaign

    NASA Astrophysics Data System (ADS)

    Huang, Z.; Huang, J.; Zhou, T.; Shi, J.; Sugimoto, N.; Tang, K.

    2016-12-01

    Atmospheric bioaerosols are relevant for public health and may play an important role in the climate system. Previous studies have shown that abundant bioaerosols (such as microorganisms) injected into the atmosphere along with dust events, could affect leeward ecosystem and human health, even induce globe climate change. However, the challenge in quantifying bioaerosol climate effects (e.g., radiative forcing and aerosol-cloud interactions) arises from large spatial and temporal heterogeneity of their concentrations, compositions, sizes, shape and optical properties. Lidar, as one of most advanced active remote sensing, is used to offer some remarkable advantages for determining the vertical structure of atmospheric aerosols and their related optical properties. In order to investigate the characterization of atmospheric bioaerosols along transported pathways of dust aerosols, we carried out DUBI (DUst BIoaerosol) 2016 Campaign over Northern China in spring of 2016. Lots of instruments, including bioaerosol sampling, lidar as well as others, were installed at three sites­ (Erenhot, Zhangbei and Jinan) simultaneously. A multi-channel lidar spectrometer system was developed to observe Mie, Raman scattering and laser-induced fluorescence excitation at 355 nm from the atmosphere. The lidar system operated polarization measurements at 355nm, aiming to identify dust particles from other aerosols. It employs a high power pulsed laser with energy of 80mJ at 355nm and a received telescope with 350mm diameter. The receiver could simultaneously detect a wide fluorescent spectrum between 360nm and 720nm with spectral resolution 5.7 nm using two spectrometers simultaneously. The spectrometer mainly includes an F/3.7 Crossed Czerny-Turner spectrographs, a grating (1200 gr/mm) and a PMT array with 32 photocathode elements. Vertical structure of fluorescent aerosols in the atmosphere was observed by the developed lidar system at Zhangbei during DUBI 2016 Campaign. It has been

  19. Sources, Composition, and Properties of Newly Formed and Regional Organic Aerosol in a Boreal Forest during the Biogenic Aerosol: Effects on Clouds and Climate Field Campaign Report

    SciTech Connect

    Thornton, Joel

    2016-05-01

    The Thornton Laboratory participated in the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility’s Biogenic Aerosol Effects on Clouds and Climate (BAECC) campaign in Finland by deploying our mass spectrometer. We then participated in environmental simulation chamber studies at Pacific Northwest National Laboratory (PNNL). Thereafter, we analyzed the results as demonstrated in the several presentations and publications. The field campaign and initial environmental chamber studies are described below.

  20. Aerosol light-scattering enhancement due to water uptake during the TCAP campaign

    NASA Astrophysics Data System (ADS)

    Titos, G.; Jefferson, A.; Sheridan, P. J.; Andrews, E.; Lyamani, H.; Alados-Arboledas, L.; Ogren, J. A.

    2014-07-01

    Aerosol optical properties were measured by the DOE/ARM (US Department of Energy Atmospheric Radiation Measurements) Program Mobile Facility during the Two-Column Aerosol Project (TCAP) campaign deployed at Cape Cod, Massachusetts, for a 1-year period (from summer 2012 to summer 2013). Measured optical properties included aerosol light-absorption coefficient (σap) at low relative humidity (RH) and aerosol light-scattering coefficient (σsp) at low and at RH values varying from 30 to 85%, approximately. Calculated variables included the single scattering albedo (SSA), the scattering Ångström exponent (SAE) and the scattering enhancement factor (f(RH)). Over the period of measurement, f(RH = 80%) had a mean value of 1.9 ± 0.3 and 1.8 ± 0.4 in the PM10 and PM1 fractions, respectively. Higher f(RH = 80%) values were observed for wind directions from 0 to 180° (marine sector) together with high SSA and low SAE values. The wind sector from 225 to 315° was identified as an anthropogenically influenced sector, and it was characterized by smaller, darker and less hygroscopic aerosols. For the marine sector, f(RH = 80%) was 2.2 compared with a value of 1.8 obtained for the anthropogenically influenced sector. The air-mass backward trajectory analysis agreed well with the wind sector analysis. It shows low cluster to cluster variability except for air masses coming from the Atlantic Ocean that showed higher hygroscopicity. Knowledge of the effect of RH on aerosol optical properties is of great importance for climate forcing calculations and for comparison of in situ measurements with satellite and remote sensing retrievals. In this sense, predictive capability of f(RH) for use in climate models would be enhanced if other aerosol parameters could be used as proxies to estimate hygroscopic growth. Toward this goal, we propose an exponential equation that successfully estimates aerosol hygroscopicity as a function of SSA at Cape Cod. Further work is needed to determine if

  1. Impact of springtime biomass-burning aerosols on radiative forcing over northern Thailand during the 7SEAS campaign

    NASA Astrophysics Data System (ADS)

    Pani, Shantanu Kumar; Wang, Sheng-Hsiang; Lin, Neng-Huei; Lee, Chung-Te; Tsay, Si-Chee; Holben, Brent; Janjai, Serm; Hsiao, Ta-Chih; Chuang, Ming-Tung; Chantara, Somporn

    2016-04-01

    Biomass-burning (BB) aerosols are the significant contributor to the regional/global aerosol loading and radiation budgets. BB aerosols affect the radiation budget of the earth and atmosphere by scattering and absorbing directly the incoming solar and outgoing terrestrial radiation. These aerosols can exert either cooling or warming effect on climate, depending on the balance between scattering and absorption. BB activities in the form of wildland forest fires and agricultural crop burning are very pronounced in the Indochina peninsular regions in Southeast Asia mainly in spring (late February to April) season. The region of interest includes Doi Ang Khang (19.93° N, 99.05° E, 1536 msl) in northern Thailand, as part of the Seven South East Asian Studies (7-SEAS)/BASELInE (Biomass-burning Aerosols & Stratocumulus Environment: Lifecycles & Interactions Experiment) campaign in 2013. In this study, for the first time, the direct aerosol radiative effects of BB aerosols over near-source BB emissions, during the peak loading spring season, in northern Indochina were investigated by using ground-based physical, chemical, and optical properties of aerosols as well as the aerosol optical and radiative transfer models. Information on aerosol parameters in the field campaign was used in the OPAC (Optical Properties of Aerosols and Clouds) model to estimate various optical properties corresponding to aerosol compositions. Clear-sky shortwave direct aerosol radiative effects were further estimated with a raditive transfer model SBDART (Santa Barbara DISORT Atmospheric Radiative Transfer). The columnar aerosol optical depth (AOD500) was found to be ranged from 0.26 to 1.13 (with the mean value 0.71 ± 0.24). Fine-mode (fine mode fraction ≈0.98, angstrom exponent ≈1.8) and significantly absorbing aerosols (columnar single-scattering albedo ≈0.89, asymmetry-parameter ≈0.67 at 441 nm wavelength) dominated in this region. Water soluble and black carbon (BC) aerosols mainly

  2. Application of AERONET Single Scattering Albedo and Absorption Angstrom Exponent to Classify Dominant Aerosol Types during DRAGON Campaigns

    NASA Astrophysics Data System (ADS)

    Giles, D. M.; Holben, B. N.; Eck, T. F.; Schafer, J.; Crawford, J. H.; Kim, J.; Sano, I.; Liew, S.; Salinas Cortijo, S. V.; Chew, B. N.; Lim, H.; Smirnov, A.; Sorokin, M.; Kenny, P.; Slutsker, I.

    2013-12-01

    Aerosols can have major implications on human health by inducing respiratory diseases due to inhalation of fine particles from biomass burning smoke or industrial pollution and on radiative forcing whereby the presence of absorbing aerosol particles (e.g., black carbon) increases atmospheric heating. Aerosol classification techniques have utilized aerosol loading and aerosol properties derived from multi-spectral and multi-angle observations by ground-based (e.g., AERONET) and satellite instrumentation (e.g., MISR). Aerosol Robotic Network (AERONET) data have been utilized to determine aerosol types by implementing various combinations of measured aerosol optical depth or retrieved size and absorption aerosol properties (e.g., Gobbi et al., 2007; Russell et al., 2010). Giles et al. [2012] showed single scattering albedo (SSA) relationship with extinction Angstrom exponent (EAE) can provide an estimate of the general classification of dominant aerosol types (i.e., desert dust, urban/industrial pollution, biomass burning smoke, and mixtures) based on data from ~20 AERONET sites located in known aerosol source regions. In addition, the absorption Angstrom exponent relationship with EAE can provide an indication of the dominant absorbing aerosol type such as dust, black carbon, brown carbon, or mixtures of them. These classification techniques are applied to the AERONET Level 2.0 quality assured data sets collected during Distributed Regional Aerosol Gridded Observational Network (DRAGON) campaigns in Maryland (USA), Japan, South Korea, Singapore, Penang (Malaysia), and California (USA). An analysis of aerosol type classification for DRAGON sites is performed as well as an assessment of the spatial variability of the aerosol types for selected DRAGON campaigns. Giles, D. M., B. N. Holben, T. F. Eck, A. Sinyuk, A. Smirnov, I. Slutsker, R. R. Dickerson, A. M. Thompson, and J. S. Schafer (2012), An analysis of AERONET aerosol absorption properties and classifications

  3. Aerosol Properties over the Eastern North Pacific based on Measurements from the MAGIC Field Campaign

    NASA Astrophysics Data System (ADS)

    Lewis, E. R.; Senum, G.; Springston, S. R.; Kuang, C.

    2015-12-01

    The MAGIC field campaign, funded and operated by the ARM (Atmospheric Radiation Measurement) Climate Research Facility of the US Department of Energy, occurred between September 2012 and October, 2013 aboard the Horizon Lines cargo container ship Spirit making regular trips between Los Angeles, CA and Honolulu, HI. Along this route, which lies very near the GPCI (GCSS Pacific Cross-section Intercomparison) transect, the predominant cloud regime changes from stratocumulus near the California coast to trade-wind cumulus near Hawaii. The transition between these two regimes is poorly understood and not accurately represented in models. The goal of MAGIC was to acquire statistic of this transition and thus improve its representation in models by making repeated transects through this region and measuring properties of clouds and precipitation, aerosols, radiation, and atmospheric structure. To achieve these goals, the Second ARM Mobile Facility (AMF2) was deployed on the Horizon Spirit as it ran its regular route between Los Angeles and Honolulu. AMF2 consists of three 20-foot SeaTainers and includes three radars and other instruments to measure properties of clouds and precipitation; the Aerosol Observing System (AOS), which has a suite of instruments to measure properties of aerosols; and other instruments to measure radiation, meteorological quantities, and sea surface temperature. Two technicians accompanied the AMF2, and scientists rode the ship as observers. MAGIC made nearly 20 round trips between Los Angeles and Honolulu (and thus nearly 40 excursions through the stratocumulus-to-cumulus transition) and spent 200 days at sea, collecting an unprecedented data set. Aerosol properties measured with the AOS include number concentration and size distribution, CCN activity, hygroscopic growth, and light-scattering and absorption. Additionally, more than one hundred filter samples were collected. Aerosol properties and their spatial and temporal behavior are discussed

  4. Aerosol hygroscopicity and CCN activity during the AC3Exp campaign: Implications for CCN parameterization

    NASA Astrophysics Data System (ADS)

    Zhang, Fang; Li, Yanan; Li, Zhanqing

    2015-04-01

    Atmospheric aerosol particles acting as CCN are pivotal elements of the hydrological cycle and climate change. In this study, we measured and characterized NCCN in relatively clean and polluted air during the AC3Exp campaign conducted at Xianghe, China during summer 2013. The aim was to examine CCN activation properties under high aerosol loading conditions in a polluted region and to assess the impacts of particle size and chemical composition on the CCN AR which acts as a proxy of the total number of aerosol particles in the atmosphere. A gradual increase in size-resolved AR with particle diameter suggests that aerosol particles have different hygroscopicities. For particles in the accumulation mode, values of κapa range from 0.31-0.38 under background conditions, which is about 20% higher than that derived under polluted conditions. For particles in the nucleation or Aitken mode, κ range from 0.20-0.34 under both background and polluted conditions. Larger particles were on average more hygroscopic than smaller particles. However, the case is more complex for particles originating from heavy pollution due to the diversity in particle composition and mixing state. The low R2 for the NPO CCN closure test suggests a 30%-40% uncertainty in total NCCN estimation. Using bulk chemical composition data from ACSM measurements, the relationship between bulk AR and the physical and chemical properties of atmospheric aerosols is investigated. Based on a case study, it has been concluded that one cannot use a parameterized formula using only total NCN to estimate total NCCN. Our results showed a possibility of using bulk κchem and f44 in combination with bulk NCN > 100 nm to parameterize CCN number concentrations.

  5. Highly time-resolved trace element concentrations in aerosols during the Megapoli Paris campaigns

    NASA Astrophysics Data System (ADS)

    Furger, Markus; Visser, Suzanne; Slowik, Jay G.; Crippa, Monica; Poulain, Laurent; Appel, Karen; Flechsig, Uwe; Prevot, Andre S. H.; Baltensperger, Urs

    2014-05-01

    Trace elements contribute typically only a few percent to the total mass of air pollutants, however, they can affect the environment in significant ways, especially those that are toxic. Furthermore, they are advantageous with respect to a refinement of source apportionment when measured with high time resolution and appropriate size segregation. This approach is especially advantageous in an urban environment with numerous time-variant emission sources distributed across a relatively narrow space, as is typically the setting of a megacity. Two 1-month long field campaigns took place in the framework of the Megapoli project in Paris, France, in the summer of 2009 and in the winter of 2010. Rotating drum impactors (RDI) were operated at two sites in each campaign, one urban, the other one suburban. The RDI segregated the aerosols into three size ranges (PM10-2.5, PM2.5-1 and PM1-0.1) and sampled with 2-hour time resolution. The samples were analyzed with synchrotron radiation induced X-ray fluorescence spectrometry (SR-XRF) at the synchrotron facilities of Paul Scherrer Institute (SLS) and Deutsches Elektronen-Synchrotron (HASYLAB), where a broad range of elements (Na, Mg, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Se, Sr, Zr, Cd, Sn, Sb, Ba, Pb) was analyzed for each size range. Time series of the analyzed elements for the different sites and campaigns were prepared to characterize the aerosol trace element composition and temporal behavior for the different weather situations and urban environments. They allow for the distinction of regional vs. local sources and transport, and provide a basis for source apportionment calculations. Local and regional contributions of traffic, including re-suspension, break wear and exhaust, wood burning, marine and other sources will be discussed. Indications of long-range transport from Polish coal emissions in the city center of Paris were also found.

  6. Ambient aerosol chlorine concentrations and artefacts during the MEGAPOLI Paris campaigns

    NASA Astrophysics Data System (ADS)

    Furger, Markus; Visser, Suzanne; Slowik, Jay; Crippa, Monica; Poulain, Laurent; Sciare, Jean; Flechsig, Uwe; Prévôt, André; Baltensperger, Urs

    2015-04-01

    Trace elements, especially those that are toxic, can affect the environment in significant ways. Studying them is advantageous with respect to a refinement of source apportionment when measured with high time resolution and appropriate size segregation. This approach is especially useful in urban environments with numerous time-variant emission sources distributed across a relatively narrow space. Two field campaigns took place in the framework of the MEGAPOLI project in Paris, France: one in the summer of 2009 (1-31 July), the other in the winter of 2010 (11 Jan - 10 Feb). Rotating drum impactors (RDI) were operated at an urban and a suburban site in each campaign. The RDI segregated the aerosols into three size ranges (PM10-2.5, PM2.5-1.0 and PM1.0-0.3) and sampled with 2-hour time resolution. The samples were analyzed with synchrotron radiation-induced X-ray fluorescence spectrometry (SR-XRF) at the synchrotron facility of the Paul Scherrer Institute (SLS), where a broad range of elements (Na, Mg, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn) was analyzed for each size range. Time series of the analyzed elements for the different sites and campaigns were prepared to characterize the aerosol trace element composition and temporal behavior for different weather situations and urban environments. Quality assurance was performed partly by intercomparison with independent measurements. An exceptional behavior was observed for chlorine (Cl), where periods with zero RDI concentration alternated with periods of normal load. Zero concentrations were not observed in particle-into-liquid (PILS) measurements. This identifies the observed behavior as a RDI sampling artefact. Nevertheless, the non-zero periods of Cl concentrations are still a gain in information compared to conventional sampling techniques, mainly due to the high time resolution.

  7. Ground-based aerosol measurements during CHARMEX/ADRIMED campaign at Granada station

    NASA Astrophysics Data System (ADS)

    Granados-Muñoz, Maria Jose; Bravo-Aranda, Juan Antonio; Navas-Guzman, Francisco; Guerro-Rascado, Juan Luis; Titos, Gloria; Lyamani, Hassan; Valenzuela, Antonio; Cazorla, Alberto; Olmo, Francisco Jose; Mallet, Marc; Alados-Arboledas, Lucas

    2015-04-01

    In the framework of ChArMEx/ADRIMED (Chemistry-Aerosol Mediterranean Experiment, http://charmex.lsce.ipsl.fr/; Aerosol Direct Radiative Impact on the regional climate in the MEDiterranean region) projects, a field experiment based on in situ and remote sensing measurements from surface and airborne platforms was performed. The ADRIMED project aimed to capture the high complexity of the Mediterranean region by using an integrated approach based on intensive experimental field campaign and spaceborne observations, radiative transfer calculations and climate modelling with Regional Climate Models better adapted than global circulation models. For this purpose, measurements were performed at different surface super-sites (including Granada station) over the Occidental Mediterranean region during summer 2013 for creating an updated database of the physical, chemical, optical properties and the vertical distribution of the major "Mediterranean aerosols". Namely, measurements at Granada station were performed on 16 and 17 July 2013, in coincidence with the overpasses of the ATR aircraft over the station. The instrumentation used for the campaign includes both remote sensing instruments (a multiwavelength Raman lidar and a sun photometer) and in-situ measurements (a nephelometer, a Multi-Angle Absorption Photometer (MAAP), an Aerodynamic particle sizer (APS), a high volume sampler of PM10 and an aethalometer). During the measurement period a mineral dust event was detected, with similar dust load on both days. According to in-situ measurements, the event reached the surface level on 16 of June. Vertically resolved lidar measurements indicated presence of mineral dust layers up to 5 km asl both on 16 and 17 June 2013. Temporal evolution analysis indicated that on 17 June the dust layer decoupled from the boundary layer and disappeared around 14:00 UTC. In addition, lidar and sun-photometer data were used to retrieve volume concentration profiles by means of LIRIC (Lidar

  8. A Campaign Study of Sea Spray Aerosol Properties in the Bay of Aarhus

    NASA Astrophysics Data System (ADS)

    Nguyen, Quynh; Rasmussen, Berit; Kristensen, Kasper; Sloth Nielsen, Lærke; Bilde, Merete

    2016-04-01

    The oceans of the world are a dominant source of atmospheric aerosol. Together with mineral dust, sea spray aerosols (SSA) constitute the largest mass flux of particulate matter in the atmosphere (Andreae and Rosenfeld, 2008). Due to their effects on the global radiative budget - both directly as scatterers and absorbers of solar and terrestrial radiation, and indirectly as cloud condensation nuclei (CCN), SSA are considered an important component of the climate system. The sea-surface microlayer (SML) is an ultra-thin boundary layer between the ocean and the atmosphere. The high concentration of surface-active organic compounds in the SML, compared to that of the underlying water column, creates rigid film-like layer over the surface of the ocean. The SML is believed to play an important role in the formation and composition of SSA. However, current knowledge on the SML and its impacts on SSA remain limited. To characterize the SML of natural seawater and examine its impacts on aerosol properties, a field campaign was conducted in the bay of Aarhus, Denmark, during spring 2015. Bulk seawater was collected 1-2 times every week along with selective sampling of the SML. Characterization of the sea water and SML included a wide range of measurements, including surface tension, water activity, dissolved organic matter, and chemical composition analysis by liquid chromatography/electrospray ionization high-resolution quadrupole time-of-flight mass spectrometry (UPLC/ESI-HR-Q-TOFMS). SSA was generated from sampled sea water by diffusion of air bubbles through a 10L seawater sample situated in a sea spray tank. Particle number concentration and CCN measurements were conducted along with measurements of the organic share in the aerosol phase as indicated by volatility measurements. To investigate the effect of the SML, spiking of the seawater samples with additional SML was performed and measurements repeated for comparison. Preliminary results show that the SML samples

  9. Submicron Aerosol Composition during the ARCTAS campaign: Arctic Haze, Biomass Burning, and California Pollution

    NASA Astrophysics Data System (ADS)

    Cubison, M. J.; Sueper, D.; Dunlea, E.; Jimenez, J. L.; Weinheimer, A.; Knapp, D.; Dibb, J.; Schauer, E.; Diskin, G.; Sachse, G.; Anderson, B.; Thornhill, L.; Wisthaler, A.; Mikoviny, T.; Wennberg, P.; Crounse, J.

    2008-12-01

    A High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS, DeCarlo et al., Anal. Chem., 2006) was deployed aboard the NASA DC-8 research aircraft as part of the Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) campaign during the spring and summer of 2008. One focus of the spring phase, operated out of Fairbanks, AK, was to investigate the composition and sources of Arctic Haze (see e.g. Quinn et al., Tellus B, 2007), a persistent pollution layer that accumulates under the stable springtime Polar High anti-cyclonic weather pattern. Results are presented comparing the sulfate-dominated composition of the Arctic Haze with observed North American pollution and biomass- burning layers. A further objective of the spring phase was to investigate halogen chemistry at the sea-ice surface. High-resolution spectra clearly show bromine in the aerosol phase in the marine boundary layer during periods of ozone depletion, and relate this to concurrent gas-phase observations aboard the DC-8. During the summer phase, operated out of Palmdale, CA and Cold Lake, Alberta, the focus was investigating pollution in California and the composition and evolution of the outflow from large-scale boreal forest fires, respectively. Using recently-developed software that enabled the AMS to sample at 1 Hz, the smoke plumes could be clearly differentiated from the background aerosol, detailed vertical profiles were measured during spiral descents and aerosol volatility was characterized with a thermodenuder. Aerosol biomass-burning markers exhibit high correlation with gas-phase fire markers for both Canadian boreal and Californian forest fires. Emission ratios and composition (e.g. inorganic species, organic O/C) are characterized for the different fires. Data from smoke plumes sampled over the extensive summer fires in California provide a contrast in emission profiles to the Canadian boreal biomass-burning aerosol. Finally, aerosol

  10. Using FLEXPART-WRF to Identify Source Regions Influencing Arctic Trace Gases and Aerosols During the Summer 2014 NETCARE Campaign

    NASA Astrophysics Data System (ADS)

    Thomas, J. L.

    2015-12-01

    In July and August 2014 the Canadian Network on Aerosols and Climate: Addressing Key Uncertainties in Remote Canadian Regions (NETCARE) project conducted aircraft and ship based campaigns with the goal of identifying both emissions and atmospheric processes influencing Arctic trace gas and aerosol concentrations. The aircraft campaign was conducted using the Alfred Wegener Institute's POLAR 6 aircraft (based in Resolute Bay, Canada) and the ship based campaign was conducted onboard the CCGS Amundsen (icebreaker and Arctic Ocean research vessel). Here, we use the Weather Research and Forecasting Model (WRF) to study meteorology and transport patterns that influence airmasses sampled during the aircraft campaign (5-21 July 2012) and research Legs 1a and 1b for Amundsen (1a: 8 - 24 July Quebec City to Resolute and 24 July - 14 August Resolute to Kugluktuk). The FLEXible PARTicle dispersion model driven by WRF meteorology (FLEXPART-WRF) run in backwards mode is used to study source regions that influenced enhanced concentrations in trace gases including DMS and NH3 as well as aerosols. Links between biomass burning in Northern Canada and measurements during the campaign are discussed. Finally FLEXPART-WRF run in forward mode is used to study links between shipping emissions from the Amundsen and enhanced pollution sampled by the POLAR 6 aircraft when both were operating in the same region of Lancaster Sound during the campaigns.

  11. Analysis of DIAL/HSRL aerosol backscatter and extinction profiles during the SEAC4RS campaign with an aerosol assimilation system

    NASA Astrophysics Data System (ADS)

    Weaver, C. J.; da Silva, A. M., Jr.; Colarco, P. R.; Randles, C. A.

    2015-12-01

    We retrieve aerosol concentrations and optical information from vertical profiles of airborne 532 nm extinction and 532 and 1064 nm backscatter measurements made during the SEAC4RS summer 2013 campaign. The observations are from the High Spectral Resolution Lidar (HSRL) Airborne Differential Absorption Lidar (DIAL) on board the NASA DC-8. Instead of retrieving information about aerosol microphysical properties such as indexes of refraction, we seek information more directly applicable to an aerosol transport model - in our case the Goddard Chemistry Aerosol Radiation and Transport (GOCART) module used in the GEOS-5 Earth modeling system. A joint atmosphere/aerosol mini-reanalysis was performed for the SEAC4RS period using GEOS-5. The meteorological reanalysis followed the MERRA-2 atmospheric reanalysis protocol, and aerosol information from MODIS, MISR, and AERONET provided a constraint on the simulated aerosol optical depth (i.e., total column loading of aerosols). We focus on the simulated concentrations of 10 relevant aerosol species simulated by the GOCART module: dust, sulfate, and organic and black carbon. Our first retrieval algorithm starts with the SEAC4RS mini-reanalysis and adjusts the concentration of each GOCART aerosol species so that differences between the observed and simulated backscatter and extinction measurements are minimized. In this case, too often we are unable to simulate the observations by simple adjustment of the aerosol concentrations. A second retrieval approach adjusts both the aerosol concentrations and the optical parameters (i.e., assigned mass extinction efficiency) associated with each GOCART species. We present results from DC-8 flights over smoke from forest fires over the western US using both retrieval approaches. Finally, we compare our retrieved quantities with in-situ observations of aerosol absorption, scattering, and mass concentrations at flight altitude.

  12. A Lidar and Backscatter Sonde Aerosol Measurement Campaign at Table Mountain During February-March 1997: Observations of Stratospheric Background Aerosols and Cirrus Clouds

    NASA Technical Reports Server (NTRS)

    Beyerle, G.; Gross, M.; Haner, D.; Kjome, N.; McDermid, I.; McGee, T.; Rosen, J.; Schafer, H. J.; Schrems, O.

    1999-01-01

    Altitude profiles of backscater ratio of the stratospheric background aerosol layer at altitudes between 15 and 25 km and high-altitude cirrus clouds at altitudes below 13 km are analyzed and discussed. Cirrus clouds were present on 16 of the 26 campaign nights.

  13. Ice nucleation properties of atmospheric aerosol particles collected during a field campaign in Cyprus

    NASA Astrophysics Data System (ADS)

    Yordanova, Petya; Maier, Stefanie; Lang-Yona, Naama; Tamm, Alexandra; Meusel, Hannah; Pöschl, Ulrich; Weber, Bettina; Fröhlich-Nowoisky, Janine

    2017-04-01

    Atmospheric aerosol particles, including desert and soil dust as well as marine aerosols, are well known to act as ice nuclei (IN) and thus have been investigated in numerous ice nucleation studies. Based on their cloud condensation nuclei potential and their impacts on radiative properties of clouds (via scattering and absorption of solar radiation), aerosol particles may significantly affect the cloud and precipitation development. Atmospheric aerosols of the Eastern Mediterranean have been described to be dominated by desert dust, but only little is known on their composition and ice nucleating properties. In this study we investigated the ice nucleating ability of total suspended particles (TSP), collected at the remote site Agia Marina Xyliatou on Cyprus during a field campaign in April 2016. Airborne TSP samples containing air masses of various types such as African (Saharan) and Arabian dust and European and Middle Eastern pollution were collected on glass fiber filters at 24 h intervals. Sampling was performed ˜5 m above ground level and ˜521 m above sea level. During the sampling period, two major dust storms (PM 10max 118 μg/m3 and 66 μg/m3) and a rain event (rainfall amount: 3.4 mm) were documented. Chemical and physical characterizations of the particles were analyzed experimentally through filtration, thermal, chemical and enzyme treatments. Immersion freezing experiments were performed at relatively high subzero temperatures (-1 to -15˚ C) using the mono ice nucleation array. Preliminary results indicate that highest IN particle numbers (INPs) occurred during the second dust storm event with lower particle concentrations. Treatments at 60˚ C lead to a gradual IN deactivation, indicating the presence of biological INPs, which were observed to be larger than 300 kDa. Additional results originating from this study will be shown. Acknowledgement: This work was funded by the DFG Ice Nuclei Research Unit (INUIT).

  14. Impact of Aerosol Direct Effect on East Asian Air Quality During the EAST-AIRE Campaign

    NASA Astrophysics Data System (ADS)

    Wang, J.; Allen, D. J.; Pickering, K. E.; Li, Z.

    2015-12-01

    Three WRF-Chem simulations were conducted for East Asia region during March 2005 East Asian Studies of Tropospheric Aerosols: an International Regional Experiment (EAST-AIRE) Intensive Observation Campaign (IOC) period to investigate the direct effects of aerosols on surface radiation and air quality. WRF-Chem captured the temporal and spatial variations of meteorological fields, trace gases, and aerosol loadings. Surface shortwave radiation changes due to the aerosol direct effect (ADE) were calculated and compared with data from six World Radiation Data Center (WRDC) stations. The comparison indicated that WRF-Chem can simulate the surface short wave radiation moderately well, with temporal correlations between 0.4 and 0.7, and high biases between 9 to 120 W/m2. Domain-wide, WRF-Chem showed a decrease of 22 W/m2 in surface SW radiation due to the aerosol direct effect, consistent with observational studies. The ADE demonstrates diverse influences on air quality in East Asian. For example, the surface concentration of PM2.5 increases in eastern China (~11.1%) due to ADE, but decreases in central China (-7.3%), western China (-8.8%), and Sichuan Basin (-4%). Surface 1-hour maximum ozone is reduced by 2.3%, owing to less radiation reaching the surface due to the ADE. Since PM2.5 pollution raises serious public concern in China, regulations that control the emissions of PM2.5 and its precursors have been implemented. We investigate the impact of reducing two different types of aerosols, sulfate (scattering) and black carbon (absorbing), by cutting 80% of SO2 and black carbon (BC) emissions in two sensitivity simulations. We found that reducing SO2 emissions results in the decline of PM2.5 as much as 16mg/m3 in eastern China, and 20mg/m3 in the Sichuan Basin. Reducing the BC emissions by the same percentage causes the PM2.5 to decrease as much as 40mg/m3 in eastern China, and 25mg/m3 in the Sichuan Basin. The monthly averaged surface 1-hour maximum ozone increases 3

  15. Evaluation of aerosol optical properties of GEOS-Chem over East Asia during the DRAGON-Asia 2012 campaign

    NASA Astrophysics Data System (ADS)

    Jo, D. S.; Park, R.; Kim, J.

    2015-12-01

    A nested version of 3-D chemical transport model (GEOS-Chem v9-01-02) is evaluated over East Asia during the Distributed Regional Aerosol Gridded Observation Networks (DRAGON)-Asia 2012 campaign period, focusing on fine-mode aerosol optical depth (fAOD) and single scattering albedo (SSA). Both are important to assess the effect of anthropogenic aerosols on climate. We compare the daily mean simulated optical properties of aerosols with the observations from DRAGON-Asia campaign for March-May, 2012 (provided in level 2.0: cloud screened and quality assured). We find that the model reproduces the observed daily variability of fAOD (R=0.67), but overestimates the magnitude by 30%, which is in general consistent with other global model comparisons from ACCMIP. However, a significant high bias in the model is found compared to the observed SSA at 440 nm, which is important for determining the sign of aerosol radiative forcing. In order to understand causes for this gap we conduct several sensitivity tests by changing source magnitudes and input parameters of aerosols, affecting the aerosol optical properties under various atmospheric conditions, which allows us to reduce the gap and to find the optimal values in the model.

  16. Vertical profiling of aerosol hygroscopic properties in the planetary boundary layer during the PEGASOS campaigns

    NASA Astrophysics Data System (ADS)

    Rosati, B.; Gysel, M.; Rubach, F.; Mentel, T. F.; Goger, B.; Poulain, L.; Schlag, P.; Miettinen, P.; Pajunoja, A.; Virtanen, A.; Bialek, J.; Klein Baltink, H.; Henzing, J. S.; Größ, J.; Gobbi, G. P.; Wiedensohler, A.; Kiendler-Scharr, A.; O'Dowd, C.; Decesari, S.; Facchini, M. C.; Weingartner, E.; Baltensperger, U.

    2015-03-01

    Airborne measurements of the aerosol hygroscopic and optical properties as well as chemical composition were performed in the Netherlands and northern Italy on board of a Zeppelin NT airship during the PEGASOS field campaigns in 2012. The vertical changes in aerosol properties during the development of the mixing layer were studied. Hygroscopic growth factors (GF) at 95% relative humidity were determined using the white-light humidified optical particles spectrometer (WHOPS) for dry diameters of 300 and 500 nm particles. These measurements were supplemented by an aerosol mass spectrometer (AMS) and an aethalometer providing information on the aerosol chemical composition. Several vertical profiles between 100 and 700 m a.g. were flown just after sunrise close to the San Pietro Capofiume ground station in the Po Valley, Italy. During the early morning hours the lowest layer (newly developing mixing layer) contained a high nitrate fraction (20%) which was coupled with enhanced hygroscopic growth. In the layer above (residual layer) small nitrate fractions of ~ 2% were measured as well as low GFs. After full mixing of the layers, typically around noon and with increased temperature, the nitrate fraction decreased to 2% at all altitudes and led to similar hygroscopicity values as found in the residual layer. These distinct vertical and temporal changes underline the importance of airborne campaigns to study aerosol properties during the development of the mixed layer. The aerosol was externally mixed with 22 and 67% of the 500 nm particles in the range GF < 1.1 and GF > 1.5, respectively. Contributors to the non-hygroscopic mode in the observed size range are most likely mineral dust and biological material. Mean hygroscopicity parameters (κ) were 0.34, 0.19 and 0.18 for particles in the newly forming mixing layer, residual layer and fully mixed layer, respectively. These results agree well with those from chemical analysis which found values of κ = 0.27, 0.21 and 0

  17. An overview of dust aerosol effect on semi-arid climate during 2008 China-US joined field campaign

    NASA Astrophysics Data System (ADS)

    Huang, J.; Bi, J.; Zhang, W.; Shi, J.; Tsay, S.; Li, Z.; Chen, H.; Wang, X.; Huang, Z.; Zhang, B.; Wang, G.; Zhang, L.

    2009-12-01

    To improve understanding and capture the direct evident of the impact of dust aerosol on semi-arid climate, the 2008 China-US joined field campaign are conducted. Three sites involved this campaign, including one permanent site (Semi-Arid Climate & Environment Observatory of Lanzhou University (SACOL)) (located in Yuzhong, 35.95°N/104.1°E), one SACOL’s Mobile Facility (SMF) (deployed in Jintai, 37.57°N/104.23°E) and the U.S. Department of Energy Atmospheric Radiation Measurements(ARM) Ancillary Facility (AAF mobile laboratories, SMART-COMMIT) (deployed in Zhangye, 39.08°N/100.27°E). This study presents a description the objectives, measurements, and sampling strategies for this joined campaign. Major dust episodes captured during the campaign were investigated. Preliminary observation results show that the semi-direct effect may be dominated by the interaction between dust aerosols and clouds over arid and semi-arid areas and partly contribute to reduced precipitation. These results suggest that the local anthropogenic and nature absorbing aerosols make significant contribution to the regional interaction among aerosol-cloud-radiation-precipitation processes and need to be future investigation.

  18. Aerosols upwind of Mexico City during the MILAGRO campaign: regional scale biomass burning, dust and volcanic ash from aircraft measurements

    NASA Astrophysics Data System (ADS)

    Junkermann, W.; Steinbrecher, R.

    2009-04-01

    During the MILAGRO Campaign March/April 2006 a series of aircraft flights with the FZK microlight D-MIFU were performed in the area southeast of Mexico City starting from Puebla airport, circling the national park area of Ixtachiuatl and Popocatepetl and scanning the Chalco valley down to Cuautla in the Cuernavaca province. All flights were combined with vertical profiles up to 4500 m a.s.l. in several locations, typically north of volcano Ixtachiuatl on the Puebla side, above Chalco or Tenago del Aire and south of volcano Popocatepetl, either at Cuautla or Atlixco. In Tenango del Aire a ceilometer was additionally operated continuously for characterization of the planetary boundary layer. The aircraft carried a set of aerosol instrumentation, fine and coarse particles and size distributions as well as a 7 wavelength aethalometer. Additionally meteorological parameters, temperature and dewpoint, global radiation and actinic radiation balance, respectively photolysis rates, and ozone concentrations were measured. The instrumentation allowed to characterize the aerosol according to their sources and also their impact on radiation transfer. Biomass burning aerosol, windblown dust and volcanic ash were identified within the upwind area of Mexico City with large differences between the dry season in the first weeks of the campaign and the by far cleaner situation after beginning thunderstorm activity towards the end of the campaign. Also the aerosol characteristics inside and outside the Mexico City basin were often completely different. With wind speeds of ~ 5 m/sec from southerly directions in the Chalco valley the aerosol mixture can reach the City within ~ 2 h. Rural aerosol mixtures from the Cuernavaca plain were mixed during the transport with dust from the MC basin. Very high intensity biomass burning plumes normally reached higher altitudes and produced pyrocumulus clouds. These aerosols were injected mainly into the free troposphere. Within the MC basin a large

  19. A modelling perspective of the summer 2013 CHARMEX chemistry intensive campaign : origin of photo-oxidant and aerosol formation

    NASA Astrophysics Data System (ADS)

    Beekmann, Matthias; Cholakian, Arineh; Siour, Guillaume; Laurent, Benoit; Borbon, Agnes; Colette, Augustin; Durand, Pierre; Formetti, Paula; Freney, Evelyne; Gros, Valerie; Jambert, Corinne; Marchand, Nicolas; Sartelet, Karine; Sauvage, Stephane; Sciare, Jean; Sellegri, Karine; Armengaud, Alexandre; Kermen, Pierre; Hamonou, Eric; Dulac, François

    2014-05-01

    During summer 2013, a three week intensive campaign took place over the western Mediterranean basin in order to investigate photo-oxidant and aerosol sources over the region. Within the frame of the MISTRAL/CHARMEX program, this campaign included an extensive experimental set-up based on ground based, balloon borne and ship and aircraft measurements. In this paper, a modelling perspective of the campaign is given, based on simulations with the regional CHIMERE chemistry-transport model in a configuration shaped for the Mediterranean region. Major sources of photo-oxidants (in particular ozone), and aerosol are addressed: long range transport from continental Europe, pollution build-up from shipping emissions, specifically organic aerosol formation from biogenic and anthropogenic VOC emissions, dust emissions. The simulations are evaluated with measurements at places and during periods when these particular sources were predominant. This will give a first overview of driving forces of the pollutant variability over the domain during the campaign. In addition, we will address, how well model forecasts (CHIMERE run by INERIS, Polyphemus run by CEREA) used for campaign planning agree with measurements.

  20. Analysis of aerosol optical properties over Korea during the 2015 MAPS-Seoul campaign using AERONET and GOCI

    NASA Astrophysics Data System (ADS)

    Kim, J.; Choi, M.; Lee, J.; Lee, S.; Holben, B. N.; Eck, T. F.; KIM, M.

    2015-12-01

    To investigate aerosol characteristics over East Asia, many campaigns using in-situ measurements, ground and satellite based remote sensing, and air quality modeling have been conducted as ACE-Asia in 2001, ABC-EAREX in 2005, and DRAGON-NE Asia in 2012, and planned KORUS-AQ in 2016. Planned KORUS-AQ 2016 campaigns provides excellent opportunity to monitor and analyze air quality including aerosol and trace gases from diverse platform including ground-based, airborne, shipborne and satellite platform. Prior to the upcoming KORUS-AQ campaign, the Megacity Air Pollution Studies (MAPS)-Seoul campaign was held from May 18 to June14, 2015. During the campaign, total 8 AERONET sunphotometers are deployed over Korea. GOCI Yonsei aerosol retrieval (YAER) algorithm was developed, improved and evaluated through the DRAGON-NE Asia campaign. GOCI YAER AOD at 550 nm with spatial resolution of 6 km showed good agreement with AERONET AOD (R > 0.88) during the DRAGON-NE Asia campaign. In this study, aerosol optical properties from AERONET and GOCI are analyzed together during the MAPS-Seoul campaign. Mean AERONET AOD at 550 nm over a megacity site, Seoul and a coastal site Gosan shows the lowest values in 2015 as 0.338 and 0.214, respectively, compared with values during the same period from 2011 to 2014 (0.557-0.645 at Seoul, and 0.447-0.618 at Gosan). GOCI YAER algorithm uses the minimum reflectivity technique from the composited Rayleigh-corrected reflectance during a month thus low AOD increase a possibility to find clear pixels to obtain accurate surface reflectance. To improve surface reflectance quality, multi-year GOCI data are also analyzed. Furthermore higher spatial resolution retrieval in 3 km is tested to detect small-scale aerosol features and point sources in megacities. DRAGON-NE Asia in 2012, MAPS-Seoul in 2015, and planned KORUS-AQ in 2016 field campaigns contribute to the continuous assessment of GOCI YAER algorithm performance for the improvements.

  1. In situ cloud and aerosol measurements over Coastal Antarctica during intensive field campaigns in 2010, 2011 and 2015

    NASA Astrophysics Data System (ADS)

    O'Shea, Sebastian; Choularton, Tom; Flynn, Michael; Bower, Keith; Gallagher, Martin; Fleming, Zoe; Listowski, Constantino; Kirchgaessner, Amelie; Ladkin, Russell; Lachlan-Cope, Tom; Crosier, Jonathan

    2017-04-01

    Few direct measurements have been made of Antarctic aerosol and cloud properties. As a result, a number of studies have suggested they are poorly represented within weather/climate models. This has important consequences for predictions of the mass balance of the Antarctic ice sheet and both weather patterns in the region and worldwide. In situ measurements of cloud and aerosol properties were collected over the Antarctic Peninsula, coastal continent and Weddell Sea during intensive observation periods in 2010, 2011 and 2015. Airborne measurements were collected using British Antarctic Survey's instrumented Twin Otter research aircraft for all 3 campaigns and additional ground based measurements were made at Halley's Clean Air Sector Laboratory in 2015. This presentation will focus on the aerosol measurements from these intensive observation periods. The aerosol in the region was found to have strong vertical gradients and to be hygroscopic in nature. The hygroscopicity parameter, κ had a mean value during the 2015 campaign of 0.69, which is consistent with other remote marine locations that are dominated by sea spray emissions. Aerosol properties will be investigated in terms of their air mass history. The relative contribution of emissions from the Antarctic Continent, sea ice and Sea/Ocean regions will be examined. The ice nucleating properties of the aerosol will also be discussed.

  2. Comparative analysis of hygroscopic properties of atmospheric aerosols at ZOTTO Siberian background station during summer and winter campaigns of 2011

    NASA Astrophysics Data System (ADS)

    Ryshkevich, T. I.; Mironov, G. N.; Mironova, S. Yu.; Vlasenko, S. S.; Chi, X.; Andreae, M. O.; Mikhailov, E. F.

    2015-09-01

    The results of measurements of hygroscopic properties and chemical analysis of atmospheric aerosol samples collected from June 10 to 20 and December 15 to 25, 2011, at the ZOTTO background stations (60.8° N, 89.35° E) in Central Siberia are presented. The sorption properties of aerosols are studied with the help of a differential analyzer of absorbed water mass in the relative humidity range of 5 to 99%. It has been found that the hygroscopic growth factor of aerosol particles collected during the winter campaign is on average 45% higher than that of the aerosol collected in the summer campaign, which leads to a 40% decrease in the critical supersaturation threshold of cloud activation of particles. The measurement data are analyzed and parameterized using a new approach that takes into account the concentration effects in the particle—water vapor system at low humidities. Based on the chemical analysis, the content of water-soluble substances in the winter sample is 2.5 times higher than in the summer sample. Here, the amount of sulfates and nitrates increases 20 and 88 times, respectively. A trajectory analysis of air mass motion shows that the increased content of inorganic ions in aerosols for the winter sample is caused by long-range transport of pollutants from industrial areas of Siberia. This difference in the chemical composition is the main source of the observed difference in hygroscopic and condensation properties of the aerosol particles.

  3. Submicron organic aerosol in Tijuana, Mexico, from local and Southern California sources during the CalMex campaign

    NASA Astrophysics Data System (ADS)

    Takahama, S.; Johnson, A.; Guzman Morales, J.; Russell, L. M.; Duran, R.; Rodriguez, G.; Zheng, J.; Zhang, R.; Toom-Sauntry, D.; Leaitch, W. R.

    2013-05-01

    The CalMex campaign was conducted from May 15 to June 30 of 2010 to study the properties and sources of air pollution in Tijuana, Mexico. In this study, submicron organic aerosol mass (OM) composition measured by Fourier Transform Infrared Spectroscopy (FTIR), Aerosol Chemical Speciation Monitor (ACSM), and X-ray spectromicroscopy are combined with statistical analysis and measurements of other atmospheric constituents. The average (±one standard deviation) OM concentration was 3.3 ± 1.7 μg m-3. A large source of submicron aerosol mass at this location was determined to be vehicular sources, which contributed approximately 40% to the submicron OM; largely during weekday mornings. The O/C ratio estimated from ACSM measurements was 0.64 ± 0.19; diurnal variations in this value and the more oxygenated fraction of OM as determined from Positive Matrix Factorization and classification analyses suggest the high degree of oxygenation originates from aged OM, rather than locally-produced secondary organic aerosol. A large contribution of this oxygenated aerosol to Tijuana from various source classes was observed; some fraction of this aerosol mass may be associated with non-refractory components, such as dust or BC. Backtrajectory simulations using the HYSPLIT model suggest that the mean wind vector consistently originated from the northwest region, over the Pacific Ocean and near the Southern California coast, which suggests that the origin of much of the oxygenated organic aerosol observed in Tijuana (as much as 60% of OM) may have been the Southern California Air Basin. The marine aerosol contribution to OM during the period was on average 23 ± 24%, though its contribution varied over synoptic rather than diurnal timescales. BB aerosol contributed 20 ± 20% of the OM during the campaign period, with notable BB events occurring during several weekend evenings.

  4. Chemical characterization and source apportionment of submicron aerosols measured in Senegal during the 2015 SHADOW campaign

    NASA Astrophysics Data System (ADS)

    Rivellini, Laura-Hélèna; Chiapello, Isabelle; Tison, Emmanuel; Fourmentin, Marc; Féron, Anaïs; Diallo, Aboubacry; N'Diaye, Thierno; Goloub, Philippe; Canonaco, Francesco; Prévôt, André Stephan Henry; Riffault, Véronique

    2017-09-01

    The present study offers the first chemical characterization of the submicron (PM1) fraction in western Africa at a high time resolution, thanks to collocated measurements of nonrefractory (NR) species with an Aerosol Chemical Speciation Monitor (ACSM), black carbon and iron concentrations derived from absorption coefficient measurements with a 7-wavelength Aethalometer, and total PM1 determined by a TEOM-FDMS (tapered element oscillating microbalance-filtered dynamic measurement system) for mass closure. The field campaign was carried out over 3 months (March to June 2015) as part of the SHADOW (SaHAran Dust Over West Africa) project at a coastal site located in the outskirts of the city of Mbour, Senegal. With an averaged mass concentration of 5.4 µg m-3, levels of NR PM1 in Mbour were 3 to 10 times lower than those generally measured in urban and suburban polluted environments. Nonetheless the first half of the observation period was marked by intense but short pollution events (NR PM1 concentrations higher than 15 µg m-3), sea breeze phenomena and Saharan desert dust outbreaks (PM10 up to 900 µg m-3). During the second half of the campaign, the sampling site was mainly under the influence of marine air masses. The air masses on days under continental and sea breeze influences were dominated by organics (36-40 %), whereas sulfate particles were predominant (40 %) for days under oceanic influence. Overall, measurements showed that about three-quarters of the total PM1 were explained by NR PM1, BC (black carbon) and Fe (a proxy for dust) concentrations, leaving approximately one-quarter for other refractory species. A mean value of 4.6 % for the Fe / PM1 ratio was obtained. Source apportionment of the organic fraction, using positive matrix factorization (PMF), highlighted the impact of local combustion sources, such as traffic and residential activities, which contribute on average to 52 % of the total organic fraction. A new organic aerosol (OA) source

  5. First highlights of the Dynamics-Aerosol-Chemistry-Cloud Interactions in West Africa (DACCIWA) field campaigns

    NASA Astrophysics Data System (ADS)

    Liousse, C.; Knippertz, P.; Flamant, C.; Adon, J.; Akpo, A.; Annesi-Maesano, I.; Assamoi, E.; Baeza, A.; Julien, B.; Bedou, M.; Brooks, B. J.; Chiu, J. Y. C.; Chiron, C.; Coe, H.; Danuor, S.; Djossou, J.; Evans, M. J.; Fayomi, B.; Fink, A. H.; Galy-Lacaux, C.; Gardrat, E.; Jegede, O.; Kalthoff, N.; Kedote, M.; Keita, S.; Kouame, K.; Konare, A.; Leon, J. F.; Mari, C. H.; Lohou, F.; Roblou, L.; Schlager, H.; Schwarzenboeck, A.; Toure, E. N.; Veronique, Y.

    2016-12-01

    The EU-funded project DACCIWA (Dynamics-Aerosol-Chemistry-Cloud Interactions in West Africa) is investigating the relationship between weather, climate, air pollution and health in southern West Africa. The air over the coastal region of West Africa is a unique mixture of natural and anthropogenic gases, liquids and particles, emitted in an environment, in which multi-layer cloud decks frequently form. These exert a large influence on the local weather and climate, which has never been studied in detail over West Africa: this information is currently not included in the majority of weather and climate models. For the first time, the entire chain of impacts of natural and manmade emissions on the West African atmosphere was investigated in a coordinated field campaign. As part of this campaign, three research aircraft (Falcon 20, Twin Otter and ATR) based in Lomé (Togo) flew targeted 50 missions over West Africa from 27 June to 16 July 2016. In that campaign also, three highly instrumented measuring sites inland were set up with weather balloons launched several times a day across the region. The main objective was to build robust statistics of cloud properties in southern West Africa in different chemical landscapes (background state, ship/flaring emissions, polluted megacities, agricultural and forest areas, dust from the Sahel/Sahara). In addition, DACCIWA scientists working on measurements of urban emissions, air pollution, and health have set up four urban sites in Abidjan (Cote d'Ivoire) and Cotonou (Benin) focusing on main specific regional combustion sources (domestic fires, traffic and waste burning). Long-term measurements of gases and particles and census of hospital admissions for respiratory diseases were started in January 2015 and will continue until March 2017 to determine the links between human health and air pollution. Intensive measurement periods took place in July 2015, January 2016, and July 2016 (a final one is planned for January 2017) in

  6. Assimilation of satellite Aerosol Optical Depth measurements in the CTM MOCAGE during the ChArMEx campaign

    NASA Astrophysics Data System (ADS)

    Sic, Bojan; El Amraoui, Laaziz; Piacentini, Andrea; Emili, Emanuele

    2014-05-01

    Aerosols are of great importance for atmospheric chemistry, climate, and public health. Consequently, it is important to well simulate the spatial and temporal aerosol distribution. The atmospheric aerosols are a chemically and physically complex mixture of solid and liquid particles from natural and anthropogenic sources. Thus, modelling of different types of aerosols is subject of many uncertainties related to their parameterizations or sources/sinks. This contribution deals with the improvement of the spatial and temporal representation of different types of aerosols within the chemistry-transport model of Météo-France, MOCAGE. This consists of assimilating Aerosol Optical Depth (AOD) from satellite observations. The used approach during AOD assimilation consists in choosing the total aerosol concentrations as the control variable. First, we will present the methodology and the advantages of such an approach. Second, we will evaluate the AOD analyses by comparison to the independent aerosol measurements performed during the ChArMEx campaign (summer 2013). ChArMEx is a French initiative which aimed to characterize the atmospheric pollution in the western-Mediterranean basin using airborne measurements from balloons and aircrafts as well as ground-based measurements.

  7. Multi-year Satellite and Surface Observations of AOD in support of Two-Column Aerosol Project (TCAP) Field Campaign

    SciTech Connect

    Kassianov, Evgueni I.; Chand, Duli; Berg, Larry K.; Fast, Jerome D.; Tomlinson, Jason M.; Ferrare, R.; Hostetler, Chris A.; Hair, John

    2012-11-01

    We use combined multi-year measurements from the surface and space for assessing the spatial and temporal distribution of aerosol properties within a large (~400x400 km) region centered on Cape Cod, Massachusetts, along the East Coast of the United States. The ground-based Aerosol Robotic Network (AERONET) measurements at Martha’s Vineyard Coastal Observatory (MVCO) site and Moderate Resolution Imaging Spectrometer (MODIS) sensors on board the Terra and Aqua satellites provide horizontal and temporal variations of aerosol optical depth, while the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) offers the altitudes of aerosol-layers. The combined ground-based and satellite measurements indicated several interesting features among which were the large differences in the aerosol properties observed in July and February. We applied the climatology of aerosol properties for designing the Two-Column Aerosol Project (TCAP), which is supported by the U.S. Department of Energy’s (DOE’s) Atmospheric Radiation Measurement (ARM) Program. The TCAP field campaign involves 12-month deployment (started July 1, 2012) of the ground-based ARM Mobile Facility (AMF) and Mobile Aerosol Observing System (MAOS) on Cape Cod and complimentary aerosol observations from two research aircraft: the DOE Gulfstream-1 (G-1) and the National Aeronautics and Space Administration (NASA) B200 King Air. Using results from the coordinated G-1 and B200 flights during the recent (July, 2012) Intensive Observation Period, we demonstrated that the G-1 in situ measurements and B200 active remote sensing can provide complementary information on the temporal and spatial changes of the aerosol properties off the coast of North America.

  8. Aerosol Optical Thickness comparisons between NASA LaRC Airborne HSRL and AERONET during the DISCOVER-AQ field campaigns

    NASA Astrophysics Data System (ADS)

    Scarino, A. J.; Ferrare, R. A.; Burton, S. P.; Hostetler, C. A.; Hair, J. W.; Rogers, R. R.; Berkoff, T.; Cook, A. L.; Harper, D. B.; Hoff, R. M.; Holben, B. N.; Schafer, J.; McGill, M. J.; Yorks, J. E.; Lantz, K. O.; Michalsky, J. J.; Hodges, G.

    2013-12-01

    The first- and second-generation NASA airborne High Spectral Resolution Lidars (HSRL-1 and HSRL-2) have been deployed on board the NASA Langley Research Center King Air aircraft during the Deriving Information on Surface Conditions from Column and VERtically Resolved Observations Relevant to Air Quality (DISCOVER-AQ) field campaigns. These included deployments during July 2011 over Washington, D.C. and Baltimore, MD and during January and February 2013 over the San Joaquin Valley (SJV) of California and also a scheduled deployment during September 2013 over Houston, TX. Measurements of aerosol extinction, backscatter, and depolarization are available from both HSRL-1 and HSRL-2 in coordination with other participating research aircraft and ground sites. These measurements constitute a diverse data set for use in characterizing the spatial and temporal distribution of aerosols, aerosol optical thickness (AOT), as well as the Mixing Layer Height (MLH). HSRL AOT is compared to AOT measured by the Distributed Regional Aerosol Gridded Observation Networks (DRAGON) and long-term AERONET sites. For the 2011 campaign, comparisons of AOT at 532nm between HSRL-1 and AERONET showed excellent agreement (r = 0.98, slope = 1.01, intercept = 0.037) when the King Air flights were within 2.5 km of the ground site and 10 min from the retrieval time. The comparison results are similar for the 2013 DISCOVER-AQ campaign in the SJV. Additional ground-based (MPL) and airborne (CPL) lidar data were used to help screen for clouds in the AERONET observations during the SJV portion. AOT values from a Multi-Filter Rotating Shadowband Radiometer (MFRSR) located at the Porterville, CA site during the SJV campaign are also compared to HSRL-2 AOT. Lastly, using the MLH retrieved from HSRL aerosol backscatter profiles, we describe the distribution of AOT relative to the MLH.

  9. The Paris MEGAPOLI campaign to better quantify carbonaceous aerosol formation in a tertiary type mid-latitude Megacity

    NASA Astrophysics Data System (ADS)

    Beekmann, M.; Baltensperger, U.; Pandis, S. N.; Prevot, A. S.; Sciare, J.; Gros, V.; Borbon, A.; Drewnick, F.; Wiedensohler, A.; Baklanov, A.; Lawrence, M. G.; Megapoli Campaign Team

    2011-12-01

    Within the EU MEGAPOLI project, two intensive field campaigns have been conducted in the Greater Paris region during July 2009 and January/February 2010. The major aim was to quantify sources of primary and secondary aerosol, and the interaction with gaseous precursors, within a large agglomeration, and in its plume. Greater Paris has been chosen for such a campaign because it is a major and dense pollution source (more than 10 million inhabitants), surrounded by rural areas and relatively flat terrain. A particular focus was put on carbonaceous aerosol, for which primary emissions and secondary formation are still not well quantified. Detailed aerosol and gaseous precursor measurements have been conducted at an urban and two sub-urban sites, from five mobile platforms and from the French ATR-42 research aircraft (for plume characterization). In this paper, the campaign set-up and objectives, and an overview over the major results obtained so far will be given. First, the regional/ local share of sources of fine aerosol component are analysed from a set of AMS and PILS measurements obtained at several urban and peri-urban sites (located up or downwind of the agglomeration as a function of wind direction), and from air quality modelling. Despite the fact that the campaign took place in a Megacity with nearly 12 millions of inhabitants, the regional impact through advection from other European sources turned out to be dominant for secondary organic and inorganic aerosol, which accounts for the major fraction of total PM1 and PM2.5. In addition, different source apportionnement methods (Positive matrix factorisation of AMS and PILS measurements, C14 analysis, specific chemical tracer methods ) concomitantly made evident a major wintertime local and probably continental source of residential woodburning for organic aerosol, which also affects black carbon. Lower boundary layer heights (typically about 500 meters), made evident by lidar measurements, are another factor

  10. Evaluation of biomass burning aerosols in the HadGEM3 climate model with observations from the SAMBBA field campaign

    NASA Astrophysics Data System (ADS)

    Johnson, Ben T.; Haywood, James M.; Langridge, Justin M.; Darbyshire, Eoghan; Morgan, William T.; Szpek, Kate; Brooke, Jennifer K.; Marenco, Franco; Coe, Hugh; Artaxo, Paulo; Longo, Karla M.; Mulcahy, Jane P.; Mann, Graham W.; Dalvi, Mohit; Bellouin, Nicolas

    2016-11-01

    We present observations of biomass burning aerosol from the South American Biomass Burning Analysis (SAMBBA) and other measurement campaigns, and use these to evaluate the representation of biomass burning aerosol properties and processes in a state-of-the-art climate model. The evaluation includes detailed comparisons with aircraft and ground data, along with remote sensing observations from MODIS and AERONET. We demonstrate several improvements to aerosol properties following the implementation of the Global Model for Aerosol Processes (GLOMAP-mode) modal aerosol scheme in the HadGEM3 climate model. This predicts the particle size distribution, composition, and optical properties, giving increased accuracy in the representation of aerosol properties and physical-chemical processes over the Coupled Large-scale Aerosol Scheme for Simulations in Climate Models (CLASSIC) bulk aerosol scheme previously used in HadGEM2. Although both models give similar regional distributions of carbonaceous aerosol mass and aerosol optical depth (AOD), GLOMAP-mode is better able to capture the observed size distribution, single scattering albedo, and Ångström exponent across different tropical biomass burning source regions. Both aerosol schemes overestimate the uptake of water compared to recent observations, CLASSIC more so than GLOMAP-mode, leading to a likely overestimation of aerosol scattering, AOD, and single scattering albedo at high relative humidity. Observed aerosol vertical distributions were well captured when biomass burning aerosol emissions were injected uniformly from the surface to 3 km. Finally, good agreement between observed and modelled AOD was gained only after scaling up GFED3 emissions by a factor of 1.6 for CLASSIC and 2.0 for GLOMAP-mode. We attribute this difference in scaling factor mainly to different assumptions for the water uptake and growth of aerosol mass during ageing via oxidation and condensation of organics. We also note that similar agreement

  11. Urban and rural aerosol characterization of summer smog events during the PIPAPO field campaign in Milan, Italy

    NASA Astrophysics Data System (ADS)

    Baltensperger, U.; Streit, N.; Weingartner, E.; Nyeki, S.; Prévôt, A. S. H.; Van Dingenen, R.; Virkkula, A.; Putaud, J.-P.; Even, A.; ten Brink, H.; Blatter, A.; Neftel, A.; Gäggeler, H. W.

    2002-10-01

    A comprehensive range of aerosol parameters was measured at an urban and a rural site in the Milan, Italy metropolitan region during summer smog events in summer 1998. Measurements were performed as part of the Pianura Padana Produzione di Ozono (PIPAPO) field campaign to determine the sensitivity of O3 production to NOX and volatile organic carbon concentrations at several ground stations. Primary aerosol parameters (i.e., direct emissions) such as aerosol black carbon showed a distinct diurnal variation with maxima at about 0000 and 0800 central European summer time (CEST), in contrast to secondary aerosol parameters such as sulfate and nitrate. Aerosol number size distributions were measured under ambient conditions as well as after conditioning with volatility and hygroscopicity systems. A mode at d = 20-30 nm in the number concentration was found at 0800 CEST and exhibited high volatility at 110°C (~80% volume lost upon heating) but no hygroscopic behavior. Based on these measurements, small particles (d < 40 nm) are thought to consist mainly of hydrophobic particulate organic matter, rather than soot or H2SO4 aerosols. Two distinct hygroscopic modes with average growth factors d/d0 ~ 1.02 and 1.21-1.28 were found for particles with dry (relative humidity of <30%) diameters d0 = 50-200 nm. Submicrometer aerosols exhibited lower volatility at the rural than at the urban site, which is attributed to additional particulate mass produced by secondary particle formation.

  12. Urban and rural aerosol characterization of summer smog events during the PIPAPO field campaign in Milan, Italy

    NASA Astrophysics Data System (ADS)

    Baltensperger, U.; Streit, N.; Weingartner, E.; Nyeki, S.; PréVôT, A. S. H.; van Dingenen, R.; Virkkula, A.; Putaud, J.-P.; Even, A.; ten Brink, H.; Blatter, A.; Neftel, A.; GäGgeler, H. W.

    2002-11-01

    A comprehensive range of aerosol parameters was measured at an urban and a rural site in the Milan, Italy metropolitan region during summer smog events in summer 1998. Measurements were performed as part of the Pianura Padana Produzione di Ozono (PIPAPO) field campaign to determine the sensitivity of O3 production to NOX and volatile organic carbon concentrations at several ground stations. Primary aerosol parameters (i.e., direct emissions) such as aerosol black carbon showed a distinct diurnal variation with maxima at about 0000 and 0800 central European summer time (CEST), in contrast to secondary aerosol parameters such as sulfate and nitrate. Aerosol number size distributions were measured under ambient conditions as well as after conditioning with volatility and hygroscopicity systems. A mode at d = 20-30 nm in the number concentration was found at 0800 CEST and exhibited high volatility at 110°C (˜80% volume lost upon heating) but no hygroscopic behavior. Based on these measurements, small particles (d < 40 nm) are thought to consist mainly of hydrophobic particulate organic matter, rather than soot or H2SO4 aerosols. Two distinct hygroscopic modes with average growth factors d/d0 ˜ 1.02 and 1.21-1.28 were found for particles with dry (relative humidity of <30%) diameters d0 = 50-200 nm. Submicrometer aerosols exhibited lower volatility at the rural than at the urban site, which is attributed to additional particulate mass produced by secondary particle formation.

  13. Measurements of Biogenic and Anthropogenic Ozone and Aerosol Precursors during the SENEX (Southeast Nexus) Campaign 2013

    NASA Astrophysics Data System (ADS)

    Warneke, C.; Trainer, M.; De Gouw, J. A.

    2013-12-01

    Natural emissions of ozone and aerosol precursor gases such as isoprene and monoterpenes are the highest in the southeast of the U.S. and rival those found in tropical forests. In addition, anthropogenic emissions are significant in the Southeast and photochemistry is rapid. The southeast U.S. has not warmed like other parts of the U.S. in response to global climate change, and the temperature anomaly has been suggested to be related to aerosols derived from a combination of anthropogenic and biogenic precursors. The NOAA SENEX aircraft campaign took place in June-July 2013 in the southeast U.S. as part of the Southeast Atmosphere Study (SAS). The NOAA WP-3 aircraft conducted 20 research flights between May 27 and July 10, 2013 based out of Smyrna, TN. To investigate the combination of anthropogenic and biogenic emissions several flights were designed to follow the emissions of cities and power plants as they are transported over forested regions in the Southeast. For example, over-flights of Atlanta, Birmingham and Nashville were performed and the plumes were followed to the forested areas with high isoprene and monoterpene emissions. The same was done for several power plants such as EC Gaston, Scherer and Johnsonville. In the anthropogenic plumes, effects such as the modulation of the isoprene chemistry by high NOx and particle formation and growth were investigated. The same strategy was used for three nighttime flights over Atlanta, Birmingham and the New Madrid and White Bluff power plants. Flights over and downwind of St Lois and Indianapolis were used as a contrast in areas with smaller biogenic emissions. Other anthropogenic emissions sources that were investigated during SENEX included bio refineries, paper mills, coalmines, poultry and pork farming. Also biomass burning emissions were observed during one daytime and one nighttime flight. Another focus of the SENEX campaign was to determine the emissions of natural gas and oil production from the

  14. Organic aerosol composition and sources in Pasadena, California, during the 2010 CalNex campaign

    NASA Astrophysics Data System (ADS)

    Hayes, P. L.; Ortega, A. M.; Cubison, M. J.; Froyd, K. D.; Zhao, Y.; Cliff, S. S.; Hu, W. W.; Toohey, D. W.; Flynn, J. H.; Lefer, B. L.; Grossberg, N.; Alvarez, S.; Rappenglück, B.; Taylor, J. W.; Allan, J. D.; Holloway, J. S.; Gilman, J. B.; Kuster, W. C.; Gouw, J. A.; Massoli, P.; Zhang, X.; Liu, J.; Weber, R. J.; Corrigan, A. L.; Russell, L. M.; Isaacman, G.; Worton, D. R.; Kreisberg, N. M.; Goldstein, A. H.; Thalman, R.; Waxman, E. M.; Volkamer, R.; Lin, Y. H.; Surratt, J. D.; Kleindienst, T. E.; Offenberg, J. H.; Dusanter, S.; Griffith, S.; Stevens, P. S.; Brioude, J.; Angevine, W. M.; Jimenez, J. L.

    2013-08-01

    Organic aerosols (OA) in Pasadena are characterized using multiple measurements from the California Research at the Nexus of Air Quality and Climate Change (CalNex) campaign. Five OA components are identified using positive matrix factorization including hydrocarbon-like OA (HOA) and two types of oxygenated OA (OOA). The Pasadena OA elemental composition when plotted as H : C versus O : C follows a line less steep than that observed for Riverside, CA. The OOA components from both locations follow a common line, however, indicating similar secondary organic aerosol (SOA) oxidation chemistry at the two sites such as fragmentation reactions leading to acid formation. In addition to the similar evolution of elemental composition, the dependence of SOA concentration on photochemical age displays quantitatively the same trends across several North American urban sites. First, the OA/ΔCO values for Pasadena increase with photochemical age exhibiting a slope identical to or slightly higher than those for Mexico City and the northeastern United States. Second, the ratios of OOA to odd-oxygen (a photochemical oxidation marker) for Pasadena, Mexico City, and Riverside are similar, suggesting a proportional relationship between SOA and odd-oxygen formation rates. Weekly cycles of the OA components are examined as well. HOA exhibits lower concentrations on Sundays versus weekdays, and the decrease in HOA matches that predicted for primary vehicle emissions using fuel sales data, traffic counts, and vehicle emission ratios. OOA does not display a weekly cycle—after accounting for differences in photochemical aging —which suggests the dominance of gasoline emissions in SOA formation under the assumption that most urban SOA precursors are from motor vehicles.

  15. Atmospheric Aging and Its Impacts on Physical Properties of Soot Aerosols: Results from the 2009 SHARP/SOOT Campaign

    NASA Astrophysics Data System (ADS)

    Zhang, R.; Khalizov, A. F.; Zheng, J.; Reed, C. C.; Collins, D. R.; Olaguer, E. P.

    2009-12-01

    Atmospheric aerosols impact the Earth energy balance directly by scattering solar radiation back to space and indirectly by changing the albedo, frequency, and lifetime of clouds. Carbon soot (or black carbon) produced from incomplete combustion of fossil fuels and biomass burning represents a major component of primary aerosols. Because of high absorption cross-sections over a broad range of the electromagnetic spectra, black carbon contributes significantly to climate change by direct radiative forcing and is the second most important component causing global warming after carbon dioxide. In areas identified as aerosol hotspots, which include many megacities, solar heating by soot-containing aerosols is roughly comparable to heating due to greenhouse gases. In addition, light absorbing soot aerosols may reduce photolysis rates at the surface level, producing a noticeable impact on photochemistry. Enhanced light absorption and scattering by soot can stabilize the atmosphere, retarding vertical transport and exacerbating accumulation of gaseous and particulate matter (PM) pollutants within the planetary boundary layer. Less surface heating and atmospheric stabilization may decrease formation of clouds, and warming in the atmosphere can evaporate existing cloud droplets by lowering relative humidity. Furthermore, soot-containing aerosols represent a major type of PM that has adverse effects on human health. When first emitted, soot particles are low-density aggregates of loosely connected primary spherules. Freshly emitted soot particles are typically hydrophobic, but may become cloud condensation nuclei (CCN) during atmospheric aging by acquiring hydrophilic coatings. Hygroscopic soot particles, being efficient CCN, can exert indirect forcing on climate. In this talk, results will be presented on measurements of soot properties during the 2009 SHARP/SOOT Campaign. Ambient aerosols and fresh soot particles injected into a captured air chamber were monitored to

  16. Transport of aerosol to the Arctic: analysis of CALIOP and French aircraft data during the spring 2008 POLARCAT campaign

    NASA Astrophysics Data System (ADS)

    Ancellet, G.; Pelon, J.; Blanchard, Y.; Quennehen, B.; Bazureau, A.; Law, K. S.; Schwarzenboeck, A.

    2014-08-01

    Lidar and in situ observations performed during the Polar Study using Aircraft, Remote Sensing, Surface Measurements and Models, Climate, Chemistry, Aerosols and Transport (POLARCAT) campaign are reported here in terms of statistics to characterize aerosol properties over northern Europe using daily airborne measurements conducted between Svalbard and Scandinavia from 30 March to 11 April 2008. It is shown that during this period a rather large number of aerosol layers was observed in the troposphere, with a backscatter ratio at 532 nm of 1.2 (1.5 below 2 km, 1.2 between 5 and 7 km and a minimum in between). Their sources were identified using multispectral backscatter and depolarization airborne lidar measurements after careful calibration analysis. Transport analysis and comparisons between in situ and airborne lidar observations are also provided to assess the quality of this identification. Comparison with level 1 backscatter observations of the spaceborne Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) were carried out to adjust CALIOP multispectral observations to airborne observations on a statistical basis. Recalibration for CALIOP daytime 1064 nm signals leads to a decrease of their values by about 30%, possibly related to the use of the version 3.0 calibration procedure. No recalibration is made at 532 nm even though 532 nm scattering ratios appear to be biased low (-8%) because there are also significant differences in air mass sampling between airborne and CALIOP observations. Recalibration of the 1064 nm signal or correction of -5% negative bias in the 532 nm signal both could improve the CALIOP aerosol colour ratio expected for this campaign. The first hypothesis was retained in this work. Regional analyses in the European Arctic performed as a test emphasize the potential of the CALIOP spaceborne lidar for further monitoring in-depth properties of the aerosol layers over Arctic using infrared and depolarization observations. The CALIOP

  17. LIDAR Observations of the Vertical Ozone and Aerosol Distribution over Mexico City during the MCMA-2003 Field Campaign

    NASA Astrophysics Data System (ADS)

    Simeonov, V.; Ristori, P.; Taslakov, M.; Dinoev, T.; van den Bergh, H.; Frey, S.; Molina, L. T.; Molina, M. J.

    2004-12-01

    An international field measurement campaign was held in April - May 2003 in the Mexico City Metropolitan Area (MCMA) as part of an effort to understand the complex urban air pollution problems in large cities. Gas phase and aerosol constituents were studied intensively during the campaign. LIDAR played an important role for measuring boundary layer dynamics and photochemical processes by monitoring the vertical distribution of aerosols and ozone. Two elastic DIAL and one Raman DIAL for ozone measurements were operated quasi-simultaneously during the campaign at the CENICA super site. The lidar of the Swiss Federal Institute of Technology, Lausanne (EPFL), Switzerland is an elastic three-wavelength UV DIAL combined with an aerosol lidar at 532 nm with an operational range of 200-6000 m for ozone measurements and 200-10000 m for aerosol measurements. The other elastic system is a commercial, stand alone two-wavelength DIAL produced and operated by ELIGHT Laser Systems GmbH. It performed ozone measurements from 400 to 2000 m. A combined Raman DIAL and aerosol Raman system was on loan from Freie Universität Berlin. This instrument was operated by the MIT team and provided ozone concentration from 350 to 2600 m and multicolor aerosol backscatter, Raman and depolarization. The campaign was designed to cover the height of the annual photochemical season. Rain episodes during the afternoons and the evenings at the beginning of the campaign caused discontinuity in the observation. Improved meteorological conditions from April 25 to May 3 made continuous measurements of all participating Lidars possible. A cloud-topped boundary layer (BL) was the frequently observed in the afternoon during this period. The top of the BL estimated from the aerosol measurements showed steady day-to-day increase, reaching altitudes of up to 4 km, comparable to the altitudes of the surrounding mountains. An obvious detachment of the top of the BL was also observed by the EPFL Lidar during the

  18. Simulations of the Aerosol Index and the Absorption Aerosol Optical Depth and Comparisons with OMI Retrievals During ARCTAS-2008 Campaign

    NASA Technical Reports Server (NTRS)

    2010-01-01

    We have computed the Aerosol Index (AI) at 354 nm, useful for observing the presence of absorbing aerosols in the atmosphere, from aerosol simulations conducted with the Goddard Chemistry, Aerosol, Radiation, and Transport (GOCART) module running online the GEOS-5 Atmospheric GCM. The model simulates five aerosol types: dust, sea salt, black carbon, organic carbon and sulfate aerosol and can be run in replay or data assimilation modes. In the assimilation mode, information's provided by the space-based MODIS and MISR sensors constrains the model aerosol state. Aerosol optical properties are then derived from the simulated mass concentration and the Al is determined at the OMI footprint using the radiative transfer code VLIDORT. In parallel, model derived Absorption Aerosol Optical Depth (AAOD) is compared with OMI retrievals. We have focused our study during ARCTAS (June - July 2008), a period with a good sampling of dust and biomass burning events. Our ultimate goal is to use OMI measurements as independent validation for our MODIS/MISR assimilation. Towards this goal we document the limitation of OMI aerosol absorption measurements on a global scale, in particular sensitivity to aerosol vertical profile and cloud contamination effects, deriving the appropriate averaging kernels. More specifically, model simulated (full) column integrated AAOD is compared with model derived Al, this way identifying those regions and conditions under which OMI cannot detect absorbing aerosols. Making use of ATrain cloud measurements from MODIS, C1oudSat and CALIPSO we also investigate the global impact on clouds on OMI derived Al, and the extent to which GEOS-5 clouds can offer a first order representation of these effects.

  19. First Transmitted Hyperspectral Light Measurements and Cloud Properties from Recent Field Campaign Sampling Clouds Under Biomass Burning Aerosol

    NASA Technical Reports Server (NTRS)

    Leblanc, S.; Redemann, Jens; Shinozuka, Yohei; Flynn, Connor J.; Segal Rozenhaimer, Michal; Kacenelenbogen, Meloe Shenandoah; Pistone, Kristina Marie Myers; Schmidt, Sebastian; Cochrane, Sabrina

    2016-01-01

    We present a first view of data collected during a recent field campaign aimed at measuring biomass burning aerosol above clouds from airborne platforms. The NASA ObseRvations of CLouds above Aerosols and their intEractionS (ORACLES) field campaign recently concluded its first deployment sampling clouds and overlying aerosol layer from the airborne platform NASA P3. We present results from the Spectrometer for Sky-Scanning, Sun-Tracking Atmospheric Research (4STAR), in conjunction with the Solar Spectral Flux Radiometers (SSFR). During this deployment, 4STAR sampled transmitted solar light either via direct solar beam measurements and scattered light measurements, enabling the measurement of aerosol optical thickness and the retrieval of information on aerosol particles in addition to overlying cloud properties. We focus on the zenith-viewing scattered light measurements, which are used to retrieve cloud optical thickness, effective radius, and thermodynamic phase of clouds under a biomass burning layer. The biomass burning aerosol layer present above the clouds is the cause of potential bias in retrieved cloud optical depth and effective radius from satellites. We contrast the typical reflection based approach used by satellites to the transmission based approach used by 4STAR during ORACLES for retrieving cloud properties. It is suspected that these differing approaches will yield a change in retrieved properties since light transmitted through clouds is sensitive to a different cloud volume than reflected light at cloud top. We offer a preliminary view of the implications of these differences in sampling volumes to the calculation of cloud radiative effects (CRE).

  20. First transmitted hyperspectral light measurements and cloud properties from recent field campaign sampling clouds under biomass burning aerosol

    NASA Astrophysics Data System (ADS)

    LeBlanc, S. E.; Redemann, J.; Shinozuka, Y.; Flynn, C. J.; Segal-Rosenhaimer, M.; Kacenelenbogen, M. S.; Pistone, K.; Schmidt, S.; Cochrane, S.

    2016-12-01

    We present a first view of data collected during a recent field campaign aimed at measuring biomass burning aerosol above clouds from airborne platforms. The NASA ObseRvations of CLouds above Aerosols and their intEractionS (ORACLES) field campaign recently concluded its first deployment sampling clouds and overlying aerosol layer from the airborne platform NASA P3. We present results from the Spectrometer for Sky-Scanning, Sun-Tracking Atmospheric Research (4STAR), in conjunction with the Solar Spectral Flux Radiometers (SSFR). During this deployment, 4STAR sampled transmitted solar light either via direct solar beam measurements and scattered light measurements, enabling the measurement of aerosol optical thickness and the retrieval of information on aerosol particles in addition to overlying cloud properties. We focus on the zenith-viewing scattered light measurements, which are used to retrieve cloud optical thickness, effective radius, and thermodynamic phase of clouds under a biomass burning layer. The biomass burning aerosol layer present above the clouds is the cause of potential bias in retrieved cloud optical depth and effective radius from satellites. We contrast the typical reflection based approach used by satellites to the transmission based approach used by 4STAR during ORACLES for retrieving cloud properties. It is suspected that these differing approaches will yield a change in retrieved properties since light transmitted through clouds is sensitive to a different cloud volume than reflected light at cloud top. We offer a preliminary view of the implications of these differences in sampling volumes to the calculation of cloud radiative effects (CRE).

  1. Assessment of the Aerosol Optics Component of the Coupled WRF-CMAQ Model usingCARES Field Campaign data and a Single Column Model

    EPA Science Inventory

    The Carbonaceous Aerosols and Radiative Effects Study (CARES), a field campaign held in central California in June 2010, provides a unique opportunity to assess the aerosol optics modeling component of the two-way coupled Weather Research and Forecasting (WRF) – Community Multisc...

  2. Assessment of the Aerosol Optics Component of the Coupled WRF-CMAQ Model usingCARES Field Campaign data and a Single Column Model

    EPA Science Inventory

    The Carbonaceous Aerosols and Radiative Effects Study (CARES), a field campaign held in central California in June 2010, provides a unique opportunity to assess the aerosol optics modeling component of the two-way coupled Weather Research and Forecasting (WRF) – Community Multisc...

  3. Impact of long-range transport pollution on aerosol properties over West Africa: observations during the DACCIWA airborne campaign

    NASA Astrophysics Data System (ADS)

    Denjean, Cyrielle; Bourrianne, Thierry; Burnet, Frederic; Deroubaix, Adrien; Brito, Joel; Dupuy, Régis; Colomb, Aurélie; Schwarzenboeck, Alfons; Sellegri, Karine; Chazette, Patrick; Duplissy, Jonathan; Flamant, Cyrille

    2017-04-01

    Southern West Africa (SWA) is a region highly vulnerable to climate change. Emissions of anthropogenic pollution have increased substantially over the past decades in the region and are projected to keep increasing. The region is also strongly impacted by important natural pollution from distant locations. Biomass burning mainly from vegetation fires in Central Africa and mineral dust from the Saharan and Sahel-Sudan regions are advected by winds to the SWA region especially in summer. Both biomass burning and mineral dust aerosols scatter and absorb solar radiation and are able to significantly modify the regional radiative budget. Presently, the potential radiative impact of dust and biomass burning particles on SWA is unclear due to inadequate data information on the aerosols properties and vertical distribution. In the framework of the Dynamics-Aerosol-Chemistry-Cloud Interactions in West Africa (DACCIWA) project, an unprecedented field campaign took place in summer 2016 in West Africa. The ATR-42 research aircraft operated by SAFIRE performed twenty flights to sample the local air pollution from maritime traffic and coastal megacities, as well as regional pollution from biomass burning and desert dust. The aircraft was equipped with state of the art in situ instrumentation to measure the aerosol optical properties (CAPS, nephelometer, PSAP), the aerosol size distribution (SMPS, GRIMM, USHAS, PCASP, FSSP) and the aerosol chemical composition (SP2, AMS). A mini backscattered lidar system provided additional measurements of the aerosol vertical structure and the aerosol optical properties such as the particulate depolarization ratio. The CHIMERE chemistry and transport model has been used to characterize the source area and the long-range transport of dust and biomass burning plumes. Here, we investigate the aerosol microphysical, chemical and optical properties of biomass burning and dust aerosols transported in SWA. In particular the following questions will be

  4. Airborne measurements of hygroscopicity and mixing state of aerosols in the planetary boundary layer during the PEGASOS campaigns

    NASA Astrophysics Data System (ADS)

    Rosati, Bernadette; Weingartner, Ernest; Gysel, Martin; Rubach, Florian; Mentel, Thomas; Baltensperger, Urs

    2014-05-01

    properties and mixing state. By combining these results with measurements from an aerosol mass spectrometer (AMS) and an aethalometer, insights can be gathered to explain their hygroscopicity. In this work we will present vertical profiles of the hygroscopic growth and mixing state of aerosol particles measured during Zeppelin flights of the PEGASOS campaigns in the Netherlands, Italy and Finland. Results from ground measurements will also be included to compare the aerosol directly at the surface with different heights. W.T. Morgan et al., Enhancement of the aerosol direct radiative effect by semi-volatile aerosol components: Airborne measurements in North-Western Europe, Atmospheric Chemistry and Physics 10(2010), pp. 8151-8171. P. Zieger et al., Comparison of ambient aerosol extinction coefficients obtained from in-situ, MAX-DOAS and LIDAR measurements at Cabauw, Atmospheric Chemistry and Physics 11(2011), pp. 2603-2624.

  5. Toward understanding the role of the atmosphere in pan Arctic change and sea ice loss; an update on the status of focused campaigns under POLARCAT.

    NASA Astrophysics Data System (ADS)

    Burkhart, J. F.; Bates, T.; Brock, C. A.; Clerbaux, C.; Crawford, J. H.; Dibb, J. E.; Elansky, N.; Ghan, S.; Hirdman, D.; Honrath, R. E.; Jacob, D. J.; Law, K.; Paris, J.; Quinn, P.; Schlager, H.; Singh, H. B.; Sodemann, H.; Stohl, A.

    2008-12-01

    Sea ice loss reached an extraordinary extent in 2007, decreasing in area more than 2.5 million square kilometres below the 1979 extent. Sea ice loss is one of many Arctic processes resulting from a warming climate. The dynamics of a changing Arctic system are particularly sensitive to climate change and filled with uncertainties and complex feedback mechanisms - most being simply unknown. During the International Polar Year (IPY) a number of international partnerships were formed to establish the Polar Study using Aircraft, Remote Sensing, Surface Measurements and Models, of Climate, Chemistry, Aerosols, and Transport (POLARCAT). Under the umbrella of POLARCAT projects cooperated with national funding to undertake the most comprehensive assessment of air pollution impacts on the Arctic to date. In the spring and summer of 2008 more than 20 institutes from ten nations participated in intensive aircraft, ship, and station-based campaigns with accompanying efforts from the satellite and modelling communities to provide near real time products for mission planning and analysis. The campaigns provided an assessment of the role that tropospheric chemistry, aerosols, and transport play in the Arctic. The spring campaigns focused on anthropogenic pollution, while the summer campaigns targeted biomass burning. During the spring of 2008, over 80 flights were flown by five different aircraft as part of the ARCTAS, ISDAC, ARCPAC, and French POLARCAT campaigns, the ICEALOT campaign commissioned the R/V Knorr to travel over 12,000 km, and numerous specialty satellite and modelling products were developed with near real time distribution. These same products were again used for flight planning and forecasting in the summer when an additional 50+ flights were flown by the ARCTAS, French POLARCAT, Siberian YAK, and GRACE campaigns. Several ground based stations and the Siberian TROICA campaign also conducted intensive operating periods (IOPs). We present an overview of the

  6. Two-Column Aerosol Project (TCAP): Ground-Based Radiation and Aerosol Validation Using the NOAA Mobile SURFRAD Station Field Campaign Report

    SciTech Connect

    Michalsky, Joseph; Lantz, Kathy

    2016-05-01

    The National Oceanic and Atmospheric Administration (NOAA) is preparing for the launch of the Geostationary Operational Environmental Satellite R-Series (GOES-R) satellite in 2015. This satellite will feature higher time (5-minute versus 30-minute sampling) and spatial resolution (0.5 km vs 1 km in the visible channel) than current GOES instruments provide. NOAA’s National Environmental Satellite Data and Information Service has funded the Global Monitoring Division at the Earth System Research Laboratory to provide ground-based validation data for many of the new and old products the new GOES instruments will retrieve specifically related to radiation at the surface and aerosol and its extensive and intensive properties in the column. The Two-Column Aerosol Project (TCAP) had an emphasis on aerosol; therefore, we asked to be involved in this campaign to de-bug our new instrumentation and to provide a new capability that the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility’s Mobile Facilities (AMF) did not possess, namely surface albedo measurement out to 1625 nm. This gave us a chance to test remote operation of our new multi-filter rotating shadowband radiometer/multi-filter radiometer (MFRSR/MFR) combination. We did not deploy standard broadband shortwave and longwave radiation instrumentation because ARM does this as part of every AMF deployment. As it turned out, the ARM standard MFRSR had issues, and we were able to provide the aerosol column data for the first 2 months of the campaign covering the summer flight phase of the deployment. Using these data, we were able to work with personnel at Pacific Northwest National Laboratory (PNNL) to retrieve not only aerosol optical depth (AOD), but single scattering albedo and asymmetry parameter, as well.

  7. Multiwavelength In-Situ Aerosol Scattering and Absorption During the NEAQS-ITCT 2004 Field Campaign: Aerosol Classification, Case Studies, and Data Interpretation

    NASA Astrophysics Data System (ADS)

    Sierau, B.; Covert, D.; Coffman, D.; Quinn, P.; Bates, T.

    2005-12-01

    In-situ, three wavelength measurements of aerosol scattering and absorption of the New York and Boston urban pollution outflow were carried out aboard the NOAA research vessel Ronald H. Brown during the NEAQS-ITCT 2004 (New England Air Quality Study-Intercontinental Transport and Chemical Transformation Study) field campaign during July 2004 in the Gulf of Maine. Aerosol scattering, backscattering and absorption-coefficients were measured using integrating nephelometers and multiwavelength, filter-based absorption photometers (PSAPs) at ~55-60% RH (nephelometers). Two data sets were collected, one for particles with diameters dp<10μm and one for particles <1μm. The purpose of the latter was to focus on the largely pollution related accumulation mode and to minimize the uncertainty due to highly variable near-surface sea salt aerosol. Combining the aerosol scattering and absorption coefficients σsp and σap yields the derived, intensive parameters, single-scattering albedo, ω=σsp/(σsp+σap), Ångström exponents, å, for σsp, and σap, the hemispheric backscattering ratio, and the fine mode fraction of the aerosol, FMF =σsp(dp<1μm)/σsp(dp<10μm). These are key parameters in estimating aerosol direct radiative forcing and they provide constraints on model building and closure studies with physical and chemical aerosol properties. They are important for relating in-situ optical properties to those sensed remotely, e.g., optical depth from ground- or aircraft-based sun photometry or optical depth from satellite, and to the FMF retrieved from satellite data. The measured and derived data will be classified based on a trajectory analysis of the sampled air masses to identify distinct aerosol populations and sources. Case studies describing the aging of pollution plumes are calculated and analyzed in context of other measurements and the prevailing meteorology and the upwind sources. The obtained relationship between in-situ Ångström and FMF will be compared

  8. Hygroscopic Measurements of Aerosol Particles in the San Joaquin Valley California during the DRAGON and Discover AQ Campaign 2013

    NASA Astrophysics Data System (ADS)

    Orozco, D.; Delgado, R.; Hoff, R. M.

    2013-12-01

    In the ambient atmosphere, aerosol particles experience hygroscopic growth due to the influence of relative humidity (RH). Wet aerosols particles are larger than their dry equivalents, therefore they scatter more light. Quantitative knowledge of the RH effect and its influence on the light scattering coefficient on aerosol particles is of substantial importance when comparing ground based observations with other optical aerosol measurements techniques such satellite and sunphotometric retrievals of aerosol optical depth. The DISCOVER-AQ campaign is focused in improving the interpretation and relation between satellite observations and surface conditions related to air quality. In the winter of 2013, this campaign was held in the San Joaquin Valley, California, where systematic and concurrent observations of column integrated surface, and vertically resolved distributions of aerosols and trace gases relevant to air quality and their evolution during the day were observed. Different instruments such as particulate samplers, lidars, meteorological stations and airborne passive and active monitoring were coordinated to measure the aerosol structure of the San Joaquin Valley in a simultaneous fashion. A novel humidifier-dryer system for a TSI 3563 Nephelometer was implemented in the Penn State University NATIVE trailer located in Porterville California in order to measure the scattering coefficient σsp(λ) at three different wavelengths (λ=440, 550 and 700nm) in a RH range from 30 to 95%. The system was assembled by combining Nafion tubes to humidify and dry the aerosols and stepping motor valves to control the flow and the amount of humidity entering to the Nephelometer. Measurements in Porterville California reached dry scattering coefficient readings greater than 300Mm-1 at 550nm indicating the presence of a large amount of particles in the region. However, the ratio between scattering coefficients at high and low humidity, called the enhancement factor f

  9. Chemical composition and sources of organic aerosols over London from the ClearfLo 2012 campaigns

    NASA Astrophysics Data System (ADS)

    Finessi, Emanuela; Holmes, Rachel; Hopkins, James; Lee, James; Harrison, Roy; Hamilton, Jacqueline

    2014-05-01

    Air quality in urban areas represents a major public health issue with around one third of the European population concentrated in cities and numbers expected to increase at global scale, particularly in developing countries. Particulate matter (PM) represents a primary threat for human health as numerous studies have confirmed the association between increased levels of cardiovascular and respiratory diseases with the exposure to PM. Despite considerable efforts made in improving air quality and progressively stricter emissions regulations, the PM concentrations have not changed much over the past decades for reasons that remain unclear, and highlight that studies on PM source apportionment are required for the formulation of effective policy. We investigated the chemical composition of organic aerosol (OA) collected during two intensive field campaigns held in winter and summer 2012 in the frame of the project Clean air for London (http://www.clearflo.ac.uk/). PM samples were collected both at a city background site (North Kensington) and at a rural site 50 km southeast of London (Detling) with 8 to 24 hours sampling schedule and analysed using off-line methods. Thermal-optical analysis was used to quantify OC-EC components while a suite of soft ionization mass spectrometric techniques was deployed for detailed chemical characterization. Liquid chromatography mass Spectrometry (LC-MSn) was mostly used for the simultaneous detection and quantification of various tracers for both primary and secondary OA sources. Well-established markers for wood burning primary OA like levoglucosan and azelaic acid were quantified together with various classes of nitroaromatics including methyl-nitrocatechols that are potential tracers for wood burning secondary OA. In addition, oxidation products of biogenic VOCs such as isoprene and monoterpenes were also quantified for both seasons and sites. A non-negligible contribution from biogenic SOA to urban OA was found in summertime

  10. Chemical Aerosol Characterization Sampling in Santa Ana during the MCMA-2003 Field Campaign

    NASA Astrophysics Data System (ADS)

    Bernabe, R.; Castro, T.; Marquez, C.; Cardenas, B.; Salcedo, D.

    2004-12-01

    Aerosol samples were collected during the intensive MCMA-2003 campaign in Santa Ana (19.1772° N, 98.99° W), Mexico City. This small rural town lies near the southeastern border of Mexico City and on the western rim of a mountain pass that channels the southern outflow of air from the city. Particles smaller than 10 μ m in aerodynamic diameter were collected on aluminum foils using three 8-stage micro orifice uniform deposit impactor (MOUDI), while fine particles (PM2.5) were collected in quartz fiber filters using manual samplers (MiniVol air samplers, Airmetrics). Samples were taken every 3 days starting at 2am in 6 hr intervals (total time 18 hrs for MOUDI and 24 hrs for MiniVol) from April 10-22, 2003. The MOUDI was operated at a flow rate of 30 l/min with calibrated impaction cut-points in the range of 10 - 0.18 μ m; while the MiniVol operation flow rate was 5 l/min. Prior to sampling, the aluminum foils were pre-conditioned (at 450° C) in a furnace for 8 hrs to eliminate impurities. Both types of filters were weighted using an Ultra Microbalance (Cahn, with a sensitivity of 0.1 μ g) for particulate matter under controlled conditions (20° C and 50% relative humidity). The aluminum foils were cut in halves, one half for Total Carbon (TC) determination with a thermal method, Evolved Gas Analysis (EGA), and the other half for analysis of inorganic ions (Cl-, NO3, SO42-, NA+, NH4+, K+, Ca2+ and Mg+) by liquid chromatography and mass spectrometer analytic method. Organic and elemental carbon was done according to the IMPROVE Thermal Protocol. Aerosol measurements made with MOUDI showed that the particle size distribution was bimodal in the three sampling periods. During daylight periods, 75% of the collected samples consisted of particles with aerodynamic diameter < 1 μ m whereas the major mass concentration was dominated by particles > 1 μ m during night. PM2.5 results reveal that the highest and lowest levels were obtained during the afternoon (60.6 μ g

  11. Measurements of Ultra-fine and Fine Aerosol Particles over Siberia: Large-scale Airborne Campaigns

    NASA Astrophysics Data System (ADS)

    Arshinov, Mikhail; Paris, Jean-Daniel; Stohl, Andreas; Belan, Boris; Ciais, Philippe; Nédélec, Philippe

    2010-05-01

    In this paper we discuss the results of in-situ measurements of ultra-fine and fine aerosol particles carried out in the troposphere from 500 to 7000 m in the framework of several International and Russian State Projects. Number concentrations of ultra-fine and fine aerosol particles measured during intensive airborne campaigns are presented. Measurements carried over a great part of Siberia were focused on particles with diameters from 3 to 21 nm to study new particle formation in the free/upper troposphere over middle and high latitudes of Asia, which is the most unexplored region of the Northern Hemisphere. Joint International airborne surveys were performed along the following routes: Novosibirsk-Salekhard-Khatanga-Chokurdakh-Pevek-Yakutsk-Mirny-Novosibirsk (YAK-AEROSIB/PLARCAT2008 Project) and Novosibirsk-Mirny-Yakutsk-Lensk-Bratsk-Novosibirsk (YAK-AEROSIB Project). The flights over Lake Baikal was conducted under Russian State contract. Concentrations of ultra-fine and fine particles were measured with automated diffusion battery (ADB, designed by ICKC SB RAS, Novosibirsk, Russia) modified for airborne applications. The airborne ADB coupled with CPC has an additional aspiration unit to compensate ambient pressure and changing flow rate. It enabled to classify nanoparticles in three size ranges: 3-6 nm, 6-21 nm, and 21-200 nm. To identify new particle formation events we used similar specific criteria as Young et al. (2007): (1) N3-6nm >10 cm-3, (2) R1=N3-6/N621 >1 and R2=N321/N21200 >0.5. So when one of the ratios R1 or R2 tends to decrease to the above limits the new particle formation is weakened. It is very important to notice that space scale where new particle formation was observed is rather large. All the events revealed in the FT occurred under clean air conditions (low CO mixing ratios). Measurements carried out in the atmospheric boundary layer over Baikal Lake did not reveal any event of new particle formation. Concentrations of ultra

  12. Oxidative Aging of Gas and Aerosol Products from the Ozonolysis of alpha-Pinene; Results from the MUCHACHAS-2 Campaign

    NASA Astrophysics Data System (ADS)

    Decarlo, Peter; Tritscher, Torsten; Praplan, Arnaud; Barmet, Peter; Mertes, Peter; Donahue, Neil; Dommen, Josef; Prevot, Andre; Baltensperger, Urs

    2010-05-01

    The MUltiple CHamber Aerosol CHemical Aging Study 2 (MUCHACHAS-2) took place at the Paul Scherrer Institute 27 meter cubed chamber in January-February 2009. The campaign was designed to study the oxidation of the volatile components from the ozonolysis of alpha-pinene (AP). Experiments began with the dark ozonolysis of AP at low and high AP concentrations (10 and 40 ppb, respectively) followed by OH exposure via several methods including HONO photolysis and dark OH generation from the ozonolysis of tetramethylethene (TME). OH generation via HONO experiments were conducted at both high and low NOx levels. Gas and aerosol phase evolution was monitored with Proton Transfer Reaction Mass Spectrometry (PTRMS), Ion Chromatography Mass Spectrometry (IC-MS), High Resolution Time-of-Flight Aerosol Mass Spectrometry (AMS), and a Volatility Hygroscopicity Tandem Differential Mobility Analyzer (VHTDMA). AMS results indicate continued chemical evolution of ozonolysis generated secondary organic aerosol (SOA) without additional OH exposure and after the precursor had been consumed, showing that the AP ozonolysis system does not reach a equilibrium but continues to react. A NOx dependence on specific m/z aerosol markers was also seen in both the high and low concentration AP experiments. The ratio of m/z 44 to total organics showed a strong correlation with integrated OH exposure. Increases in signal intensity with time were observed for several high molecular weight (150-250 amu) species with significant increases after OH exposure following ozonolysis. These and other results will be presented.

  13. Campaign datasets for Holistic Interactions of Shallow Clouds, Aerosols, and Land-Ecosystems (HISCALE)

    SciTech Connect

    Fast,Jerome; Mei,Fan; Hubbe,John; Kalukin,Andrew; Long,Chuck; Matthews,Alyssa; Pekour, Mikhail; Schobesberger,Siegfried; Shilling,John; Springston,Stephen; Tomlinson,Jason; Wang,Jian; Zelenyuk-Imre,Alla

    2016-11-21

    Most of the instruments were deployed on the ARM Aerial Facility (AAF) Gulfstream-159 (G-1) aircraft, including those that measure atmospheric turbulence, cloud water content and drop size distributions, aerosol precursor gases, aerosol chemical composition and size distributions, and cloud condensation nuclei concentrations. Aerosol microphysical property measurements supplemented routine ARM aerosol measurements made at the surface. The G-1 completed transects over the SGP Central Facility at multiple altitudes within the boundary layer, and within and above clouds.

  14. Transport of aerosol to the Arctic: analysis of CALIOP and French aircraft data during the spring 2008 POLARCAT campaign

    NASA Astrophysics Data System (ADS)

    Ancellet, G.; Pelon, J.; Blanchard, Y.; Quennehen, B.; Bazureau, A.; Law, K. S.; Schwarzenboeck, A.

    2014-03-01

    Lidar and in situ observations performed during POLARCAT campaign are reported here in terms of statistics to characterize aerosol properties over northern Europe using daily airborne measurements conducted between Svalbard Island and Scandinavia from 30 March to 11 April 2008. It is shown that during this period, a rather large number of aerosol layers was observed in the troposphere, with a backscatter ratio at 532 nm of 1.2 (1.5 below 2 km, 1.2 between 5 and 7 km and a minimum in-between). Their sources were identified using multispectral backscatter and depolarization airborne lidar measurements after careful calibration analysis. Transport analysis and comparisons between in situ and airborne lidar observations are also provided to assess the quality of this identification. Comparison with level 1 backscatter observations of the spaceborne CALIOP lidar were done to adjust CALIOP multispectral observations to airborne observations on a statistical basis. Re-calibration for CALIOP daytime 1064 nm signals led to an increase of their values by about 30% in agreement with previous analyses. No re-calibration is made at 532 nm, but scattering ratios appear to be biased low. Regional analyses in the European Arctic then performed as a test, emphasize the potential of the CALIOP spaceborne lidar to further monitor more in depth properties of the aerosol layers over Arctic using infrared and depolarization observations. The CALIOP April 2008 global distribution of the aerosol backscatter reveal two regions with large backscatter below 2 km: the Northern Atlantic between Greenland and Norway, and Northern Siberia. The aerosol color ratio increase between the sources regions and the observations at latitudes above 70° N is consistent with a growth of the aerosol size once transported to the Arctic. The distribution of the aerosol optical properties in the mid troposphere supports the known main transport pathways between mid-latitudes and the Arctic.

  15. Analysis of the Interaction and Transport of Aerosols with Cloud or Fog in East Asia from AERONET and Satellite Remote Sensing: 2012 DRAGON Campaigns and Climatological Data

    NASA Astrophysics Data System (ADS)

    Eck, T. F.; Holben, B. N.; Reid, J. S.; Lynch, P.; Schafer, J.; Giles, D. M.; Kim, J.; Kim, Y. J.; Sano, I.; Arola, A. T.; Munchak, L. A.; O'Neill, N. T.; Lyapustin, A.; Sayer, A. M.; Hsu, N. Y. C.; Randles, C. A.; da Silva, A. M., Jr.; Govindaraju, R.; Hyer, E. J.; Pickering, K. E.; Crawford, J. H.; Sinyuk, A.; Smirnov, A.

    2015-12-01

    Ground-based remote sensing observations from Aerosol Robotic Network (AERONET) sun-sky radiometers have recently shown several instances where cloud-aerosol interaction had resulted in modification of aerosol properties and/or in difficulty identifying some major pollution transport events due to aerosols being imbedded in cloud systems. Major Distributed Regional Aerosol Gridded Observation Networks (DRAGON) field campaigns involving multiple AERONET sites in Japan and South Korea during Spring of 2012 have yielded observations of aerosol transport associated with clouds and/or aerosol properties modification as a result of fog interaction. Analysis of data from the Korean and Japan DRAGON campaigns shows that major fine-mode aerosol transport events are sometimes associated with extensive cloud cover and that cloud-screening of observations often filter out significant pollution aerosol transport events. The Spectral De-convolution Algorithm (SDA) algorithm was utilized to isolate and analyze the fine-mode aerosol optical depth (AODf) signal from AERONET data for these cases of persistent and extensive cloud cover. Satellite retrievals of AOD from MODIS sensors (from Dark Target, Deep Blue and MAIAC algorithms) were also investigated to assess the issue of detectability of high AOD events associated with high cloud fraction. Underestimation of fine mode AOD by the Navy Aerosol Analysis and Prediction System (NAAPS) and by the NASA Modern-Era Retrospective Analysis For Research And Applications Aerosol Re-analysis (MERRAaero) models at very high AOD at sites in China and Korea was observed, especially for observations that are cloud screened by AERONET (Level 2 data). Additionally, multi-year monitoring at several AERONET sites are examined for climatological statistics of cloud screening of fine mode aerosol events. Aerosol that has been affected by clouds or the near-cloud environment may be more prevalent than AERONET data suggest due to inherent difficulty in

  16. Observation and simulation of dust aerosol cycle and impact on radiative fluxes during the FENNEC campaign in summer 2011

    NASA Astrophysics Data System (ADS)

    Minvielle, Fanny; Derimian, Yevgeny; Pere, Jean-Christophe; Flamant, Cyrille; Brogniez, Gérard

    2013-04-01

    The Sahara desert is one of the principal worldwide sources of dust aerosol emissions that play significant role in the climatic system. In the framework of the FENNEC campaign, conducted during the summer 2011, we focus on dust radiative effect and impact on the atmospheric dynamics and profile structure. We study the variability of the measured radiative parameters and model atmospheric dynamics during dust plume observations at the FENNEC sites, therefore, trying to understand the link between the Saharan heat low system and dust aerosols. Due to its large size the airborne dust can absorb and scatter not only solar, but also thermal infrared radiation, which requires consideration of both spectral ranges. Analysis of AERONET and other optical observations during the period of intensive campaign in summer 2011 provides information on variability of aerosol optical characteristics and perturbation of solar and TIR flux. We use these observations in conjunction with the meso-scale model RAMS to understand the impact of the dust plumes on the atmospheric dynamics. We also simulate the dust cycle in order to find the contribution of the different emission sources and identify structure of transport over an extended domain. Then, coupling the radiative code (GAME) we calculate the radiative forcing of dust and compare it to the radiative flux observed and computed based on the AERONET observations. Validation of simulations is made using measurements from space-borne CALIOP lidar, SEVIRI and OMI satellites, AERONET ground-based stations and observations acquired onboard the SAFIRE Falcon 20 research aircraft.

  17. Characterization of carbonaceous aerosols during the MINOS campaign in Crete, July-August 2001: a multi-analytical approach

    NASA Astrophysics Data System (ADS)

    Sciare, J.; Cachier, H.; Oikonomou, K.; Ausset, P.; Sarda-Estève, R.; Mihalopoulos, N.

    2003-07-01

    During the major part of the Mediterranean Intensive Oxidant Study (MINOS) campaign (summer 2001, Crete Isl.), the Marine Boundary Layer (MBL) air was influenced by long range transport of biomass burning from the northern and western part of the Black Sea. During this campaign, carbonaceous aerosols were collected on quartz filters at a Free Tropospheric (FT) site, and at a MBL site together with size-resolved distribution of aerosols. Three Evolution Gas Analysis (EGA) protocols have been tested in order to better characterize the collected aged biomass burning smoke: A 2-step thermal method (Cachier et al., 1989) and a thermo-optical technique using two different temperature programs. The later temperature programs are those used for IMPROVE (Interagency Monitoring of Protected Visual Environments) and NIOSH 5040 (National Institute of Occupational Safety and Health). Artifacts were observed using the NIOSH temperature program and identified as interactions between carbon and dust deposited on the filter matrix at high temperature (T=550°C) under the pure helium step of the analysis. During the MINOS campaign, Black Carbon (BC) and Organic Carbon (OC) concentrations were on average respectively 1.19±0.56 and 3.62±1.08 μgC/m3 for the IMPROVE temperature program, and 1.09±0.36 and 3.75±1.24 μgC/m3 for the thermal method. Though these values compare well on average and the agreement between the Total Carbon (TC) measurements sample to sample was excellent (slope = 1.00, r2=0.93, n=56), important discrepancies were observed in determining BC concentrations from these two methods (average error of 33±22%). BC from the IMPROVE temperature program compared well with non-sea-salt potassium (nss-K) pointing out an optical sensitivity to biomass burning. On the other hand, BC from the thermal method showed a better agreement with non-sea-salt sulfate (nss-SO4), considered as a tracer for fossil fuel combustion during the MINOS campaign. The coupling between

  18. Characterization of carbonaceous aerosols during the MINOS campaign in Crete, July August 2001: a multi-analytical approach

    NASA Astrophysics Data System (ADS)

    Sciare, J.; Cachier, H.; Oikonomou, K.; Ausset, P.; Sarda-Estève, R.; Mihalopoulos, N.

    2003-10-01

    During the major part of the Mediterranean Intensive Oxidant Study (MINOS) campaign (summer 2001, Crete Isl.), the Marine Boundary Layer (MBL) air was influenced by long range transport of biomass burning from the northern and western part of the Black Sea. During this campaign, carbonaceous aerosols were collected on quartz filters at a Free Tropospheric (FT) site, and at a MBL site together with size-resolved distribution of aerosols. Three Evolution Gas Analysis (EGA) protocols have been tested in order to better characterize the collected aged biomass burning smoke: A 2-step thermal method (Cachier et al., 1989) and a thermo-optical technique using two different temperature programs. The later temperature programs are those used for IMPROVE (Interagency Monitoring of Protected Visual Environments) and NIOSH 5040 (National Institute of Occupational Safety and Health). Artifacts were observed using the NIOSH temperature program and identified as interactions between carbon and dust deposited on the filter matrix at high temperature (T>550ºC) under the pure helium step of the analysis. During the MINOS campaign, Black Carbon (BC) and Organic Carbon (OC) mass concentrations were on average respectively 1.19±0.56 and 3.62±1.08 mgC/m3 for the IMPROVE temperature program, and 1.09±0.36 and 3.75±1.24 mgC/m3 for the thermal method. Though these values compare well on average and the agreement between the Total Carbon (TC) measurements sample to sample was excellent (slope=1.00, r2=0.93, n=56), important discrepancies were observed in determining BC concentrations from these two methods (average error of 33±22%). BC from the IMPROVE temperature program compared well with non-sea-salt potassium (nss-K) pointing out an optical sensitivity to biomass burning. On the other hand, BC from the thermal method showed a better agreement with non-sea-salt sulfate (nss-SO4), considered as a tracer for fossil fuel combustion during the MINOS campaign. The coupling between these

  19. Hygroscopic properties of urban aerosols and their cloud condensation nuclei activities measured in Seoul during the MAPS-Seoul campaign

    NASA Astrophysics Data System (ADS)

    Kim, Najin; Park, Minsu; Yum, Seong Soo; Park, Jong Sung; Song, In Ho; Shin, Hye Jung; Ahn, Joon Young; Kwak, Kyung-Hwan; Kim, Hwajin; Bae, Gwi-Nam; Lee, Gangwoong

    2017-03-01

    Aerosol physical properties, chemical compositions, hygroscopicity and cloud condensation nuclei (CCN) activities were measured in Seoul, the highly populated capital city of Korea, during the Megacity Air Pollution Studies (MAPS-Seoul) campaign, in May-June 2015. The average aerosol concentration for particle diameters >10 nm was 11787 ± 7421 cm-3 with dominant peaks at morning rush hours and in the afternoon due to frequent new particle formation (NPF) events. The average CCN concentration was 4075 ± 1812 cm-3 at 0.6% supersaturation, with little diurnal variation. The average hygroscopicity parameter (κ) value determined using a humidified tandem differential mobility analyzer (HTDMA) ranged 0.17-0.27 for a range of particle diameters (30-150 nm). The κ values derived using the aerosol mass spectrometer (AMS) data with three different methods were 0.32-0.34, significantly higher than those from HTDMA due to the uncertainties in the hygroscopicity values of different chemical compositions, especially organics and black carbon. Factors affecting the aerosol hygroscopicity seemed to be traffic and chemical processes during the NPF events. The CCN concentration predicted based on HTDMA κ data showed very good agreement with the measured one. Because of the overestimation of κ, CCN closure with the predicted CCN concentration based on AMS κ data over-predicted CCN concentration although the linear correlation between measured and predicted CCN concentration was still very good.

  20. Particle size distribution and inorganic aerosol characterization during DAURE 2009 winter field campaign at Montseny site

    NASA Astrophysics Data System (ADS)

    Aranzazu Revuelta, M.; Gómez-Moreno, Francisco J.; Plaza, Javier; Coz, Esther; Pey, Jorge; Cusack, Michael; Pandolfi, Marco; Rodríguez-Maroto, Jesús J.; Pujadas, Manuel

    2010-05-01

    During DAURE 2009 winter field campaign, one of the sampling sites was Montseny, a rural background station located 40 km NNE from Barcelona and 25 km W from the Mediterranean Sea. It is a Natural Park and a protected area, thus with low human activity, mainly agriculture. The sampling station was located on a valley with it axis oriented on the direction NW-SE. At this site, a TSI-SMPS (DMA 3071 and CPC 3022) was installed in order to measure the particle number distribution in the size range 15-600 nm during the period March 19-27 with a measurement cycle of 12 minutes The particle mass distribution was measured by a micro-orifice uniform deposit impactor (MOUDI) using eleven size stages with aluminum substrates and a quartz fiber backup filter. Four samples were taken during the period 13-19 March, two during 24 hours and other two during 48 hours. This impactor has a wider size range allowing to measure from 56 to 18000 nm. The substrates and filters obtained were later analyzed for determining soluble ions (sulfate, nitrate, ammonium and calcium) by IC. There are mainly two different kinds of events measured with the SMPS. When the air masses were coming from SE, which meant that they could come from the park but also from the urban and industrial areas located in the pre-coastal depression, it was characterized by higher particle number concentrations and by size distributions centered on 80 nm. This meant it was an aged aerosol, which had grown up by coagulation, condensation and oxidation processes. When the air masses were coming from NW (the second valley axis side), the particle measured were much smaller, the instrument started to detect particles with 15 nm, but smaller ones could be possible. This meant that new particle nucleation could have occurred in the valley, just before arriving to the sampling point. From MOUDI samplings, two different types of events were also observed. Three of the four samplings coincided with stagnation of air masses or

  1. Azimuthal variability of trace gases and aerosols measured during the MADCAT campaign in summer 2013 in Mainz, Germany

    NASA Astrophysics Data System (ADS)

    Remmers, Julia; Wagner, Thomas

    2015-04-01

    With the MAX-DOAS technique it is possible to retrieve vertical profiles of trace gases and aerosols in the lower troposphere. Often these instruments monitor the atmosphere in one azimuthal direction only. Therefore horizontal variability is not resolved. Especially the comparison to satellite data close to strong emission sources (one main application of MAX-DOAS) is possibly biased. MADCAT (Multi-Axis DOAS Comparison campaign for Aerosols and Trace gases) took place in summer 2013 in Mainz, a city in the Rhine-Main region close to Frankfurt, with high population density and many industrial complexes. The main focus of this campaign was on the comparison of the results from the different instruments. Therefore 16 MAX-DOAS instruments from 10 different institutes were operated on the roof of the MPI for Chemistry. In standard operation mode, vertical scans at one or several selected azimuth viewing direction were performed. In addition, 6 instruments scanned the sky also in azimuth direction every two hours. These scans were performed under a low elevation angle (2°) to capture the pollution close to the ground. A comparison of the trace gas columns derived from these instruments will be shown for NO2 and O4, the latter is used to retrieve information about aerosols. The observed variation for different azimuth angles does not only reflect a gradient in the trace gas, but also differences in the light path length, which is affected by sun and viewing geometry as well as aerosols. To distinguish between the different effects comparisons with radiative transfer models are performed. The results of the azimuth scans are also compared to car-DOAS measurements around Mainz, which were conducted at least twice a day.

  2. Evaluation of sun photometer capabilities for retrievals of aerosol optical depth at high latitudes: The POLAR-AOD intercomparison campaigns

    NASA Astrophysics Data System (ADS)

    Mazzola, M.; Stone, R. S.; Herber, A.; Tomasi, C.; Lupi, A.; Vitale, V.; Lanconelli, C.; Toledano, C.; Cachorro, V. E.; O'Neill, N. T.; Shiobara, M.; Aaltonen, V.; Stebel, K.; Zielinski, T.; Petelski, T.; Ortiz de Galisteo, J. P.; Torres, B.; Berjon, A.; Goloub, P.; Li, Z.; Blarel, L.; Abboud, I.; Cuevas, E.; Stock, M.; Schulz, K.-H.; Virkkula, A.

    2012-06-01

    Accuracy requirements for aerosol optical depth (AOD) in polar regions are much more stringent than those usually encountered in established sun photometer networks, while comparability of data from different archive centres is a further important issue. Therefore, two intercomparison campaigns were held during spring 2006 at Ny-Ålesund (Svalbard) and autumn 2008 at Izaña (Tenerife) within the framework of the IPY POLAR-AOD project, with the participation of various research institutions routinely employing different instrument models at Arctic and Antarctic stations. As reported here, a common algorithm was used for data analysis with the aim of minimizing a large part of the discrepancies affecting the previous studies. During the Ny-Ålesund campaign, spectral values of AOD derived from measurements taken with different instruments were found to agree, presenting at both 500 nm and 870 nm wavelengths average values of root mean square difference (RMSD) and standard deviation of the difference (SDD) equal to 0.003. Correspondingly, the mean bias difference (MBD) varied mainly between -0.003 and +0.003 at 500 nm, and between -0.004 and +0.003 at 870 nm. During the Izaña campaign, which was also intended as an intercalibration opportunity, RMSD and SDD values were estimated to be equal to 0.002 for both channels on average, with MBD ranging between -0.004 and +0.004 at 500 nm and between -0.002 and +0.003 at 870 nm. RMSD and SDD values for Ångström exponent α were estimated equal to 0.06 during the Ny-Ålesund campaign and 0.39 at Izaña. The results confirmed that sun photometry is a valid technique for aerosol monitoring in the pristine atmospheric turbidity conditions usually observed at high latitudes.

  3. Cloud Condensation Nuclei Activity of Aerosols during GoAmazon 2014/15 Field Campaign Report

    SciTech Connect

    Wang, J.; Martin, S. T.; Kleinman, L.; Thalman, R. M.

    2016-03-01

    Aerosol indirect effects, which represent the impact of aerosols on climate through influencing the properties of clouds, remain one of the main uncertainties in climate predictions (Stocker et al. 2013). Reducing this large uncertainty requires both improved understanding and representation of aerosol properties and processes in climate models, including the cloud activation properties of aerosols. The Atmospheric System Research (ASR) science program plan of January 2010 states that: “A key requirement for simulating aerosol-cloud interactions is the ability to calculate cloud condensation nuclei and ice nuclei (CCN and IN, respectively) concentrations as a function of supersaturation from the chemical and microphysical properties of the aerosol.” The Observations and Modeling of the Green Ocean Amazon (GoAmazon 2014/15) study seeks to understand how aerosol and cloud life cycles are influenced by pollutant outflow from a tropical megacity (Manaus)—in particular, the differences in cloud-aerosol-precipitation interactions between polluted and pristine conditions. One key question of GoAmazon2014/5 is: “What is the influence of the Manaus pollution plume on the cloud condensation nuclei (CCN) activities of the aerosol particles and the secondary organic material in the particles?” To address this question, we measured size-resolved CCN spectra, a critical measurement for GoAmazon2014/5.

  4. Application of the LIRIC algorithm for the characterization of aerosols during the Airborne Romanian Measurements of Aerosols and Trace gases (AROMAT) campaign

    NASA Astrophysics Data System (ADS)

    Stefanie, Horatiu; Nicolae, Doina; Nemuc, Anca; Belegante, Livio; Toanca, Florica; Ajtai, Nicolae; Ozunu, Alexandru

    2015-04-01

    The ESA/ESTEC AROMAT campaign (Airborne Romanian Measurements of Aerosols and Trace gases) was held between 1st and 14th of September 2014 with the purpose to test and inter-compare newly developed airborne and ground-based instruments dedicated to air quality studies in the context of validation programs of the forthcoming European Space Agency satellites (Sentinel 5P, ADM-Aeolus and EarthCARE). Ground-based remote sensing and airborne in situ measurements were made in southern Romania in order to assess the level and the variability of NO2 and particulate matter, focusing on two areas of interest: SW (Turceni), where many coal based power plants are operating, and SE (Bucharest), affected by intense traffic and partially by industrial pollution. In this paper we present the results obtained after the application of the Lidar - Radiometer Inversion Code (LIRIC) algorithm on combined lidar and sunphotometer data collected at Magurele, 6 km South Bucharest. Full lidar data sets in terms of backscatter signals at 355, 532 and 1064 nm, as well as depolarization at 532 nm were used and combined with Aerosol Robotic Network (AERONET) data, in order to retrieve the profiles of aerosol volume concentrations, separated as fine, spherical and spheroidal coarse modes. Preliminary results showed that aerosols generated by traffic and industrial activities were present in the Planetary Boundary Layer, while biomass burning aerosols transported from the Balkan Peninsula were detected in the upper layers. Acknowledgements: ***This work has been supported by Programme for Research- Space Technology and Advanced Research - STAR, project number 55/2013 - CARESSE. ***The financial support by the European Community's FP7 - PEOPLE 2011 under ITaRS Grant Agreement n° 289923 is gratefully acknowledged.

  5. A modeling perspective of the ChArMEx intensive campaign: origin of photo-oxidant and organic aerosol formation

    NASA Astrophysics Data System (ADS)

    Cholakian, Arineh; Beekmann, Matthias; Siour, Guillaume; Coll, Isabelle; Colette, Augustin; Gros, Valerie; Marchand, Nicolas; Sciare, Jean; Colomb, Aurélie; Gheusi, François; Sauvage, Stéphane

    2016-04-01

    During the summers of 2013 and 2014, two three-week intensive campaigns took place over the western Mediterranean in order to investigate the origins of photo-oxidants as well as the sources and processes of formation of organic aerosols in this region. Within the frame of the MISTRAL/ChArMEx program, an extensive number of chemical compounds were investigated by means of ground-based and also airborne measurements. In this paper, a modeling perspective of the 2013 campaign is given, using the CHIMERE chemistry-transport model, dealing with two aspects: 1) representativeness of the simulations with respect to the complex orography of Cape Corsica, 2) evaluation of secondary organic aerosol simulations in the western Mediterranean region with different model configurations using a variety of experimental data. The model has been configured in a way to fit the specificities of this unique region. The base simulations are performed in a domain covering the entire Europe as well as the northern Africa with a low resolution (30 km). In order to take into account the orographic complexity of the area where the ground-based measurements were performed (Ersa, Cape Corsica), nested simulations with a high resolution (1km horizontal resolution) focused on this site were performed with the goal of increasing the representativeness of the simulations. Still, this resolution does not allow to correctly represent the altitude of the Cape Corsica measurement site (533 m asl). To solve this problem, a large number of grid cells in the vicinity of the measurements site, all having different altitudes, were used to find the extrapolated concentration of an indicative list of species towards the exact altitude of the aforementioned site and to estimate an orographic representativeness error, which was shown to be less important for organic aerosols among said species. Alongside the base simulations, other series of simulations using multiple configurations of the Volatility Basis Set

  6. Regional Influence of Aerosol Emissions from Wildfires Driven by Combustion Efficiency: Insights from the BBOP Campaign

    DOE PAGES

    Collier, Sonya; Zhou, Shan; Onasch, Timothy B.; ...

    2016-07-11

    Wildfires are important contributors to atmospheric aerosols and a large source of emissions that impact regional air quality and global climate. In this study, the regional and nearfield influences of wildfire emissions on ambient aerosol concentration and chemical properties in the Pacific Northwest region of the United States were studied using real-time measurements from a fixed ground site located in Central Oregon at the Mt. Bachelor Observatory (~2700 m a.s.l.) as well as near their sources using an aircraft. In addition, the regional characteristics of biomass burning aerosols were found to depend strongly on the modified combustion efficiency (MCE), anmore » index of the combustion processes of a fire. Organic aerosol emissions had negative correlations with MCE, whereas the oxidation state of organic aerosol increased with MCE and plume aging. The relationships between the aerosol properties and MCE were consistent between fresh emissions (~1 h old) and emissions sampled after atmospheric transport (6–45 h), suggesting that biomass burning organic aerosol concentration and chemical properties were strongly influenced by combustion processes at the source and conserved to a significant extent during regional transport. In conclusion, these results suggest that MCE can be a useful metric for describing aerosol properties of wildfire emissions and their impacts on regional air quality and global climate.« less

  7. Regional Influence of Aerosol Emissions from Wildfires Driven by Combustion Efficiency: Insights from the BBOP Campaign

    SciTech Connect

    Collier, Sonya; Zhou, Shan; Onasch, Timothy B.; Jaffe, Daniel A.; Kleinman, Lawrence; Sedlacek, III, Arthur J.; Briggs, Nicole L.; Hee, Jonathan; Fortner, Edward; Shilling, John E.; Worsnop, Douglas; Yokelson, Robert J.; Parworth, Caroline; Ge, Xinlei; Xu, Jianzhong; Butterfield, Zachary; Chand, Duli; Dubey, Manvendra K.; Pekour, Mikhail S.; Springston, Stephen; Zhang, Qi

    2016-07-11

    Wildfires are important contributors to atmospheric aerosols and a large source of emissions that impact regional air quality and global climate. In this study, the regional and nearfield influences of wildfire emissions on ambient aerosol concentration and chemical properties in the Pacific Northwest region of the United States were studied using real-time measurements from a fixed ground site located in Central Oregon at the Mt. Bachelor Observatory (~2700 m a.s.l.) as well as near their sources using an aircraft. In addition, the regional characteristics of biomass burning aerosols were found to depend strongly on the modified combustion efficiency (MCE), an index of the combustion processes of a fire. Organic aerosol emissions had negative correlations with MCE, whereas the oxidation state of organic aerosol increased with MCE and plume aging. The relationships between the aerosol properties and MCE were consistent between fresh emissions (~1 h old) and emissions sampled after atmospheric transport (6–45 h), suggesting that biomass burning organic aerosol concentration and chemical properties were strongly influenced by combustion processes at the source and conserved to a significant extent during regional transport. In conclusion, these results suggest that MCE can be a useful metric for describing aerosol properties of wildfire emissions and their impacts on regional air quality and global climate.

  8. Regional Influence of Aerosol Emissions from Wildfires Driven by Combustion Efficiency: Insights from the BBOP Campaign

    SciTech Connect

    Collier, Sonya; Zhou, Shan; Onasch, Timothy B.; Jaffe, Daniel A.; Kleinman, Lawrence; Sedlacek, III, Arthur J.; Briggs, Nicole L.; Hee, Jonathan; Fortner, Edward; Shilling, John E.; Worsnop, Douglas; Yokelson, Robert J.; Parworth, Caroline; Ge, Xinlei; Xu, Jianzhong; Butterfield, Zachary; Chand, Duli; Dubey, Manvendra K.; Pekour, Mikhail S.; Springston, Stephen; Zhang, Qi

    2016-07-11

    Wildfires are important contributors to atmospheric aerosols and a large source of emissions that impact regional air quality and global climate. In this study, the regional and nearfield influences of wildfire emissions on ambient aerosol concentration and chemical properties in the Pacific Northwest region of the United States were studied using real-time measurements from a fixed ground site located in Central Oregon at the Mt. Bachelor Observatory (~2700 m a.s.l.) as well as near their sources using an aircraft. In addition, the regional characteristics of biomass burning aerosols were found to depend strongly on the modified combustion efficiency (MCE), an index of the combustion processes of a fire. Organic aerosol emissions had negative correlations with MCE, whereas the oxidation state of organic aerosol increased with MCE and plume aging. The relationships between the aerosol properties and MCE were consistent between fresh emissions (~1 h old) and emissions sampled after atmospheric transport (6–45 h), suggesting that biomass burning organic aerosol concentration and chemical properties were strongly influenced by combustion processes at the source and conserved to a significant extent during regional transport. In conclusion, these results suggest that MCE can be a useful metric for describing aerosol properties of wildfire emissions and their impacts on regional air quality and global climate.

  9. Physical and chemical properties of aerosols at a coastal site Paposo (Chile) during VOCALS campaign

    NASA Astrophysics Data System (ADS)

    Cordova, A. M.; Chand, D.; Wood, R.; Wallace, D.; Hegg, D. A.; Shaw, G. E.; Krejci, R.; Fochesatto, G. J.; Gallardo, L.

    2009-12-01

    One of the primary goals of the VOCALS (VAMOS* Ocean-Cloud-Atmosphere-Land Study) Regional Experiment (REx) and associated modeling program is an improved understanding of aerosol indirect effects over the southeast Pacific (SEP). Details on the program are available online at www.eol.ucar.edu/projects/vocals/. To this end, detailed aerosol physical and chemical measurements were made during REx at a coastal land site at Paposo (25o 0.4' S, 70o 27.011' W, 690 masl) in northern Chile, a site ideally positioned for studying continental aerosol sources advecting over the SEP. We present initial analysis of data from Paposo. Detailed measurements of aerosol properties were made from mid October to mid November 2008. Observations from optical particle counters (OPC), nephelometers, aethalometer, scanning mobility particle sizer (SMPS) and the chemical analysis of the submicron aerosols samples collected on teflon filters are being used in this study. Large variations in aerosols parameters were observed which corresponded with changes in meteorology, as determined using trajectory analysis. Ion Chromatograph (IC) analysis of submicron aerosol samples shows that about 41% of submicron mass is sulfate. The light scattering coefficient shows a strong non-linear correlation with aerosol size observed using an OPC. Detailed results will be presented in the AGU meeting.

  10. Regional Influence of Aerosol Emissions from Wildfires Driven by Combustion Efficiency: Insights from the BBOP Campaign.

    PubMed

    Collier, Sonya; Zhou, Shan; Onasch, Timothy B; Jaffe, Daniel A; Kleinman, Lawrence; Sedlacek, Arthur J; Briggs, Nicole L; Hee, Jonathan; Fortner, Edward; Shilling, John E; Worsnop, Douglas; Yokelson, Robert J; Parworth, Caroline; Ge, Xinlei; Xu, Jianzhong; Butterfield, Zachary; Chand, Duli; Dubey, Manvendra K; Pekour, Mikhail S; Springston, Stephen; Zhang, Qi

    2016-08-16

    Wildfires are important contributors to atmospheric aerosols and a large source of emissions that impact regional air quality and global climate. In this study, the regional and nearfield influences of wildfire emissions on ambient aerosol concentration and chemical properties in the Pacific Northwest region of the United States were studied using real-time measurements from a fixed ground site located in Central Oregon at the Mt. Bachelor Observatory (∼2700 m a.s.l.) as well as near their sources using an aircraft. The regional characteristics of biomass burning aerosols were found to depend strongly on the modified combustion efficiency (MCE), an index of the combustion processes of a fire. Organic aerosol emissions had negative correlations with MCE, whereas the oxidation state of organic aerosol increased with MCE and plume aging. The relationships between the aerosol properties and MCE were consistent between fresh emissions (∼1 h old) and emissions sampled after atmospheric transport (6-45 h), suggesting that biomass burning organic aerosol concentration and chemical properties were strongly influenced by combustion processes at the source and conserved to a significant extent during regional transport. These results suggest that MCE can be a useful metric for describing aerosol properties of wildfire emissions and their impacts on regional air quality and global climate.

  11. Gravity-wave effects on tracer gases and stratospheric aerosol concentrations during the 2013 ChArMEx campaign

    NASA Astrophysics Data System (ADS)

    Chane Ming, Fabrice; Vignelles, Damien; Jegou, Fabrice; Berthet, Gwenael; Renard, Jean-Baptiste; Gheusi, François; Kuleshov, Yuriy

    2016-07-01

    Coupled balloon-borne observations of Light Optical Aerosol Counter (LOAC), M10 meteorological global positioning system (GPS) sondes, ozonesondes, and GPS radio occultation data, are examined to identify gravity-wave (GW)-induced fluctuations on tracer gases and on the vertical distribution of stratospheric aerosol concentrations during the 2013 ChArMEx (Chemistry-Aerosol Mediterranean Experiment) campaign. Observations reveal signatures of GWs with short vertical wavelengths less than 4 km in dynamical parameters and tracer constituents, which are also correlated with the presence of thin layers of strong local enhancements of aerosol concentrations in the upper troposphere and the lower stratosphere. In particular, this is evident from a case study above Ile du Levant (43.02° N, 6.46° E) on 26-29 July 2013. Observations show a strong activity of dominant mesoscale inertia GWs with horizontal and vertical wavelengths of 370-510 km and 2-3 km respectively, and periods of 10-13 h propagating southward at altitudes of 13-20 km during 27-28 July. The European Centre for Medium-Range Weather Forecasts (ECMWF) analyses also show evidence of mesoscale inertia GWs with similar horizontal characteristics above the eastern part of France. Ray-tracing experiments indicate the jet-front system as the main source of observed GWs. Using a simplified linear GW theory, synthetic vertical profiles of dynamical parameters with large stratospheric vertical wind maximum oscillations of ±40 mms-1 are produced for the dominant mesoscale GW observed at heights of 13-20 km. Parcel advection method reveals signatures of GWs in the ozone mixing ratio and the tropospheric-specific humidity. Simulated vertical wind perturbations of the dominant GWs and small-scale perturbations of aerosol concentration (aerosol size of 0.2-0.7 µm) are revealed to be in phase in the lower stratosphere. Present results support the importance of vertical wind perturbations in the GW-aerosol relationship

  12. Aerosol, Cloud and Trace Gas Observations Derived from Airborne Hyperspectral Radiance and Direct Beam Measurements in Recent Field Campaigns

    NASA Technical Reports Server (NTRS)

    Redemann, J.; Flynn, C. J.; Shinozuka, Y.; Kacenelenbogen, M.; Segal-Rosenheimer, M.; LeBlanc, S.; Russell, P. B.; Livingston, J. M.; Schmid, B.; Dunagan, S. E.; Johnson, R. R.

    2014-01-01

    4STAR capabilities for airborne field campaigns, with an emphasis on comparisons between 4STAR and AERONET sky radiances, and retrievals of aerosol microphysical properties based on sky radiance measurements, column trace gas amounts from spectral direct beam measurements and cloud property retrievals from zenith mode observations for a few select case studies in the SEAC4RS and TCAP experiments. We summarize the aerosol, trace gas, cloud and airmass characterization studies made possible by the combined 4STAR direct beam, and sky/zenith radiance observations.

  13. 2014 iAREA campaign on aerosol in Spitsbergen - Part 1: Study of physical and chemical properties

    NASA Astrophysics Data System (ADS)

    Lisok, J.; Markowicz, K. M.; Ritter, C.; Makuch, P.; Petelski, T.; Chilinski, M.; Kaminski, J. W.; Becagli, S.; Traversi, R.; Udisti, R.; Rozwadowska, A.; Jefimow, M.; Markuszewski, P.; Neuber, R.; Pakszys, P.; Stachlewska, I. S.; Struzewska, J.; Zielinski, T.

    2016-09-01

    This paper presents the results of measurements of aerosol physical and chemical properties during iAREA2014 campaign that took place on Svalbard between 15th of Mar and 4th of May 2014. With respect to field area, the experiment consisted of two sites: Ny-Ålesund (78°55‧N, 11°56‧E) and Longyearbyen (78°13‧N, 15°33‧E) with further integration of Aerosol Robotic Network (AERONET) station in Hornsund (77°00‧N, 15°33‧E). The subject of this study is to investigate the in-situ, passive and active remote sensing observations as well as numerical simulations to describe the temporal variability of aerosol single-scattering properties during spring season on Spitsbergen. The retrieval of the data indicates several event days with enhanced single-scattering properties due to the existence of sulphate and additional sea-salt load in the atmosphere which is possibly caused by relatively high wind speed. Optical results were confirmed by numerical simulations made by the GEM-AQ model and by chemical observations that indicated up to 45% contribution of the sea-salt to a PM10 total aerosol mass concentration. An agreement between the in-situ optical and microphysical properties was found, namely: the positive correlation between aerosol scattering coefficient measured by the nephelometer and effective radius obtained from laser aerosol spectrometer as well as negative correlation between aerosol scattering coefficient and the Ångstrom exponent indicated that slightly larger particles dominated during special events. The in-situ surface observations do not show any significant enhancement of the absorption coefficient as well as the black carbon concentration which might occur during spring. All of extensive single-scattering properties indicate a diurnal cycle in Longyearbyen, where 21:00-5:00 data stays at the background level, however increasing during the day by the factor of 3-4. It is considered to be highly connected with local emissions originating

  14. Susceptibility of Aerosol Retrievals to Cirrus Contamination during the BASE-ASIA Campaign and at Global View

    NASA Astrophysics Data System (ADS)

    Huang, J.; Hsu, C.; Tsay, S.; Jeong, M.; Holben, B.; Berkoff, T.; Welton, E. J.

    2010-12-01

    Cirrus clouds, particularly subvisual high thin cirrus with low optical thickness, are difficult to be screened out in the operational aerosol retrieval algorithms. In this study, we jointly used ground measurements (AERONET, aerosol robotic network; MPLNET, micro-pulse lidar network) and satellite data (MODIS, moderate resolution imaging spectroradiometer; CALIPSO, cloud-aerosol lidar and infrared pathfinder satellite observations) to closely examine the susceptibility of satellite retrieved and ground measured aerosol optical thickness (AOT) to cirrus contamination. Special cases were selected at Phimai (102.56°E, 15.18°N, also known as Pimai), Thailand, during the Biomass-burning Aerosols in South East-Asia: Smoke Impact Assessment (BASE-ASIA) campaign (February-May 2006). By taking advantage of space-borne and ground lidars in detecting cirrus clouds, we conducted the statistical analysis by matching up concurrent cirrus and aerosol observations at four levels: MPLNET vs AERONET, MPLNET vs MODIS, CALIPSO vs AERONET, and CALIPSO vs MODIS. Results suggest that the susceptibility of current operational AERONET and MODIS AOT products to cirrus features strong regional and seasonal variability, particularly in cirrus prevailing regions. The values of AOT and aerosol particle size appear to be larger for cirrus-susceptible cases than those for confidently non-cirrus cases, a possible signature of cirrus contamination. To further assess cirrus-screening algorithms, we tested 8 MODIS-derived cirrus screening parameters against lidar observations for their performance and robustness on cirrus screening: apparent reflectance at 1.38μm (R1.38), cirrus reflectance at 0.66μm (CR0.66), CR0.66 cirrus flag, reflectance ratio between 1.38μm and 0.66μm (RR1.38/0.66), reflectance ratio between 1.38μm and 1.24μm (RR1.38/1.24), brightness temperature difference between 8.6μm and 11μm (BTD8.6-11), brightness temperature difference between 11μm and 12μm (BTD11-12), and

  15. Preliminary results from two intensive campaigns characterizing urban aerosols at two high altitude cities in the Tropical Andes

    NASA Astrophysics Data System (ADS)

    Andrade, M. F.; Wiedensohler, A.; Velarde, F.; Moreno, I.; Weinhold, K.; Avila, F.

    2013-05-01

    Preliminary results from a short campaign carried out between September and December of 2012 at the cities of El Alto (16°30'36.09"S; 68°11'55.31"W; 4040 masl) and La Paz (16°30'13.83"S; 68° 7'45.56"W; 3580 masl), Bolivia are presented on this work. Particle size distribution was measured using a Mobility Particle Size Spectrometer (Reference of the World Calibration Center for Aerosol Physics) whereas concentration of black carbon was measured using a Multi Angle Absorption Photometer (MAAP). In addition meteorological parameters as well as CO concentration were collected on both locations. In the case of El Alto, the instruments were located within the International Airport of the city at approximately 300 m from the main and only landing strip and at least 1.5 km away from the main roads. On the other hand, in the case of La Paz, the instruments were set up at the Planetarium of University Mayor de San Andres. The building is located besides a road with heavy traffic. Because the two cities are part of the same metropolitan area (the sites were located 7.5 km apart), the cars and trucks produce a similar signature and therefore both background and non-background urban aerosols were sampled during the campaign. In addition, an interesting case was registered at La Paz where a day with practically no vehicular traffic was studied.

  16. Observations of Ozone-aerosol Correlated Behaviour in the Lower Stratosphere During the EASOE Campaign

    NASA Technical Reports Server (NTRS)

    Digirolamo, P.; Cacciani, M.; Disarra, A.; Fiocco, G.; Fua, D.; Joergensen, T. S.; Knudsen, B.; Larsen, N.

    1992-01-01

    The question of possible interactions between ozone and stratospheric aerosol has been open for a long time. Measurements carried out after the Mt. Agung and El Chicon eruptions showed evidence of negative correlations between the presence of volcanic stratospheric aerosols and ozone concentration. Evidence for negative correlations in the polar winter has been also found. It is only after the discovery of the Antarctic ozone hole that catalytic effects related to low temperature heterogeneous chemistry have become the object of much investigation, now extended to the role of volcanic aerosol in the ozone reduction. These phenomena can be the object of various interpretations, not mutually exclusive, including the effect of transport, diffuse radiation as well as heterogeneous chemistry. The present paper provides preliminary results of simultaneous measurements of ozone and aerosol, carried out at Thule, Greenland, during the winter 1991-92. The European Stratospheric Ozone Experiment (EASOE) was aimed at monitoring the winter Arctic stratosphere in order to obtain a deeper insight of the ozone destruction processes taking place in the polar regions. A large amount of aerosol was injected into the lower stratosphere by the recent eruption of Volcano Pinatubo. A lidar system, already operational in Thule since November 1990, has provided detailed measurements of the stratospheric aerosol concentration during EASOE. In the same period, a large number of ozonesondes were launched. Although no PSC formation was detected over Thule, the simultaneous measurement of the stratospheric aerosol and ozone profiles give the possibility to study interactions occurring in the stratosphere between these two constituents.

  17. Regional Influence of Aerosol Emissions from Wildfires Driven by Combustion Efficiency: Insights from the BBOP Campaign

    SciTech Connect

    Collier, Sonya; Zhou, Shan; Onasch, Timothy B.; Jaffe, Daniel A.; Kleinman, Lawrence; Sedlacek, Arthur J.; Briggs, Nicole L.; Hee, Jonathan; Fortner, Edward; Shilling, John E.; Worsnop, Douglas; Yokelson, Robert J.; Parworth, Caroline; Ge, Xinlei; Xu, Jianzhong; Butterfield, Zachary; Chand, Duli; Dubey, Manvendra K.; Pekour, Mikhail S.; Springston, Stephen; Zhang, Qi

    2016-08-16

    Abstract Wildfires are important contributors to atmospheric aerosols and a large source of emissions that impact regional air quality and global climate. In this study, wildfire emissions in the Pacific Northwest region of the United States were characterized using real-time measurements near their sources using an aircraft, and farther downwind from a fixed ground site located at the Mt. Bachelor Observatory (~ 2700 m a.s.l.). The characteristics of aerosol emissions were found to depend strongly on the modified combustion efficiency (MCE), a qualitative index of the combustion processes of a fire. Organic aerosol emissions had negative correlations with MCE, whereas the carbon oxidation state of organic aerosol increased with MCE. The relationships between the aerosol properties and MCE were consistent between fresher emissions (~1 hour old) and emissions sampled after atmospheric transport (6 - 45 hours), suggesting that organic aerosol mass loading and chemical properties were strongly influenced by combustion processes at the source and conserved to a significant extent during regional transport. These results suggest that MCE can be a useful metric for describing aerosol properties of regionally transported wildfire emissions and their impacts on regional air quality and global climate.

  18. Vertical distribution of aerosols in the vicinity of Mexico City during MILAGRO-2006 Campaign

    SciTech Connect

    Lewandowski, P.A.; Kleinman, L.; Eichinger, W. E.; Holder, H.; Prueger, J.; Wang, J.

    2010-02-01

    On 7 March 2006, a mobile, ground-based, vertical pointing, elastic lidar system made a North-South transect through the Mexico City basin. Column averaged, aerosol size distribution (ASD) measurements were made on the ground concurrently with the lidar measurements. The ASD ground measurements allowed calculation of the column averaged mass extinction efficiency (MEE) for the lidar system (1064 nm). The value of column averaged MEE was combined with spatially resolved lidar extinction coefficients to produce total aerosol mass concentration estimates with the resolution of the lidar (1.5 m vertical spatial and 1 s temporal). Airborne ASD measurements from DOE G-1 aircraft made later in the day on 7 March 2006, allowed the evaluation of the assumptions of constant ASD with height and time used for estimating the column averaged MEE. The results showed that the aerosol loading within the basin is about twice what is observed outside of the basin. The total aerosol base concentrations observed in the basin are of the order of 200 {mu}g/m{sup 3} and the base levels outside are of the order of 100 {mu}g/m{sup 3}. The local heavy traffic events can introduce aerosol levels near the ground as high as 900 {mu}g/m{sup 3}. The article presents the methodology for estimating aerosol mass concentration from mobile, ground-based lidar measurements in combination with aerosol size distribution measurements. An uncertainty analysis of the methodology is also presented.

  19. Characterization of Ambient Aerosols in Mexico City during the MCMA-2003 Campaign with Aerosol Mass Spectrometry. Results from the CENICA Supersite

    SciTech Connect

    Salcedo, D; Onasch, Timothy B; Dzepina, K; Canagaratna, M R; Zhang, Q; Huffman, A J; DeCarlo, Peter; Jayne, J T; Mortimer, P; Worsnop, Douglas R; Kolb, C E; Johnson, Kirsten S; Zuberi, Bilal M; Marr, L; Volkamer, Rainer M; Molina, Luisa; Molina, Mario J; Cardenas, B; Bernabe, R; Marquez, C; Gaffney, Jeffrey S; Marley, Nancy A; Laskin, Alexander; Shutthanandan, V; Xie, YuLong; Brune, W H; Lesher, R; Shirley, T; Jiminez, J L

    2006-03-24

    An Aerodyne Aerosol Mass Spectrometer (AMS) was deployed at the CENICA Supersite, while another was deployed in the Aerodyne Mobile Laboratory (AML) during the Mexico City Metropolitan Area field study (MCMA-2003) from March 29-May 4, 2003 to investigate particle concentrations, sources, and processes. This is the first of a series of papers reporting the AMS results from this campaign. The AMS provides real time information on mass concentration and composition of the non-refractory species in particulate matter less than 1 μm (NR PM1) with high time and size resolution. For the first time, we report field results from a beam width probe, which was used to study the shape and mixing state of the particles and to quantify potential losses of irregular particles due to beam broadening inside the AMS. Data from this probe show that no significant amount of irregular particles was lost due to excessive beam broadening. A comparison of the CENICA and AML AMSs measurements is presented, being the first published intercomparison between two quadrupole AMSs. The speciation, and mass concentrations reported by the two AMSs compared well. In order to account for the refractory material in the aerosol, we also present measurements of Black Carbon (BC) using an aethalometer and an estimate of the aerosol soil component obtained from PIXE analysis of filters. Comparisons of (AMS + BC + soil) mass concentration with other collocated particle instruments (a LASAIR Optical Particle Counter, a Tapered Element Oscillating Microbalance (TEOM) and a DustTrack Aerosol Monitor) are also presented. The comparisons show that the (AMS + BC + soil) mass concentration during MCMC-2003 is a good approximation to the total PM₂.₅ mass concentration.

  20. The Southern Ocean Clouds, Radiation, Aerosol Transport Experimental Study (SOCRATES): An Observational Campaign for Determining Role of Clouds, Aerosols and Radiation in Climate System

    NASA Astrophysics Data System (ADS)

    McFarquhar, G. M.; Wood, R.; Bretherton, C. S.; Alexander, S.; Jakob, C.; Marchand, R.; Protat, A.; Quinn, P.; Siems, S. T.; Weller, R. A.

    2014-12-01

    The Southern Ocean (SO) region is one of the cloudiest on Earth, and as such clouds determine its albedo and play a major role in climate. Evidence shows Earth's climate sensitivity and the Intertropical Convergence Zone location depend upon SO clouds. But, climate models are challenged by uncertainties and biases in the simulation of clouds, aerosols, and air-sea exchanges in this region which trace back to a poor process-level understanding. Due to the SO's remote location, there have been sparse observations of clouds, aerosols, precipitation, radiation and the air-sea interface apart from those from satellites. Plans for an upcoming observational program, SOCRATES, are outlined. Based on feedback on observational and modeling requirements from a 2014 workshop conducted at the University of Washington, a plan is described for obtaining a comprehensive dataset on the boundary-layer structure and associated vertical distributions of liquid and mixed-phase cloud and aerosol properties across a range of synoptic settings, especially in the cold sector of cyclonic storms. Four science themes are developed: improved climate model simulation of SO cloud and boundary layer structure in a rapidly varying synoptic setting; understanding seasonal and synoptic variability in SO cloud condensation and ice nucleus concentration and the role of local biogenic sources; understanding supercooled liquid and mixed-phase clouds and their impacts; and advancing retrievals of clouds, precipitation, aerosols, radiation and surface fluxes. Testable hypotheses for each theme are identified. The observational strategy consists of long-term ground-based observations from Macquarie Island and Davis, continuous data collection onboard Antarctic supply ships, satellite retrievals, and a dedicated field campaign covering 2 distinct seasons using in-situ and remote sensors on low- and high-altitude aircraft, UAVs, and a ship-borne platform. A timeline for these activities is proposed.

  1. Overview of balloon-borne aerosol measurements with the aerosol counter LOAC, with focus on the ChArMEx 2013 campaign

    NASA Astrophysics Data System (ADS)

    Dulac, François; Renard, Jean-Baptiste

    LOAC (Light Optical Aerosol Counter) is a new small optical particle counter/sizer of 250 grams designed to fly under all kinds of balloons. The measurements are conducted at two scattering angles: the first one, at 12°, is used to determine the aerosol particle concentrations in 19 size classes within a diameter range of 0.2-100 mm; the second angle, at 60°, is used to discriminate between different types of particles dominating different size classes. The sensor particularly discriminates wet or liquid particles, mineral dust, soot carbon particles and salts. Comparisons with measurements from other sensors at the surface are shown. We shall give a quick review of balloon-borne experiences since 2011 with LOAC under all kinds of balloons including tethered, sounding, open stratospheric, and new boundary-layer pressurized drifting balloons (BLBP) from CNES. Observation domains include the atmospheric surface layer, the boundary layer, the free troposphere and the lower stratosphere up to more than 35 km in altitude. Operations encompass a variety of environments including the Arctic (Reykjavik, Island, and Kiruna, Sweden), Brazil (Sao Paolo), the western Mediterranean Basin, southwestern France, peri-urban (Ile de France) and urban areas (Paris and Vienna). Results from the various campaigns will be illustrated including the study of fog events, urban aerosols, Saharan dust transport over France, stratospheric soot... Emphasis will be put on the ChArMEx campaign (the Chemistry-Aerosol Mediterranean Experiment) performed in summer 2013 in the Mediterranean basin: 19 LOAC flights have been performed under meteorological balloons and 12 under low altitude drifting balloons, most of them from Minorca Island (Spain) in June and early July and others from Levant Island (south of France) in late July and early August. Most of the flights were coupled with ozone concentration measurements (see presentation by F. Gheusi et al.). LOAC balloons were especially, but not

  2. From hygroscopic aerosols to cloud droplets: The HygrA-CD campaign in the Athens basin - An overview.

    PubMed

    Papayannis, A; Argyrouli, A; Bougiatioti, A; Remoundaki, E; Vratolis, S; Nenes, A; Solomos, S; Komppula, M; Giannakaki, E; Kalogiros, J; Banks, R; Eleftheriadis, K; Mantas, E; Diapouli, E; Tzanis, C G; Kazadzis, S; Binietoglou, I; Labzovskii, L; Vande Hey, J; Zerefos, C S

    2017-01-01

    The international experimental campaign Hygroscopic Aerosols to Cloud Droplets (HygrA-CD), organized in the Greater Athens Area (GAA), Greece from 15 May to 22 June 2014, aimed to study the physico-chemical properties of aerosols and their impact on the formation of clouds in the convective Planetary Boundary Layer (PBL). We found that under continental (W-NW-N) and Etesian (NE) synoptic wind flow and with a deep moist PBL (~2-2.5km height), mixed hygroscopic (anthropogenic, biomass burning and marine) particles arrive over the GAA, and contribute to the formation of convective non-precipitating PBL clouds (of ~16-20μm mean diameter) with vertical extent up to 500m. Under these conditions, high updraft velocities (1-2ms(-1)) and cloud condensation nuclei (CCN) concentrations (~2000cm(-3) at 1% supersaturation), generated clouds with an estimated cloud droplet number of ~600cm(-3). Under Saharan wind flow conditions (S-SW) a shallow PBL (<1-1.2km height) develops, leading to much higher CCN concentrations (~3500-5000cm(-3) at 1% supersaturation) near the ground; updraft velocities, however, were significantly lower, with an estimated maximum cloud droplet number of ~200cm(-3) and without observed significant PBL cloud formation. The largest contribution to cloud droplet number variance is attributed to the updraft velocity variability, followed by variances in aerosol number concentration. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. First results from the aerosol lidar and backscatter sonde intercomparison campaign STRAIT'1997 at table mountain facility during February-March 1997

    NASA Technical Reports Server (NTRS)

    Beyerle, G.; Gross, M. R.; Haner, D. A.; Kjome, N. T.; McDermid, I. S.; McGee, T. J.; Rosen, J. M.; Schaefer, H. - J.; Schrems, O.

    1998-01-01

    First results of an intercomparison measurement campaign between three aerosol lidar instruments and in-situ backscatter sondes performed at Table Mountain Facility (34.4 deg N, 117.7 deg E, 2280 m asl) in February-March 1997 are presented. During the campaign a total of 414 hours of lidar data were acquired by the Aerosol-Temperature-Lidar (ATL, Goddard Space Flight Center) the Mobile-aerosol-Raman-Lidar (MARL, Alfred Wegener Institute), and the TMF-Aerosol-Lidar (TAL, Jet Propulsion Laboratory), and four backscatter sondes were launched. From the data set altitude profiles of backscatter ratio and volume depolarization of stratospheric background aerosols at altitudes between 15 and 25 km and optically thin high-altitude cirrus clouds at altitudes below 13 km are derived. On the basis of a sulfuric acid aerosol model color ratio profiles obtained from two wavelength lidar data are compared to the corresponding profiles derived from the sonde observations. We find an excellent agreement between the in-situ and ATL lidar data with respect to backscatter and color ratio. Cirrus clouds were present on 16 of 26 nights during the campaign. Lidar observations with 17 minute temporal and 120-300 m spatial resolution indicate high spatial and temporal variability of the cirrus layers. Qualitative agreement is found between concurrent lidar measurements of backscatter ratio and volume depolarization.

  4. Vertical profiles of aerosol and black carbon in the Arctic: a seasonal phenomenology along 2 years (2011-2012) of field campaigns

    NASA Astrophysics Data System (ADS)

    Ferrero, Luca; Cappelletti, David; Busetto, Maurizio; Mazzola, Mauro; Lupi, Angelo; Lanconelli, Christian; Becagli, Silvia; Traversi, Rita; Caiazzo, Laura; Giardi, Fabio; Moroni, Beatrice; Crocchianti, Stefano; Fierz, Martin; Močnik, Griša; Sangiorgi, Giorgia; Perrone, Maria G.; Maturilli, Marion; Vitale, Vito; Udisti, Roberto; Bolzacchini, Ezio

    2016-10-01

    We present results from a systematic study of vertical profiles of aerosol number size distribution and black carbon (BC) concentrations conducted in the Arctic, over Ny-Ålesund (Svalbard). The campaign lasted 2 years (2011-2012) and resulted in 200 vertical profiles measured by means of a tethered balloon (up to 1200 m a.g.l.) during the spring and summer seasons. In addition, chemical analysis of filter samples, aerosol size distribution and a full set of meteorological parameters were determined at ground. The collected experimental data allowed a classification of the vertical profiles into different typologies, which allowed us to describe the seasonal phenomenology of vertical aerosol properties in the Arctic. During spring, four main types of profiles were found and their behavior was related to the main aerosol and atmospheric dynamics occurring at the measuring site. Background conditions generated homogenous profiles. Transport events caused an increase of aerosol concentration with altitude. High Arctic haze pollution trapped below thermal inversions promoted a decrease of aerosol concentration with altitude. Finally, ground-based plumes of locally formed secondary aerosol determined profiles with decreasing aerosol concentration located at different altitude as a function of size. During the summer season, the impact from shipping caused aerosol and BC pollution plumes to be constrained close to the ground, indicating that increasing shipping emissions in the Arctic could bring anthropogenic aerosol and BC in the Arctic summer, affecting the climate.

  5. The analysis of in situ and retrieved aerosol properties measured during three airborne field campaigns

    NASA Astrophysics Data System (ADS)

    Corr, Chelsea A.

    Aerosols can directly influence climate, visibility, and photochemistry by scattering and absorbing solar radiation. Aerosol chemical and physical properties determine how efficiently a particle scatters and/or absorbs incoming short-wave solar radiation. Because many types of aerosol can act as nuclei for cloud droplets (CCN) and a smaller population of airborne particles facilitate ice crystal formation (IN), aerosols can also alter cloud-radiation interactions which have subsequent impacts on climate. Thus aerosol properties determine the magnitude and sign of both the direct and indirect impacts of aerosols on radiation-dependent Earth System processes. This dissertation will fill some gaps in our understanding of the role of aerosol properties on aerosol absorption and cloud formation. Specifically, the impact of aerosol oxidation on aerosol spectral (350nm < lambda< 500nm) absorption was examined for two biomass burning plumes intercepted by the NASA DC-S aircraft during the Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) mission in Spring and Summer 2008. Spectral aerosol single scattering albedo (SSA) retrieved using actinic flux measured aboard the NASA DC-8 was used to calculate the aerosol absorption Angstrom exponents (AAE) for a 6-day-old plume on April 17 th and a 3-hour old plume on June 29th. Higher AAE values for the April 17th plume (6.78+/-0.38) indicate absorption by aerosol was enhanced in the ultraviolet relative to the visible portion of the short-wave spectrum in the older plume compared to the fresher plume (AAE= 3.34 0.11). These differences were largely attributed to the greater oxidation of the organic aerosol in the April 17th plume which can arise either from the aging of primary organic aerosol or the formation of spectrally-absorbing secondary organic aerosol. The validity of the actinic flux retrievals used above were also evaluated in this work by the comparison of SSA retrieved using

  6. Simulating the formation of carbonaceous aerosol in a European Megacity (Paris) during the MEGAPOLI summer and winter campaigns

    NASA Astrophysics Data System (ADS)

    Fountoukis, Christos; Megaritis, Athanasios G.; Skyllakou, Ksakousti; Charalampidis, Panagiotis E.; Denier van der Gon, Hugo A. C.; Crippa, Monica; Prévôt, André S. H.; Fachinger, Friederike; Wiedensohler, Alfred; Pilinis, Christodoulos; Pandis, Spyros N.

    2016-03-01

    We use a three-dimensional regional chemical transport model (PMCAMx) with high grid resolution and high-resolution emissions (4 × 4 km2) over the Paris greater area to simulate the formation of carbonaceous aerosol during a summer (July 2009) and a winter (January/February 2010) period as part of the MEGAPOLI (megacities: emissions, urban, regional, and global atmospheric pollution and climate effects, and Integrated tools for assessment and mitigation) campaigns. Model predictions of carbonaceous aerosol are compared against Aerodyne aerosol mass spectrometer and black carbon (BC) high time resolution measurements from three ground sites. PMCAMx predicts BC concentrations reasonably well reproducing the majority (70 %) of the hourly data within a factor of two during both periods. The agreement for the summertime secondary organic aerosol (OA) concentrations is also encouraging (mean bias = 0.1 µg m-3) during a photochemically intense period. The model tends to underpredict the summertime primary OA concentrations in the Paris greater area (by approximately 0.8 µg m-3) mainly due to missing primary OA emissions from cooking activities. The total cooking emissions are estimated to be approximately 80 mg d-1 per capita and have a distinct diurnal profile in which 50 % of the daily cooking OA is emitted during lunch time (12:00-14:00 LT) and 20 % during dinner time (20:00-22:00 LT). Results also show a large underestimation of secondary OA in the Paris greater area during wintertime (mean bias = -2.3 µg m-3) pointing towards a secondary OA formation process during low photochemical activity periods that is not simulated in the model.

  7. Simulating the formation of carbonaceous aerosol in a European Megacity (Paris) during the MEGAPOLI summer and winter campaigns

    NASA Astrophysics Data System (ADS)

    Fountoukis, C.; Megaritis, A. G.; Skyllakou, K.; Charalampidis, P. E.; Denier van der Gon, H. A. C.; Crippa, M.; Prévôt, A. S. H.; Freutel, F.; Wiedensohler, A.; Pilinis, C.; Pandis, S. N.

    2015-09-01

    We use a three dimensional regional chemical transport model (PMCAMx) with high grid resolution and high resolution emissions (4 km × 4 km) over the Paris greater area to simulate the formation of carbonaceous aerosol during a summer (July 2009) and a winter (January/February 2010) period as part of the MEGAPOLI (Megacities: Emissions, urban, regional, and Global Atmospheric POLlution and climate effects, and Integrated tools for assessment and mitigation) campaigns. Model predictions of carbonaceous aerosol are compared against Aerodyne aerosol mass spectrometer and black carbon (BC) high time resolution measurements from three ground sites. PMCAMx predicts BC concentrations reasonably well reproducing the majority (70 %) of the hourly data within a factor of two during both periods. The agreement for the summertime secondary organic aerosol (OA) concentrations is also encouraging (mean bias = 0.1 μg m-3) during a photochemically intense period. The model tends to underpredict the summertime primary OA concentrations in the Paris greater area (by approximately 0.8 μg m-3) mainly due to missing primary OA emissions from cooking activities. The total cooking emissions are estimated to be approximately 80 mg d-1 per capita and have a distinct diurnal profile in which 50 % of the daily cooking OA is emitted during lunch time (12:00-14:00 LT) and 20 % during dinner time (20:00-22:00 LT). Results also show a large underestimation of secondary OA in the Paris greater area during wintertime (mean bias = -2.3 μg m-3) pointing towards a secondary OA formation process during low photochemical activity periods that is not simulated in the model.

  8. Analysis of Aerosol Distribution over North East Asia Using a Geostationary Satellite Measurement during Filed Campaigns of DRAGON-Asia 2012 and MAPS-Seoul 2015

    NASA Astrophysics Data System (ADS)

    KIM, M.; Kim, J.; Jeong, U.; Kim, W.; Choi, M.; Holben, B. N.; Eck, T. F.; Lim, J.; Ahn, J.

    2015-12-01

    Considering diverse source and high concentration of aerosol, numerous manners have been applied to detect aerosol properties in North East Asia (NEA). Above all, a geostationary orbit satellite, COMS has monitored atmosphere and ocean conditions over the NEA using two payloads of Meteorological Imager (MI) and Geostationary Ocean Color Imager (GOCI) since 2010. By using the MI measurements, an AOD retrieval algorithm was developed (Kim et al., 2014). Additionally, a number of ground-based network such as Aerosol Robotic Network (AERONET), Sky Radiometer Network (SKYNET), and Mie-scattering Light Detector and Ranging (LIDAR) Network have been in operation to capture aerosol variability. And, occasionally, field campaigns were conducted. In 2012 (March to May), the DRAGON-Asia campaign was performed by AERONET science team and NIER (National Institute of Environmental Research), and 40 sun/sky-radiometer was deployed. Subsequently, MAPS-Seoul campaign for detecting air quality was performed with 8 AERONET sites and 6 Pandora instruments in Korea. Those ground-based measurements provide validation dataset for satellite retrieval algorithm, as well as detect detail of aerosol characteristics at each local point. Thus, in this study, the AODs obtained from the aforementioned campaigns were applied to assess and improve the accuracy of MI AOD. For the DRAGON-Asia 2012, the comparison between MI AOD and AERONET AOD shows correlation coefficient of 0.85, regression slope of 1.00 and RMSE of 0.18. Furthermore, AOPs obtained from those field campaign results and the MI AOD were analyzed to understand temporal and spatial variance of aerosol in NEA during spring.

  9. First results of the aerosol measurements at San Pietro Capofiume during the PEGASOS Po Valley campaign 2012

    NASA Astrophysics Data System (ADS)

    Poulain, Laurent; Größ, Johannes; Iinuma, Yoshiteru; van Pinxteren, Dominik; Wiedensohler, Alfred; Herrmann, Hartmut

    2014-05-01

    In the frame of the Pan-European Gas-Aerosol-Climate Interaction Study (PEGASOS) a field campaign was carried out at the San Pietro Capofiume site in the North Eastern of the Po Valley, Northern Italy, from June 9 to July 10, 2012. A large set of online instruments measuring aerosol physico-chemical properties were sitting in a laboratory container and connecting to a common PM10 inlet. These instruments were including SMPS, APS, HR-ToF-AMS, MAAP, Nephelometer and HH-TDMA. In parallel off-line aerosol measurements including DIGITEL High-Volume PM1 sampler and 5-stages BERNER impactor were deployed and collected twice a day (day time, 09:00 to 21:00 and nighttime 21:00 to 09:00). Additionally, VOC samples were also collected with TENAX TA cartridges six times a day (1:00-5:00, 5:00-9:00, 9:00-13:00, 13:00-17:00, 17:00-21:00, 21:00-01:00) and subsequently analyzed by thermal desorption GC-MS. The data quality insurance of the aerosol measurements was performed by successfully comparing our measurements with collocated instrumentation including SP-AMS, Nephelometer, MAAP, PILS and MARGA. The first results of these measurements will be presented. During the sampling period, different meteorological conditions occurred: for example at the beginning of the measurements, anticyclonic conditions with very low wind and extremely high temperature brought to the highest aerosol concentrations while different wind regimes and air mass origins characterized the second part of the sampling periods. In averaged over the period, aerosols were mainly made of organics (46 %) and sulfate (27%). Nitrate appears to be more important during nighttime than day time, indicating an important temperature dependency. However, a strong increase of the nitrate concentration after sunrise early in the morning when temperature already started to increase was also regularly observed and can be related to either influence of mixing layer higher or local nitrate formation after sunrise. Almost

  10. Overview of the Chemistry-Aerosol Mediterranean Experiment/Aerosol Direct Radiative Forcing on the Mediterranean Climate (ChArMEx/ADRIMED) summer 2013 campaign

    NASA Astrophysics Data System (ADS)

    Mallet, M.; Dulac, F.; Formenti, P.; Nabat, P.; Sciare, J.; Roberts, G.; Pelon, J.; Ancellet, G.; Tanré, D.; Parol, F.; Denjean, C.; Brogniez, G.; di Sarra, A.; Alados-Arboledas, L.; Arndt, J.; Auriol, F.; Blarel, L.; Bourrianne, T.; Chazette, P.; Chevaillier, S.; Claeys, M.; D'Anna, B.; Derimian, Y.; Desboeufs, K.; Di Iorio, T.; Doussin, J.-F.; Durand, P.; Féron, A.; Freney, E.; Gaimoz, C.; Goloub, P.; Gómez-Amo, J. L.; Granados-Muñoz, M. J.; Grand, N.; Hamonou, E.; Jankowiak, I.; Jeannot, M.; Léon, J.-F.; Maillé, M.; Mailler, S.; Meloni, D.; Menut, L.; Momboisse, G.; Nicolas, J.; Podvin, T.; Pont, V.; Rea, G.; Renard, J.-B.; Roblou, L.; Schepanski, K.; Schwarzenboeck, A.; Sellegri, K.; Sicard, M.; Solmon, F.; Somot, S.; Torres, B.; Totems, J.; Triquet, S.; Verdier, N.; Verwaerde, C.; Waquet, F.; Wenger, J.; Zapf, P.

    2016-01-01

    The Chemistry-Aerosol Mediterranean Experiment (ChArMEx; http://charmex.lsce.ipsl.fr) is a collaborative research program federating international activities to investigate Mediterranean regional chemistry-climate interactions. A special observing period (SOP-1a) including intensive airborne measurements was performed in the framework of the Aerosol Direct Radiative Impact on the regional climate in the MEDiterranean region (ADRIMED) project during the Mediterranean dry season over the western and central Mediterranean basins, with a focus on aerosol-radiation measurements and their modeling. The SOP-1a took place from 11 June to 5 July 2013. Airborne measurements were made by both the ATR-42 and F-20 French research aircraft operated from Sardinia (Italy) and instrumented for in situ and remote-sensing measurements, respectively, and by sounding and drifting balloons, launched in Minorca. The experimental setup also involved several ground-based measurement sites on islands including two ground-based reference stations in Corsica and Lampedusa and secondary monitoring sites in Minorca and Sicily. Additional measurements including lidar profiling were also performed on alert during aircraft operations at EARLINET/ACTRIS stations at Granada and Barcelona in Spain, and in southern Italy. Remote-sensing aerosol products from satellites (MSG/SEVIRI, MODIS) and from the AERONET/PHOTONS network were also used. Dedicated meso-scale and regional modeling experiments were performed in relation to this observational effort. We provide here an overview of the different surface and aircraft observations deployed during the ChArMEx/ADRIMED period and of associated modeling studies together with an analysis of the synoptic conditions that determined the aerosol emission and transport. Meteorological conditions observed during this campaign (moderate temperatures and southern flows) were not favorable to producing high

  11. Understanding the Effect of Aerosol Properties on Cloud Droplet Formation during TCAP Field Campaign Report

    SciTech Connect

    Cziczo, Daniel

    2016-05-01

    The formation of clouds is an essential element in understanding the Earth’s radiative budget. Liquid water clouds form when the relative humidity exceeds saturation and condensedphase water nucleates on atmospheric particulate matter. The effect of aerosol properties such as size, morphology, and composition on cloud droplet formation has been studied theoretically as well as in the laboratory and field. Almost without exception these studies have been limited to parallel measurements of aerosol properties and cloud formation or collection of material after the cloud has formed, at which point nucleation information has been lost. Studies of this sort are adequate when a large fraction of the aerosol activates, but correlations and resulting model parameterizations are much more uncertain at lower supersaturations and activated fractions.

  12. Simulated Transport and Mixing of Anthropogenic and Biogenic Aerosol and Their Entrainment into Clouds during the Goamazon Campaign

    NASA Astrophysics Data System (ADS)

    Fast, J. D.; Shrivastava, M. B.; Fan, J.; Berg, L. K.; Chand, D.; Fortner, E.; Mei, F.; Pekour, M. S.; Shilling, J. E.; Springston, S. R.; Tomlinson, J. M.; Wang, J.

    2014-12-01

    Several recent studies have suggested that anthropogenic emissions enhance the production of biogenic secondary organic aerosol (SOA). Because Manaus, Brazil is an isolated large city within the Amazon rainforest, measurements collected within and outside of the downwind urban plume during the 2014 Green Ocean Amazon (GoAmazon) campaign (supported by the U.S. Department of Energy's Atmospheric Radiation and Measurement program) will provide valuable information needed by regional and global models to evaluate parameterizations of SOA. The isolated urban plume should also provide distinct patterns of mixing with biogenic emissions and eliminate complications of multiple anthropogenic sources found in most other regions of the world. The objective of this study is to evaluate the performance of preliminary simulations of the transport, mixing, and chemical evolution of the Manaus urban plume from the chemistry version of the Weather Research and Forecasting model (WRF-Chem) using the available surface and aircraft measurements collected during the first intensive observation period (IOP) of GoAmazon. Simulations are performed using both a 10 km or 2 km grid spacing as well as a newly developed treatment that couples a sectional aerosol model and its parameterization of SOA using a volatility basis set approach with resolved clouds and a sub-grid scale cloud parameterization. Since the first IOP of GoAmazon was conducted during the wet season, shallow and deep convection were observed on most days and likely impacts the transport and vertical mixing of the Manaus plume. Therefore, we are using the available field campaign cloud measurements to evaluate the impact of sub-grid scale clouds on the horizontal and vertical distribution of aerosols. Satellite data is also used to assess the regional variability in simulated clouds and precipitation. Analyses of the simulations during the first IOP will be presented. Simulations with and without anthropogenic emissions will

  13. Overview of aerosol properties associated with air masses sampled by the ATR-42 during the EUCAARI campaign (2008)

    NASA Astrophysics Data System (ADS)

    Crumeyrolle, S.; Schwarzenboeck, A.; Sellegri, K.; Burkhart, J. F.; Stohl, A.; Gomes, L.; Quennehen, B.; Roberts, G.; Weigel, R.; Roger, J. C.; Villani, P.; Pichon, J. M.; Bourrianne, T.; Laj, P.

    2012-04-01

    Within the frame of the European Aerosol Cloud Climate and Air Quality Interactions (EUCAARI) project the Météo-France aircraft ATR-42 performed 22 research flights, over central Europe and the North Sea during the intensive observation period in May 2008. For the campaign, the ATR-42 was equipped in order to study aerosol physical, chemical and optical properties, as well as cloud microphysics. During the campaign, continental air masses from Eastern and Western Europe were encountered, along with polar and Scandinavian air masses. For the 22 research flights, retroplume analyses along the flight tracks were performed with FLEXPART in order to classify air masses into five sectors of origin which allows for a qualitative evaluation of emission influence on the respective air parcel. In the polluted boundary layer (BL), typical concentrations of particles with diameters larger than 10 nm (N10) are of the order of 5000-6000 cm-3, whereas N10 concentrations of clean air masses were lower than 1300 cm-3. The detection of the largest particle number concentrations occurred in air masses coming from Polar and Scandinavian regions for which an elevated number of nucleation mode (25-28 nm) particles was observed and attributed to new particle formation over open sea. In the free troposphere (FT), typical observed N10 are of the order of 900 cm-3 in polluted air masses and 400-600 cm-3 in clean air masses, respectively. In both layers, the chemical composition of submicron aerosol particles is dominated by organic matter and nitrate in polluted air masses, while, sulphate and ammonium followed by organics dominate the submicron aerosols in clean air masses. The highest CCN/CN ratios were observed within the polar air masses while the CCN concentration values are the highest within the polluted air masses. Within the five air mass sectors defined and the two layers (BL and FT), observations have been distinguished into anticyclonic (first half of May 2008) and cyclonic

  14. Vertical profiling of aerosol hygroscopic properties in the planetary boundary layer during the PEGASOS campaigns

    NASA Astrophysics Data System (ADS)

    Rosati, Bernadette; Gysel, Martin; Rubach, Florian; Mentel, Thomas F.; Goger, Brigitta; Poulain, Laurent; Schlag, Patrick; Miettinen, Pasi; Pajunoja, Aki; Virtanen, Annele; Klein Baltink, Henk; Bas Henzing, J. S.; Größ, Johannes; Gobbi, Gian Paolo; Wiedensohler, Alfred; Kiendler-Scharr, Astrid; Decesari, Stefano; Facchini, Maria Cristina; Weingartner, Ernest; Baltensperger, Urs

    2016-06-01

    Vertical profiles of the aerosol particles hygroscopic properties, their mixing state as well as chemical composition were measured above northern Italy and the Netherlands. An aerosol mass spectrometer (AMS; for chemical composition) and a white-light humidified optical particle spectrometer (WHOPS; for hygroscopic growth) were deployed on a Zeppelin NT airship within the PEGASOS project. This allowed one to investigate the development of the different layers within the planetary boundary layer (PBL), providing a unique in situ data set for airborne aerosol particles properties in the first kilometre of the atmosphere. Profiles measured during the morning hours on 20 June 2012 in the Po Valley, Italy, showed an increased nitrate fraction at ˜ 100 m above ground level (a.g.l.) coupled with enhanced hygroscopic growth compared to ˜ 700 m a. g. l. This result was derived from both measurements of the aerosol composition and direct measurements of the hygroscopicity, yielding hygroscopicity parameters (κ) of 0.34 ± 0.12 and 0.19 ± 0.07 for 500 nm particles, at ˜ 100 and ˜ 700 m a. g. l., respectively. The difference is attributed to the structure of the PBL at this time of day which featured several independent sub-layers with different types of aerosols. Later in the day the vertical structures disappeared due to the mixing of the layers and similar aerosol particle properties were found at all probed altitudes (mean κ ≈ 0.18 ± 0.07). The aerosol properties observed at the lowest flight level (100 m a. g. l.) were consistent with parallel measurements at a ground site, both in the morning and afternoon. Overall, the aerosol particles were found to be externally mixed, with a prevailing hygroscopic fraction. The flights near Cabauw in the Netherlands in the fully mixed PBL did not feature altitude-dependent characteristics. Particles were also externally mixed and had an even larger hygroscopic fraction compared to the results in Italy. The mean κ from

  15. Aerosol light-scattering enhancement due to water uptake during TCAP campaign

    NASA Astrophysics Data System (ADS)

    Titos, G.; Jefferson, A.; Sheridan, P. J.; Andrews, E.; Lyamani, H.; Alados-Arboledas, L.; Ogren, J. A.

    2014-02-01

    Aerosol optical properties were measured by the DOE/ARM (US Department of Energy Atmospheric Radiation Measurements) Program Mobile Facility in the framework of the Two-Column Aerosol Project (TCAP) deployed at Cape Cod, Massachusetts, for a~one year period (from summer 2012 to summer 2013). Measured optical properties included aerosol light-absorption coefficient (σap) at low relative humidity (RH) and aerosol light-scattering coefficient (σsp) at low and at RH values varying from 30 to 85%, approximately. Calculated variables included the single scattering albedo (SSA), the scattering Ångström exponent (SAE) and the scattering enhancement factor (f(RH)). Over the period of measurement, f(RH = 80%) had a mean value of 1.9 ± 0.3 and 1.8 ± 0.4 in the PM10 and PM1 fractions, respectively. Higher f(RH = 80%) values were observed for wind directions from 0-180° (marine sector) together with high SSA and low SAE values. The wind sector from 225 to 315° was identified as an anthropogenically-influenced sector, and it was characterized by smaller, darker and less hygroscopic aerosols. For the marine sector, f(RH = 80%) was 2.2 compared with a value of 1.8 obtained for the anthropogenically-influenced sector. The air-mass backward trajectory analysis agreed well with the wind sector analysis. It shows low cluster to cluster variability except for air-masses coming from the Atlantic Ocean that showed higher hygroscopicity. Knowledge of the effect of RH on aerosol optical properties is of great importance for climate forcing calculations and for comparison of in-situ measurements with satellite and remote sensing retrievals. In this sense, predictive capability of f(RH) for use in climate models would be enhanced if other aerosol parameters could be used as proxies to estimate hygroscopic growth. Toward this goal, we propose an exponential equation that successfully estimates aerosol hygroscopicity as a function of SSA at Cape Cod. Further work is needed to determine

  16. Aerosol radiative effects on the meteorology and distribution of pollutants in the Mexico City Metropolitan Area during MCMA-2006/MILAGRO Campaign

    NASA Astrophysics Data System (ADS)

    Li, Guohui; Bei, Naifang; Molina, Luisa

    2013-04-01

    Aerosols scatter or absorb incoming solar radiation, perturb the temperature structure of the atmosphere, and impact meteorological fields and further the distribution of gas phase species and aerosols. In the present study, the aerosol radiative effects on the meteorology and photochemistry in the Mexico City Metropolitan Area (MCMA) are investigated using the WRF-CHEM model during the period from March 24th to 29th associated with the MILAGRO-2006 campaign. Aerosols decrease incoming solar radiation by up to 20% and reduce the surface temperature by up to 0.5 °C due to scattering and absorbing the incoming solar radiation in Mexico City. The absorption of black carbon aerosols can also enhance slightly the temperature in the planetary boundary layer (PBL). Generally, the change of the PBL height in the city is less than 200 m during daytime due to the aerosol-induced perturbation of temperature profile. Wind fields are also adjusted with the variation of temperatures, but all the aerosol-induced meteorological changes cannot significantly influence the distribution of pollutants in the city. In addition, when convective events occur in the city, the aerosol radiative effects reduce the convective available potential energy (CAPE) and the convective precipitation is generally decreased. Further studies still need to be performed to evaluate the aerosol indirect effect on precipitation in Mexico City.

  17. Comparison and statistics of aerosol properties measured in situ in the tropopause region during the aircraft campaigns of POLSTAR, LACE 98, UFA, EXPORT, INCA and SCAVEX

    NASA Astrophysics Data System (ADS)

    Minikin, A.; Petzold, A.; Fiebig, M.; Hendricks, J.; Schröder, F.; Schlager, H.

    2003-04-01

    In the past few years the DLR Falcon 20, a German twin-jet research aircraft with a maximum ceiling of 13~km, has participated in a number of experiments devoted to the characterization of aerosol properties in the troposphere and the tropopause region. Total aerosol number concentrations for Aitken mode and ultrafine particles have been measured with condensation particle counters with different lower cut-off diameters in the range from 3 to 15~nm. For a subset of data, the fractionation between volatile, semi-volatile and refractory particles was determined. Total concentration of accumulation mode particles as well as aerosol size distributions were determined from measurements of a combination of optical aerosol spectrometer probes (PMS PCASP-100X and FSSP-300). In this contribution we report on mean tropospheric vertical profiles of aerosol properties and the statistics of aerosol abundance and size distributions in the upper troposphere for different campaigns mainly conducted in Europe but with differing continental character. Results of the projects LACE~98, UFA, EXPORT and SCAVEX refer to measurements over Germany and neighboring countries in spring, summer and autumn. Contrasting geographical regions are addressed by the results of the POLSTAR and INCA campaigns (high latitudes of the northern hemisphere and mid-latitudes of the southern and northern hemisphere, respectively, the latter with only small continental influence). We compare the results of the different campaigns in order to assess the representativity and natural variability of aerosol properties measured in situ in the upper troposphere and in the transition to the lower stratosphere. Experimental results are compared to simulations of the ECHAM global climate model. Simulated aerosol mass concentrations are in good agreement with observations of the mean vertical distribution of accumulation mode particles and the contrasting concentration level in the northern and southern hemisphere mid-latitudes.

  18. Submicron aerosol organic functional groups, ions, and water content at the Centreville SEARCH site (Alabama), during SOAS campaign

    NASA Astrophysics Data System (ADS)

    Ruggeri, G.; Ergin, G.; Modini, R. L.; Takahama, S.

    2013-12-01

    The SOAS campaign was conducted from June 1 to July 15 of 2013 in order to understand the relationship between biogenic and anthropogenic emissions in the South East US1,2. In this study, the organic and inorganic composition of submicron aerosol in the Centreville SEARCH site was measured by Fourier Transform Infrared Spectroscopy (FTIR) and the Ambient Ion Monitor (AIM; URG Corporation), whereas the aerosol water content was measured with a Dry Ambient Aerosol Size Spectrometer (DAASS)3. Organic functional group analysis was performed on PM1 aerosol selected by cyclone and collected on teflon filters with a time resolution of 4-12 hours, using one inlet heated to 50 °C and the other operated either at ambient temperature or 70 °C 4. The AIM measured both condensed and gas phase composition with a time resolution of 1 hour, providing partitioning behavior of inorganic species such as NH3/NH4+, HNO3/NO3-. These measurements collectively permit calculation of pure-component vapor pressures of candidate organic compounds and activity coefficients of interacting components in the condensed phase, using models such as SIMPOL.15, E-AIM6, and AIOMFAC7. From these results, the water content of the aerosol is predicted, and a comparison between modeled and measured partitioning of inorganic compounds and water vapor are discussed, in addition to organic aerosol volatility prediction based on functional group analysis. [1]- Goldstein, A.H., et al., Biogenic carbon and anthropogenic pollutants combine to form a cooling haze over the southeastern United States. Proceedings of the National Academy of Sciences of the United States of America, 2009. 106(22), 8835-8840. [2]- Carlton, A.G., Turpin, B.J., 2013. Particle partitioning potential of organic compounds is highest in the Eastern US and driven by anthropogenic water. Atmospheric Chemistry and Physics Discussions 13, 12743-12770. [3]- Khlystov, A., Stanier, C.O., Takahama, S., Pandis, S.N., 2005. Water content of ambient

  19. Measurements of submicron aerosols at the California-Mexico border during the Cal-Mex 2010 field campaign

    NASA Astrophysics Data System (ADS)

    Levy, Misti E.; Zhang, Renyi; Zheng, Jun; Tan, Haobo; Wang, Yuan; Molina, Luisa T.; Takahama, S.; Russell, L. M.; Li, Guohui

    2014-05-01

    We present measurements of submicron aerosols in Tijuana, Mexico during the Cal-Mex 2010 field campaign. A suite of aerosol instrumentations were deployed, including a hygroscopic-volatility tandem differential mobility analyzer (HV-TDMA), aerosol particle mass analyzer (APM), condensation particle counter (CPC), cavity ring-down spectrometer (CRDS), and nephelometer to measure the aerosol size distributions, effective density, hygroscopic growth factors (HGF), volatility growth factors (VGF), and optical properties. The average mass concentration of PM0.6 is 10.39 ± 7.61 μg m-3, and the derived average black carbon (BC) mass concentration is 2.87 ± 2.65 μg m-3. There is little new particle formation or particle growth during the day, and the mass loading is dominated by organic aerosols and BC, which on average are 37% and 27% of PM1.0, respectively. For four particle sizes of 46, 81, 151, and 240 nm, the measured particle effective density, HGFs, and VGFs exhibit distinct diurnal trends and size-dependence. For smaller particles (46 and 81 nm), the effective density distribution is unimodal during the day and night, signifying an internally mixed aerosol composition. In contrast, larger particles (151 and 240 nm) exhibit a bi-modal effective density distribution during the daytime, indicating an external mixture of fresh BC and organic aerosols, but a unimodal distribution during the night, corresponding to an internal mixture of BC and organic aerosols. The smaller particles show a noticeable diurnal trend in the effective density distribution, with the highest effective density (1.70 g cm-3) occurring shortly after midnight and the lowest value (0.90 g cm-3) occurring during the afternoon, corresponding most likely to primary organic aerosols and BC, respectively. Both HGFs and VGFs measured are strongly size-dependent. HGFs increase with increasing particle size, indicating that the largest particles are more hygroscopic. VGFs decrease with increasing

  20. Formation and Growth of Sulfate Aerosols in the Presence of Hydrocarbons: Results from the 2013 Summer Oil Sands FOSSILs Field Campaign, Alberta, Canada

    NASA Astrophysics Data System (ADS)

    Amiri, N.; Ghahremaninezhad, R.; Rempillo, O. T.; Norman, A. L.

    2014-12-01

    Sulfur dioxide oxidation and the effect of oxidation products in formation and growth of aerosols have been studied widely. Despite this, significant gaps still exist in understanding the role of organic matter in SO2 oxidation. Organic molecules, such as Criegee radicals originating from biogenic sources, are expected to be important for SO2 oxidation in addition to organic molecules of anthropogenic origin. A study of SO2 and aerosol sulfate downwind of the oil sands region was conducted as part of the FOSSILS campaign in the summer of 2013 to better understand aerosol growth from SO2 oxidation in the presence of hydrocarbons and the distribution of sulfate in size-segregated aerosols. Hydrocarbons present in the atmosphere during the sampling campaign, collected using evacuated canisters, were characterized using a pre-concentration trap coupled to a GC-FID. The results from this campaign will be explored to determine SO2 oxidation pathways and the effects of oxidation products to aerosol formation and growth.

  1. Clouds, Aerosol, and Precipitation in the Marine Boundary Layer (CAP-MBL) Final Campaign Report

    SciTech Connect

    Wood, R.

    2016-01-01

    The extensive coverage of low clouds over the subtropical eastern oceans greatly impacts the current climate. In addition, the response of low clouds to changes in atmospheric greenhouse gases and aerosols is a major source of uncertainty, which thwarts accurate prediction of future climate change. Low clouds are poorly simulated in climate models, partly due to inadequate long-term simultaneous observations of their macrophysical and microphysical structure, radiative effects, and associated aerosol distribution in regions where their impact is greatest. The thickness and extent of subtropical low clouds is dependent on tight couplings between surface fluxes of heat and moisture, radiative cooling, boundary layer turbulence, and precipitation (much of which evaporates before reaching the ocean surface and is closely connected to the abundance of cloud condensation nuclei). These couplings have been documented as a result of past field programs and model studies. However, extensive research is still required to achieve a quantitative understanding sufficient for developing parameterizations, which adequately predict aerosol indirect effects and low cloud response to climate perturbations. This is especially true of the interactions between clouds, aerosol, and precipitation. These processes take place in an ever-changing synoptic environment that can confound interpretation of short time period observations.

  2. Comparing Aerosol Retrievals from Ground-Based Instruments at the Impact-Pm Field Campaign

    NASA Astrophysics Data System (ADS)

    Kupinski, M.; Bradley, C. L.; Kalashnikova, O. V.; Xu, F.; Diner, D. J.; Clements, C. B.; Camacho, C.

    2016-12-01

    Detection of aerosol types, components having different size and chemical composition, over urban areas is important for understanding their impact on health and climate. In particular, sustained contact with size-differentiated airborne particulate matter: PM10 and PM2.5 can lead to adverse health effects such as asthma attacks, heart and lung diseases, and premature mortality. Multi-angular polarimetric measurements have been advocated in recent years as an additional tool to better understand and retrieve the aerosol properties needed for improved predictions of aerosol impart on air quality and climate. We deployed the ground-based Multiangle SpectroPolarimetric Imager (GroundMSPI) for accurate spectropolarimetric and radiance measurements co-located with the AERONET CIMEL sun photometer and a Halo Doppler 18 m resolution lidar from San José State University at the Garland-Fresno Air Quality supersite in Fresno, CA on July 7 during the Imaging Polarimetric Assessment and Characterization of Tropospheric Particulate Matter (ImPACT-PM) field experiment. GroundMSPI sampled the atmospheric scattering phase function in and 90 degrees out of the principal plane every 15 minutes in an automated manner, utilizing the 2-axis gimbal mount in elevation and azimuth. The goal of this work is verify atmospheric measurement of GroundMSPI with the coincident CIMEL sun photometer and ground-based lidar. Diffuse-sky radiance measurements of GroundMSPI are compared with the CIMEL sun photometer throughout the day. AERONET aerosol parameters such as size, shape, and index of refraction as well as lidar aerosol extinction profiles will be used in a forward radiative transfer model to compare with GroundMSPI observations and optimize these parameters to best match GroundMSPI data.

  3. Overview of the Chemistry-Aerosol Mediterranean Experiment/Aerosol Direct Radiative Forcing on the Mediterranean Climate (ChArMEx/ADRIMED) summer 2013 campaign

    NASA Astrophysics Data System (ADS)

    Mallet, M.; Dulac, F.; Formenti, P.; Nabat, P.; Sciare, J.; Roberts, G.; Pelon, J.; Ancellet, G.; Tanré, D.; Parol, F.; di Sarra, A.; Alados, L.; Arndt, J.; Auriol, F.; Blarel, L.; Bourrianne, T.; Brogniez, G.; Chazette, P.; Chevaillier, S.; Claeys, M.; D'Anna, B.; Denjean, C.; Derimian, Y.; Desboeufs, K.; Di Iorio, T.; Doussin, J.-F.; Durand, P.; Féron, A.; Freney, E.; Gaimoz, C.; Goloub, P.; Gómez-Amo, J. L.; Granados-Muñoz, M. J.; Grand, N.; Hamonou, E.; Jankowiak, I.; Jeannot, M.; Léon, J.-F.; Maillé, M.; Mailler, S.; Meloni, D.; Menut, L.; Momboisse, G.; Nicolas, J.; Podvin, J.; Pont, V.; Rea, G.; Renard, J.-B.; Roblou, L.; Schepanski, K.; Schwarzenboeck, A.; Sellegri, K.; Sicard, M.; Solmon, F.; Somot, S.; Torres, B.; Totems, J.; Triquet, S.; Verdier, N.; Verwaerde, C.; Wenger, J.; Zapf, P.

    2015-07-01

    The Chemistry-Aerosol Mediterranean Experiment (ChArMEx; http://charmex.lsce.ipsl.fr) is a collaborative research program federating international activities to investigate Mediterranean regional chemistry-climate interactions. A special observing period (SOP-1a) including intensive airborne measurements was performed in the framework of the Aerosol Direct Radiative Forcing on the Mediterranean Climate (ADRIMED) project during the Mediterranean dry season over the western and central Mediterranean basins, with a focus on aerosol-radiation measurements and their modeling. The SOP-1a took place from 11 June to 5 July 2013. Airborne measurements were made by both the ATR-42 and F-20 French research aircraft operated from Sardinia (Italy) and instrumented for in situ and remote-sensing measurements, respectively, and by sounding and drifting balloons, launched in Minorca. The experimental set-up also involved several ground-based measurement sites on islands including two ground-based reference stations in Corsica and Lampedusa and secondary monitoring sites in Minorca and Sicily. Additional measurements including lidar profiling were also performed on alert during aircraft operations at EARLINET/ACTRIS stations at Granada and Barcelona in Spain, and in southern Italy. Remote sensing aerosol products from satellites (MSG/SEVIRI, MODIS) and from the AERONET/PHOTONS network were also used. Dedicated meso-scale and regional modelling experiments were performed in relation to this observational effort. We provide here an overview of the different surface and aircraft observations deployed during the ChArMEx/ADRIMED period and of associated modeling studies together with an analysis of the synoptic conditions that determined the aerosol emission and transport. Meteorological conditions observed during this campaign (moderate temperatures and southern flows) were not favorable to produce high level of atmospheric pollutants nor

  4. Chemical composition and sources of coastal marine aerosol particles during the 2008 VOCALS-REx campaign

    SciTech Connect

    Lee, Y. -N.; Springston, S.; Jayne, J.; Wang, J.; Hubbe, J.; Senum, G.; Kleinman, L.; Daum, P. H.

    2014-01-01

    The chemical composition of aerosol particles (Dp ≤ 1.5 μm) was measured over the southeast Pacific Ocean during the VAMOS (Variability of the American Monsoon Systems) Ocean-Cloud-Atmosphere-Land Study Regional Experiment (VOCALS-Rex) between 16 October and 15 November 2008 using the US Department of Energy (DOE) G-1 aircraft. The objective of these flights was to gain an understanding of the sources and evolution of these aerosols, and of how they interact with the marine stratus cloud layer that prevails in this region of the globe. Our measurements showed that the marine boundary layer (MBL) aerosol mass was dominated by non-sea-salt SO42−, followed by Na+, Cl, Org (total organics), NH4+, and NO3, in decreasing order of importance; CH3SO3 (MSA), Ca2+, and K+ rarely exceeded their limits of detection. Aerosols were strongly acidic with a NH4+ to SO42− equivalents ratio typically < 0.3. Sea-salt aerosol (SSA) particles, represented by NaCl, exhibited Cl deficits caused by both HNO3 and H2SO4, but for the most part were externally mixed with particles, mainly SO42−. SSA contributed only a small fraction of the total accumulation mode particle number concentration. It was inferred that all aerosol species (except SSA) were of predominantly continental origin because of their strong land-to-sea concentration gradient. Comparison of relative changes in median values suggests that (1) an oceanic source of NH3 is present between 72° W and 76° W, (2) additional organic aerosols from biomass burns or biogenic precursors were emitted from coastal regions south of 31° S, with possible cloud processing, and (3) free tropospheric (FT) contributions to MBL gas and aerosol

  5. Field calibration of multi-scattering correction factor for aethalometer aerosol absorption coefficient during CAPMEX Campaign, 2008

    NASA Astrophysics Data System (ADS)

    Kim, J. H.; Kim, S. W.; Yoon, S. C.; Park, R.; Ogren, J. A.

    2014-12-01

    Filter-based instrument, such as aethalometer, is being widely used to measure equivalent black carbon(EBC) mass concentration and aerosol absorption coefficient(AAC). However, many other previous studies have poited that AAC and its aerosol absorption angstrom exponent(AAE) are strongly affected by the multi-scattering correction factor(C) when we retrieve AAC from aethalometer EBC mass concentration measurement(Weingartner et al., 2003; Arnott et al., 2005; Schmid et al., 2006; Coen et al., 2010). We determined the C value using the method given in Weingartner et al. (2003) by comparing 7-wavelngth aethalometer (AE-31, Magee sci.) to 3-wavelength Photo-Acoustic Soot Spectrometer (PASS-3, DMT) at Gosan climate observatory, Korea(GCO) during Cheju ABC plume-asian monsoon experiment(CAPMEX) campaign(August and September, 2008). In this study, C was estimated to be 4.04 ± 1.68 at 532 nm and AAC retrieved with this value was decreased as approximately 100% as than that retrieved with soot case value from Weingartner et al (2003). We compared the AAC determined from aethalomter measurements to that from collocated Continuous Light Absorption Photometer (CLAP) measurements from January 2012 to December 2013 at GCO and found good agreement in both AAC and AAE. This result suggests the determination of site-specific C is crucially needed when we calculate AAC from aethalometer measurements.

  6. Aerosol Chemical Composition in Asian Continental Outflow during the TRACE-P Campaign: Comparison with PEM-West B

    NASA Technical Reports Server (NTRS)

    Dibb, Jack E.; Talbot, Robert W.; Scheuer, Eric M.; Seid, Garry; Avery, Melody A.; Singh, Hanwant B.

    2003-01-01

    Aerosol associated soluble ions and the radionuclide tracers (7)Be and (210)Pb were quantified in 414 filter samples collected in spring 2001 from the DC-8 during the Transport and Chemical Evolution over the Pacific (TRACE-P) campaign. Binning the data into near Asia (flights from Hong Kong and Japan) and remote Pacific (all other flights) revealed large enhancements of NO3(-), SO4(-), C2O4(-), NH4(+), K(+), Mg2(+), and Ca2(+) near Asia. The boundary layer and lower troposphere were most strongly influenced by continental outflow, and the largest enhancements were seen in Ca2(+) (a dust tracer) and NO3(-) (reflecting uptake of HNO3 onto the dust). Comparing the TRACE P near Asia bin with earlier results from the same region during PEM-West B (in 1994) shows at least twofold enhancements during TRACE P in most of the ions listed above. Calcium and NO3(-) were most enhanced in this comparison as well (more than sevenfold higher in the boundary layer and threefold higher in the lower troposphere). Independent estimation of Asian emissions of gaseous precursors of the aerosol-associated ions suggest only small changes between the two missions, and precipitation fields do not suggest any significant difference in the efficiency of the primary sink, precipitation scavenging. It thus appears that with the possible exception of dust, the enhancements of aerosol-associated species during TRACE P cannot be explained by stronger sources or weaker sinks. We argue that the enhancements largely reflect the fact that TRACE P focused on characterizing Asian outflow, and thus the DC-8 was more frequently flown into regions that were influenced by well-organized flow off the continent.

  7. Transmission Electron Microscopy Analysis of Tarball Formation and Volatility from Biomass-burning Aerosol Particles during the 2013 BBOP Campaign

    NASA Astrophysics Data System (ADS)

    Buseck, P. R.; Adachi, K.; Chand, D.; Kleinman, L. I.; Sedlacek, A. J., III

    2014-12-01

    Tar balls, a subset of organic aerosol that is characterized by spherical shape and amorphous composition, are presumed to be brown-carbon (BrC) particles that contribute to light absorption in the atmosphere. Because of their distinctive shapes, compositions, and lack of crystallinity, tar balls are uniquely identifiable using transmission electron microscopy (TEM). Using samples collected during BBOP, we performed a detailed investigation of their compositions, formation processes, and occurrence. They primarily originated from wildfires and are most abundant in relatively aged plumes (>several hours from emission). Their features are similar to those from Mexico measured during the 2006 MILAGRO campaign, but their number fractions are more abundant in the Idaho, Oregon, and Washington samples of BBOP. In order to determine the TB robustness with respect to heating, an experiment was carried out on a TEM grid containing a mixture of organic particles, nanosphere soot, and TBs during which the sample temperature was ramped from ~30 to 650 ºC. The TEM results collected at 30 and 600 ºC, the latter representing the filament temperature used by the AMS, indicate that material of lower volatility is lost by 600 ºC. Although there was some loss of material during the 15-minute temperature ramp, TBs were still present at the higher temperature. These preliminary findings suggest that the efficiency of AMS detection of TBs may be significantly less than unity and potentially translate to an underreporting of the aerosol mass for wildfire plumes. If tar balls have low AMS detection efficiencies, an underestimate in organic aerosol mass will result.

  8. Aerosol Chemical Composition in Asian Continental Outflow during the TRACE-P Campaign: Comparison with PEM-West B

    NASA Technical Reports Server (NTRS)

    Dibb, Jack E.; Talbot, Robert W.; Scheuer, Eric M.; Seid, Garry; Avery, Melody A.; Singh, Hanwant B.

    2003-01-01

    Aerosol associated soluble ions and the radionuclide tracers (7)Be and (210)Pb were quantified in 414 filter samples collected in spring 2001 from the DC-8 during the Transport and Chemical Evolution over the Pacific (TRACE-P) campaign. Binning the data into near Asia (flights from Hong Kong and Japan) and remote Pacific (all other flights) revealed large enhancements of NO3(-), SO4(-), C2O4(-), NH4(+), K(+), Mg2(+), and Ca2(+) near Asia. The boundary layer and lower troposphere were most strongly influenced by continental outflow, and the largest enhancements were seen in Ca2(+) (a dust tracer) and NO3(-) (reflecting uptake of HNO3 onto the dust). Comparing the TRACE P near Asia bin with earlier results from the same region during PEM-West B (in 1994) shows at least twofold enhancements during TRACE P in most of the ions listed above. Calcium and NO3(-) were most enhanced in this comparison as well (more than sevenfold higher in the boundary layer and threefold higher in the lower troposphere). Independent estimation of Asian emissions of gaseous precursors of the aerosol-associated ions suggest only small changes between the two missions, and precipitation fields do not suggest any significant difference in the efficiency of the primary sink, precipitation scavenging. It thus appears that with the possible exception of dust, the enhancements of aerosol-associated species during TRACE P cannot be explained by stronger sources or weaker sinks. We argue that the enhancements largely reflect the fact that TRACE P focused on characterizing Asian outflow, and thus the DC-8 was more frequently flown into regions that were influenced by well-organized flow off the continent.

  9. Radiative Energetics of Mineral Dust Aerosol over Zhangye China during the AMY 2008 Field Campaign

    NASA Astrophysics Data System (ADS)

    Hansell, R. A.; Tsay, S.; Ji, Q.; Hsu, C.; Bell, S.; Li, C.; Wang, C.

    2010-12-01

    In support of the DOE ARM program, NASA Goddard’s mobile ground-based laboratories (SMART-COMMIT) were deployed to Zhangye China (39.082°N; 100.276°E) from April-June 2008 as an ARM Ancillary Facility (AAF) to support the Asian Monsoon Year (AMY) field study. The primary objective at Zhangye, a semi-arid region located between the Taklimakan and Gobi deserts, was to both capture and characterize dust aerosol near the source region and to determine its direct aerosol radiative effects (DARE). To facilitate this study, the AAF’s Atmospheric Emitted Radiance Interferometer (AERI), a key instrument for spectrally characterizing the thermal IR, is employed to retrieve the daytime/nighttime dust IR aerosol optical thickness (AOT) for several notable dust events. Regional dust microphysical and mineralogy measurements are also used for developing a representative aerosol optical model of dust single-scattering properties. The retrieved AOT are then inputted into a 1-D radiative transfer model constrained by local measurements to evaluate dust’s local instantaneous shortwave (SW) and longwave (LW) DARE at the surface and top of the atmosphere (TOA) along with the heating rate profiles under cloud-free atmospheres. Comparisons of the SW DARE are made with a previous study over the same area using broadband data from thermal dome effect corrected pyranometers and the significance of the LW effects relative to the SW is examined. This study is part of an on-going effort to complete a global assessment of dust DARE for the major dust source regions of the world.

  10. Identifying precursors and aqueous organic aerosol formation pathways during the SOAS campaign

    NASA Astrophysics Data System (ADS)

    Sareen, Neha; Carlton, Annmarie G.; Surratt, Jason D.; Gold, Avram; Lee, Ben; Lopez-Hilfiker, Felipe D.; Mohr, Claudia; Thornton, Joel A.; Zhang, Zhenfa; Lim, Yong B.; Turpin, Barbara J.

    2016-11-01

    Aqueous multiphase chemistry in the atmosphere can lead to rapid transformation of organic compounds, forming highly oxidized, low-volatility organic aerosol and, in some cases, light-absorbing (brown) carbon. Because liquid water is globally abundant, this chemistry could substantially impact climate, air quality, and health. Gas-phase precursors released from biogenic and anthropogenic sources are oxidized and fragmented, forming water-soluble gases that can undergo reactions in the aqueous phase (in clouds, fogs, and wet aerosols), leading to the formation of secondary organic aerosol (SOAAQ). Recent studies have highlighted the role of certain precursors like glyoxal, methylglyoxal, glycolaldehyde, acetic acid, acetone, and epoxides in the formation of SOAAQ. The goal of this work is to identify additional precursors and products that may be atmospherically important. In this study, ambient mixtures of water-soluble gases were scrubbed from the atmosphere into water at Brent, Alabama, during the 2013 Southern Oxidant and Aerosol Study (SOAS). Hydroxyl (OH⚫) radical oxidation experiments were conducted with the aqueous mixtures collected from SOAS to better understand the formation of SOA through gas-phase followed by aqueous-phase chemistry. Total aqueous-phase organic carbon concentrations for these mixtures ranged from 92 to 179 µM-C, relevant for cloud and fog waters. Aqueous OH-reactive compounds were primarily observed as odd ions in the positive ion mode by electrospray ionization mass spectrometry (ESI-MS). Ultra high-resolution Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) spectra and tandem MS (MS-MS) fragmentation of these ions were consistent with the presence of carbonyls and tetrols. Products were observed in the negative ion mode and included pyruvate and oxalate, which were confirmed by ion chromatography. Pyruvate and oxalate have been found in the particle phase in many locations (as salts and complexes). Thus

  11. Interpreting Aerosol Sources and Seasonality over the Southeast United States with the GEOS-Chem Model: Lessons from the SEAC4rs Campaign

    NASA Astrophysics Data System (ADS)

    Kim, S.; Jacob, D. J.; Fisher, J. A.; Travis, K.; Zhu, L.; Yu, K.; Yantosca, R.; Payer Sulprizio, M.; Jimenez, J. L.; Campuzano Jost, P.; Dibb, J. E.; Froyd, K. D.; Liao, J.; Hair, J. W.; Butler, C. F.; Fenn, M. A.; Wiedinmyer, C.

    2014-12-01

    The factors driving the aerosol seasonal cycle in the Southeast United States is an open problem in atmospheric chemistry. Satellite studies show strong seasonality of aerosol optical depth (AOD) peaking in summer and collocated with biogenic emissions, suggesting strong organic aerosol (OA) influence. In contrast, surface station measurements show a weaker seasonal cycle, primarily driven by sulfate. Previous studies have attempted to reconcile this apparent disconnect between the satellite and surface data by hypothesizing various sources of aerosol aloft. Here we interpret data from the SEAC4RS aircraft campaign in 2013, together with EPA AQS surface station measurements and MODIS and AERONET AOD, in a high-resolution version of the GEOS-Chem chemical transport model (CTM) with detailed ozone-aerosol chemistry. We use the aircraft observations to examine the consistency between the satellite and surface aerosol data. We quantify the contributions of anthropogenic, biogenic, and open fire sources to the different aerosol species, and examine relationships between species and their precursors as constraints on emissions and chemistry. This provides new insights on the factors that control aerosol concentrations, seasonality, and long-term trends in the Southeast US.

  12. Extended Elemental Mixing State of Aerosols Collected during IOP2 of the GoAmazon Campaign

    NASA Astrophysics Data System (ADS)

    Fraund, M. W.; Pham, D.; Bonanno, D.; Harder, T.; China, S.; Pöhlker, C.; Wang, B.; Laskin, A.; Gilles, M. K.; Moffet, R.

    2016-12-01

    The complex and uncertain role of anthropogenic aerosols in climate is driven by the dependence of aerosol properties on individual particle composition. One of the barriers to accurate modeling of aerosols is determining how their particle-specific composition changes over time through reaction, condensation and coagulation. The particle-specific nature of these changes necessitates the use of single particle spectromicroscopy techniques. Here, we characterize this aging process and the effect of anthropogenic emissions on this process by analyzing aerosol samples collected around the Amazonian city of Manaus. Anthropogenic effects (e.g. soot, oxidants, SOx, NOx, etc.) are identified by collecting aerosol samples downwind of Manaus and comparing them with samples collected far from the city's influence. First, these samples are analyzed with scanning transmission x-ray microscopy (STXM). Afterwards the identical particles are analyzed again with scanning electron microscopy coupled with energy dispersive x-ray spectroscopy (SEM/EDX) to obtain the masses of 14 atmospherically relevant elements on a per-particle basis. The masses of C, N, and O are obtained via STXM and SEM/EDX provides masses of higher Z elements such as Na, Mg, P, S, Cl, K, Ca, Mn, Fe, Ni, and Zn. The two data sets were overlapped manually using pattern matching to combine the techniques on a per-particle basis. Previously established procedures for calculating a mixing state index are then applied. This mixing state parameterization was applied to 9 samples: 5 samples downwind of Manaus at site T3, 1 sample unaffected by Manaus at the ATTO site, and 3 samples downwind of ATTO at site ZF2. The mixing state of the relatively clean samples from ATTO and ZF2 showed a general trend towards internal mixing (χ > 0.8) whereas the T3 samples generally trended towards more externally mixed (χ <0.8). This combination of techniques lends itself to future work developing a molecular based mixing state which

  13. Analysis of charged aerosols in the mesosphere during the MASS/ECOMA rocket campaign

    NASA Astrophysics Data System (ADS)

    Knappmiller, Scott Robert

    In the polar summer mesosphere ice particles grow sufficiently large to scatter sunlight, giving rise to visible cloud displays called Noctilucent Clouds (NLC). In August of 2007, two sounding rockets were launched from the Andoya Rocket Range, Norway carrying the newly developed MASS instrument (Mesospheric Aerosol Sampling Spectrometer) to study NLC. The instrument detects charged aerosols in four different mass ranges on four pairs of biased collector plates, one set for positive particles and one set for negative particles. The first sounding rocket was launched into a Polar Mesospheric Summer echo (PMSE) and into a NLC on 3 August. The solar zenith angle was 93 degrees and NLC were seen in the previous hour at 83 km by the ALOMAR RMR lidar. NLC were also detected at the same altitude by rocket-borne photometer measurements. The data from the MASS instrument shows a negatively charged population with radii >3 nm in the 83--89 km altitude range, which is collocated with PMSE detected by the ALWIN radar. Smaller particles, 1--2 nm in radius with both positive and negative polarity were detected between 86--88 km. Positively charged particles <1 nm in radius were detected at the same altitude. This is the first time the charge number densities of positive and negative NLC particles have been measured simultaneously. A charging model is developed to investigate the coexistence of positively and negatively charged aerosols in the NLC environment as measured by the MASS instrument. Natanson's rate equations are used for the attachment of free electrons and ions and the model includes charging by photo-electron emission and photo-detachment. Although the MASS flight occurred during twilight conditions, the solar UV flux was still sufficient to affect the charge state of the aerosols. The calculations are done assuming three types of particles with different photo-electron charging properties: (1) Icy NLC particles, (2) Hematite particles of meteoric origin as

  14. Aerosol properties measured by MAX-DOAS in Gwangju during the DRAGON NE-Asia Campaign and comparison with AERONET and MODIS data sets

    NASA Astrophysics Data System (ADS)

    Chong, J.; Kim, Y. J.; Irie, H.; Kanaya, Y.; Shin, D.; Kim, K.; Lee, K.; Kim, J.; Song, C.

    2013-12-01

    Atmospheric aerosol interacts both directly and indirectly with the Earth's radiation budget and cause climate change. Aerosols also can act as sites for chemical reactions to take place (heterogeneous chemistry). In Asia, the Distributed Regional Aerosol Gridded Observation Networks (DRAGON) campaign for validation of satellite aerosol products and comparison/validation of ground-based aerosol retrievals had been conducted in Korea (DRAGON-Korea) from March to May 2012 for three months with 21 CIMEL sunphotometers, 2 Pandoras, a MAX-DOAS and a multichannel Raman Lidar system. Level 2.0 sunphotometer data (cloud screened and quality assured) at the Gwangju AERONET 321 site (35.2°N, 126.8°E, 52 m above sea level) were used for comparing aerosol optical depths (AODs) derived from the GIST MAX-DOAS observations. Information on O4 slant column densities at several different elevation angles is used to determine the atmospheric aerosol optical depth within the lower troposphere using the MAX-DOAS measurement data. Also, in order to evaluate satellite aerosol products, MODIS Terra satellite aerosol products were compared with the ground-based AERONET aerosol data at the 550 nm spectral wavelength. Significant linear relationship was resulted with a correlation coefficient larger than 0.66 between the sunphotometer measured AODs and GIST MAX-DOAS retrieved AODs values at 476 nm. There is significant linear relationship with a correlation coefficient larger than 0.79 between the sunphotometer measured AODs and MODIS Terra AODs at 550 nm. Aerosol extinction coefficient values from MAX-DOAS and Lidar system were compared. Results from sunphotometer and MAX-DOAS measurements can be used for validation of geostationary satellite measurement in the near future.

  15. Sources of black carbon aerosols in South Asia and surrounding regions during the Integrated Campaign for Aerosols, Gases and Radiation Budget (ICARB)

    SciTech Connect

    Kumar, R.; Barth, M. C.; Nair, V. S.; Pfister, G. G.; Babu, S. Suresh; Satheesh, S. K.; Moorthy, K. Krishna; Carmichael, G. R.; Lu, Z.; Streets, D. G.

    2015-01-01

    This study examines differences in the surface black carbon (BC) aerosol loading between the Bay of Bengal (BoB) and the Arabian Sea (AS) and identifies dominant sources of BC in South Asia and surrounding regions during March-May 2006 (Integrated Campaign for Aerosols, Gases and Radiation Budget, ICARB) period. A total of 13 BC tracers are introduced in the Weather Research and Forecasting Model coupled with Chemistry to address these objectives. The model reproduced the temporal and spatial variability of BC distribution observed over the AS and the BoB during the ICARB ship cruise and captured spatial variability at the inland sites. In general, the model underestimates the observed BC mass concentrations. However, the model-observation discrepancy in this study is smaller compared to previous studies. Model results show that ICARB measurements were fairly well representative of the AS and the BoB during the pre-monsoon season. Elevated BC mass concentrations in the BoB are due to 5 times stronger influence of anthropogenic emissions on the BoB compared to the AS. Biomass burning in Burma also affects the BoB much more strongly than the AS. Results show that anthropogenic and biomass burning emissions, respectively, accounted for 60 and 37% of the average +/- standard deviation (representing spatial and temporal variability) BC mass concentration (1341 +/- 2353 ng m(-3)) in South Asia. BC emissions from residential (61 %) and industrial (23 %) sectors are the major anthropogenic sources, except in the Himalayas where vehicular emissions dominate. We find that regional-scale transport of anthropogenic emissions contributes up to 25% of BC mass concentrations in western and eastern India, suggesting that surface BC mass concentrations cannot be linked directly to the local emissions in different regions of South Asia.

  16. Sources of black carbon aerosols in South Asia and surrounding regions during the Integrated Campaign for Aerosols, Gases and Radiation Budget (ICARB)

    DOE PAGES

    Kumar, R.; Barth, M. C.; Nair, V. S.; ...

    2015-05-19

    This study examines differences in the surface black carbon (BC) aerosol loading between the Bay of Bengal (BoB) and the Arabian Sea (AS) and identifies dominant sources of BC in South Asia and surrounding regions during March–May 2006 (Integrated Campaign for Aerosols, Gases and Radiation Budget, ICARB) period. A total of 13 BC tracers are introduced in the Weather Research and Forecasting Model coupled with Chemistry to address these objectives. The model reproduced the temporal and spatial variability of BC distribution observed over the AS and the BoB during the ICARB ship cruise and captured spatial variability at the inlandmore » sites. In general, the model underestimates the observed BC mass concentrations. However, the model–observation discrepancy in this study is smaller compared to previous studies. Model results show that ICARB measurements were fairly well representative of the AS and the BoB during the pre-monsoon season. Elevated BC mass concentrations in the BoB are due to 5 times stronger influence of anthropogenic emissions on the BoB compared to the AS. Biomass burning in Burma also affects the BoB much more strongly than the AS. Results show that anthropogenic and biomass burning emissions, respectively, accounted for 60 and 37% of the average ± standard deviation (representing spatial and temporal variability) BC mass concentration (1341 ± 2353 ng m-3) in South Asia. BC emissions from residential (61%) and industrial (23%) sectors are the major anthropogenic sources, except in the Himalayas where vehicular emissions dominate. We find that regional-scale transport of anthropogenic emissions contributes up to 25% of BC mass concentrations in western and eastern India, suggesting that surface BC mass concentrations cannot be linked directly to the local emissions in different regions of South Asia.« less

  17. Aerosol properties computed from aircraft-based observations during the ACE- Asia campaign. 2; A case study of lidar ratio closure and aerosol radiative effects

    NASA Technical Reports Server (NTRS)

    Kuzmanoski, Maja; Box, M. A.; Schmid, B.; Box, G. P.; Wang, J.; Russell, P. B.; Bates, D.; Jonsson, H. H.; Welton, Ellsworth J.; Flagan, R. C.

    2005-01-01

    For a vertical profile with three distinct layers (marine boundary, pollution and dust), observed during the ACE-Asia campaign, we carried out a comparison between the modeled lidar ratio vertical profile and that obtained from collocated airborne NASA AATS-14 sunphotometer and shipborne Micro-Pulse Lidar (MPL) measurements. Vertically resolved lidar ratio was calculated from two size distribution vertical profiles - one obtained by inversion of sunphotometer-derived extinction spectra, and one measured in-situ - combined with the same refractive index model based on aerosol chemical composition. The aerosol model implies single scattering albedos of 0.78 - 0.81 and 0.93 - 0.96 at 0.523 microns (the wavelength of the lidar measurements), in the pollution and dust layers, respectively. The lidar ratios calculated from the two size distribution profiles have close values in the dust layer; they are however, significantly lower than the lidar ratios derived from combined lidar and sunphotometer measurements, most probably due to the use of a simple nonspherical model with a single particle shape in our calculations. In the pollution layer, the two size distribution profiles yield generally different lidar ratios. The retrieved size distributions yield a lidar ratio which is in better agreement with that derived from lidar/sunphotometer measurements in this layer, with still large differences at certain altitudes (the largest relative difference was 46%). We explain these differences by non-uniqueness of the result of the size distribution retrieval and lack of information on vertical variability of particle refractive index. Radiative transfer calculations for this profile showed significant atmospheric radiative forcing, which occurred mainly in the pollution layer. We demonstrate that if the extinction profile is known then information on the vertical structure of absorption and asymmetry parameter is not significant for estimating forcing at TOA and the surface

  18. Sources of black carbon aerosols in South Asia and surrounding regions during the Integrated Campaign for Aerosols, Gases and Radiation Budget (ICARB)

    SciTech Connect

    Kumar, R.; Barth, M. C.; Nair, V. S.; Pfister, G. G.; Suresh Babu, S.; Satheesh, S. K.; Moorthy, K. Krishna; Carmichael, G. R.; Lu, Z.; Streets, D. G.

    2015-05-19

    This study examines differences in the surface black carbon (BC) aerosol loading between the Bay of Bengal (BoB) and the Arabian Sea (AS) and identifies dominant sources of BC in South Asia and surrounding regions during March–May 2006 (Integrated Campaign for Aerosols, Gases and Radiation Budget, ICARB) period. A total of 13 BC tracers are introduced in the Weather Research and Forecasting Model coupled with Chemistry to address these objectives. The model reproduced the temporal and spatial variability of BC distribution observed over the AS and the BoB during the ICARB ship cruise and captured spatial variability at the inland sites. In general, the model underestimates the observed BC mass concentrations. However, the model–observation discrepancy in this study is smaller compared to previous studies. Model results show that ICARB measurements were fairly well representative of the AS and the BoB during the pre-monsoon season. Elevated BC mass concentrations in the BoB are due to 5 times stronger influence of anthropogenic emissions on the BoB compared to the AS. Biomass burning in Burma also affects the BoB much more strongly than the AS. Results show that anthropogenic and biomass burning emissions, respectively, accounted for 60 and 37% of the average ± standard deviation (representing spatial and temporal variability) BC mass concentration (1341 ± 2353 ng m-3) in South Asia. BC emissions from residential (61%) and industrial (23%) sectors are the major anthropogenic sources, except in the Himalayas where vehicular emissions dominate. We find that regional-scale transport of anthropogenic emissions contributes up to 25% of BC mass concentrations in western and eastern India, suggesting that surface BC mass concentrations cannot be linked directly to the local emissions in different regions of South Asia.

  19. Sources of black carbon aerosols in South Asia and surrounding regions during the Integrated Campaign for Aerosols, Gases and Radiation Budget (ICARB)

    NASA Astrophysics Data System (ADS)

    Kumar, R.; Barth, M. C.; Nair, V. S.; Pfister, G. G.; Babu, S. Suresh; Satheesh, S. K.; Krishna Moorthy, K.; Carmichael, G. R.; Lu, Z.; Streets, D. G.

    2015-05-01

    This study examines differences in the surface black carbon (BC) aerosol loading between the Bay of Bengal (BoB) and the Arabian Sea (AS) and identifies dominant sources of BC in South Asia and surrounding regions during March-May 2006 (Integrated Campaign for Aerosols, Gases and Radiation Budget, ICARB) period. A total of 13 BC tracers are introduced in the Weather Research and Forecasting Model coupled with Chemistry to address these objectives. The model reproduced the temporal and spatial variability of BC distribution observed over the AS and the BoB during the ICARB ship cruise and captured spatial variability at the inland sites. In general, the model underestimates the observed BC mass concentrations. However, the model-observation discrepancy in this study is smaller compared to previous studies. Model results show that ICARB measurements were fairly well representative of the AS and the BoB during the pre-monsoon season. Elevated BC mass concentrations in the BoB are due to 5 times stronger influence of anthropogenic emissions on the BoB compared to the AS. Biomass burning in Burma also affects the BoB much more strongly than the AS. Results show that anthropogenic and biomass burning emissions, respectively, accounted for 60 and 37% of the average ± standard deviation (representing spatial and temporal variability) BC mass concentration (1341 ± 2353 ng m-3) in South Asia. BC emissions from residential (61%) and industrial (23%) sectors are the major anthropogenic sources, except in the Himalayas where vehicular emissions dominate. We find that regional-scale transport of anthropogenic emissions contributes up to 25% of BC mass concentrations in western and eastern India, suggesting that surface BC mass concentrations cannot be linked directly to the local emissions in different regions of South Asia.

  20. Aerosol concentration measurements with a lidar ceilometer: results of a one year measuring campaign

    NASA Astrophysics Data System (ADS)

    Muenkel, Christoph; Emeis, Stefan; Mueller, Wolfgang J.; Schaefer, Klaus P.

    2004-02-01

    The Vaisala ceilometer CT25K is an eye-safe commercial lidar mainly used to report cloud base heights and vertical visibility for aviation safety purposes. Compared to ceilometers with biaxial optics, its single lens design provides a higher signal-to-noise ratio for lidar return signals from distances below about 600 m, thus increasing its abilities to examine the mixing layer. A CT25K ceilometer took part in the environmental research project VALIUM at the Lower Saxony State Agency for Ecology (NLO) in Hannover, Germany, investigating the air pollution in an urban surrounding with various sensors. Lidar return signals are reported every 15 s with a height resolution of 15 m. This paper covers two aspects of the interpretation of these signals. The aerosol backscatter of the atmosphere up to 30 m is compared to the PM10 concentration reported by an in situ sensor every 30 minutes, and the results are interpreted in respect of meteorological parameters such as humidity, temperature, wind, and global radiation. With relative humidity values below 62 % and no rain present the correlation between ceilometer backscatter and PM10 values is good enough to qualify standard ceilometers as instruments for a quantitative analysis of the atmospheric aerosol contents. Backscatter values up to 1000 m height are presented that allow an estimation of the convective boundary layer top in dry weather situations. The atmospheric boundary layer structures derived from ceilometer data are compared to those reported by a SODAR and a RASS that also took part in the VALIUM research project. Finally the backscatter data quality of a double lens ceilometer is compared to that of the single lens CT25K ceilometer to investigate to what extent these lidar systems are also able to report aerosol concentration.

  1. Highlights from 4STAR Sky-Scanning Retrievals of Aerosol Intensive Optical Properties from Multiple Field Campaigns with Detailed Comparisons of SSA Reported During SEAC4RS

    NASA Technical Reports Server (NTRS)

    Dunagan, Stephen E.

    2016-01-01

    The 4STAR (Spectrometer for Sky-Scanning, Sun-Tracking Atmospheric Research) instrument combines airborne sun tracking capabilities of the Ames Airborne Tracking Sun Photometer (AATS-14) with AERONET (Aerosol Robotic Network)-like sky-scanning capability and adds state-of-the-art fiber-coupled grating spectrometry to yield hyperspectral measurements of direct solar irradiance and angularly resolved sky radiance. The combination of sun-tracking and sky-scanning capability enables retrievals of wavelength-dependent aerosol optical depth (AOD), mode-resolved aerosol size distribution (SD), asphericity, and complex refractive index, and thus also the scattering phase function, asymmetry parameter, single-scattering albedo (SSA), and absorption aerosol optical thickness (AAOT). From 2012 to 2014 4STAR participated in four major field campaigns: the U.S. Dept. of Energy's TCAP (Two-Column Aerosol Project) I & II campaigns, and NASA's SEAC4RS (Studies of Emissions, Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys) and ARISE (Arctic Radiation - IceBridge Sea & Ice Experiment) campaigns. Establishing a strong performance record, 4STAR operated successfully on all flights conducted during each of these campaigns. Sky radiance spectra from scans in either constant azimuth (principal plane) or constant zenith angle (almucantar) were interspersed with direct beam measurements during level legs. During SEAC4RS and ARISE, 4STAR airborne measurements were augmented with flight-level albedo from the collocated Shortwave Spectral Flux Radiometer (SSFR) providing improved specification of below-aircraft radiative conditions for the retrieval. Calibrated radiances and retrieved products will be presented with particular emphasis on detailed comparisons of ambient SSA retrievals and measurements during SEAC4RS from 4STAR, AERONET, HSRL2 (High Spectral Resolution Lidar), and from in situ measurements.

  2. Tropospheric Vertical Profiles of Aerosol Optical, Microphysical and Concentration Properties in the Frame of the Hygra-CD Campaign (Athens, Greece 2014): A Case Study of Long-Range Transport of Mixed Aerosols

    NASA Astrophysics Data System (ADS)

    Papayannis, Alexandros; Argyrouli, Athina; Müller, Detlef; Tsaknakis, Georgios; Kokkalis, Panayotis; Binietoglou, Ioannis; Kazadzis, Stelios; Solomos, Stavros; Amiridis, Vassilis

    2016-06-01

    Combined multi-wavelength aerosol Raman lidar and sun photometry measurements were performed during the HYGRA-CD campaign over Athens, Greece during May-June 2014. The retrieved aerosol optical properties (3 aerosol backscatter at 355-532-1064 nm and 2 aerosol extinction profiles at 355-532 nm) were used as input to an inversion code to retrieve the aerosol microphysical properties (effective radius reff and number concentration N) using regularization techniques. Additionally, the volume concentration profile was derived for fine particles using the LIRIC code. In this paper we selected a complex case study of long-range transport of mixed aerosols (biomass burning particles mixed with dust) arriving over Athens between 10-12 June 2014 in the 1.5-4 km height. Between 2-3 km height we measured mean lidar ratios (LR) ranging from 45 to 58 sr (at 355 and 532 nm), while the Ångström exponent (AE) aerosol extinction-related values (355nm/532nm) ranged between 0.8-1.3. The retrieved values of reff and N ranged from 0.19±0.07 to 0.22±0.07 μm and 460±230 to 2200±2800 cm-3, respectively. The aerosol linear depolarization ratio (δ) at 532 nm was lower than 5-7% (except for the Saharan dust cases, where δ~10-15%).

  3. Formation of semivolatile inorganic aerosols in the Mexico City Metropolitan Area during the MILAGRO campaign

    NASA Astrophysics Data System (ADS)

    Karydis, V. A.; Tsimpidi, A. P.; Lei, W.; Molina, L. T.; Pandis, S. N.

    2011-12-01

    One of the most challenging tasks for chemical transport models (CTMs) is the prediction of the formation and partitioning of the major semi-volatile inorganic aerosol components (nitrate, chloride, ammonium) between the gas and particulate phases. In this work the PMCAMx-2008 CTM, which includes the recently developed aerosol thermodynamic model ISORROPIA-II, is applied in the Mexico City Metropolitan Area in order to simulate the formation of the major inorganic aerosol components. The main sources of SO2 (such as the Miguel Hidalgo Refinery and the Francisco Perez Rios Power Plant) in the Mexico City Metropolitan Area (MCMA) are located in Tula, resulting in high predicted PM1 (particulate matter with diameter less than 1 μm) sulfate concentrations (over 25 μg m-3) in that area. The average predicted PM1 nitrate concentrations are up to 3 μg m-3 (with maxima up to 11 μg m-3) in and around the urban center, mostly produced from local photochemistry. The presence of calcium coming from the Tolteca area (7 μg m-3) as well as the rest of the mineral cations (1 μg m-3 potassium, 1 μg m-3 magnesium, 2 μg m-3 sodium, and 3 μg m-3 calcium) from the Texcoco Lake resulted in the formation of a significant amount of aerosol nitrate in the coarse mode with concentrations up to 3 μg m-3 over these areas. PM1-10 (particulate matter with diameter between 1 and 10 μm) chloride is also high and its concentration exceeds 2 μg m-3 in Texcoco Lake. PM1 ammonium concentrations peak at the center of Mexico City (2 μg m-3) and the Tula vicinity (2.5 μg m-3). The performance of the model for the major inorganic PM components (sulfate, ammonium, nitrate, chloride, sodium, calcium, and magnesium) is encouraging. At the T0 measurement site, located in the Mexico City urban center, the average measured values of PM1 sulfate, nitrate, ammonium, and chloride are 3.5 μg m-3, 3.5 μg m-3, 2.1 μg m-3, and 0.36 μg m-3, respectively. The corresponding predicted values are 3.7

  4. Estimation of the microphysical aerosol properties over Thessaloniki, Greece, during the SCOUT-O3 campaign with the synergy of Raman lidar and Sun photometer data

    NASA Astrophysics Data System (ADS)

    Balis, D.; Giannakaki, E.; Müller, D.; Amiridis, V.; Kelektsoglou, K.; Rapsomanikis, S.; Bais, A.

    2010-04-01

    An experimental campaign was held at Thessaloniki, Greece (40.6°N, 22.9°E), in July 2006, in the framework of the integrated project Stratosphere-Climate Links with Emphasis on the Upper Troposphere and Lower Stratosphere (SCOUT-O3). One of the main objectives of the campaign was to determine the local aerosol properties and their impact on the UV irradiance at the Earth's surface. In this article, we present vertically resolved microphysical aerosol properties retrieved from the inversion of optical data that were obtained from a combined one-wavelength Raman/two-wavelength backscatter lidar system and a CIMEL Sun photometer. A number of assumptions were undertaken to overcome the limitations of the existing optical input data needed for the retrieval of microphysical properties. We found acceptable agreement with Aerosol Robotic Network retrievals for the fine-mode particle effective radius, which ranged between 0.11 and 0.19 for the campaign period. It is shown that under complex layering of the aerosols, general assumptions may result in unrealistic retrievals, especially in the presence of aged smoke aerosols. Furthermore, with this instrument setup, the inversion algorithm can also be applied successfully for the complex refractive index in cases of vertically homogeneous layers of continental polluted aerosols. For these inversion cases, the vertically resolved retrievals for the single-scattering albedo resulted in values around 0.9 at 532 nm, which were in very good agreement with estimates from airborne in situ observations obtained in the vicinity of the lidar site.

  5. Optical, physical, and chemical properties of springtime aerosol over Barrow Alaska in 2008

    SciTech Connect

    Shantz, Nicole C.; Gultepe, Ismail; Andrews, Elisabeth; Earle, Michael; MacDonald, A. M.; Liu, Peter S.K.; Leaitch, W. R.

    2014-03-06

    Airborne observations from four flights during the 2008 Indirect and Semi-Direct Aerosol Campaign (ISDAC) are used to examine some cloud-free optical, physical, and chemical properties of aerosol particles in the springtime Arctic troposphere. The number concentrations of particles larger than 0.12 μm (Na>120), important for light extinction and cloud droplet formation, ranged from 15 to 2260 cm-3, with the higher Na>120 cases dominated by measurements from two flights of long-range transported biomass burning (BB) aerosols. The two other flights examined here document a relatively clean aerosol and an Arctic Haze aerosol impacted by larger particles largely composed of dust. For observations from the cleaner case and the BB cases, the particle light scattering coefficients at low relative humidity (RH<20%) increased nonlinearly with increasing Na>120, driven mostly by an increase in mean sizes of particles with increasing Na>120 (BB cases). For those three cases, particle light absorption coefficients also increased nonlinearly with increasing Na>120 and linearly with increasing submicron particle volume concentration. In addition to black carbon, brown carbon was estimated to have increased light absorption coefficients by 27% (450 nm wavelength) and 14% (550 nm) in the BB cases. For the case with strong dust influence, the absorption relative to submicron particle volume was small compared with the other cases. There was a slight gradient of Passive Cavity Aerosol Spectrometer Probe (PCASP) mean volume diameter (MVD) towards smaller sizes with increasing height, which suggests more scavenging of the more elevated particles, consistent with a typically longer lifetime of particles higher in the atmosphere. However, in approximately 10% of the cases, the MVD increased (>0.4 μm) with increasing altitude, suggesting transport of larger fine particle mass (possibly coarse particle mass) at high levels over the Arctic. This may be because of transport of

  6. Temporal consistency of lidar observations during aerosol transport events in the framework of the ChArMEx/ADRIMED campaign at Minorca in June 2013

    NASA Astrophysics Data System (ADS)

    Chazette, Patrick; Totems, Julien; Ancellet, Gérard; Pelon, Jacques; Sicard, Michaël

    2016-03-01

    We performed synergetic daytime and nighttime active and passive remote-sensing observations at Minorca (Balearic Islands, Spain), over more than 3 weeks during the Chemistry-Aerosol Mediterranean Experiment/Aerosol Direct Radiative Effect in the Mediterranean (ChArMEx/ADRIMED) special observation period (SOP 1a, June-July 2013). We characterized the aerosol optical properties and type in the low and middle troposphere using an automated procedure combining Rayleigh-Mie-Raman lidar (355, 387 and 407 nm) with depolarization (355 nm) and AERONET Cimel® sun-photometer data. Results show a high variability due to varying dynamical forcing. The mean column-averaged lidar backscatter-to-extinction ratio (BER) was close to 0.024 sr-1 (lidar ratio of ˜ 41.7 sr), with a large dispersion of ±33 % over the whole observation period due to changing atmospheric transport regimes and aerosol sources. The ground-based remote-sensing measurements, coupled with satellite observations, allowed the documentation of (i) dust particles up to 5 km (above sea level) in altitude originating from Morocco and Algeria from 15 to 18 June with a peak in aerosol optical thickness (AOT) of 0.25 ± 0.05 at 355 nm, (ii) a long-range transport of biomass burning aerosol (AOT = 0.18 ± 0.16) related to North American forest fires detected from 26 to 28 June 2013 by the lidar between 2 and 7 km and (iii) mixture of local sources including marine aerosol particles and pollution from Spain. During the biomass burning event, the high value of the particle depolarization ratio (8-14 %) may imply the presence of dust-like particles mixed with the biomass burning aerosols in the mid-troposphere. For the field campaign period, we also show linearity with SEVIRI retrievals of the aerosol optical thickness despite 35 % relative bias, which is discussed as a function of aerosol type.

  7. Variability of fine and coarse aerosol over the Western Mediterranean Basin during the Minerva 2015 research cruise campaign

    NASA Astrophysics Data System (ADS)

    Castagna, Jessica; Carbone, Francesco; Naccarato, Attilio; Moretti, Sacha; Esposito, Giulio; Bencardino, Mariantonia; D'Amore, Francesco; Sprovieri, Francesca; Pirrone, Nicola

    2016-04-01

    The Mediterranean Basin, due to its semi-enclosed configuration, is heavily affected by air pollution and it is becoming, in the last years, a region of particular interest of study for its implications regarding both health effects and environmental impacts. The area is surrounded by a densely populated as well as industrialized coast, and even affected by natural sources. So, it is important to know how the various sources contributes to increase air pollution levels and discriminate among them. With special regard to aerosol pollution, natural sources, like Saharan dust, volcanoes, and fires, as well as anthropogenic sources, such as industry, road and marine traffic, and fuel combustion from heating, can equally increase the values of this dangerous pollutant. While on the land we can find numerous monitoring sites, there are not continuous measurements on the sea. For this reason, since 2000 the Institute of Atmospheric Pollution of the National Research Council (CNR-IIA) is conducting regular oceanographic campaigns of measurements in the Mediterranean Sea. In this context, here we report the results obtained during the last cruise campaign, which took place in the Western Mediterranean sector and was conducted on-board the Italian research vessel Minerva during summer 2015 (from June 27th to July 13th). Fine (PM2.5) and Coarse (PM2.5-10) particulate size fractions were collected on PTFE membrane filters (Advantec MFS) and their mass concentrations determined gravimetrically. Successively, all the filters were digested with a mixture of HNO3/H2O2 in an microwaves digestion system and then analyzed by ICP-MS for the determination of the major and trace elements. Outcomes regarding the particulate mass concentration, the content and the distribution of the analyzed elements over both PM size fractions will be discussed taking into account potential contributing sources as well as different meteorological conditions.

  8. Surface Measurements of dust/local aerosol properties over Northern China during 2008 China-US joined dust field campaign

    NASA Astrophysics Data System (ADS)

    Wang, X.; Huang, J.

    2009-12-01

    The objective of this study is to understand the detailed characteristics and underlying mechanisms of aerosol physical and optical parameters over China Loess Plateau and its potential impacts on the regional/global climate. In order to characterize the emission, transport, and removal of atmospheric pollutants emitted from East Asia, the 2008 China-US joined field campaign are conducted from late April to May 2008 focused specifically on the Asian direct measurements of dust and pollution transport, following the plume from the Northern China which from the Taklamakan desert and Gobi desert to the Eastern Pacific and into North America. Such measurements are crucial to understanding how the dust and the pollution plume (including black carbon) are modified as their age. Three sites involved this campaign, including one permanent site (Semi-Arid Climate & Environment Observatory of Lanzhou University (SACOL)) (located in Yuzhong, 35.95N/104.1E), one SACOL's Mobile Facility (SMF) (deployed in Jintai, 37.57N/104.23E) and the U.S. Department of Energy Atmospheric Radiation Measurements(ARM) Ancillary Facility (AAF mobile laboratories, SMART-COMMIT) (deployed in Zhangye, 39.08N/100.27E). Results indicate that the dust plumes are transported from the surface to a long distance from their sources have a significant influence on the air quality in the study area. The meteorological analysis indicates that these polluted layers are not from local sources during dust plume and this large-scale transport of dust and pollutants remains a major uncertainty in quantifying the global effect of emissions from Northern China.

  9. Formation of semivolatile inorganic aerosols in the mexico city metropolitan area during the milagro campaign

    NASA Astrophysics Data System (ADS)

    Karydis, V. A.; Tsimpidi, A. P.; Lei, W.; Molina, L. T.; Pandis, S. N.

    2011-08-01

    One of the most challenging tasks for chemical transport models (CTMs) is the prediction of the formation and partitioning of the major semi-volatile inorganic aerosol components (nitrate, chloride, ammonium) between the gas and particulate phases. In this work the PMCAMx-2008 CTM, which includes the recently developed aerosol thermodynamic model ISORROPIA-II, is applied in the Mexico City Metropolitan Area in order to simulate the formation of the major inorganic aerosol components. The main sources of SO2 (such as the Miguel Hidalgo Refinery and the Francisco Perez Rios Power Plant) in the Mexico City Metropolitan Area (MCMA) are located in Tula, resulting in high predicted PM1 sulfate concentrations (over 25 μg m-3) in that area. The average predicted PM1 nitrate concentrations are up to 3 μg m-3 (with maxima up to 11 μg m-3) in and around the urban center, mostly produced from local photochemistry. The presence of calcium coming from the Tolteca area (7 μg m-3) as well as the rest of the mineral cations (1 μg m-3 potassium, 1 μg m-3 magnesium, 2 μg m-3 sodium, and 3 μg m-3 calcium) from the Texcoco Lake resulted in the formation of a significant amount of aerosol nitrate in the coarse mode with concentrations up to 3 μg m-3 over these areas. PM1-10 chloride is also high and its concentration exceeds 2 μg m-3 in Texcoco Lake. PM ammonium concentrations peak at the center of Mexico City (2 μg m-3) and the Tula vicinity (2.5 μg m-3). The performance of the model for the major inorganic PM components (sulfate, ammonium, nitrate, chloride, sodium, calcium, and magnesium) is encouraging. At T0, the average measured values of PM1 sulfate, nitrate, ammonium, and chloride are 3.6 μg m-3, 3.6 μg m-3, 2.1 μg m-3, and 0.35 μg m-3 respectively. The corresponding predicted values are 3.7 μg m-3, 2.8 μg m-3, 1.7 μg m-3, and 0.25 μg m-3. Additional improvements are possible by (i) using a day-dependent emission inventory, (ii) improving the performance of

  10. Composition of Stratospheric Aerosol Particles collected during the SOLVE campaign 2000

    NASA Astrophysics Data System (ADS)

    Schütze, Katharina; Nathalie, Benker; Martin, Ebert; Ralf, Weigel; Wilson James, C.; Stephan, Borrmann; Stephan, Weinbruch

    2016-04-01

    Stratospheric Aerosol particles were collected during the SAGE III Ozone loss and validation Experiment (SOLVE) in January-March 2000 in Kiruna/ Sweden onboard the scientific ER-2 aircraft with the Multi-Sample Aerosol Collection System. The particles are deposited on Cu transmission electron microscopy (TEM) grids. Particles of six samples from different flights (including one PSC sample) were analyzed by TEM and Energy Dispersive X-ray detection (EDX) regarding their size, chemical composition and morphology. Most particles are sulfates (formed from droplets of sulfuric acid) which are not resistant to the electron beam. In addition, refractory particles in the size range of 100-500 nm are found. They are either embedded in the sulfates or occur as single particles. The refractory particles are mainly carbonaceous showing only C and O as major peaks in their X-ray spectra. Some particles contain minor amounts of Si and Fe. Both, the O/C (median from 0.10-0.40), as well as Si/C (median from 0.05-0.32) ratios are increasing with time, from the middle of January to the end of February. The largest Fe/C ratio (median: 0.37) is found in a sample of the end of January. Based on the nanostructure and the absence of potassium as a tracer, biomass burning can be excluded as a source. Soot from diesel engines as well as from aircrafts show a nanostructure which is not found in the refractory particles. Due to the fact that large volcanic eruptions, which introduced material directly into the stratosphere, were missing since the eruption of Mt. Pinatubo in 1991, they are a very unlikely source of the refractory particles. The most likely source of the refractory particles is thus extraterrestrial material.

  11. Characteristics of aerosol optical properties and total amount of trace gases over Korea during the 2015 MAPS-Seoul campaign using AERONET and Pandora spectrometer

    NASA Astrophysics Data System (ADS)

    Lee, S.; Kim, J.; Choi, M.; Kim, W.; Lee, H.; Kim, J. H.; Chong, H.; Koo, J. H.; Holben, B. N.; Eck, T. F.; Herman, J. R.; Abuhassan, N.; Ahn, J. Y.; Park, J.; Hong, J.; Kim, S. K.

    2016-12-01

    To investigate characteristics of air quality and enhance the performance of the air quality model prediction and satellite retrieval, Korea-US Air Quality (KORUS-AQ) campaign was conducted over Korea in May-June, 2016. As pre-campaign of the KORUS-AQ, Megacity Air Pollution Studies (MAPS)-Seoul campaign was held from May 18 to June 14, 2015. During this campaign, eight AErosol RObotic NETwork (AERONET) sunphotometers and six Pandora spectrometers observed the aerosol optical properties and total column density of O3 and NO2 over Korea, respectively. Using these data set, we examine the general spatiotemporal characteristic of aerosol optical properties and some trace gases in South Korea. Mean aerosol optical depth (AOD) at 550nm at Seoul (megacity region) and Gosan (coastal region) are 0.338 and 0.214 respectively during MAPS campaign, which are quite lower values compare to other recent years (2011 to 2014); The range of mean AOD in the same period is 0.557-0.684 at Seoul and 0.447-0.618 at Gosan. The reason of low AOD during MAPS period is not clearly understood yet. In this period, most of AERONET sites show the black carbon dominance except Gosan, showing a dominance of non-absorbing particles. This looks because the Gosan site is affected by the relatively clean maritime air-mass. Pandora O3 measurements have low spatial variability, but NO2 measurements shows larger spatiotemporal variability. Pandora total O3 vertical column density (VCD) shows a good agreement OMI O3 VCD (R > 0.9) probably due to low spatial variability of O3, In the contrast, Pandora total NO2 VCD does not much correlates with OMI NO2 VCDs. In addition to high variability of NO2, the influence of regional aerosol optical properties on the estimation of total NO2 VCD seems another reason to explain the poor relationship between Pandora and OMI NO2 VCD. To investigate the effect of aerosol optical properties on total NO2 VCD, AOD, single scattering albedo and fine mode fraction from

  12. Simulations of organic aerosol concentrations in Mexico City using the WRF-CHEM model during the MCMA-2006/MILAGRO campaign

    NASA Astrophysics Data System (ADS)

    Li, G.; Zavala, M.; Lei, W.; Tsimpidi, A. P.; Karydis, V. A.; Pandis, S. N.; Canagaratna, M. R.; Molina, L. T.

    2011-04-01

    Organic aerosol concentrations are simulated using the WRF-CHEM model in Mexico City during the period from 24 to 29 March in association with the MILAGRO-2006 campaign. Two approaches are employed to predict the variation and spatial distribution of the organic aerosol concentrations: (1) a traditional 2-product secondary organic aerosol (SOA) model with non-volatile primary organic aerosols (POA); (2) a non-traditional SOA model including the volatility basis-set modeling method in which primary organic components are assumed to be semi-volatile and photochemically reactive and are distributed in logarithmically spaced volatility bins. The MCMA (Mexico City Metropolitan Area) 2006 official emission inventory is used in simulations and the POA emissions are modified and distributed by volatility based on dilution experiments for the non-traditional SOA model. The model results are compared to the Aerosol Mass Spectrometry (AMS) observations analyzed using the Positive Matrix Factorization (PMF) technique at an urban background site (T0) and a suburban background site (T1) in Mexico City. The traditional SOA model frequently underestimates the observed POA concentrations during rush hours and overestimates the observations in the rest of the time in the city. The model also substantially underestimates the observed SOA concentrations, particularly during daytime, and only produces 21% and 25% of the observed SOA mass in the suburban and urban area, respectively. The non-traditional SOA model performs well in simulating the POA variation, but still overestimates during daytime in the urban area. The SOA simulations are significantly improved in the non-traditional SOA model compared to the traditional SOA model and the SOA production is increased by more than 100% in the city. However, the underestimation during daytime is still salient in the urban area and the non-traditional model also fails to reproduce the high level of SOA concentrations in the suburban area

  13. Simulations of organic aerosol concentrations in Mexico City using the WRF-CHEM model during the MCMA-2006/MILAGRO campaign

    NASA Astrophysics Data System (ADS)

    Li, G.; Zavala, M.; Lei, W.; Tsimpidi, A. P.; Karydis, V. A.; Pandis, S. N.; Molina, L. T.

    2010-12-01

    Organic aerosol concentrations are simulated using the WRF-CHEM model in Mexico City during the period from 24 to 29 March in association with the MILAGRO-2006 campaign. Two approaches are employed to predict the variation and spatial distribution of the organic aerosol concentrations: (1) a traditional 2-product secondary organic aerosol (SOA) model with non-volatile primary organic aerosols (POA); (2) a non-traditional SOA model including the volatility basis-set modeling method in which primary organic components are assumed to be semi-volatile and photochemically reactive and are distributed in logarithmically spaced volatility bins. The MCMA 2006 official emission inventory is used in simulations and the POA emissions are modified and distributed by volatility based on dilution experiments for the non-traditional SOA model. The model results are compared to the Aerosol Mass Spectrometry (AMS) observations analyzed using the Positive Matrix Factorization (PMF) technique at an urban background site (T0) and a suburban background site (T1) in Mexico City. The traditional SOA model frequently underestimates the observed POA concentrations during rush hours and overestimates the observations in the rest of the time in the city. The model also substantially underestimates the observed SOA concentrations, particularly during daytime, and only produces 21% and 25% of the observed SOA mass in the suburban and urban area, respectively. The non-traditional SOA model performs well in simulating the POA variation, but still overestimates during daytime in the urban area. The SOA simulations are significantly improved in the non-traditional SOA model compared to the traditional SOA model and the SOA production is increased by more than 100% in the city. However, the underestimation during daytime is still salient in the urban area and the non-traditional model also fails to reproduce the high level of SOA concentrations in the suburban area. In the non-traditional SOA model

  14. Size-segregated compositional analysis of aerosol particles collected in the European Arctic during the ACCACIA campaign

    NASA Astrophysics Data System (ADS)

    Young, G.; Jones, H. M.; Darbyshire, E.; Baustian, K. J.; McQuaid, J. B.; Bower, K. N.; Connolly, P. J.; Gallagher, M. W.; Choularton, T. W.

    2016-03-01

    Single-particle compositional analysis of filter samples collected on board the Facility for Airborne Atmospheric Measurements (FAAM) BAe-146 aircraft is presented for six flights during the springtime Aerosol-Cloud Coupling and Climate Interactions in the Arctic (ACCACIA) campaign (March-April 2013). Scanning electron microscopy was utilised to derive size-segregated particle compositions and size distributions, and these were compared to corresponding data from wing-mounted optical particle counters. Reasonable agreement between the calculated number size distributions was found. Significant variability in composition was observed, with differing external and internal mixing identified, between air mass trajectory cases based on HYbrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) analyses. Dominant particle classes were silicate-based dusts and sea salts, with particles notably rich in K and Ca detected in one case. Source regions varied from the Arctic Ocean and Greenland through to northern Russia and the European continent. Good agreement between the back trajectories was mirrored by comparable compositional trends between samples. Silicate dusts were identified in all cases, and the elemental composition of the dust was consistent for all samples except one. It is hypothesised that long-range, high-altitude transport was primarily responsible for this dust, with likely sources including the Asian arid regions.

  15. Aerosol and ozone observations during six cruise campaigns across the Mediterranean basin: temporal, spatial, and seasonal variability.

    PubMed

    Bencardino, Mariantonia M; Pirrone, Nicola N; Sprovieri, Francesca F

    2014-03-01

    The Mediterranean basin, because of its semi-enclosed configuration, is one of the areas heavily affected by air pollutants. Despite implications on both human health and radiative budget involving an increasing interest, monitoring databases measuring air pollution directly over this area are yet relatively limited. Owing to this context, concentrations of fine (PM2.5) and coarse (PM2.5-10) particles along with other ancillary data, such as ozone levels and meteorological parameters, were measured during six cruise campaigns covering almost the whole Mediterranean basin. Elemental composition of both PM2.5 and PM2.5-10 was also determined to identify specific tracers for different classes of particles that can be found in the Mediterranean atmosphere. Outcomes resulting from the integration of a preliminary qualitative examination with a more quantitative analysis, based on receptor modelling, suggested that European continental influence, Saharan dust outbreaks, wildfire events, sea spray and fossil fuel combustion were the leading causes of the aerosol-ozone variations within the Mediterranean basin. Shipping emissions, consisting in both local harbours and maritime traffic across the basin, were also tested using the marker ratio of V/Ni. Peak values observed for coarse fraction have shown to be driven by the occurrence of African dust events. Considering the major influence of Continental pollution and wildfire events, the spatial variability resulted in larger fine particle concentrations and higher ozone levels over the Eastern Mediterranean side in comparison to the Western one.

  16. Exploring the variability of aerosol particle composition in the Arctic: a study from the springtime ACCACIA campaign

    NASA Astrophysics Data System (ADS)

    Young, G.; Jones, H. M.; Darbyshire, E.; Baustian, K. J.; McQuaid, J. B.; Bower, K. N.; Connolly, P. J.; Gallagher, M. W.; Choularton, T. W.

    2015-10-01

    Single-particle compositional analysis of filter samples collected on-board the FAAM BAe-146 aircraft is presented for six flights during the springtime Aerosol-Cloud Coupling and Climate Interactions in the Arctic (ACCACIA) campaign (March-April 2013). Scanning electron microscopy was utilised to derive size distributions and size-segregated particle compositions. These data were compared to corresponding data from wing-mounted optical particle counters and reasonable agreement between the calculated number size distributions was found. Significant variability in composition was observed, with differing external and internal mixing identified, between air mass trajectory cases based on HYSPLIT analyses. Dominant particle classes were silicate-based dusts and sea salts, with particles notably rich in K and Ca detected in one case. Source regions varied from the Arctic Ocean and Greenland through to northern Russia and the European continent. Good agreement between the back trajectories was mirrored by comparable compositional trends between samples. Silicate dusts were identified in all cases, and the elemental composition of the dust was consistent for all samples except one. It is hypothesised that long-range, high-altitude transport was primarily responsible for this dust, with likely sources including the Asian arid regions.

  17. Impacts of Aerosol, Surface and Meteorological Conditions on Polar Cloud Properties: Use of In-Situ Cloud Probe Data

    NASA Astrophysics Data System (ADS)

    McFarquhar, Greg; Wu, Wei; Maahn, Maximilian

    2017-04-01

    Over the Southern Oceans, models from the Coupled Model Intercomparison Project 5 (CMIP5) almost universally underestimate sunlight reflected by near surface cloud in the Austral summer compared to Clouds and the Earth's Radiant Energy System (CERES) data. These and other biases in radiative fluxes over the Arctic are believed to be associated with the poorly modeled properties of low-level clouds that are frequently composed of supercooled water. Because changes in cloud macrophysical (heights, coverage) and microphysical (sizes, shapes and phases of particles) can alter the radiative impact of clouds, it is important to understand the processes that control cloud properties. In this presentation, in-situ microphysical observations obtained in prior arctic field campaigns (e.g., the Indirect and Semi-Direct Aerosol Campaign ISDAC, the Mixed-Phase Arctic Cloud Experiment M-PACE, and the Atmospheric Radiation Measurement Carbon Measurements Program-V ACME-V) are discussed. Strategies for comparing data collected in campaigns with different probes and processed with varying algorithms are introduced, along with procedures for using cloud probe data to refine assumptions about cloud properties in model schemes (e.g., size distributions, mass-dimension, and velocity-dimension relations) that affect rates at which mass and number are transferred between hydrometeor categories and hence estimates of latent and radiative heating, which feeds back on dynamics and hence cloud properties. Such observations from past arctic field experiments have enhanced our understanding of aerosol-cloud interactions acting in single-layer mixed phase clouds that are ubiquitous in the Arctic. But, it is still unknown what controls the amount of supercooled water in polar clouds (especially in frequently occurring complex multi-layer clouds), how probability distributions of cloud properties vary with aerosol loading and composition in different surface and meteorological conditions, and how

  18. Organic and Elemental Carbon Aerosol Particulates at the Southern Great Plains Site Field Campaign Report

    SciTech Connect

    Cary, Robert

    2016-04-01

    The purpose of this study was to measure the organic carbon (OC) and elemental carbon (EC) fractions of PM2.5 particulate matter at the U.S. Department of Energy (DOE)’s Atmospheric Radiation Measurement (ARM) Climate Research Facility Southern Great Plains (SGP) sampling site for a 6-month period during the summer of 2013. The site is in a rural location remote from any populated areas, so it would be expected to reflect carbon concentration over long-distance transport patterns. During the same period in 2012, a number of prairie fires in Oklahoma and Texas had produced large plumes of smoke particles, but OC and EC particles had not been quantified. In addition, during the summer months, other wild fires, such as forest fires in the Rocky Mountain states and other areas, can produce carbon aerosols that are transported over long distances. Both of these source types would be expected to contain mixtures of both OC and EC.

  19. Simulating Inorganic Aerosol Components Using ISORROPIA II in a Chemical Transport Model (PMCAMx) - Evaluation for the MILAGRO Campaign 2006 in Mexico City

    NASA Astrophysics Data System (ADS)

    Karydis, V. A.; Tsimpidi, A. P.; Nenes, A.; Pandis, S. N.; Zavala, M.; Lei, W.; Molina, L. T.

    2007-12-01

    Aerosols have a significant role in the atmosphere having adverse impacts on human health and directly affecting air quality, visibility and climate change. One of the most challenging tasks for the available models is the prediction of the partitioning of the semivolatile inorganic aerosol components (ammonia, nitric acid, hydrochloric acid, etc) between the gas and aerosol phases. Moreover, the effects of mineral aerosols in the atmosphere remain largely unquantified. As a result, most current models have serious difficulties in reproducing the observed particulate nitrate and chloride concentrations. The aerosol thermodynamic model ISORROPIA has been improved as it now simulates explicitly the chemistry of Ca, Mg, and K salts and is linked to PMCAMx (Gaydos et al., 2007). PMCAMx also includes the inorganic aerosol growth module (Gaydos et al., 2003; Koo et al., 2003a) and the aqueous-phase chemistry module (Fahey and Pandis, 2001). The hybrid approach (Koo et al., 2003b) for modeling aerosol dynamics is applied in order to accurately simulate the inorganic components in coarse mode. This approach assumes that the smallest particles are in equilibrium while the condensation/evaporation equation is solved for the larger ones. PMCAMx is applied in Mexico City Metropolitan Area (MCMA) covering a 180x180x6 km region. The emission inventory used has as a starting point the MCMA 2004 official emissions inventory (CAM, 2006) and includes more accurate dust and NaCl emissions. The March 2006 dataset (MILAGRO Campaign) is used to evaluate the inorganic aerosol module of PMCAMx in order to test our understanding of aerosol thermodynamics and the equilibrium assumption. Gaydos, T., Pinder, R., Koo, B., Fahey, Κ., Yarwood, G., and Pandis, S. N., (2007). Development and application of a three-dimensional Chemical Transport Model, PMCAMx. Atmospheric Environment, 41, 2594- 2611. Gaydos, T., Koo, B., and Pandis, S. N., (2003). Development and application of an efficient moving

  20. Validation of the on-line aerosol retrieval and error characterization algorithm from the OMI Near-UV observations during the DRAGON-NE Asia 2012 campaign

    NASA Astrophysics Data System (ADS)

    Jeong, U.; Ahn, C.; Kim, J.; Bhartia, P. K.; Torres, O.; Spurr, R. J. D.; Liu, X.; Chance, K.; Holben, B. N.

    2014-12-01

    One of the representative advantages of using ultraviolet channel to retrieve aerosol optical property is that the results are less affected by the uncertainty of surface reflectance database. The retrieved aerosol products have relatively uniform quality at both land and ocean except the ice-snow surface. The near UV technique of aerosol remote sensing has additional merit that it has long period database since TOMS (Total Ozone Mapping Spectrometer) including aerosol absorption properties. Thus the retrieved product using the near UV technique using TOMS and OMI (Ozone Monitoring Instrument) measurement is quite appropriate for climatological research. For such purposes, assessment of accuracy of the retrieved product is essential to evaluate the radiative forcing of the aerosols. In this study, the error characterizations of the near UV technique using OMI measurements have been performed with the optimal estimation method during the DRAGON-NE Asia 2012 campaign. In order to avoid the interpolation error, we developed the on-line retrieval scheme based on the traditional near UV method. The retrieval noise and smoothing error of retrieved AOT (Aerosol Optical Thickness) were compared with the biases between 380 nm AOT from AERONET and retrieved 388 nm AOT. They showed positive correlations which infer the possibility of the estimated errors using the optimal estimation method to be used to evaluate the error of retrieved products. Forward model parameter errors were analyzed separately which depends on the quality of the used database, thus can be reduced by improving the database.

  1. Aerosol Optical Properties Derived from the DRAGON-NE Asia Campaign, and Implications for a Single-Channel Algorithm to Retrieve Aerosol Optical Depth in Spring from Meteorological Imager (MI) On-Board the Communication, Ocean, and Meteorological Satellite (COMS)

    NASA Technical Reports Server (NTRS)

    Kim, M.; Kim, J.; Jeong, U.; Kim, W.; Hong, H.; Holben, B.; Eck, T. F.; Lim, J.; Song, C.; Lee, S.; hide

    2016-01-01

    An aerosol model optimized for northeast Asia is updated with the inversion data from the Distributed Regional Aerosol Gridded Observation Networks (DRAGON)-northeast (NE) Asia campaign which was conducted during spring from March to May 2012. This updated aerosol model was then applied to a single visible channel algorithm to retrieve aerosol optical depth (AOD) from a Meteorological Imager (MI) on-board the geostationary meteorological satellite, Communication, Ocean, and Meteorological Satellite (COMS). This model plays an important role in retrieving accurate AOD from a single visible channel measurement. For the single-channel retrieval, sensitivity tests showed that perturbations by 4 % (0.926 +/- 0.04) in the assumed single scattering albedo (SSA) can result in the retrieval error in AOD by over 20 %. Since the measured reflectance at the top of the atmosphere depends on both AOD and SSA, the overestimation of assumed SSA in the aerosol model leads to an underestimation of AOD. Based on the AErosol RObotic NETwork (AERONET) inversion data sets obtained over East Asia before 2011, seasonally analyzed aerosol optical properties (AOPs) were categorized by SSAs at 675 nm of 0.92 +/- 0.035 for spring (March, April, and May). After the DRAGON-NE Asia campaign in 2012, the SSA during spring showed a slight increase to 0.93 +/- 0.035. In terms of the volume size distribution, the mode radius of coarse particles was increased from 2.08 +/- 0.40 to 2.14 +/- 0.40. While the original aerosol model consists of volume size distribution and refractive indices obtained before 2011, the new model is constructed by using a total data set after the DRAGON-NE Asia campaign. The large volume of data in high spatial resolution from this intensive campaign can be used to improve the representative aerosol model for East Asia. Accordingly, the new AOD data sets retrieved from a single-channel algorithm, which uses a precalculated look-up table (LUT) with the new aerosol model, show

  2. Aerosol optical properties derived from the DRAGON-NE Asia campaign, and implications for a single-channel algorithm to retrieve aerosol optical depth in spring from Meteorological Imager (MI) on-board the Communication, Ocean, and Meteorological Satellite (COMS)

    NASA Astrophysics Data System (ADS)

    Kim, M.; Kim, J.; Jeong, U.; Kim, W.; Hong, H.; Holben, B.; Eck, T. F.; Lim, J. H.; Song, C. K.; Lee, S.; Chung, C.-Y.

    2016-02-01

    An aerosol model optimized for northeast Asia is updated with the inversion data from the Distributed Regional Aerosol Gridded Observation Networks (DRAGON)-northeast (NE) Asia campaign which was conducted during spring from March to May 2012. This updated aerosol model was then applied to a single visible channel algorithm to retrieve aerosol optical depth (AOD) from a Meteorological Imager (MI) on-board the geostationary meteorological satellite, Communication, Ocean, and Meteorological Satellite (COMS). This model plays an important role in retrieving accurate AOD from a single visible channel measurement. For the single-channel retrieval, sensitivity tests showed that perturbations by 4 % (0.926 ± 0.04) in the assumed single scattering albedo (SSA) can result in the retrieval error in AOD by over 20 %. Since the measured reflectance at the top of the atmosphere depends on both AOD and SSA, the overestimation of assumed SSA in the aerosol model leads to an underestimation of AOD. Based on the AErosol RObotic NETwork (AERONET) inversion data sets obtained over East Asia before 2011, seasonally analyzed aerosol optical properties (AOPs) were categorized by SSAs at 675 nm of 0.92 ± 0.035 for spring (March, April, and May). After the DRAGON-NE Asia campaign in 2012, the SSA during spring showed a slight increase to 0.93 ± 0.035. In terms of the volume size distribution, the mode radius of coarse particles was increased from 2.08 ± 0.40 to 2.14 ± 0.40. While the original aerosol model consists of volume size distribution and refractive indices obtained before 2011, the new model is constructed by using a total data set after the DRAGON-NE Asia campaign. The large volume of data in high spatial resolution from this intensive campaign can be used to improve the representative aerosol model for East Asia. Accordingly, the new AOD data sets retrieved from a single-channel algorithm, which uses a precalculated look-up table (LUT) with the new aerosol model, show an

  3. Altitude effect in UV radiation during the Evaluation of the Effects of Elevation and Aerosols on the Ultraviolet Radiation 2002 (VELETA-2002) field campaign

    NASA Astrophysics Data System (ADS)

    Sola, Y.; Lorente, J.; Campmany, E.; de Cabo, X.; Bech, J.; RedañO, A.; MartíNez-Lozano, J. A.; Utrillas, M. P.; Alados-Arboledas, L.; Olmo, F. J.; DíAz, J. P.; Expósito, F. J.; Cachorro, V.; Sorribas, M.; Labajo, A.; Vilaplana, J. M.; Silva, A. M.; Badosa, J.

    2008-12-01

    The Evaluation of the Effects of Elevation and Aerosols on the Ultraviolet Radiation 2002 (VELETA-2002) field campaign was designed to study the influence of aerosols and altitude on solar UV irradiance. The altitude effect (AE) was evaluated for UV irradiance under cloudless conditions by taking spectral and broadband measurements in SE Spain in the summer of 2002 at three nearby sites located at different heights (680 m, 2200 m, and 3398 m). A spectral radiative transfer model (Santa Barbara DISORT Atmospheric Radiative Transfer (SBDART)) was also applied, mainly to evaluate the tropospheric ozone impact on AE. Results are related to the optical properties and air mass origin of the aerosols as determined by back-trajectory analysis. During the 1-week observing period of the campaign, there were two main synoptic situations with different air masses (polar maritime and tropical continental air mass associated with a Saharan dust event). The AE showed a high dependency on wavelength, solar zenith angle, and aerosols, although the growth of the mixing layer during the day also caused substantial AE variability. Saharan dust caused an increase in AE, especially in the UVB region and in the erythemal irradiance. In the UVA (320-400 nm) band the AE ranged 6-8% km-1 at noon, while for the UVB (280-320 nm) band it reached 7-11% km-1. The AE for erythemally weighted irradiance ranged from 11 to 14% km-1 between the lowest and highest stations when it was calculated from spectral measurements.

  4. Investigation of the CCN Activity, BC and UVBC Mass Concentrations of Biomass Burning Aerosols during the 2013 BASELInE Campaign

    NASA Technical Reports Server (NTRS)

    Hsiao, Ta-Chih; Ye, Wei-Cheng; Wang, Sheng-Hsiang; Tsay, Si-Chee; Chen, Wei-Nai; Lin, Neng-Huei; Lee, Chung-Te; Hung, Hui-Ming; Chuang, Ming-Tung; Chantara, Somporn

    2015-01-01

    Biomass-burning (BB) aerosols, acting as cloud condensation nuclei (CCN), can influence cloud microphysical and radiative properties. In this study, we present CCN measured near the BB source regions over northern Southeast Asia (Doi Ang Khang, Thailand) and at downwind receptor areas (Lulin Atmospheric Background Station, Taiwan), focusing exclusively on 13-20 March 2013 as part of 2013 spring campaign of the Seven SouthEast Asian Studies (7-SEAS) intensive observation. One of the campaigns objectives is to characterize BB aerosols serving as CCN in SouthEast Asia (SEA). CCN concentrations were measured by a CCN counter at 5 supersaturation (SS) levels: 0.15%, 0.30%, 0.45%, 0.60%, and 0.75%. In addition, PM2.5 and black carbon mass concentrations were analyzed by using a tapered element oscillating microbalance and an aethalometer. It was found the number-size distributions and the characteristics of hygroscopicity (e.g., activation ratio and k) of BB aerosols in SEA have a strong diurnal pattern, and different behaviors of patterns were characterized under two distinct weather systems. The overall average value was low (0.05-0.1) but comparable with previous CCN studies in other BB source regions. Furthermore, a large fraction of UV-absorbing organic material (UVBC) and high Delta-C among BB aerosols were also observed, which suggest the existence of substantial particulate organic matter in fresh BB aerosols. These data provide the most extensive characterization of BB aerosols in SEA until now.

  5. Sources of Black Carbon Aerosols in South Asia and Surrounding Regions During the Integrated Campaign for Aerosols, Gases and Radiation Budget (ICARB)

    NASA Astrophysics Data System (ADS)

    Kumar, R.; Barth, M. C.; Nair, V. S.; Pfister, G.; Babu, S. S.; Satheesh, S. K.; Krishnamoorthy, K.; Carmichael, G. R.

    2014-12-01

    The dominant sources of black carbon (BC) in South Asia and surrounding regions are inferred during March-May 2006 (Integrated Campaign for Aerosols, Gases and Radiation Budget (ICARB)) by introducing BC tracers in the Weather Research and Forecasting Model coupled with Chemistry. Model results show that ICARB measurements were fairly well representative of the Arabian Sea and the Bay of Bengal during the pre-monsoon season. The model reproduced well the magnitude, temporal and spatial variability of BC concentrations observed during the ICARB ship-cruise. Average and standard deviation (representing the spatial and temporal variability) in observed and modeled BC mass concentrations along the ship-track are estimated as 755±734 ng m-3 and 732±913 ng m-3 respectively, where the standard deviation represents the spatial and temporal variability in the region. Average modeled values at most of the inland stations were also found to fall within the range of observed values. Results show that anthropogenic and biomass burning emissions, respectively, accounted for 70% and 28% of the BC mass concentration in South Asia. BC emissions from residential (49%) and industrial (37%) sectors appear to be the major anthropogenic sources, except in the Himalayas where vehicular emissions dominate. We find that, while all parts of continental India contributed to anthropogenic BC over Bay of Bengal, contribution over the Arabian Sea came mostly from southern Peninsula. We also show that long-range transport of anthropogenic emissions contribute up to 30% of BC concentrations in western and eastern India, suggesting that it is important to consider non-local sources along with the local emissions while designing strategies for mitigating BC emissions.

  6. Sources of black carbon aerosols in South Asia and surrounding regions during the Integrated Campaign for Aerosols, Gases and Radiation Budget (ICARB)

    NASA Astrophysics Data System (ADS)

    Kumar, R.; Barth, M. C.; Nair, V. S.; Pfister, G. G.; Babu, S. S.; Satheesh, S. K.; Moorthy, K. K.; Carmichael, G. R.

    2014-12-01

    The dominant sources of black carbon (BC) in South Asia and surrounding regions are inferred during March-May 2006 (Integrated Campaign for Aerosols, Gases and Radiation Budget, ICARB) period by introducing BC tracers in the Weather Research and Forecasting Model coupled with Chemistry. The model reproduced the magnitude, temporal and spatial variability of BC distribution observed during the ICARB ship-cruise. Average and SD (representing the spatial and temporal variability) in observed and modeled BC mass concentrations along the ship-track are estimated as 755 ± 734 and 732 ± 913 ng m-3 respectively. Average modeled values at most of the inland stations were also found to fall within the range of observed values. Model results show that ICARB measurements were fairly well representative of the Arabian Sea and the Bay of Bengal during the pre-monsoon season. Results show that anthropogenic and biomass burning emissions, respectively, accounted for 70 and 28 % of the average ± SD BC mass concentration (1480 ± 5920 ng m-3) in South Asia. BC emissions from residential (49 %) and industrial (37 %) sectors appear to be the major anthropogenic sources, except in the Himalayas where vehicular emissions dominated. We find that, while all parts of continental India contributed to anthropogenic BC over the Bay of Bengal, contribution over the Arabian Sea came mostly from southern Peninsula. We also show that regional-scale transport of anthropogenic emissions contribute up to 30 % of BC mass concentrations in western and eastern India, suggesting that it is important to consider non-local sources along with the local emissions while designing strategies for mitigating BC emissions.

  7. Hygroscopic growth of atmospheric aerosol particles based on lidar, radiosonde, and in situ measurements: Case studies from the Xinzhou field campaign

    NASA Astrophysics Data System (ADS)

    Lv, Min; Liu, Dong; Li, Zhanqing; Mao, Jietai; Sun, Yele; Wang, Zhenzhu; Wang, Yingjian; Xie, Chenbo

    2017-02-01

    Lidar, radiosonde, and ground-based in situ nephelometer measurements made during an intensive field campaign carried out from July to September 2014 at the Xinzhou meteorological station were used to determine the aerosol hygroscopic growth effect in a cloud-capped, well-mixed boundary layer. Aerosol hygroscopic properties at 355 and 532 nm were examined for two cases with distinct aerosol layers. Lidar-derived maximum enhancement factors in terms of aerosol backscatter coefficient derived using a relative humidity (RH) reference value of 85% were 1.19 at 532 nm and 1.10 at 355 nm for Case I and 2.32 at 532 nm and 1.94 at 355 nm for Case II. To derive the aerosol particle hygroscopic growth factor at specific RH values, the Kasten and Hänel models were used. A comparison of the goodness of fit for the two models showed that the Kasten model performed better. The hygroscopic growth curve for RH>90% was much steeper than that for RH in the range of 85-90%. The slopes of the lidar-derived enhancement factor curve (measured from 85% to 95% RH) and the nephelometer-derived enhancement factor curve (measured from 40% to 62% RH) in Case I show similar trends, which lends confidence to using lidar measurements for studying aerosol particle hygroscopic growth. Data from a ground aerosol chemical speciation monitor showed that the larger values of aerosol hygroscopic enhancement factor in Case II corresponded to greater mass concentrations of sulfate and nitrate in the atmosphere.

  8. Wet removal of black carbon in Asian outflow: Aerosol Radiative Forcing in East Asia (A-FORCE) aircraft campaign

    NASA Astrophysics Data System (ADS)

    Oshima, N.; Kondo, Y.; Moteki, N.; Takegawa, N.; Koike, M.; Kita, K.; Matsui, H.; Kajino, M.; Nakamura, H.; Jung, J. S.; Kim, Y. J.

    2012-02-01

    The Aerosol Radiative Forcing in East Asia (A-FORCE) aircraft campaign was conducted over East Asia in March-April 2009. During the A-FORCE campaign, 120 vertical profiles of black carbon (BC) and carbon monoxide (CO) were obtained in the planetary boundary layer (PBL) and the free troposphere. This study examines the wet removal of BC in Asian outflow using the A-FORCE data. The concentrations of BC and CO were greatly enhanced in air parcels sampled at 3-6 km in altitude over the Yellow Sea on 30 March 2009, associated with upward transport due to a cyclone with modest amounts of precipitation over northern China. In contrast, high CO concentrations without substantial enhancements of BC concentrations were observed in air parcels sampled at 5-6 km over the East China Sea on 23 April 2009, caused by uplifting due to cumulus convection with large amounts of precipitation over central China. The transport efficiency of BC (TEBC, namely the fraction of BC particles not removed during transport) in air parcels sampled above 2 km during the entire A-FORCE period decreased primarily with the increase in the precipitation amount that air parcels experienced during vertical transport, although their correlation was modest (r2 = 0.43). TEBC also depended on the altitude to which air parcels were transported from the PBL and the latitude where they were uplifted locally over source regions. The median values of TEBC for air parcels originating from northern China (north of 33°N) and sampled at 2-4 km and 4-9 km levels were 86% and 49%, respectively, during the A-FORCE period. These median values were systematically greater than the corresponding median values (69% and 32%, respectively) for air parcels originating from southern China (south of 33°N). Use of the A-FORCE data set will contribute to the reduction of large uncertainties in wet removal process of BC in global- and regional-scale models.

  9. 4STAR Sky-Scanning Retrievals of Aerosol Intensive Optical Properties from Multiple Field Campaigns with Detailed Comparisons of SSA Reported During SEAC4RS

    NASA Technical Reports Server (NTRS)

    Flynn, Connor; Dahlgren, R. P.; Dunagan, S.; Johnson, R.; Kacenelenbogen, M.; LeBlanc, S.; Livingston, J.; Redemann, J.; Schmid, B.; Segal Rozenhaimer, M.; Shinozuka, Y.; Zhang, Q.; Schmidt, S.; Holben, B.; Sinyuk, A.; Hair, J.; Anderson, B.; Ziemba, L.

    2015-01-01

    The 4STAR (Spectrometer for Sky-Scanning, Sun-Tracking Atmospheric Research) instrument combines airborne sun tracking capabilities of the Ames Airborne Tracking Sun Photometer (AATS-14) with AERONET-like sky-scanning capability and adds state-of-the-art fiber-coupled grating spectrometry to yield hyper spectral measurements of direct solar irradiance and angularly resolved sky radiance. The combination of sun-tracking and sky-scanning capability enables retrievals of wavelength-dependent aerosol optical depth (AOD), mode-resolved aerosol size distribution (SD), asphericity, and complex refractive index, and thus also the scattering phase function, asymmetry parameter, single-scattering albedo (SSA), and absorption aerosol optical thickness (AAOT).From 2012 to 2014 4STAR participated in four major field campaigns: the U.S. Dept. of Energy TCAP I II campaigns, and NASAs SEAC4RS and ARISE campaigns. Establishing a strong performance record, 4STAR operated successfully on all flights conducted during each of these campaigns. Sky radiance spectra from scans in either constant azimuth (principal plane) or constant zenith angle (almucantar) were interspersed with direct beam measurements during level legs. During SEAC4RS and ARISE, 4STAR airborne measurements were augmented with flight-level albedo from the collocated Shortwave Spectral Flux Radiometer (SSFR) providing improved specification of below-aircraft radiative conditions for the retrieval. Calibrated radiances and retrieved products will be presented with particular emphasis on detailed comparisons of ambient SSA retrievals and measurements during SEAC4RS from 4STAR, AERONET, HSRL2, and from in situ measurements.

  10. 2014 iAREA campaign on aerosol in Spitsbergen - Part 2: Optical properties from Raman-lidar and in-situ observations at Ny-Ålesund

    NASA Astrophysics Data System (ADS)

    Ritter, C.; Neuber, R.; Schulz, Alexander; Markowicz, K. M.; Stachlewska, I. S.; Lisok, J.; Makuch, P.; Pakszys, P.; Markuszewski, P.; Rozwadowska, A.; Petelski, T.; Zielinski, T.; Becagli, S.; Traversi, R.; Udisti, R.; Gausa, M.

    2016-09-01

    In this work multi wavelength Raman lidar data from Ny-Ålesund, Spitsbergen have been analysed for the spring 2014 Arctic haze season, as part of the iAREA campaign. Typical values and probability distributions for aerosol backscatter, extinction and depolarisation, the lidar ratio and the color ratio for 4 different altitude intervals within the troposphere are given. These quantities and their dependencies are analysed and the frequency of altitude-dependent observed aerosol events are given. A comparison with ground-based size distribution and chemical composition is performed. Hence the aim of this paper is to provide typical and statistically meaningful properties of Arctic aerosol, which may be used in climate models or to constrain the radiative forcing. We have found that the 2014 season was only moderately polluted with Arctic haze and that sea salt and sulphate were the most dominant aerosol species. Moreover the drying of an aerosol layer after cloud disintegration has been observed. Hardly any clear temporal evolution over the 4 week data set on Arctic haze is obvious with the exception of the extinction coefficient and the lidar ratio, which significantly decreased below 2 km altitude by end April. In altitudes between 2 and 5 km the haze season lasted longer and the aerosol properties were generally more homogeneous than closer to the surface. Above 5 km only few particles were found. The variability of the lidar ratio is discussed. It was found that knowledge of the aerosol's size and shape does not determine the lidar ratio. Contrary to shape and lidar ratio, there is a clear correlation between size and backscatter: larger particles show a higher backscatter coefficient.

  11. In-situ, sunphotometer and Raman lidar observations of aerosol transport events in the western Mediterranean during the June 2013 ChArMEx campaign

    NASA Astrophysics Data System (ADS)

    Totems, Julien; Sicard, Michael; Bertolin, Santi; Boytard, Mai-Lan; Chazette, Patrick; Comeron, Adolfo; Dulac, Francois; Hassanzadeh, Sahar; Lange, Diego; Marnas, Fabien; Munoz, Constantino; Shang, Xiaoxia

    2014-05-01

    We present a preliminary analysis of aerosol observations performed in June 2013 in the western Mediterranean at two stations set up in Barcelona and Menorca (Spain) in the framework of the ChArMEx (Chemistry Aerosol Mediterranean Experiment) project. The Barcelona station was equipped with the following fixed instruments belonging to the Universitat Politècnica de Catalunya (UPC): an AERONET (Aerosol Robotic Network) sun-photometer, an MPL (Micro Pulse Lidar) lidar and the UPC multi-wavelength lidar. The MPL lidar works at 532 nm and has a depolarization channel, while the UPC lidar works at 355, 532 and 1064 nm, and also includes two N2- (at 387 and 607 nm) and one H2O-Raman (at 407 nm) channels. The MPL system works continuously 24 hour/day. The UPC system was operated on alert in coordination with the research aircrafts plans involved in the campaign. In Cap d'en Font, Menorca, the mobile laboratory of the Laboratoire des Sciences du Climat et de l'Environnement hosted an automated (AERONET) and a manual (Microtops) 5-lambda sunphotometer, a 3-lambda nephelometer, a 7-lambda aethalometer, as well as the LSCE Water vapor Aerosol LIdar (WALI). This mini Raman lidar, first developed and validated for the HyMEX (Hydrological cycle in the Mediterranean eXperiment) campaign in 2012, works at 355 nm for eye safety and is designed with a short overlap distance (<300m) to probe the lower troposphere. It includes depolarization, N2- and H2O-Raman channels. H2O observations have been calibrated on-site by different methods and show good agreement with balloon measurements. Observations at Cap d'en Font were quasi-continuous from June 10th to July 3rd, 2013. The lidar data at both stations helped direct the research aircrafts and balloon launches to interesting plumes of particles in real time for in-situ measurements. Among some light pollution background from the European continent, a typical Saharan dust event and an unusual American dust/biomass burning event are

  12. Primary and secondary biomass burning aerosols determined by proton nuclear magnetic resonance (1H-NMR) spectroscopy during the 2008 EUCAARI campaign in the Po Valley (Italy)

    NASA Astrophysics Data System (ADS)

    Paglione, M.; Saarikoski, S.; Carbone, S.; Hillamo, R.; Facchini, M. C.; Finessi, E.; Giulianelli, L.; Carbone, C.; Fuzzi, S.; Moretti, F.; Tagliavini, E.; Swietlicki, E.; Eriksson Stenström, K.; Prévôt, A. S. H.; Massoli, P.; Canaragatna, M.; Worsnop, D.; Decesari, S.

    2014-05-01

    Atmospheric organic aerosols are generally classified as primary and secondary (POA and SOA) according to their formation processes. An actual separation, however, is challenging when the timescales of emission and gas-to-particle formation overlap. The presence of SOA formation in biomass burning plumes leads to scientific questions about whether the oxidized fraction of biomass burning aerosol is rather of secondary or primary origin, as some studies would suggest, and about the chemical compositions of oxidized biomass burning POA and SOA. In this study, we apply nuclear magnetic resonance (NMR) spectroscopy to investigate the functional group composition of fresh and aged biomass burning aerosols during an intensive field campaign in the Po Valley, Italy. The campaign was part of the EUCAARI project and was held at the rural station of San Pietro Capofiume in spring 2008. Factor analysis applied to the set of NMR spectra was used to apportion the wood burning contribution and other organic carbon (OC) source contributions, including aliphatic amines. Our NMR results, referred to the polar, water-soluble fraction of OC, show that fresh wood burning particles are composed of polyols and aromatic compounds, with a sharp resemblance to wood burning POA produced in wood stoves, while aged samples are clearly depleted of alcohols and are enriched in aliphatic acids with a smaller contribution of aromatic compounds. The comparison with biomass burning organic aerosols (BBOA) determined by high-resolution aerosol mass spectrometry (HR-TOF-AMS) at the site shows only a partial overlap between NMR BB-POA and AMS BBOA, which can be explained by either the inability of BBOA to capture all BB-POA composition, especially the alcohol fraction, or the fact that BBOA account for insoluble organic compounds unmeasured by the NMR. Therefore, an unambiguous composition for biomass burning POA could not be derived from this study, with NMR analysis indicating a higher O / C ratio

  13. Assessment of the aerosol optics component of the coupled WRF-CMAQ model using CARES field campaign data and a single column model

    NASA Astrophysics Data System (ADS)

    Gan, Chuen Meei; Binkowski, Francis; Pleim, Jonathan; Xing, Jia; Wong, David; Mathur, Rohit; Gilliam, Robert

    2015-08-01

    The Carbonaceous Aerosols and Radiative Effects Study (CARES), a field campaign held in central California in June 2010, provides a unique opportunity to assess the aerosol optics modeling component of the two-way coupled Weather Research and Forecasting (WRF) - Community Multiscale Air Quality (CMAQ) model. This campaign included comprehensive measurements of aerosol composition and optical properties at two ground sites and aloft from instrumentation on-board two aircraft. A single column model (SCM) was developed to evaluate the accuracy and consistency of the coupled model using both observation and model information. Two cases (June 14 and 24, 2010) are examined in this study. The results show that though the coupled WRF-CMAQ estimates of aerosol extinction were underestimated relative to these measurements, when measured concentrations and characteristics of ambient aerosols were used as input to constrain the SCM calculations, the estimated extinction profiles agreed well with aircraft observations. One of the possible causes of the WRF-CMAQ extinction errors is that the simulated sea-salt (SS) in the accumulation mode in WRF-CMAQ is very low in both cases while the observations indicate a considerable amount of SS. Also, a significant amount of organic carbon (OC) is present in the measurement. However, in the current WRF-CMAQ model all OC is considered to be insoluble whereas most secondary organic aerosol is water soluble. In addition, the model does not consider external mixing and hygroscopic effects of water soluble OC which can impact the extinction calculations. In conclusion, the constrained SCM results indicate that the scattering portion of the aerosol optics calculations is working well, although the absorption calculation could not be effectively evaluated. However, a few factors such as greatly underestimated accumulation mode SS, misrepresentation of water soluble OC, and incomplete mixing state representation in the full coupled model

  14. Primary and secondary biomass burning aerosols determined by proton nuclear magnetic resonance (H-NMR) spectroscopy during the 2008 EUCAARI campaign in the Po Valley (Italy)

    NASA Astrophysics Data System (ADS)

    Paglione, M.; Saarikoski, S.; Carbone, S.; Hillamo, R.; Facchini, M. C.; Finessi, E.; Giulianelli, L.; Carbone, C.; Fuzzi, S.; Moretti, F.; Tagliavini, E.; Swietlicki, E.; Eriksson Stenström, K.; Prévôt, A. S. H.; Massoli, P.; Canaragatna, M.; Worsnop, D.; Decesari, S.

    2013-12-01

    Atmospheric organic aerosols are generally classified into primary and secondary (POA and SOA) according to their formation processes. An actual separation, however, is challenging when the timescales of emission and of gas-to-particle formation overlap. The presence of SOA formation in biomass burning plumes leads to scientific questions about whether the oxidized fraction of biomass burning aerosol is rather of secondary or primary origin, as some studies would suggest, and about the chemical compositions of oxidized biomass burning POA and SOA. In this study, we apply nuclear magnetic resonance (NMR) spectroscopy to investigate the functional group composition of fresh and aged biomass burning aerosols during an intensive field campaign in the Po Valley, Italy. The campaign was part of the EUCAARI project and was held at the rural station of San Pietro Capofiume in spring 2008. Factor analysis applied to the set of NMR spectra was used to apportion the wood burning contribution and other organic carbon (OC) source contributions, including aliphatic amines. Our NMR results, referred to the polar, water-soluble fraction of OC, show that fresh wood burning particles are composed of polyols and aromatic compounds, with a sharp resemblance with wood burning POA produced in wood stoves, while aged samples are clearly depleted of alcohols and are enriched in aliphatic acids with a smaller contribution of aromatic compounds. The comparison with biomass burning organic aerosols (BBOA) determined by high resolution aerosol mass spectrometry (HR-TOF-AMS) at the site shows only a partial overlap between NMR BB-POA and AMS BBOA, which can be explained by either the inability of BBOA to capture all BB-POA composition, especially the alcohol fraction, or the fact that BBOA account for insoluble organic compounds unmeasured by the NMR. Therefore, an unambiguous composition for biomass burning POA could not be derived from this study, with NMR analysis indicating a higher O / C

  15. Determining Best Estimates and Uncertainties in Cloud Microphysical Parameters from ARM Field Data: Implications for Models, Retrieval Schemes and Aerosol-Cloud-Radiation Interactions

    SciTech Connect

    McFarquhar, Greg

    2015-12-28

    We proposed to analyze in-situ cloud data collected during ARM/ASR field campaigns to create databases of cloud microphysical properties and their uncertainties as needed for the development of improved cloud parameterizations for models and remote sensing retrievals, and for evaluation of model simulations and retrievals. In particular, we proposed to analyze data collected over the Southern Great Plains (SGP) during the Mid-latitude Continental Convective Clouds Experiment (MC3E), the Storm Peak Laboratory Cloud Property Validation Experiment (STORMVEX), the Small Particles in Cirrus (SPARTICUS) Experiment and the Routine AAF Clouds with Low Optical Water Depths (CLOWD) Optical Radiative Observations (RACORO) field campaign, over the North Slope of Alaska during the Indirect and Semi-Direct Aerosol Campaign (ISDAC) and the Mixed-Phase Arctic Cloud Experiment (M-PACE), and over the Tropical Western Pacific (TWP) during The Tropical Warm Pool International Cloud Experiment (TWP-ICE), to meet the following 3 objectives; derive statistical databases of single ice particle properties (aspect ratio AR, dominant habit, mass, projected area) and distributions of ice crystals (size distributions SDs, mass-dimension m-D, area-dimension A-D relations, mass-weighted fall speeds, single-scattering properties, total concentrations N, ice mass contents IWC), complete with uncertainty estimates; assess processes by which aerosols modulate cloud properties in arctic stratus and mid-latitude cumuli, and quantify aerosol’s influence in context of varying meteorological and surface conditions; and determine how ice cloud microphysical, single-scattering and fall-out properties and contributions of small ice crystals to such properties vary according to location, environment, surface, meteorological and aerosol conditions, and develop parameterizations of such effects.In this report we describe the accomplishments that we made on all 3 research objectives.

  16. Vicarious calibration of the solar reflection channels of radiometers onboard satellites through the field campaigns with measurements of refractive index and size distribution of aerosols

    NASA Astrophysics Data System (ADS)

    Arai, K.

    A comparative study on vicarious calibration for the solar reflection channels of radiometers onboard satellite through the field campaigns between with and without measurements of refractive index and size distribution of aerosols is made. In particular, it is noticed that the influence due to soot from the cars exhaust has to be care about for the test sites near by a heavy trafficked roads. It is found that the 0.1% inclusion of soot induces around 10% vicarious calibration error so that it is better to measure refractive index properly at the test site. It is found that the vicarious calibration coefficients with the field campaigns at the different test site, Ivanpah (near road) and Railroad (distant from road) shows approximately 10% discrepancy. It seems that one of the possible causes for the difference is the influence due to soot from cars exhaust.

  17. Biogenic Aerosols – Effects on Climate and Clouds. Cloud Optical Depth (COD) Sensor Three-Waveband Spectrally-Agile Technique (TWST) Field Campaign Report

    SciTech Connect

    Niple, E. R.; Scott, H. E.

    2016-04-01

    This report describes the data collected by the Three-Waveband Spectrally-agile Technique (TWST) sensor deployed at Hyytiälä, Finland from 16 July to 31 August 2014 as a guest on the Biogenic Aerosols Effects on Climate and Clouds (BAECC) campaign. These data are currently available from the Atmospheric Radiation Measurement (ARM) Data Archive website and consists of Cloud Optical Depth (COD) measurements for the clouds directly overhead approximately every second (with some dropouts described below) during the daylight periods. A good range of cloud conditions were observed from clear sky to heavy rainfall.

  18. Simulating secondary organic aerosol from missing diesel-related intermediate-volatility organic compound emissions during the Clean Air for London (ClearfLo) campaign

    NASA Astrophysics Data System (ADS)

    Ots, Riinu; Young, Dominique E.; Vieno, Massimo; Xu, Lu; Dunmore, Rachel E.; Allan, James D.; Coe, Hugh; Williams, Leah R.; Herndon, Scott C.; Ng, Nga L.; Hamilton, Jacqueline F.; Bergström, Robert; Di Marco, Chiara; Nemitz, Eiko; Mackenzie, Ian A.; Kuenen, Jeroen J. P.; Green, David C.; Reis, Stefan; Heal, Mathew R.

    2016-05-01

    We present high-resolution (5 km × 5 km) atmospheric chemical transport model (ACTM) simulations of the impact of newly estimated traffic-related emissions on secondary organic aerosol (SOA) formation over the UK for 2012. Our simulations include additional diesel-related intermediate-volatility organic compound (IVOC) emissions derived directly from comprehensive field measurements at an urban background site in London during the 2012 Clean Air for London (ClearfLo) campaign. Our IVOC emissions are added proportionally to VOC emissions, as opposed to proportionally to primary organic aerosol (POA) as has been done by previous ACTM studies seeking to simulate the effects of these missing emissions. Modelled concentrations are evaluated against hourly and daily measurements of organic aerosol (OA) components derived from aerosol mass spectrometer (AMS) measurements also made during the ClearfLo campaign at three sites in the London area. According to the model simulations, diesel-related IVOCs can explain on average ˜ 30 % of the annual SOA in and around London. Furthermore, the 90th percentile of modelled daily SOA concentrations for the whole year is 3.8 µg m-3, constituting a notable addition to total particulate matter. More measurements of these precursors (currently not included in official emissions inventories) is recommended. During the period of concurrent measurements, SOA concentrations at the Detling rural background location east of London were greater than at the central London location. The model shows that this was caused by an intense pollution plume with a strong gradient of imported SOA passing over the rural location. This demonstrates the value of modelling for supporting the interpretation of measurements taken at different sites or for short durations.

  19. Cross-polar transport and scavenging of Siberian aerosols containing black carbon during the 2012 ACCESS summer campaign

    DOE PAGES

    Raut, Jean-Christophe; Marelle, L.; Fast, Jerome D.; ...

    2017-09-15

    During the ACCESS airborne campaign in July 2012, extensive boreal forest fires resulted in significant aerosol transport to the Arctic. A 10 day episode combining intense biomass burning over Siberia and low-pressure systems over the Arctic Ocean resulted in efficient transport of plumes containing black carbon (BC) towards the Arctic, mostly in the upper troposphere (6 − 8 km). A combination of in situ observations (DLR Falcon aircraft), satellite analysis and WRF-Chem simulations are used to understand the vertical and horizontal transport mechanisms of BC with a focus on the role of wet removal. Between the northwestern Norwegian coast andmore » the Svalbard archipelago, the Falcon aircraft sampled plumes with enhanced CO concentrations up to 200 ppbv and BC mixing ratios up to 25 ng kg−1. During transport to the Arctic region, a large fraction of BC particles are scavenged by two wet deposition processes, namely wet removal by large-scale precipitation and removal in wet convective updrafts, with both processes contributing almost equally to the total accumulated deposition of BC. Our results underline that applying a finer horizontal resolution (40 instead of 100 km) improves the model performance, as it significantly reduces the overestimation of BC levels observed at a coarser resolution in the mid-troposphere. According to the simulations at 40 km, the transport efficiency of BC (TEBC) in biomass burning plumes is about 60%, which is impacted by small accumulated precipitation along trajectory (APT) (1 mm). In contrast TEBC is very small (< 30%) and APT is larger (5 − 10 mm) in plumes influenced by urban anthropogenic sources and flaring activities in Northern Russia, resulting in as it significantly reduces the overestimation of BC levels observed at a coarser resolution in the mid-troposphere. According to the simulations at 40 km, the transport efficiency of BC (TEBC) in biomass burning plumes is about 60%, which is impacted by small accumulated

  20. Characteristics of carbonaceous aerosols in Emilia-Romagna (Northern Italy) based on two fall/winter field campaigns

    NASA Astrophysics Data System (ADS)

    Costa, V.; Bacco, D.; Castellazzi, S.; Ricciardelli, I.; Vecchietti, R.; Zigola, C.; Pietrogrande, M. C.

    2016-01-01

    The carbonaceous aerosol in Emilia-Romagna region (Northern Italy) was characterized in two fall/winter monitoring campaigns conducted through the years 2011-2012 and 2012-2013. Nearly 650 PM2.5 samples were collected at three monitoring stations describing urban background (main city Bologna, MS, Parma and Rimini) and one rural background site (San Pietro, SP). OC and EC values were measured by the thermal-optical transmittance method (TOT). Low flow-rate sampling strategy (24 m3 air volume per day) was used to reduce loading of light absorbing material on the filter surface in order to ensure the correct OC/EC discrimination. The TC values measured in winter 2011-2012 ranged from 9.8 μgC m- 3 at San Pietro to 12.0 μgC m- 3 at Parma, consisting of OC from 8.6 μgC m- 3 at SP to 9.9 μgC m- 3 at MS and EC from 1.3 μgC m- 3 at SP to 2.5 μgC m- 3 at Rimini. In winter 2012-2013, lower values were in general found with TC values ranging from 7.8 to 9.1 μgC m- 3 consisting of OC from 5.1 to 7.0 μgC m- 3 and EC from 1.5 to 2.2 μgC m- 3. Such differences can be likely explained by higher pollutant emissions related to domestic heating in colder fall/winter 2011/2012 (mean temperature ≈ 2 °C in comparison with ≈ 7 °C in winter 2012/2013). This hypothesis is supported by high levels of levoglucosan, as unambiguous tracer for biomass burning emission, and of polycyclic aromatic hydrocarbons related to combustion (levoglucosan ≃ 1000 ng m- 3 and burning PAHs ≃ 4 ng m- 3 at MS and SP sites).

  1. Cross-polar transport and scavenging of Siberian aerosols containing black carbon during the 2012 ACCESS summer campaign

    NASA Astrophysics Data System (ADS)

    Raut, Jean-Christophe; Marelle, Louis; Fast, Jerome D.; Thomas, Jennie L.; Weinzierl, Bernadett; Law, Katharine S.; Berg, Larry K.; Roiger, Anke; Easter, Richard C.; Heimerl, Katharina; Onishi, Tatsuo; Delanoë, Julien; Schlager, Hans

    2017-09-01

    During the ACCESS airborne campaign in July 2012, extensive boreal forest fires resulted in significant aerosol transport to the Arctic. A 10-day episode combining intense biomass burning over Siberia and low-pressure systems over the Arctic Ocean resulted in efficient transport of plumes containing black carbon (BC) towards the Arctic, mostly in the upper troposphere (6-8 km). A combination of in situ observations (DLR Falcon aircraft), satellite analysis and WRF-Chem simulations is used to understand the vertical and horizontal transport mechanisms of BC with a focus on the role of wet removal. Between the northwestern Norwegian coast and the Svalbard archipelago, the Falcon aircraft sampled plumes with enhanced CO concentrations up to 200 ppbv and BC mixing ratios up to 25 ng kg-1. During transport to the Arctic region, a large fraction of BC particles are scavenged by two wet deposition processes, namely wet removal by large-scale precipitation and removal in wet convective updrafts, with both processes contributing almost equally to the total accumulated deposition of BC. Our results underline that applying a finer horizontal resolution (40 instead of 100 km) improves the model performance, as it significantly reduces the overestimation of BC levels observed at a coarser resolution in the mid-troposphere. According to the simulations at 40 km, the transport efficiency of BC (TEBC) in biomass burning plumes was larger (60 %), because it was impacted by small accumulated precipitation along trajectory (1 mm). In contrast TEBC was small (< 30 %) and accumulated precipitation amounts were larger (5-10 mm) in plumes influenced by urban anthropogenic sources and flaring activities in northern Russia, resulting in transport to lower altitudes. TEBC due to large-scale precipitation is responsible for a sharp meridional gradient in the distribution of BC concentrations. Wet removal in cumulus clouds is the cause of modeled vertical gradient of TEBC, especially in the

  2. Secondary organic aerosol (SOA) derived from isoprene epoxydiols: Insights into formation, aging and distribution over the continental US from the DC3 and SEAC4RS campaigns

    NASA Astrophysics Data System (ADS)

    Campuzano Jost, P.; Palm, B. B.; Day, D. A.; Hu, W.; Ortega, A. M.; Jimenez, J. L.; Liao, J.; Froyd, K. D.; Pollack, I. B.; Peischl, J.; Ryerson, T. B.; St Clair, J. M.; Crounse, J.; Wennberg, P. O.; Mikoviny, T.; Wisthaler, A.; Ziemba, L. D.; Anderson, B. E.

    2014-12-01

    Isoprene-derived SOA formation has been studied extensively in the laboratory. However, it is still unclear to what extent isoprene contributes to the overall SOA burden over the southeastern US, an area with both strong isoprene emissions as well as large discrepancies between modeled and observed aerosol optical depth. For the low-NO isoprene oxidation pathway, the key gas-phase intermediate is believed to be isoprene epoxide (IEPOX), which can be incorporated into the aerosol phase by either sulfate ester formation (IEPOX sulfate) or direct hydrolysis. As first suggested by Robinson et al, the SOA formed by this mechanism (IEPOX-SOA) has a characteristic fragmentation pattern when analyzed by an Aerodyne Aerosol Mass Spectrometer (AMS) with enhanced relative abundances of the C5H6O+ ion (fC5H6O). Based on data from previous ground campaigns and chamber studies, we have developed a empirical method to quantify IEPOX-SOA and have applied it to the data from the DC3 and SEAC4RS aircraft campaigns that sampled the SE US during the Spring of 2012 and the Summer of 2013. We used Positive Matrix Factorization (PMF) to extract IEPOX-SOA factors that show good correlation with inside or downwind of high isoprene emitting areas and in general agree well with the IEPOX-SOA mass predicted by the empirical expression. According to this analysis, the empirical method performs well regardless of (at times very strong) BBOA or urban OA influences. On average 17% of SOA in the SE US boundary layer was IEPOX-SOA. Overall, the highest concentrations of IEPOX-SOA were typically found around 1-2 km AGL, several hours downwind of the isoprene source areas with high gas-phase IEPOX present. IEPOX-SOA was also detected up to altitudes of 6 km, with a clear trend towards more aged aerosol at altitude, likely a combination of chemical aging and physical airmass mixing. The unique instrument package aboard the NASA-DC8 allows us to examine the influence of multiple factors (aerosol

  3. Aerosol Optical Properties Measured on the Mesoscale During the TIGERZ Campaign in the Indo-Gangetic Plain Region of Kanpur, India

    NASA Astrophysics Data System (ADS)

    Giles, D. M.; Holben, B. N.; Tripathi, S. N.; Eck, T. F.; Dickerson, R. R.; Thompson, A. M.; Schafer, J. S.; Slutsker, I.

    2008-12-01

    The NASA AERONET TIGERZ campaign (May to June 2008) characterized aerosols during the late pre- monsoon to early monsoon period in the Indo-Gangetic Plain (IGP) of northern India. The IGP produces a large amount of anthropogenic pollution from urban, industrial, and rural combustion sources nearly continuously with convection-induced winds driving Thar Desert and locally-generated dust periodically into the atmosphere throughout the dry pre-monsoon season. During TIGERZ, up to seven ground-based AERONET passive radiometers were deployed in the vicinity of Kanpur, a major industrial city within the IGP. These first-of-a-kind AERONET spatial variability studies (SVSs) in India occurred six times during the TIGERZ campaign. For each SVS, instruments were deployed in and around Kanpur or along the CALIPSO track in eastern Kanpur anchored by the permanent IIT Kanpur AERONET site to the west. This mesoscale instrument distribution occurred within approximately a 50 km box providing higher spatial resolution in the Kanpur region. In addition, these instruments implemented higher measurement frequency (<3min) than the standard AERONET protocol (~15min). During one SVS, the Cimel radiometer performed higher frequency sky radiance measurements (2-3 almucantars and 1 principal plane per hour) in order to assess the variability of the aerosol properties from the AERONET inversions. Preliminary data for the discrete SVSs (May to June 2008) indicate that the ground-based, area-averaged AOD at 500nm ranged from 0.31 to 0.89 (overall: 0.63±0.25) and the 440-870nm Angstrom exponent ranged from 0.19 to 0.83 (overall: 0.39±0.23); these values suggest varying amounts of aerosol loading (mostly due to dust) during these SVSs. Further data will be presented detailing the spatial and temporal variability of aerosol optical and microphysical properties over Kanpur for TIGERZ SVSs, an analysis of the relation of SVS measurements to the historical record collected at the IIT

  4. Light absorption properties of water soluble organic aerosol from Residential Wood Burning in Fresno, CA: Results from 2013 NASA DISCOVER-AQ Campaign

    NASA Astrophysics Data System (ADS)

    Kim, H.; Zhang, Q.; Young, D. E.; Parworth, C.

    2015-12-01

    Light absorption properties of water soluble organic aerosol were investigated at Fresno, CA from 13 January to 11 February, 2013 as part of the NASA DISCOVER-AQ campaign. The light absorption spectra of water soluble organic aerosol in PM2.5 was measured using a UV/vis diode array detector (DAD) coupled with a particle into liquid sampler (PILS) that sampled downstream of a PM2.5 cyclone (URG). The PILS was also coupled with two ion chromatographs (IC) to measure inorganic and organic ionic species in PM2.5. In addition, an Aerodyne High Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) was deployed at the same site to measure size-resolved chemical composition of submicrometer aerosol (PM1) in real time during this study. Light absorption at 365 nm (Abs365), which is typically used as a proxy of water-soluble brown carbon (BrC), showed strong enhancement during night time and appeared to correlate well (r = 0.71) with biomass burning organic aerosol (BBOA) from residential wood burning for heating in the Fresno area. The tight correlations between Abs365 and biomass burning relevant tracers such as acetonitrile (r = 0.69), AMS-signature ions for phenolic compounds (r = 0.52-0.71), PAH (r = 0.74), and potassium (r = 0.67) further confirm that biomass burning contributed significantly to water soluble brown carbon during this study. The absorption angstrom exponent (Åa) values fitted between 300 and 700 nm wavelength were 3.3 ± 1.1, 2.0 ± 0.9 and 4.0 ± 0.8, respectively, in the morning, afternoon and nighttime, indicating that BrC is prevalent at night in Fresno during wintertime. However, there are also indications that small amount of BrC existed during the daytime as well, likely due to daytime wood burning and other sources such as the formation of light-absorbing secondary organic aerosol (SOA). Finally, light absorption at 300 nm, 330 nm, and 390 nm were found to correlate tightly with BBOA, which indicate that biomass burning also emits

  5. Aircraft Observations of Aerosol Composition and Ageing in New England and Mid-Atlantic States during the Summer 2002 New England Air Quality Study Field Campaign

    SciTech Connect

    Kleinman, Lawrence I.; Daum, Peter H.; Lee, Y.- N.; Senum, Gunar; Springston, Stephen R.; Wang, Jian; Berkowitz, Carl M.; Hubbe, John M.; Zaveri, Rahul A.; Brechtel, Fred J.; Jayne, J. T.; Onasch, Timothy B.; Worsnop, Douglas R.

    2007-05-11

    Aerosol chemical composition, size distributions, and optical properties were measured during 17 aircraft flights in New England and Middle Atlantic States as part of the summer 2002 NEAQS field campaign. An Aerodyne Aerosol Mass Spectrometer (AMS) was operated with a measurement cycle of 30 s, about an order of magnitude faster than used for ground-based measurements. Noise levels within a single measurement period were sub μg m-3. Volume data derived from the AMS were compared with volume measurements from a PCASP optical particle detector and an Scanning Mobility Particle Spectrometer (SMPS); calculated light scattering was compared with measured values from an integrating nephelometer. The median ratio for AMS/SMPS volume was 1.25; the median ratio for AMS/nephelometer scattering was 1.18. Size spectra were compared for subsets of samples with different effective diameters (Deff). There is good agreement between the AMS, PCASP, and SMPS spectra for larger values of Deff but an unexplained over-prediction in the AMS for small values. A dependence of the AMS collection efficiency on aerosol acidity was quantified by a comparison between AMS and PCASP volumes in 2 high sulfate plumes. Average aerosol concentrations were 11 μg m-3. The organic content was high in comparison to monitoring data from the IMPROVE network, varying from 70% in clean air to 40% in high concentration sulfate plumes. The ratio of organic aerosol to CO and light absorption acting were examined as a function of photochemical age. CO is a conservative tracer for urban emissions and light absorption is a surrogate for black carbon which is also conservative. Comparisons were made to surface ratios measured under conditions where there is little secondary organic aerosol (SOA). An increase in these ratios relative to surface values indicates that 70 - 80% of the organic aerosol in polluted air masses was secondary. Most of this SOA is rapidly formed within a few hours. At longer time scales

  6. Parameterization of the Extinction Coefficient in Ice and Mixed-Phase Arctic Clouds during the ISDAC Field Campaign

    SciTech Connect

    Korolev, A; Shashkov, A; Barker, H

    2012-03-06

    This report documents the history of attempts to directly measure cloud extinction, the current measurement device known as the Cloud Extinction Probe (CEP), specific problems with direct measurement of extinction coefficient, and the attempts made here to address these problems. Extinction coefficient is one of the fundamental microphysical parameters characterizing bulk properties of clouds. Knowledge of extinction coefficient is of crucial importance for radiative transfer calculations in weather prediction and climate models given that Earth's radiation budget (ERB) is modulated much by clouds. In order for a large-scale model to properly account for ERB and perturbations to it, it must ultimately be able to simulate cloud extinction coefficient well. In turn this requires adequate and simultaneous simulation of profiles of cloud water content and particle habit and size. Similarly, remote inference of cloud properties requires assumptions to be made about cloud phase and associated single-scattering properties, of which extinction coefficient is crucial. Hence, extinction coefficient plays an important role in both application and validation of methods for remote inference of cloud properties from data obtained from both satellite and surface sensors (e.g., Barker et al. 2008). While estimation of extinction coefficient within large-scale models is relatively straightforward for pure water droplets, thanks to Mie theory, mixed-phase and ice clouds still present problems. This is because of the myriad forms and sizes that crystals can achieve, each having their own unique extinction properties. For the foreseeable future, large-scale models will have to be content with diagnostic parametrization of crystal size and type. However, before they are able to provide satisfactory values needed for calculation of radiative transfer, they require the intermediate step of assigning single-scattering properties to particles. The most basic of these is extinction coefficient, yet it is rarely measured directly, and therefore verification of parametrizations is difficult. The obvious solution is to be able to measure microphysical properties and extinction at the same time and for the same volume. This is best done by in situ sampling by instruments mounted on either balloon or aircraft. The latter is the usual route and the one employed here. Yet the problem of actually measuring extinction coefficient directly for arbitrarily complicated particles still remains unsolved.

  7. Aerosol optical extinction during the Front Range Air Pollution and Photochemistry Éxperiment (FRAPPÉ) 2014 summertime field campaign, Colorado, USA

    NASA Astrophysics Data System (ADS)

    Dingle, Justin H.; Vu, Kennedy; Bahreini, Roya; Apel, Eric C.; Campos, Teresa L.; Flocke, Frank; Fried, Alan; Herndon, Scott; Hills, Alan J.; Hornbrook, Rebecca S.; Huey, Greg; Kaser, Lisa; Montzka, Denise D.; Nowak, John B.; Reeves, Mike; Richter, Dirk; Roscioli, Joseph R.; Shertz, Stephen; Stell, Meghan; Tanner, David; Tyndall, Geoff; Walega, James; Weibring, Petter; Weinheimer, Andrew

    2016-09-01

    Summertime aerosol optical extinction (βext) was measured in the Colorado Front Range and Denver metropolitan area as part of the Front Range Air Pollution and Photochemistry Éxperiment (FRAPPÉ) campaign during July-August 2014. An Aerodyne cavity attenuated phase shift particle light extinction monitor (CAPS-PMex) was deployed to measure βext (at average relative humidity of 20 ± 7 %) of submicron aerosols at λ = 632 nm at 1 Hz. Data from a suite of gas-phase instrumentation were used to interpret βext behavior in various categories of air masses and sources. Extinction enhancement ratios relative to CO (Δβext / ΔCO) were higher in aged urban air masses compared to fresh air masses by ˜ 50 %. The resulting increase in Δβext / ΔCO for highly aged air masses was accompanied by formation of secondary organic aerosols (SOAs). In addition, the impacts of aerosol composition on βext in air masses under the influence of urban, natural oil and gas operations (O&G), and agriculture and livestock operations were evaluated. Estimated non-refractory mass extinction efficiency (MEE) values for different air mass types ranged from 1.51 to 2.27 m2 g-1, with the minimum and maximum values observed in urban and agriculture-influenced air masses, respectively. The mass distribution for organic, nitrate, and sulfate aerosols presented distinct profiles in different air mass types. During 11-12 August, regional influence of a biomass burning event was observed, increasing the background βext and estimated MEE values in the Front Range.

  8. Primary and secondary contributions to aerosol light scattering and absorption in Mexico City during the MILAGRO 2006 campaign

    NASA Astrophysics Data System (ADS)

    Paredes-Miranda, G.; Arnott, W. P.; Jimenez, J. L.; Aiken, A. C.; Gaffney, J. S.; Marley, N. A.

    2009-06-01

    A photoacoustic spectrometer, a nephelometer, an aethalometer, and an aerosol mass spectrometer were used to measure at ground level real-time aerosol light absorption, scattering, and chemistry at an urban site located in North East Mexico City (Instituto Mexicano del Petroleo, Mexican Petroleum Institute, denoted by IMP), as part of the Megacity Impact on Regional and Global Environments field experiment, MILAGRO, in March 2006. Photoacoustic and reciprocal nephelometer measurements at 532 nm accomplished with a single instrument compare favorably with conventional measurements made with an aethalometer and a TSI nephelometer. The diurnally averaged single scattering albedo at 532 nm was found to vary from 0.60 to 0.85 with the peak value at midday and the minimum value at 07:00 a.m. local time, indicating that the Mexico City plume is likely to have a net warming effect on local climate. The peak value is associated with strong photochemical generation of secondary aerosol. It is estimated that the photochemical production of secondary aerosol (inorganic and organic) is approximately 75% of the aerosol mass concentration and light scattering in association with the peak single scattering albedo. A strong correlation of aerosol scattering at 532 nm and total aerosol mass concentration was found, and an average mass scattering efficiency factor of 3.8 m2/g was determined. Comparisons of photoacoustic and aethalometer light absorption with oxygenated organic aerosol concentration (OOA) indicate a very small systematic bias of the filter based measurement associated with OOA and the peak aerosol single scattering albedo.

  9. Primary and secondary contributions to aerosol light scattering and absorption in Mexico City during the MILAGRO 2006 campaign

    NASA Astrophysics Data System (ADS)

    Paredes-Miranda, G.; Arnott, W. P.; Jimenez, J. L.; Aiken, A. C.; Gaffney, J. S.; Marley, N. A.

    2008-09-01

    A photoacoustic spectrometer, a nephelometer, an aetholemeter, and an aerosol mass spectrometer were used to measure at ground level real-time aerosol light absorption, scattering, and chemistry at an urban site located in north east Mexico City (Instituto Mexicano del Petroleo, Mexican Petroleum Institute, denoted by IMP), as part of the Megacity Impact on Regional and Global Environments field experiment, MILAGRO, in March 2006. Photoacoustic and reciprocal nephelometer measurements at 532 nm accomplished with a single instrument compare favorably with conventional measurements made with an aethelometer and a TSI nephelometer. The diurnally averaged single scattering albedo at 532 nm was found to vary from 0.60 to 0.85 with the peak value at midday and the minimum value at 7 a.m. local time, indicating that the Mexico City plume is likely to have a net warming effect on local climate. The peak value is associated with strong photochemical generation of secondary aerosol. It is estimated that the same-day photochemical production of secondary aerosol (inorganic and organic) is approximately 40 percent of the aerosol mass concentration and light scattering in association with the peak single scattering albedo. A strong correlation of aerosol scattering at 532 nm and total aerosol mass concentration was found, and an average mass scattering efficiency factor of 3.8 m2/g was determined. Comparisons of photoacoustic and aethalometer light absorption with oxygenated organic aerosol concentration (OOA) indicate a very small systematic bias of the filter based measurement associated with OOA and the peak aerosol single scattering albedo.

  10. Profiling of aerosol microphysical properties at several EARLINET/AERONET sites during the July 2012 ChArMEx/EMEP campaign

    NASA Astrophysics Data System (ADS)

    José Granados-Muñoz, María; Navas-Guzmán, Francisco; Guerrero-Rascado, Juan Luis; Bravo-Aranda, Juan Antonio; Binietoglou, Ioannis; Nepomuceno Pereira, Sergio; Basart, Sara; María Baldasano, José; Belegante, Livio; Chaikovsky, Anatoli; Comerón, Adolfo; D'Amico, Giuseppe; Dubovik, Oleg; Ilic, Luka; Kokkalis, Panos; Muñoz-Porcar, Constantino; Nickovic, Slobodan; Nicolae, Doina; José Olmo, Francisco; Papayannis, Alexander; Pappalardo, Gelsomina; Rodríguez, Alejandro; Schepanski, Kerstin; Sicard, Michaël; Vukovic, Ana; Wandinger, Ulla; Dulac, François; Alados-Arboledas, Lucas

    2016-06-01

    The simultaneous analysis of aerosol microphysical properties profiles at different European stations is made in the framework of the ChArMEx/EMEP 2012 field campaign (9-11 July 2012). During and in support of this campaign, five lidar ground-based stations (Athens, Barcelona, Bucharest, Évora, and Granada) performed 72 h of continuous lidar measurements and collocated and coincident sun-photometer measurements. Therefore it was possible to retrieve volume concentration profiles with the Lidar Radiometer Inversion Code (LIRIC). Results indicated the presence of a mineral dust plume affecting the western Mediterranean region (mainly the Granada station), whereas a different aerosol plume was observed over the Balkans area. LIRIC profiles showed a predominance of coarse spheroid particles above Granada, as expected for mineral dust, and an aerosol plume composed mainly of fine and coarse spherical particles above Athens and Bucharest. Due to the exceptional characteristics of the ChArMEx database, the analysis of the microphysical properties profiles' temporal evolution was also possible. An in-depth analysis was performed mainly at the Granada station because of the availability of continuous lidar measurements and frequent AERONET inversion retrievals. The analysis at Granada was of special interest since the station was affected by mineral dust during the complete analyzed period. LIRIC was found to be a very useful tool for performing continuous monitoring of mineral dust, allowing for the analysis of the dynamics of the dust event in the vertical and temporal coordinates. Results obtained here illustrate the importance of having collocated and simultaneous advanced lidar and sun-photometer measurements in order to characterize the aerosol microphysical properties in both the vertical and temporal coordinates at a regional scale. In addition, this study revealed that the use of the depolarization information as input in LIRIC in the stations of Bucharest,

  11. Discussion of vicarious calibration of GOSAT/TANSO-CAI UV-band (380nm) and aerosol retrieval in wildfire region in the OCO-2 and GOSAT observation campaign at Railroad Valley in 2016

    NASA Astrophysics Data System (ADS)

    Hashimoto, M.; Kuze, A.; Bruegge, C. J.; Shiomi, K.; Kataoka, F.; Kikuchi, N.; Arai, T.; Kasai, K.; Nakajima, T.

    2016-12-01

    The GOSAT (Greenhouse Gases Observing Satellite) / TANSO-CAI (Cloud and Aerosol Imager, CAI) is an imaging sensor to measure cloud and aerosol properties and observes reflected sunlight from the atmosphere and surface of the ground. The sensor has four bands from near ultraviolet (near-UV) to shortwave infrared, 380, 674, 870 and 1600nm. The field of view size is 0.5 km for band-1 through band-3, and 1.5km for band-4. Band-1 (380nm) is one of unique function of the CAI. The near-UV observation offers several advantages for the remote sensing of aerosols over land: Low reflectance of most surfaces; Sensitivity to absorbing aerosols; Absorption of trace gases is weak (Höller et al., 2004). CAI UV-band is useful to distinguish absorbing aerosol (smoke) from cloud. GOSAT-2/TANSO-CAI-2 that will be launched in the future also has UV-bands, 340 and 380nm. We carried out an experiment to calibrate CAI UV-band radiance using data taken in a field campaign of OCO-2 and GOSAT at Railroad Valley in 2016. The campaign period is June 27 to July 3 in 2016. We measured surface reflectance by using USB4000 Spectrometer with 74-UV collimating lens (Ocean Optics) and Spectralon (Labsphere). USB4000 is a UV spectrometer, and its measurement range from 300 to 520nm. We simulated CAI UV-band radiance using a vector type of radiation transfer code, i.e. including polarization calculation, pstar3 (Ota et al., 2010) using measured surface reflectance and atmospheric data, pressure and relative humidity by radiosonde in the same campaign, and aerosol optical depth by AERONET, etc. Then, we evaluated measured UV radiances with the simulated data. We show the result of vicarious calibration of CAI UV-band in the campaign, and discuss about this method for future sensor, CAI-2. Around the campaign period, there was wildfire around Los Angeles, and aerosol optical thickness (AOT) observed by AERONET at Rail Road valley and Caltech sites is also high. We tried to detect and retrieve aerosol

  12. Phase Partitioning of Soluble Trace Gases with Size-Resolved Aerosols during the Nitrogen, Aerosol Composition, and Halogens on a Tall Tower (NACHTT) Campaign

    NASA Astrophysics Data System (ADS)

    Young, A.; Keene, W. C.; Pszenny, A.; Sander, R.; Maben, J. R.; Warrick-Wriston, C.; Bearekman, R.

    2011-12-01

    During February and March 2011, size-resolved and bulk aerosol were sampled at 22 m above the surface over nominal 12-hour (daytime and nighttime) intervals from the Boulder Atmospheric Observatory tower (40.05 N, 105.01 W, 1584-m elevation). Samples were analyzed for major organic and inorganic ionic constituents by high performance ion chromatography (IC). Soluble trace gases (HCl, HNO3, NH3, HCOOH, and CH3COOH) were sampled in parallel over 2-hour intervals with tandem mist chambers and analyzed on site by IC. NH4+, NO3-, and SO42- were the major ionic components of aerosols (median values of 57.7, 34.5, and 7.3 nmol m-3 at STP, respectively, N = 45) with 86%, 82%, and 82%, respectively, associated with sub-μm size fractions. Cl- and Na+ were present at significant concentrations (median values of 6.8 and 6.6 nmol m-3, respectively) but were associated primarily with super-μm size fractions (75% and 78%, respectively). Median values (and ranges) for HCl, HNO3, and NH3 were 21 (<20-1257), 120 (<45-1638), and 5259 (<1432-48,583) pptv, respectively. Liquid water contents of size-resolved aerosols and activity coefficients for major ionic constituents were calculated with the Extended Aerosol Inorganic Model II and IV (E-AIM) based on the measured aerosol composition, RH, temperature, and pressure. Size-resolved aerosol pHs were inferred from the measured phase partitioning of HCl, HNO3, and NH3. Major controls of phase partitioning and associated chemical dynamics will be presented.

  13. Radiative Effect of Springtime Biomass-Burning Aerosols over Northern Indochina During 7-SEAS Baseline 2013 Campaign

    NASA Technical Reports Server (NTRS)

    Pani, Shantanu Kumar; Wang, Sheng-Hsiang; Lin, Neng-Huei; Lee, Chung-Te; Tsay, Si-Chee; Holben, Brent N.; Janjai, Serm; Hsiao, Ta-Chih; Chuang, Ming-Tung; Chantara, Somporn

    2016-01-01

    The direct aerosol radiative effects of biomass-burning (BB) aerosols over northern Indochina were estimated by using aerosol properties (physical, chemical, and optical) along with the vertical profile measurements from ground-based measurements with integration of an optical and a radiative transfer model during the Seven South East Asian Studies Biomass-Burning Aerosols Stratocumulus Environment: Lifecycles Interactions Experiment (7-SEASBASELInE) conducted in spring 2013. Cluster analysis of backward trajectories showed the air masses arriving at mountainous background site (Doi Ang Khang; 19.93degN, 99.05degE, 1536 m above mean sea level) in northern Indochina, mainly from near-source inland BB activities and being confined in the planetary boundary layer. The PM(sub10) and black carbon (BC)mass were 87 +/- 28 and 7 +/- 2 micrograms m(exp -3), respectively. The aerosol optical depth (AOD (sub 500) was found to be 0.26--1.13 (0.71 +/- 0.24). Finer (fine mode fraction is approximately or equal to 0.95, angstrom-exponent at 440-870 nm is approximately or equal to 1.77) and significantly absorbing aerosols(single scattering albedo is approximately or equal to 0.89, asymmetry-parameter is approximately or equal to 0.67, and absorption AOD 0.1 at 440 nm) dominated over this region. BB aerosols (water soluble and BC) were the main contributor to the aerosol radiative forcing (ARF), while others (water insoluble, sea salt and mineral dust) were negligible mainly due to their low extinction efficiency. BC contributed only 6 to the surface aerosol mass but its contribution to AOD was 12 (2 times higher). The overall mean ARF was 8.0 and -31.4 W m(exp -2) at top-of-atmosphere (TOA) and at the surface (SFC), respectively. Likely, ARF due to BC was +10.7 and -18.1 W m(exp -2) at TOA and SFC, respectively. BC imposed the heating rate of +1.4 K d(exp -1) within the atmosphere and highlighting its pivotal role in modifying the radiation budget. We propose that to upgrade our

  14. Environmental Snapshots for Satellite Multi-Angle Aerosol Retrieval Validation During the ACE-Asia Field Campaign

    NASA Technical Reports Server (NTRS)

    Kahn, Ralph; Anderson, Jim; Anderson, Theodore L.; Bates, Tim; Brechtel, Fred; Clarke, Antony; Dutton, Ellsworth; Flagan, Richard; Fouin, Robert; Fukushima, Hajime

    2003-01-01

    On five occasions spanning the ACE-Asia field experiment in spring 2001, the multi-angle imaging MISR instrument, flying aboard the NASA Earth Observing System s Terra satellite, took quarter-kilometer data over a 400-km-wide swath, coincident with high-quality observations by multiple instruments on two or more participating surface and airborne platforms. The cases capture a range of clean, polluted, and dusty aerosol conditions. They represent some of the best opportunities during ACE- Asia for comparative studies among intensive and extensive aerosol observations in their environmental context. We inter-compare related measurements and discuss the implications of apparent discrepancies for each case, at a level of detail appropriate to the analysis of satellite observations. With a three-stage optical modeling process, we synthesize data from multiple sources into layer-by-layer snapshots that summarize what we know about the state of the atmosphere and surface at key locations during each event, to be used for satellite vicarious calibration and aerosol retrieval validation. Aerosols within a few kilometers of the surface were composed primarily of pollution and Asian dust mixtures, as expected. Accumulation and coarse-mode particle size distributions varied little among the events studied, but column aerosol optical depth changed by more than a factor of four, and the near-surface proportion of dust ranged from about 25% to 50%. The amount of absorbing material in the sub-micron fraction was highest when near-surface winds crossed Beijing and the Korean Peninsula, and was considerably lower for all other cases. Ambiguities remain in segregating size distributions by composition; having simultaneous single scattering albedo measurements at more than a single wavelength would significantly reduce the resulting optical model uncertainties, as would integral constraints from surface and atmospheric radiative flux observations. The consistency of component

  15. Aerosol properties derived from airborne sky radiance and direct beam measurements in recent NASA and DoE field campaigns

    NASA Astrophysics Data System (ADS)

    Redemann, J.; Flynn, C. J.; Shinozuka, Y.; Russell, P. B.; Kacenelenbogen, M. S.; Segal-Rosenhaimer, M.; Livingston, J. M.; Schmid, B.; Dunagan, S. E.; Johnson, R. R.; LeBlanc, S. E.; Schmidt, S.; Pilewskie, P.; Song, S.

    2014-12-01

    The AERONET (AErosol RObotic NETwork) ground-based suite of sunphotometers provides measurements of spectral aerosol optical depth (AOD), precipitable water and spectral sky radiance, which can be inverted to retrieve aerosol microphysical properties that are critical to assessments of aerosol-climate interactions. Because of data quality criteria and sampling constraints, there are significant limitations to the temporal and spatial coverage of AERONET data and their representativeness for global aerosol conditions. The 4STAR (Spectrometer for Sky-Scanning, Sun-Tracking Atmospheric Research) instrument, jointly developed by NASA Ames and PNNL with NASA Goddard collaboration, combines airborne sun tracking and AERONET-like sky scanning with spectroscopic detection. Being an airborne instrument, 4STAR has the potential to fill gaps in the AERONET data set. The 4STAR instrument operated successfully in the SEAC4RS [Studies of Emissions and Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys] experiment in Aug./Sep. 2013 aboard the NASA DC-8 and in the DoE [Department of Energy]-sponsored TCAP [Two Column Aerosol Project, July 2012 & Feb. 2013] experiment aboard the DoE G-1 aircraft. 4STAR provided direct beam measurements of hyperspectral AOD, columnar trace gas retrievals (H2O, O3, NO2), and the first ever airborne hyperspectral sky radiance scans, which can be inverted to yield the same products as AERONET ground-based observations. In this presentation, we provide an overview of the new 4STAR capabilities, with an emphasis on 26 high-quality sky radiance measurements carried out by 4STAR in SEAC4RS. We compare collocated 4STAR and AERONET sky radiances, as well as their retrievals of aerosol microphysical properties for a subset of the available case studies. We summarize the particle property and airmass characterization studies made possible by the combined 4STAR direct beam and sky radiance observations.

  16. Aerosol Properties Derived from Airborne Sky Radiance and Direct Beam Measurements in Recent NASA and DoE Field Campaigns

    NASA Technical Reports Server (NTRS)

    Redemann, J.; Flynn, C. J.; Shinozuka, Y.; Russell, P. B.; Kacenelenbogen, M.; Segal-Rosenheimer, M.; Livingston, J. M.; Schmid, B.; Dunagan, S. E.; Johnson, R. R.; hide

    2014-01-01

    The AERONET (AErosol RObotic NETwork) ground-based suite of sunphotometers provides measurements of spectral aerosol optical depth (AOD), precipitable water and spectral sky radiance, which can be inverted to retrieve aerosol microphysical properties that are critical to assessments of aerosol-climate interactions. Because of data quality criteria and sampling constraints, there are significant limitations to the temporal and spatial coverage of AERONET data and their representativeness for global aerosol conditions.The 4STAR (Spectrometer for Sky-Scanning, Sun-Tracking Atmospheric Research) instrument, jointly developed by NASA Ames and PNNL (Pacific Northwest National Laboratory) with NASA Goddard collaboration, combines airborne sun tracking and AERONET-like sky scanning with spectroscopic detection. Being an airborne instrument, 4STAR has the potential to fill gaps in the AERONET data set. The 4STAR instrument operated successfully in the SEAC4RS (Studies of Emissions and Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys) experiment in Aug./Sep. 2013 aboard the NASA DC-8 and in the DoE (Department of Energy)-sponsored TCAP (Two Column Aerosol Project, July 2012 & Feb. 2013) experiment aboard the DoE G-1 aircraft. 4STAR provided direct beam measurements of hyperspectral AOD, columnar trace gas retrievals (H2O, O3, NO2), and the first ever airborne hyperspectral sky radiance scans, which can be inverted to yield the same products as AERONET ground-based observations. In this presentation, we provide an overview of the new 4STAR capabilities, with an emphasis on 26 high-quality sky radiance measurements carried out by 4STAR in SEAC4RS. We compare collocated 4STAR and AERONET sky radiances, as well as their retrievals of aerosol microphysical properties for a subset of the available case studies. We summarize the particle property and air-mass characterization studies made possible by the combined 4STAR direct beam and sky radiance

  17. Assessing Aerosol Mixed Layer Heights from the NASA Larc Airborne High Spectral Resolution Lidar (HSRL) during the Discover-AQ Field Campaigns

    NASA Astrophysics Data System (ADS)

    Scarino, A. J.; Ferrare, R. A.; Burton, S. P.; Hostetler, C. A.; Hair, J. W.; Rogers, R. R.; Berkoff, T.; Sawamura, P.; Collins, J. E., Jr.; Seaman, S. T.; Cook, A. L.; Harper, D. B.; Follette-Cook, M. B.; daSilva, A.; Randles, C. A.

    2014-12-01

    The first- and second-generation NASA airborne High Spectral Resolution Lidars (HSRL-1 and HSRL-2) have been deployed on board the NASA Langley Research Center King Air aircraft during the Deriving Information on Surface Conditions from Column and VERtically Resolved Observations Relevant to Air Quality (DISCOVER-AQ) field campaigns. These included deployments during July 2011 over Washington, D.C. and Baltimore, MD, during January and February 2013 over the San Joaquin Valley of California, during September 2013 over Houston, TX and during July and August 2014 over Denver, CO. Measurements of aerosol extinction, backscatter, and depolarization are available from both HSRL-1 and HSRL-2 in coordination with other participating research aircraft and ground sites. These measurements constitute a diverse data set for use in characterizing the spatial and temporal distribution of aerosols, aerosol optical thickness (AOT), as well as the mixed layer (ML) height. Analysis of the ML height at these four locations is presented, including temporal and horizontal variability and comparisons between land and water, including the Chesapeake Bay and Galveston Bay. Using the ML heights, the distribution of AOT relative to the ML heights is determined, which is relevant for assessing the long-range transport of aerosols. The ML heights are also used to help relate column AOT measurements and extinction profiles to surface PM2.5 concentrations. The HSRL ML heights are also used to evaluate the performance in simulating the temporal and spatial variability of ML heights from both chemical regional models and global forecast models.

  18. Airborne measurements of spectral direct aerosol radiative forcing in INTEX/ICARTT (2004) and comparisons to previous campaigns

    NASA Astrophysics Data System (ADS)

    Redemann, J.; Pilewskie, P.; Russell, P.; Livingston, J.; Howard, S.; Schmid, B.; Pommier, J.; Gore, W.; Eilers, J.; Wendisch, M.; Bush, B.; Valero, F.

    2005-12-01

    As part of the INTEX-NA (INtercontinental chemical Transport EXperiment-North America) and ITCT (Intercontinental Transport and Chemical Transformation of anthropogenic pollution) field studies, the NASA Ames 14-channel Airborne Tracking Sunphotometer (AATS-14) and a pair of Solar Spectral Flux Radiometers (SSFR) took measurements from aboard a Jetstream 31 (J31) aircraft during 19 science flights (~ 53 flight hours) over the Gulf of Maine between 12 July and 8 August 2004. AATS-14 measures the direct solar beam transmission at 14 discrete wavelengths (354-2138 nm), yielding aerosol optical depth (AOD) spectra, while the SSFR system yields down- and upwelling solar irradiance at a spectral resolution of ~ 8-12 nm over the wavelength range 300-1700 nm. The combination of simultaneous AATS and SSFR measurements yields plots of net spectral irradiance as a function of aerosol optical depth as measured along horizontal flight legs. From the slope of these plots we determine the instantaneous aerosol-induced change in net radiative flux per change in AOD. By normalization to an aerosol optical depth change of unity we derive the spectral aerosol radiative forcing efficiency [W m-2 nm-1]. Numerical integration of the irradiance measurements over a given spectral range yields the broadband aerosol radiative forcing efficiency [W m-2]. In INTEX/ITCT, we observed a total of 16 horizontal AOD gradients, with 10 gradients well suited for our analysis because of the small changes in solar zenith angle. Within the 10 case studies we found a high variability in the derived instantaneous aerosol forcing efficiencies for the visible wavelength range (350-700 nm), with a mean of -79.6 W m-2 and a standard deviation of 21.8 W m-2 (27%). The mean instantaneous forcing efficiency for the visible plus near-IR wavelength range (350-1670 nm) was derived to be 135.3 W m-2 with a standard deviation of 36.0 W m-2 (27%). An analytical conversion of the instantaneous forcing efficiencies to

  19. Radiocarbon-based Source Apportionment of Organic, Elemental and Water-soluble Organic Carbon Aerosols and the Light Absorption of Water-soluble Organic Carbon Aerosols in the East Asia High-intensity Winter Campaigns in 2014

    NASA Astrophysics Data System (ADS)

    Fang, W.; Andersson, A.; Zheng, M.; Lee, M.; Kim, S. W.; Du, K.; Gustafsson, O.

    2016-12-01

    Improved understanding of anthropogenic aerosol effects on atmospheric chemistry and climate as well as efficient mitigation actions are hampered by the limited comprehension of the relative contributions of different sources of carbonaceous aerosols and of their subsequent atmospheric processing. Here, we present dual carbon isotope constrained source apportionment and optical properties of carbonaceous aerosols simultaneously both at urban and rural receptor sites, includes North China Plain (NCP, Beijing and Tianjin), Yangtze River Delta (YRD, Shanghai, Zhejiang), and Jeju Island (Korea Climate Observatory at Gosan) during January 2014 field campaigns. The radiocarbon (∆14C) data show that fossil combustions contribute equally ˜80 ± 5% to elemental carbon (EC) aerosol in Beijing, Tianjin, and Shanghai, and 66 ± 9% to Gosan-EC aerosol, while the specific sources of the dominant fossil fuel component were dramatically different among these sites. The mean fraction coal combustion of Beijing-EC, Tianjin-EC, and Gosan-EC is double that of Shanghai-EC. The other large fraction (72―92%) of carbonaceous aerosol is organic carbon (OC) aerosol which contains water soluble and water insoluble organic carbon (WSOC and WISOC). OC, WISOC, and WSOC in Beijing and Gosan sites were still observed largely from fossil sources (53―75%). The more 13C-enriched signature of Gosan-WSOC (-22.8 ± 0.2‰) compared to Gosan-EC (-23.9 ± 0.4‰) and Beijing-WSOC (-23.5 ± 0.7‰) reflects that WSOC is likely more affected by atmospheric aging during long-rang transport than is EC. The high light absorption coefficients of PM2.5, PM1, and TSP were observed at Gosan during this study and was frequently reaching 20―60 Mm-1 by aethalometer and continuous light absorption photometer. The mass absorption cross section of WSOC (MAC365) for above sites is high (1.5 ± 0.8 m2/g), accounted for ˜14 ± 5% of the total direct absorbance relative to EC, which is significantly higher than

  20. Green Ocean Amazon (GoAmazon) 2014/15. Semi-Volatile Thermal Desorption Aerosol Gas Chromatograph (SVTAG) Field Campaign Report

    SciTech Connect

    Goldstein, A. H.; Yee, L. D.; Issacman-VanWertz, G.; Wernis, R. A.

    2016-03-01

    In areas where biogenic emissions are oxidized in the presence of anthropogenic pollutants such as SO2, NOx, and black carbon, it has become increasingly apparent that secondary organic aerosol (SOA) formation from biogenic volatile organic compounds (VOCs) is substantially enhanced. Research is urgently needed to elucidate fundamental processes of natural and anthropogenically influenced VOC oxidation and the contribution of these processes to SOA formation. GoAmazon 2014/15 afforded study of the chemical transformations in the region downwind of Manaus, Brazil, where local biogenic VOC emissions are high, and their chemical oxidation can be studied both inside and outside of the urban plume to differentiate the role of anthropogenic influence on secondary aerosol formation during oxidation of these natural VOC emissions. To understand the connection between primary biogenic VOC emissions and their secondary products that form aerosols, we made time-resolved molecular level measurements by deploying a Semi-Volatile Thermal Desorption Aerosol Gas Chromatograph (SV-TAG) and a sequential filter sampler during two intensive operational periods (IOPs) of the GoAmazon 2014/15 field campaign. The SV-TAG measured semi-volatile organic compounds in both the gas and particle phases and the sequential filter sampler collected aerosols on quartz fiber filters in four-hour increments used for offline analysis. SV-TAG employed novel online derivatization that provided chemical speciation of highly oxygenated or functionalized compounds that comprise a substantial fraction of secondary organic aerosols, yet are poorly characterized. It also provided partitioning of these compounds between the vapor and particle phases at sufficient time resolution to define the importance of competing atmospheric processes. These measurements were supported by offline analysis of the filters using two-dimensional gas chromatography (GC x GC) with high-resolution time-of-flight mass spectrometry

  1. Aerosol Optical Extinction during the Front Range Air Pollution and Photochemistry Experiment (FRAPPE) 2014 Summertime Field Campaign, Colorado U.S.A.

    NASA Astrophysics Data System (ADS)

    Dingle, J. H.; Vu, K. K. T.; Bahreini, R.; Apel, E. C.; Campos, T. L.; Cantrell, C. A.; Cohen, R. C.; Ebben, C. J.; Flocke, F. M.; Fried, A.; Herndon, S. C.; Hills, A. J.; Hornbrook, R. S.; Huey, L. G.; Kaser, L.; Mauldin, L.; Montzka, D. D.; Nowak, J. B.; Richter, D.; Roscioli, J. R.; Shertz, S.; Stell, M. H.; Tanner, D.; Tyndall, G. S.; Walega, J.; Weibring, P.; Weinheimer, A. J.

    2015-12-01

    Aerosol optical extinction (βext) was measured in the Colorado Front Range Denver Metropolitan Area as part of the summertime air quality airborne field campaign to characterize the influence of sources, photochemical processing, and transport of pollution on local air quality. An Aerodyne Cavity Attenuated Phase Shift particle light extinction monitor (CAPS-PMex) was deployed to measure dry βext at λ=632 nm at 1 Hz. Data from a suite of gas-phase instrumentation were used to interpret the βext under various categories of aged air masses and sources. Extinction enhancement ratios of Δβext/ΔCO were evaluated under 3 differently aged air mass categories (fresh, intermediately aged, and aged) to investigate impacts of photochemistry on βext. Δβext/ΔCO was significantly increased in heavily aged air masses compared to fresh air masses (0.17 Mm-1/ppbv and 0.094 Mm-1/ppbv respectively). The resulting increase in Δβext/ΔCO under heavily aged air masses was represented by secondary organic aerosols (SOA) formation. Aerosol composition and sources from urban, natural oil and gas wells (OG), and agriculture and livestock operations were also evaluated for their impacts on βext. Linear regression fits to βext vs. organic aerosol mass showed higher correlation coefficients under the urban and OG plumes (r=0.55 and r=0.71 respectively) and weakest under agricultural and livestock plumes (r=0.28). The correlation between βext and nitrate aerosol mass however was best under the agriculture and livestock plumes (r=0.81), followed by OG plumes (r=0.74), suggesting co-location of aerosol nitrate precursor sources with OG emissions. Finally, non-refractory mass extinction efficiency (MEE) was analyzed. MEE was observed to be 1.37 g/m2 and 1.30 g/m2 in OG and urban+OG plumes, respectively.

  2. Lidar measurements of aerosol at Varanasi (25.28° N, 82.96° E), India during CAIPEEX scientific campaign

    NASA Astrophysics Data System (ADS)

    Vishnu, R.; Bhavani Kumar, Y.; Rao, Y. Jaya; Samuel, E. James J.; Thara, P.; Jayaraman, A.

    2016-05-01

    A compact dual polarization lidar (DPL) was designed and developed at National Atmospheric Research Laboratory (NARL) for daytime measurements of the boundary layer aerosol distribution and depolarization properties with very high vertical and temporal resolution. The lidar employs a compact flashlamp pumped Q-switched Nd:YAG laser and operates at 532 nm wavelength. The lidar system uses a stable biaxial configuration between transmitter and receiver units. The receiver utilizes a 150 mm Schmidt Cassegranin telescope for collecting laser returns from the atmosphere. The collected backscattered light is separated into co and cross-polarization signals using a polarization beam splitter cube. A set of mini-PMTs have been used for detection of light from atmosphere during daylight period. A two channel transient recorder system with built-in ADC has been employed for recording the detected light. The entire lidar system is housed in a compact cabinet which can be easily transported for field measurements. During 2014, the lidar system was installed at the Banaras Hindu University (BHU) campus, Varanasi (25.28° N, 82.96° E, 82 m AMSL) and operated for a period of three months in to support the cloud aerosol interaction and precipitation enhancement experiment (CAIPEEX) conducted by Indian Institute of tropical meteorology (IITM). During this campaign period, the lidar measurements were carried out in the vertical direction with spatial resolution of 7.5 m and time sampling of 30s. The lidar measurements revealed the occurrence of boundary layer growth during convective periods and also detected the long-range transport dust layers with significant depolarization. In the present paper, we present the lidar measurements obtained during the campaign period and discuss the observation of transport of dust layer over the experimental site with support of back trajectory analysis and satellite data. The Lidar observations were compared with the available satellite

  3. Levoglucosan and Lipid Class Compounds in the Asian Dusts and Marine Aerosols Collected During the ACE-Asia Campaign

    NASA Astrophysics Data System (ADS)

    Kobayashi, M.; Simoneit, B. R.; Kawamura, K.; Mochida, M.; Lee, M.; Lee, G.; Huebert, B. J.

    2002-12-01

    In order to characterize organic aerosols in the Asian Pacific region, we collected filter samples at Gosan (formerly Kosan) and Sapporo sites as well as on mobile platforms (R.V. R.H. Brown and NCAR C-130) in the western North Pacific. The aerosol extracts were analyzed by capillary GC-MS employing a TMS derivatization technique. We identified over 100 organic compounds in the samples. They are categorized into seven different classes in terms of functional groups and sources. First, sugar-type compounds were detected in the aerosols, including levoglucosan, galactosan and mannosan, which are tracers for biomass burning. Second, a homologous series of fatty acids (C12-C30) and fatty alcohols (C12-C30) mainly from plant waxes and marine lipids were present. The third group includes dicarboxylic acids (>C3) and other atmospheric oxidation products. Although oxalic (C2) and malonic (C3) acids were not detected by this method, they are very abundant in the aerosols. The fourth group includes n-alkanes (C18-C35) which usually showed a strong odd/even predominance, suggesting an important contribution from higher plant waxes. The fifth includes polynuclear aromatic hydrocarbons (PAH) ranging from phenanthrene to coronene, all combustion products of petroleum and mainly coal. Saccharides were the sixth group and consisted mainly of a- and b- glucose, sucrose and its alditol, and minor amounts of xylitol, sorbitol and arabitol. These saccharides are tracers for soil dust. Phthalates were detected as the seventh class, with a dominance of dioctyl phthalate. The results suggest that organic aerosols originate primarily from (1) natural emissions of terrestrial plant wax and marine lipids, (2) smoke from biomass burning (mainly non-conifer fuels), (3) soil resuspension due to spring agricultural activity, (4) urban/industrial emissions from fossil fuel use (coal), and (5) secondary reaction products. These compounds are transported by the strong westerly winds and therefore

  4. Coincident Aerosol and H2O Retrievals versus HSI Imager Field Campaign ReportH2O Retrievals versus HSI Imager Field Campaign Report

    SciTech Connect

    Anderson, Gail P.; Cipar, John; Armstrong, Peter S.; van den Bosch, J.

    2016-05-01

    Two spectrally calibrated tarpaulins (tarps) were co-located at a fixed Global Positioning System (GPS) position on the gravel antenna field at the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility’s Southern Great Plains (SGP) site. Their placement was timed to coincide with the overflight of a new hyperspectral imaging satellite. The intention was to provide an analysis of the data obtained, including the measured and retrieved spectral albedos for the calibration tarps. Subsequently, a full suite of retrieved values of H2O column, and the aerosol overburden, were to be compared to those determined by alternate SGP ground truth assets. To the extent possible, the down-looking cloud images would be assessed against the all-sky images. Because cloud contamination above a certain level precludes the inversion processing of the satellite data, coupled with infrequent targeting opportunities, clear-sky conditions were imposed. The SGP site was chosen not only as a target of opportunity for satellite validation, but as perhaps the best coincident field measurement site, as established by DOE’s ARM Facility. The satellite team had every expectation of using the information obtained from the SGP to improve the inversion products for all subsequent satellite images, including the cloud and radiative models and parameterizations and, thereby, the performance assessment for subsequent and historic image collections. Coordinating with the SGP onsite team, four visits, all in 2009, to the Central Facility occurred: • June 6-8 (successful exploratory visit to plan tarp placements, etc.) • July 18-24 (canceled because of forecast for heavy clouds) • Sep 9-12 (ground tarps placed, onset of clouds) • Nov 7-9 (visit ultimately canceled because of weather predictions). As noted, in each instance, any significant overcast prediction precluded image collection from the satellite. Given the long task-scheduling procedures

  5. Spatial and Temporal Patterns of Aerosols and Trace Gases over the Chesapeake Bay estuary during the Summer 2011 CBODAQ and DISCOVER-AQ campaigns

    NASA Astrophysics Data System (ADS)

    Tzortziou, M.; Loughner, C. P.; Cede, A.; Abuhassan, N.; Retscher, C.; Herman, J. R.; Holben, B.; Smirnov, A.; Pickering, K. E.; Dickerson, R. R.; Goldberg, D.; Crawford, J. H.; Mannino, A.

    2011-12-01

    Determining the sources, transport and spatio-temporal variability of aerosols, NO2 and other trace gases over coastal regions and the adjacent ocean is critical for improving modeling and prediction of coastal tropospheric air quality. It is also essential for accurate atmospheric correction of satellite coastal ocean-color observations, and for better understanding and modeling atmospheric deposition in coastal ecosystems. Space-based remote sensing provides a powerful tool for monitoring changes in atmospheric composition and transport of pollution over land and the ocean. To enhance the scientific return of satellite remote sensing, obtain a more complete picture of the atmosphere and make measurements relevant to our understanding of coastal ecosystem dynamics, satellite observations must be used in combination with model simulations and detailed ground-based observations. This becomes extremely challenging over coastal waters and the ocean, since ground-based stations that monitor tropospheric air quality come to an abrupt end at the coastlines. Here we present new measurements of aerosols and trace gases (O3 and NO2) over the Chesapeake Bay estuarine waters using ground-based and ship-based instruments. Measurements were obtained as part of the GeoCAPE CBODAQ/DISCOVER-AQ oceanographic and air quality campaigns during July 2011. High resolution model runs were performed using the CMAQ (Community Multi-scale Air Quality) and WRF (Weather Research and Forecasting) models, to examine spatial gradients and temporal variability in aerosols and trace gases over this estuarine environment where land-sea processes such as bay breezes influence the dispersion of pollutants and ozone formation.

  6. Airborne characterization of subsaturated aerosol hygroscopicity and dry refractive index from the surface to 6.5 km during the SEAC4RS campaign

    NASA Astrophysics Data System (ADS)

    Shingler, Taylor; Crosbie, Ewan; Ortega, Amber; Shiraiwa, Manabu; Zuend, Andreas; Beyersdorf, Andreas; Ziemba, Luke; Anderson, Bruce; Thornhill, Lee; Perring, Anne E.; Schwarz, Joshua P.; Campazano-Jost, Pedro; Day, Douglas A.; Jimenez, Jose L.; Hair, Johnathan W.; Mikoviny, Tomas; Wisthaler, Armin; Sorooshian, Armin

    2016-04-01

    In situ aerosol particle measurements were conducted during 21 NASA DC-8 flights in the Studies of Emissions and Atmospheric Composition, Clouds, and Climate Coupling by Regional Surveys field campaign over the United States, Canada, Pacific Ocean, and Gulf of Mexico. For the first time, this study reports rapid, size-resolved hygroscopic growth and real refractive index (RI at 532 nm) data between the surface and upper troposphere in a variety of air masses including wildfires, agricultural fires, biogenic, marine, and urban outflow. The Differential Aerosol Sizing and Hygroscopicity Spectrometer Probe (DASH-SP) quantified size-resolved diameter growth factors (GF = Dp,wet/Dp,dry) that are used to infer the hygroscopicity parameter κ. Thermokinetic simulations were conducted to estimate the impact of partial particle volatilization within the DASH-SP across a range of sampling conditions. Analyses of GF and RI data as a function of air mass origin, dry size, and altitude are reported, in addition to κ values for the inorganic and organic fractions of aerosol. Average RI values are found to be fairly constant (1.52-1.54) for all air mass categories. An algorithm is used to compare size-resolved DASH-SP GF with bulk scattering f(RH = 80%) data obtained from a pair of nephelometers, and the results show that the two can only be reconciled if GF is assumed to decrease with increasing dry size above 400 nm (i.e., beyond the upper bound of DASH-SP measurements). Individual case studies illustrate variations of hygroscopicity as a function of dry size, environmental conditions, altitude, and composition.

  7. Intercomparison of aerosol physical and physical properties derived from surface radiometers and in-situ aircraft profiles over six Maryland sites during the DRAGON and DISCOVER-AQ campaign

    NASA Astrophysics Data System (ADS)

    Schafer, J. S.; Thornhill, K. L.; Holben, B. N.; Anderson, B. E.; Eck, T. F.; Giles, D. M.; Winstead, E. L.; Ziemba, L. D.; Beyersdorf, A. J.; Smirnov, A.; Slutsker, I.; Sinyuk, A.; Kenny, P.

    2011-12-01

    The Aerosol Robotic Network (AERONET) project and international collaborators deployed more than 40 Cimel sunphotometers in the Baltimore-Washington, DC region for the summer 2011 DRAGON-USA (Distributed Regional Aerosol Gridded Observational Network) campaign. This unprecedented mesoscale network was comprised of automatic sun/sky radiometers distributed with roughly 10km grid spacing (covering an area of ~60km x 120km) which operated continuously for more than two months. The DRAGON-USA campaign was concurrent with the NASA sponsored DISCOVER-AQ air quality experiment which performed 14 days of research flights in July concentrating on repeated multiple daily profile measurements of gaseous and particulate pollution over 6 primary sun photometer sites. Atmospheric conditions varied from clean and dry to extremely hazy and humid on flight days with corresponding aerosol optical depth (AOD) at 500 nm ranging from ~0.06 to ~0.90 and precipitable water (PW) ranging from ~1.5 cm to ~4.5 cm. In-situ aerosol properties were measured on the NASA P-3B by the NASA Langley Aerosol Group Experiment (LARGE) team using a suite of instruments to characterize ambient aerosol optical and microphysical properties. Size distributions were made with a custom scanning mobility particle sizer (SMPS), an Ultrahigh Sensitivity Aerosol Spectrometer (UHSAS) from Droplet Measurement Technologies, and Aerosol Particle Sizer (APS) from TSI. Aerosol optical measurements were made with a TSI-3563 3-wavelength integrating nephelometer and a 3-wavelength Radiance Research Particle Soot Absorption Photometer (PSAP). We present preliminary comparisons of coincident single scattering albedo (at three wavelengths) and column integrated size distributions retrieved from the surface Cimel sunphotometer almucantar sky radiances and from aircraft in-situ observations during flight profiles at key sites.

  8. Observations of Processed Asian Pollution with a High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) from the C-130 Aircraft During the INTEX-B Field Campaign

    NASA Astrophysics Data System (ADS)

    Dunlea, E.; Decarlo, P.; Aiken, A.; Kimmel, J.; Bahreini, R.; Peltier, R.; Weber, R.; Tomlinson, J.; Collins, D.; Shinozuka, Y.; Howell, S.; Clarke, A.; Emmons, L.; Apel, E.; Pfister, G.; van Donkelaar, A.; Millet, D.; Jimenez, J.

    2007-12-01

    Measurements of submicron, non-refractory aerosol mass were made from the NCAR/NSF C-130 aircraft using a High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) during the spring 2006 INTEX-B field campaign based in Seattle. We intercepted numerous Asian pollution layers, some after rapid transport across the Pacific and others after slower transport which had reduced aerosol concentrations and were depleted of short-lived tracers. The aerosol in Asian pollution layers intercepted over the Eastern Pacific Ocean was shown to have a predominance of sulfate over organic material, the latter being highly oxidized. Measurements and back trajectory calculations are consistent with the following sequence: (a) relatively more rapid conversion of organic precursors to organic aerosol compared to conversion of SO2 to sulfate just downwind of Asian urban centers and pollution sources, (b) uplift and transport of air masses resulting in washout of most aerosol material leaving relatively more SO2 available, and (c) subsequent SO2 to sulfate conversion as air masses are transported across the Pacific. This is consistent with Brock et al., JGR, 2004. Two case studies will be presented to describe this evolution of aerosol chemical composition during transport from Asia. Overall correlations of several tracers will be shown for comparing MOZART and GEOS-Chem model outputs with the measurements. Also, comparisons of AMS measurements with other aerosol instruments will be shown.

  9. Anthropogenic Effects on the Mixing State of Aerosols over Manaus during the Green Ocean Amazon (GoAmazon) Campaign

    NASA Astrophysics Data System (ADS)

    Fraund, M. W.; Pham, D.; Harder, T.; O'Brien, R.; Wang, B.; Laskin, A.; Gilles, M. K.; Moffet, R.

    2015-12-01

    The role that anthropogenic aerosols play in cloud formation is uncertain and contributes largely to the uncertainty in predicting future climate. One region of particular importance is the Amazon rainforest, which accounts for over half of the world's rainforest. During GoAmazon2014/15 IOP2, aerosol samples were collected at multiple sites in and around the rapidly growing industrial city of Manaus in the Amazon basin. Manaus is of scientific interest due to the pristine nature of the surrounding rainforest and the high levels of pollution coming from the city in the form of SO2, NOx, and soot. Some sites, such as the Terrestrial Ecosystem Science center (TES, also designated ZF2) located to the north of Manaus, represent air masses which have not interacted with emissions from the city. The comparison of pristine atmosphere with heavy pollution allows both for the determination of a natural baseline level of pollutants, as well as the study of pollutant's impact on the conversion of biogenic volatile organic compounds to secondary organic aerosols. Towards this goal, samples from ZF2 and other unpolluted sites will be compared to samples from the Atmospheric Radiation Measurement (ARM) climate research facility in Manacapuru (T3), which is southwest (downwind) of Manaus. Spatially resolved spectra were recorded at the sub-particle level using scanning transmission X-ray microscopy (STXM) at the carbon, nitrogen, and oxygen K-absorption edges. Scanning electron microscopy coupled with energy dispersive x-ray spectroscopy (SEM/EDX) was also performed on to characterize higher Z elements. These two techniques together will allow for the mass fraction of atmospherically relevant elements to be determined on a per-particle basis. We will apply established procedures to determine the mixing state index for samples collected at ZF2 and T3 using elemental mass fractions. Preliminary results will be presented which focus on investigating the difference between mixing

  10. Final Report for "Improved Representations of Cloud Microphysics for Model and Remote Sensing Evaluation using Data Collected during ISDAC, TWP-ICE and RACORO

    SciTech Connect

    McFarquhar, Greg M.

    2003-06-11

    We were funded by ASR to use data collected during ISDAC and TWP-ICE to evaluate models with a variety of temporal and spatial scales, to evaluate ground-based remote sensing retrievals and to develop cloud parameterizations with the end goal of improving the modeling of cloud processes and properties and their impact on atmospheric radiation. In particular, we proposed to: 1) Calculate distributions of microphysical properties observed in arctic stratus during ISDAC for initializing and evaluating LES and GCMs, and for developing parameterizations of effective particle sizes, mean fall velocities, and mean single-scattering properties for such models; 2) Improve representations of particle sizes, fall velocities and scattering properties for tropical and arctic cirrus using TWP-ICE, ISDAC and M-PACE data, and to determine the contributions that small ice crystals, with maximum dimensions D less than 50 μm, make to mass and radiative properties; 3) Study fundamental interactions between clouds and radiation by improving representations of small quasi-spherical particles and their scattering properties. We were additionally funded 1-year by ASR to use RACORO data to develop an integrated product of cloud microphysical properties. We accomplished all of our goals.

  11. Water-soluble dicarboxylic acids and ketocarboxylic acids in the aerosols collected during ACE-Asia/C-130 aircraft campaign 2001

    NASA Astrophysics Data System (ADS)

    Kawamura, K.; Mochida, M.; Uemoto, N.; Bertram, T.; Huebert, B.

    2001-12-01

    During the ACE-Asia campaign with C-130 aircraft, aerosol samples were collected over the western North Pacific, East China Sea, and Japan Sea, as well as over Japanese Islands and Korean Peninsula in 8 April to 3 May 2001. The filter samples (N=15) were extracted with organic-free pure water to separate water-soluble dicarboxylic acids and related compounds. The extracts were reacted with 14% BF3 in n-butanol and the dibutyl esters and other derivatives were determined using a capillary GC and GC/MS. The results showed that 14 species of diacids (C2-C11) and 4 species of ketoacids (C2-C4) were detected in the aerosols over the East Asia. Total concentrations of the diacids were 113-500 (av. 330) ng/m3 whereas those of ketoacids were 43-260 (av. 103) ng/m3. The concentrations are equivalent to or more abundant than those reported for the urban Tokyo atmosphere in this season on the ground level. All the samples showed that oxalic acid (C2) is the most abundant diacid, which accounted for 58-83% of total diacids. These values are greater than that (ca. 50%) reported in the urban air near the ground, suggesting that oxalic acid is preferentially produced and/or longer diacids are selectively decomposed in the upper troposphere. Malonic (C3) acid is the second most abundant species followed by succinic (C4) acid. Longer diacids are less abundant, but azelaic (C9) acid is generally more abundant than C6-C8 diacids. Glyoxylic acid (C2) is the most abundant ketoacid followed by pyruvic acid. However, C3 and C4 omega-oxoacids were found as minor species. Although oxalic acid is the dominant component in the aerosols, few samples showed the predominance of glyoxylic acid over oxalic acid. This feature has not been reported for the urban aerosols collected near the ground level. We will discuss a potential photochemical production of water-soluble organic acids in the upper troposphere over the eastern ridge of the Asian continent.

  12. Polar organic compounds in rural PM2.5 aerosols from K-puszta, Hungary, during a 2003 summer field campaign: sources and diurnal variations

    NASA Astrophysics Data System (ADS)

    Ion, A. C.; Vermeylen, R.; Kourtchev, I.; Cafmeyer, J.; Chi, X.; Gelencsér, A.; Maenhaut, W.; Claeys, M.

    2005-03-01

    In the present study, we examined PM2.5 continental rural background aerosols, which were collected during a summer field campaign at K-puszta, Hungary (4 June-10 July 2003), a mixed coniferous/deciduous forest site characterized by intense solar radiation during summer. Emphasis was placed on polar oxygenated organic compounds that provide information on aerosol sources and source processes. Analysis was performed using gas chromatography/mass spectrometry (GC/MS) after suitable sample workup consisting of extraction with methanol and derivatisation into trimethylsilyl (TMS) derivatives. The major components detected at significant atmospheric concentrations were: (a) photo-oxidation products of isoprene including the 2-methyltetrols (2-methylthreitol and 2-methylerythritol) and 2-methylglyceric acid, (b) levoglucosan, a marker for biomass burning, (c) malic acid, an end-oxidation product of unsaturated fatty acids, and (d) the sugar alcohols, arabitol and mannitol, markers for fungal spores. Diurnal patterns with highest concentrations during day-time were observed for the isoprene oxidation products, i.e., the 2-methyltetrols and 2-methylglyceric acid, which can be regarded as supporting evidence for their fast photochemical formation from their locally emitted precursor. In addition, a diurnal pattern with highest concentrations during day-time was observed for the fungal markers, arabitol and mannitol, suggesting that the release of fungal fragments that are associated with the PM2.5 aerosol is enhanced during that time. Furthermore, a diurnal pattern was also found for levoglucosan with the highest concentrations at night when wood burning may take place in the settlements around the sampling site. In contrast, malic acid did not show day/night differences but was found to follow quite closely the particulate and organic carbon mass. This is interpreted as an indication that malic acid is formed in photochemical reactions which have a much longer overall time

  13. Polar organic compounds in rural PM2.5 aerosols from K-puszta, Hungary, during a 2003 summer field campaign: Sources and diel variations

    NASA Astrophysics Data System (ADS)

    Ion, A. C.; Vermeylen, R.; Kourtchev, I.; Cafmeyer, J.; Chi, X.; Gelencsér, A.; Maenhaut, W.; Claeys, M.

    2005-07-01

    In the present study, we examined PM2.5 continental rural background aerosols, which were collected during a summer field campaign at K-puszta, Hungary (4 June-10 July 2003), a mixed coniferous/deciduous forest site characterized by intense solar radiation during summer. Emphasis was placed on polar oxygenated organic compounds that provide information on aerosol sources and source processes. The major components detected at significant atmospheric concentrations were: (a) photo-oxidation products of isoprene including the 2-methyltetrols (2-methylthreitol and 2-methylerythritol) and 2-methylglyceric acid, (b) levoglucosan, a marker for biomass burning, (c) malic acid, an intermediate in the oxidation of unsaturated fatty acids, and (d) the sugar alcohols, arabitol and mannitol, markers for fungal spores. Diel patterns with highest concentrations during day-time were observed for the 2-methyltetrols, which can be regarded as supporting evidence for their fast photochemical formation from locally emitted isoprene. In addition, a diel pattern with highest concentrations during day-time was observed for the fungal markers, suggesting that the release of fungal fragments that are associated with the PM2.5 aerosol is enhanced during that time. Furthermore, a diel pattern was also found for levoglucosan with the highest concentrations at night when wood burning may take place in the settlements around the sampling site. In contrast, malic acid did not show day/night differences but was found to follow quite closely the particulate and organic carbon mass. This is interpreted as an indication that malic acid is formed in photochemical reactions which have a much longer overall time-scale than that of isoprene photo-oxidation, and the sources of its precursors are manifold, including both anthropogenic and natural emissions. On the basis of the high concentrations found for the isoprene oxidation products during day-time, it can be concluded that rapid photo-oxidation of

  14. Composition and major sources of organic compounds of aerosol particulate matter sampled during the ACE-Asia campaign

    NASA Astrophysics Data System (ADS)

    Simoneit, Bernd R. T.; Kobayashi, Minoru; Mochida, Michihiro; Kawamura, Kimitaka; Lee, Meehye; Lim, Ho-Jin; Turpin, Barbara J.; Komazaki, Yuichi

    2004-10-01

    The organic compound tracers of atmospheric particulate matter, as well as organic carbon (OC) and elemental carbon (EC), have been characterized for samples acquired during the Asian Pacific Regional Aerosol Characterization Experiment (ACE-Asia) from Gosan, Jeju Island, Korea, from Sapporo, Japan, and from Chichi-jima Island in the western North Pacific, as well as on the National Oceanic and Atmospheric Administration R/V Ronald H. Brown. Total extracts were analyzed by gas chromatography-mass spectrometry to determine both polar and aliphatic compounds. Total particles, organic matter, and lipid and saccharide compounds were high during the Asian dust episode (early April 2001) compared to levels at other times. The organic matter can be apportioned to seven emission sources and to significant oxidation-producing secondary products during long-range transport. Terrestrial natural background compounds are vascular plant wax lipids derived from direct emission and as part of desert sand dust. Fossil fuel utilization is obvious and derives from petroleum product and coal combustion emissions. Saccharides are a major polar (water-soluble) carbonaceous fraction derived from soil resuspension (agricultural activities). Biomass-burning smoke is evident in all samples and seasons. It contributes up to 13% of the total compound mass as water-soluble constituents. Burning of refuse is another source of organic particles. Varying levels of marine-derived lipids are superimposed during aerosol transport over the ocean. Secondary oxidation products increase with increasing transport distance and time. The ACE-Asia aerosols are composed not only of desert dust but also of soil dust, smoke from biomass and refuse burning, and emissions from fossil fuel use in urban areas.

  15. Aircraft observations of aerosol and trace gas concentrations in the tropical troposphere up to 12 km during the INCA campaign

    NASA Astrophysics Data System (ADS)

    Minikin, A.; Baehr, J.; Krejci, R.; Schlager, H.; van Velthoven, P.; Seifert, M.; Ström, J.; Petzold, A.; Schumann, U.

    2003-04-01

    During the EU funded project INCA (Interhemispheric differences in cirrus properties from anthropogenic emissions) the DLR Falcon 20, a German research aircraft with a maximum ceiling of 13~km, carried out measurements of aerosol and trace gas concentrations during transfer from Europe to South America and back in order to obtain meridional cross sections between 50^o~N and 50^o~S. At tropical latitudes the southbound transfer flights were directed along the west coast of South America, whereas the northbound transfer flights passed over Brazil and the central Atlantic Ocean. We report on observational data of number concentrations of Aitken and accumulation mode particles, the fractionation between volatile and non-volatile particles, as well as mixing ratios of carbon monoxide, reactive nitrogen species and ozone. In the tropics aerosol number concentrations above 9~km altitude increase by one order of magnitude, if compared to the sub-tropics and mid-latitudes, most pronounced for refractory particles. These elevated aerosol concentrations occur where 3-dimensional back trajectories originate from the central South American continent (Amazon basin) and have undergone systematic uplifting. The very high fraction of refractory particles, up to 50--60~% of total condensation nuclei, may indicate a strong contribution of continental ground sources. The INCA measurements confirm earlier TROPOZ II observations of an extended upper tropospheric layer of enhanced CO and NO over tropical South America during the wet season. Vertical distributions show a striking increase of CO mixing ratios above 6~km. Corresponding increases of NO and NOy and decreases of ozone were also found. During INCA an anticyclonic flow over tropical South America was persistent in the upper troposphere. This upper-level anticyclone is associated with intense convective activity over the Amazon basin and redistributes the convectively lifted air masses over a large area in the tropical middle

  16. The impact of aerosol and clouds on the radiation field during the ALBATROSS 1996 field campaign in the Atlantic Ocean

    NASA Astrophysics Data System (ADS)

    Kylling, A.; Hofzumahaus, A.; Brauers, T.; Kraus, A.

    2003-04-01

    In october-november 1996 the research vessel Polarstern traversed the Atlantic Ocean from about 66.7oN to 47.2oS. Data recorded during the cruise included the global irradiance and the 2pi downwelling actinic flux. The data are presented and discussed in terms of the various climatic conditions under which the data were recorded. The actinic flux measurements in the UV-A region of the spectrum are used to derive an effective cloud optical depth. Together with the global radiation data the cloud optical depths are used to quantify the effect of clouds on the radiative forcing. During the cruise Polarstern passed through a region with Saharan dust. The radiative impact of the aerosol on the actinic flux and the global irradiance is elucidated with the aid of radiative transfer model simulations. The impact of the aerosol depends on the solar zenith angle. The actinic flux was reduced by 8-30% with the largest reduction taking place at solar zenith angles around 70o.

  17. A brief overview of the Chemistry-Aerosol Mediterranean Experiment (ChArMEx) database and campaign operation centre (ChOC)

    NASA Astrophysics Data System (ADS)

    Ferré, Hélène; Dulac, François; Belmahfoud, Nizar; Brissebrat, Guillaume; Cloché, Sophie; Descloitres, Jacques; Fleury, Laurence; Focsa, Loredana; Henriot, Nicolas; Ramage, Karim; Vermeulen, Anne

    2016-04-01

    Initiated in 2010 in the framework of the multidisciplinary research programme MISTRALS (Mediterranean Integrated Studies at Regional and Local Scales; http:www.mistrals-home.org), the Chemistry-Aerosol Mediterranean Experiment (ChArMEx, http://charmex.lsce.ipsl.fr/) aims at federating the scientific community for an updated assessment of the present and future state of the atmospheric environment in the Mediterranean Basin, and of its impacts on the regional climate, air quality, and marine biogeochemistry. The project combines mid- and long-term monitoring, intensive field campaigns, use of satellite data, and modelling studies. In this presentation we provide an overview of the campaign operation centre (http://choc.sedoo.fr/) and project database (http://mistrals.sedoo.fr/ChArMEx), at the end of the first experimental phase of the project that included a series of large campaigns based on airborne means (including balloons and various aircraft) and a network of surface stations. Those campaigns were performed mainly in the western Mediterranean basin in the summer of 2012, 2013 and 2014 with the help of the ChArMEx Operation Centre (ChOC), an open web site that has the objective to gather and display daily quick-looks from model forecasts and near-real time in situ and remote sensing observations of physical and chemical weather conditions relevant for the everyday campaign operation decisions. The ChOC is also useful for post campaign analyses and can be completed with a number of quick-looks of campaign results obtained later in order to offer an easy access to, and comprehensive view of all available data during the campaign period. The items included are selected according to the objectives and location of the given campaigns. The second experimental phase of ChArMEx from 2015 on is more focused on the eastern basin. In addition, the project operation centre is planned to be adapted for a joint MERMEX-ChArMEx oceanographic cruise (PEACETIME) for a study at

  18. Characterization of atmospheric aerosols in the Po valley during the supersito campaigns - Part 3: Contribution of wood combustion to wintertime atmospheric aerosols in Emilia Romagna region (Northern Italy)

    NASA Astrophysics Data System (ADS)

    Pietrogrande, Maria Chiara; Bacco, Dimitri; Ferrari, Silvia; Kaipainen, Jussi; Ricciardelli, Isabella; Riekkola, Marja-Liisa; Trentini, Arianna; Visentin, Marco

    2015-12-01

    This paper investigates the influence of wood combustion on PM in fall/winter that are the most favorable seasonal periods with presumed intense biomass burning for residential heating due to low temperatures. As a part of the Supersito project, nearly 650 PM2.5 samples were daily collected at urban and rural sites in Emilia Romagna (Northern Italy) in five intensive experimental campaigns throughout the years from 2011 to 2014. From specific compounds related to wood combustion a set of 58 organic compounds was determined, such as anhydrosugars, primary biological sugars, low-molecular-weight carboxylic acids, methoxylated phenols, PAHs and carbonaceous components (EC/OC). Levoglucosan was by far the most dominant anhydrosugar, both on a relative and an absolute basis (35-1043 ng m-3), followed by mannosan (7-121 ng m-3) and galactosan (4-52 ng m-3), indicating that wood burning for domestic heating is a diffuse regional source during the seasons studied. Different diagnostic ratios between anhydrosugars and methoxylated phenols were computed to discriminate the prevalent contribution of hardwood as combustion fuel. The investigated 19 high molecular weight PAHs were more abundant at the urban than at the rural site, with mean total value of 4.3 and 3.2 ng m-3 at MS and SP, respectively. The strong contribution of wood combustion to atmospheric PAHs was indicated by the positive correlation between levoglucosan and the most abundant PAHs (R2 = 0.71÷0.79) and individually with benzo(a)pyrene (R2 = 0.79). By using this correlation, it was estimated that wood burning contributed nearly 77% to BaP concentration in the winter months. Based on the ratio between levoglucosan and OC data, it could be concluded that the wood burning contributed about 35% to OC during the cold November-February periods and the contribution was similar at both sampling sites.

  19. Raman lidar measurements of water vapor and aerosol/clouds during the FIRE/SPECTRE field campaign

    NASA Technical Reports Server (NTRS)

    Melfi, S. H.; Whiteman, D.; Ferrare, R.; Evans, K.; Goldsmith, J. E. M.; Lapp, M.; Bisson, S. E.

    1992-01-01

    Water vapor is one of the most important constituents of the earth's atmosphere. It has a major impact on both atmospheric dynamics and radiative transfer. From a dynamic standpoint, the distribution of water vapor with height determines convective stability which is the major indicator of destructive storm development. Also, water vapor stored in the planetary boundary layer acts as the fuel to intensify severe weather. In regards to radiative transfer, water vapor is the most active IR molecule in the atmosphere. It is more effective in absorbing and emitting IR radiation than either carbon dioxide or methane, and thus plays an important role in global change. The main objective of FIRE (First ISSCCP (International Satellite Cloud Climatology Project) Regional Experiment) was to study the development and radiative characteristics of cirrus clouds. The SPECTRE (Spectral Radiation Experiment) project was designed to acquire the necessary atmospheric observations to compare radiative measurements with radiative transfer theory, with special emphasis on understanding the water vapor spectral continuum. The FIRE/SPECTRE field campaign was conducted during Nov. - Dec. 1991 in Coffeyville, Kansas. A complete understanding of water vapor, its distribution with height, and its temporal variation was important for both experiments.

  20. Concentration of trace elements in fine and coarse aerosol over the Mediterranean basin during the Urania 2011 and 2012 cruise campaigns

    NASA Astrophysics Data System (ADS)

    Malaj, Naim; Ammoscato, Ivano; Andreoli, Virginia; Bencardino, Mariantonia; Cofone, Franco; Cosentino, Ugo; Mannarino, Valentino; Piazzalunga, Andrea; Pirrone, Nicola; Pitea, Demetrio; Servidio, Alessandro; Vardè, Massimiliano; Sprovieri, Francesca

    2015-04-01

    The almost unique geographic position as well as meteo-climatic characteristics of the Mediterranean basin surrounded by several anthropogenic and natural pollution sources, delineate it as one of the most polluted area. The intense maritime traffic and the industries of developed countries bordering the basin have been indicated as the major impact factors amongst the anthropogenic pollution sources while biomass burning, volcanoes fumes and frequent Saharan dust events represent the principal pollution coming from natural fonts. Land generated pollutants transported via air masses into marine atmosphere exert their impact on aquatic ecosystem, air quality and global climate. Although land-based air pollution monitoring sites are diffused through the Mediterranean countries, those regarding the atmospheric aerosol measured directly at sea surface are limited, leading to a scarce availability of the information. In order to fill this gap and to have more insights into the atmospheric dynamical and chemical mechanisms leading to high surface aerosol levels, the Institute of Atmospheric Pollution of the National Research Council (CNR-IIA) has started regular ship borne measurements over the Mediterranean Sea since 20001. In this context, here we report the results obtained during two cruise campaigns performed in two distinct routs and periods: i) Urania 2011 made within the Tyrrhenian Sea during the fall season, and ii) Urania 2012 performed during summer within the Eastern sector of the Mediterranean sea basin. Fine (PM2.5) and coarse (PM2.5-10) particles were collected on PTFE membrane filters (Advantec MFS) and their mass concentrations were determined gravimetrically. Successively, all the filters were digested with a mixture of HNO3/H2O2 in an open vessel digestion system (DigiPrep-MS, SCP SCIENCE, Canada) and analyzed by ICP-MS for the determination of the following elements: Be, Na, Mg, Al, K, Ca, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Mo, Ag, Cd, Sb, Ba, Tl

  1. Polar organic marker compounds in atmospheric aerosol in the Po Valley during the Supersito campaigns - Part 1: Low molecular weight carboxylic acids in cold seasons

    NASA Astrophysics Data System (ADS)

    Pietrogrande, Maria Chiara; Bacco, Dimitri; Visentin, Marco; Ferrari, Silvia; Poluzzi, Vanes

    2014-04-01

    In the framework of the “Supersito” project, three intensive experimental campaigns were conducted in the Po Valley (Northern Italy) in cold seasons, such as late autumn, pre-winter and deep-winter, over three years from 2011 to 2013. As a part of a study on polar marker compounds, including carboxylic acids, sugar derivatives and lignin phenols, the present study reports a detailed discussion on the atmospheric concentrations of 14 low molecular weight carboxylic acids, mainly dicarboxylic and oxo-hydroxy carboxylic acids, as relevant markers of primary and secondary organic aerosols. PM2.5 samples were collected in two monitoring sites, representing urban and rural background stations. The total quantities of carboxylic acids were 262, 167 and 249 ng m-3 at the urban site and 308, 115, 248 ng m-3 at the rural site in pre-winter, fall and deep-winter, respectively. These high concentrations can be explained by the large human emission sources in the urbanized region, combined with the stagnant atmospheric conditions during the cold seasons that accumulate the organic precursors and accelerate the secondary atmospheric reactions. The distribution profiles of the investigated markers suggest the dominant contributions of primary anthropogenic sources, such as traffic, domestic heating and biomass burning. These results are confirmed by comparison with additional emission tracers, such as anhydro-saccharides for biomass burning and fatty acids originated from different anthropogenic sources. In addition, some secondary constituents were detected in both sites, as produced by in situ photo-chemical reactions from both biogenic (e.g. pinonic acid) and anthropogenic precursors (e.g. phthalic and adipic acids). The impact of different sources from human activities was elucidated by investigating the week pattern of carboxylic and fatty acid concentrations. The weekly trends of analytes during the warmer campaign (fall 2012; mean temperature: 12 °C) may be related to

  2. Polar organic marker compounds in atmospheric aerosol in the Po Valley during the Supersito campaigns - Part 2: Seasonal variations of sugars

    NASA Astrophysics Data System (ADS)

    Pietrogrande, Maria Chiara; Bacco, Dimitri; Visentin, Marco; Ferrari, Silvia; Casali, Patrizia

    2014-11-01

    Four intensive experimental campaigns were conducted in the Po Valley (Northern Italy) in different seasons through the years 2012 and 2013, in the framework of the “Supersito” project. As a part of a study on polar tracers in atmospheric PM2.5, the present paper describes the abundances and temporal variations of sugars, as primary biogenic biomarkers, being the major form of photosynthetically assimilated carbon in the biosphere. The study includes primary saccharides (glucose, sucrose, arabinose, galactose and mycose), sugar alcohols (arabitol and mannitol) and anhydrosugars (levoglucosan, galactosan and mannosan). Strong seasonality was observed with total sugars concentration nearly 10 times higher in the cold seasons (mean 377 ng m-3) than in summer/spring (mean 36 ng m-3). Also sugar composition profiles varied seasonally, being dominated by anhydrosugars in fall and winter, i.e., levoglucosan (mean 271 ng m-3), followed by mannosan (mean 53 ng m-3) and galactosan (mean 29 ng m-3). These data indicate that in the cold seasons the biomass combustion for domestic heating is the main sugar source representing nearly 94% of the total saccharides mass measured in PM2.5. Accordingly, glucose, arabinose and galactose show the highest concentrations, since these saccharides are also emitted during the burning process as uncombusted biomass materials. In spring/summer the primary saccharides are dominant in PM2.5, with mannitol as the most abundant, followed by mycose, glucose and ribitol that are emitted by the terrestrial biomass, reflecting the higher sugar production and utilization by the ecosystem in the warm seasons. These results were confirmed by investigating other molecular markers, such as low-molecular-weight carboxylic acids and n-alkane homologs. Principal Component Analysis was applied to the data to extract three PCs that may be attributed to different saccharide sources, such as biomass burning and primary bio aerosol.

  3. Estimated contributions of primary and secondary organic aerosol from fossil fuel combustion during the CalNex and Cal-Mex campaigns

    NASA Astrophysics Data System (ADS)

    Guzman-Morales, J.; Frossard, A. A.; Corrigan, A. L.; Russell, L. M.; Liu, S.; Takahama, S.; Taylor, J. W.; Allan, J.; Coe, H.; Zhao, Y.; Goldstein, A. H.

    2014-05-01

    Observations during CalNex and Cal-Mex field campaigns at Bakersfield, Pasadena, Tijuana, and on board the R/V Atlantis show a substantial contribution of fossil fuel emissions to the ambient particle organic mass (OM). At least two fossil fuel combustion (FFC) factors with a range of contributions of oxidized organic functional groups were identified at each site and accounted for 60-88% of the total OM. Additional marine, vegetative detritus, and biomass burning or biogenic sources contribute up to 40% of the OM. Comparison of the FTIR spectra of four different unburned fossil fuels (gasoline, diesel, motor oil, and ship diesel) with PMF factors from ambient samples shows absorbance peaks from the fuels are retained in organic aerosols, with the spectra of all of the FFC factors containing at least three of the four characteristic alkane peaks observed in fuel standards at 2954, 2923, 2869 and 2855 cm-1. Based on this spectral similarity, we estimate the primary OM from FFC sources for each site to be 16-20%, with secondary FFC OM accounting for an additional 42-62%. Two other methods for estimating primary OM that use carbon monoxide (CO) and elemental carbon (EC) as tracers of primary organic mass were investigated, but both approaches were problematic for the CalNex and Cal-Mex urban sites because they were influenced by multiple emission sources that had site-specific and variable initial ratios to OM. For example, using the ΔPOM/ΔCO ratio of 0.0094 μg ppb V-1 proposed by other studies produces unrealistically high estimates of primary FFC OM of 55-100%.

  4. Characterization of ambient aerosols in Mexico City during the MCMA-2003 campaign with Aerosol Mass Spectrometry Part II: overview of the results at the CENICA supersite and comparison to previous studies

    NASA Astrophysics Data System (ADS)

    Salcedo, D.; Dzepina, K.; Onasch, T. B.; Canagaratna, M. R.; Jayne, J. T.; Worsnop, D. R.; Gaffney, J. S.; Marley, N. A.; Johnson, K. S.; Zuberi, B.; Molina, L. T.; Molina, M. J.; Shutthanandan, V.; Xie, Y.; Jimenez, J. L.

    2005-06-01

    An Aerodyne Aerosol Mass Spectrometer (AMS) was deployed at the CENICA Supersite during the Mexico City Metropolitan Area field study from 31 March-4 May 2003. The AMS provides real time information on mass concentration and composition of the non-refractory species in particulate matter less than 1 µm (NR-PM1) with high time and size-resolution. Measurements of Black Carbon (BC) using an aethalometer, and estimated soil concentrations from Proton-Induced X-Ray Emission (PIXE) analysis of impactor substrates are also presented and combined with the AMS in order to include refractory material and estimate the total PM2.5 mass concentration at CENICA during this campaign. In Mexico City, the organic fraction of the estimated PM2.5 at CENICA represents 54.6% of the mass, with the rest consisting of inorganic compounds (mainly ammonium nitrate and sulfate/ammonium salts), BC, and soil. Inorganic compounds represent 27.5% of PM2.5; BC mass concentration is about 11%; while soil represents about 6.9%. The NR species and BC have diurnal cycles that can be qualitatively interpreted as the interplay of direct emissions, photochemical production in the atmosphere followed by condensation and gas-to-particle partitioning, boundary layer dynamics, and/or advection. Bi- and trimodal size distributions are observed for the AMS species, with a small combustion (likely traffic) organic particle mode and an accumulation mode that contains mainly organic and secondary inorganic compounds. The AMS and BC mass concentrations, size distributions, and diurnal cycles are found to be qualitatively similar to those from most previous field measurements in Mexico City.

  5. Airborne Trace Gas and Aerosol Measurements in Several Shale Gas Basins during the SONGNEX (Shale Oil and Natural Gas Nexus) Campaign 2015

    NASA Astrophysics Data System (ADS)

    Warneke, C.; Trainer, M.; De Gouw, J. A.

    2015-12-01

    Oil and natural gas from tight sand and shale formations has increased strongly over the last decade. This increased production has been associated with emissions of methane, non-methane hydrocarbons and other trace gases to the atmosphere, which are concerns for air quality, climate and air toxics. The NOAA Shale Oil and Natural Gas Nexus (SONGNEX) aircraft campaign took place in 2015, when the NOAA WP-3 aircraft conducted 20 research flights between March 19 and April 27, 2015 in the following shale gas regions: Denver-Julesberg, Uintah, Upper Green River, San Juan, Bakken, Barnett, Eagle Ford, Haynesville, Woodford, and Permian. The NOAA P3 was equipped with an extensive set of gas phase measurements, including instruments for methane, ethane, CO, CO2, a new H3O+CIMS, canister and cartridge samples for VOCs, HCHO, glyoxal, HNO3, NH3, NOx, NOy, PANs, ozone, and SO2. Aerosol number and size distributions were also measured. This presentation will focus on an overview of all the measurements onboard the NOAA WP-3 aircraft and discuss the differences between the shale gas regions. Due to a drop in oil prices, drilling for oil decreased in the months prior to the mission, but nevertheless the production of oil and natural gas were near the all-time high. Many of the shale gas basins investigated during SONGNEX have quite different characteristics. For example, the Permian Basin is a well-established field, whereas the Eagle Ford and the Bakken saw an almost exponential increase in production over the last few years. The basins differ by the relative amounts of natural gas versus oil that is being produced. Previous work had shown a large variability in methane emissions relative to the production (leak rate) between different basins. By including more and qualitatively different basins during SONGNEX, the study has provided an extensive data set to address how emissions depend on raw gas composition, extraction techniques and regulation. The influence of these

  6. Size-resolved aerosol emission factors and new particle formation/growth activity occurring in Mexico City during the MILAGRO 2006 Campaign

    SciTech Connect

    Kalafut-Pettibone A. J.; Wang J.; Eichinger, W. E.; Clarke, A.; Vay, S. A.; Blake, D. R.; Stanier, C. O.

    2011-09-01

    Measurements of the aerosol size distribution from 11 nm to 2.5 microns were made in Mexico City in March 2006, during the MILAGRO (Megacity Initiative: Local and Global Research Observations) field campaign. Observations at the urban supersite, referred to as T0, could often be characterized by morning conditions with high particle mass concentrations, low mixing heights, and highly correlated particle number and CO{sub 2} concentrations, indicative that particle number is controlled by primary emissions. Average size-resolved and total number- and volume-based emission factors for combustion sources impacting T0 have been determined using a comparison of peak sizes in particle number and CO{sub 2} concentration. Peaks are determined by subtracting the measured concentration from a calculated baseline concentration time series. The number emission and volume emission factors for particles from 11 nm to 494 nm are 1.56 x 10{sup 15} particles, and 9.48 x 10{sup 11} cubic microns per kg of carbon, respectively. The uncertainty of the number emission factor is approximately plus or minus 50 %. The mode of the number emission factor was between 25 and 32 nm, while the mode of the volume factor was between 0.25 and 0.32 microns. These emission factors are reported as log normal model parameters and are compared with multiple emission factors from the literature. In Mexico City in the afternoon, the CO{sub 2} concentration drops during ventilation of the polluted layer, and the coupling between CO{sub 2} and particle number breaks down, especially during new particle formation events when particle number is no longer controlled by primary emissions. Using measurements of particle number and CO{sub 2} taken aboard the NASA DC-8, the determined primary emission factor was applied to the Mexico City Metropolitan Area (MCMA) plume to quantify the degree of secondary particle formation in the plume; the primary emission factor accounts for less than 50 % of the total particle

  7. Aerosol optical depth and its relation to regional-scale circulations over Korea during MAPS-Seoul (May-June, 2015) and KORUS-AQ campaigns (May-June, 2016)

    NASA Astrophysics Data System (ADS)

    Yoon, Hyunhye; Kim, Sang-Woo; Kim, Ji-Hyoung; Park, Jin-Soo; Ahn, Joon-Young; Lee, Jae-Bum; Lim, Yong-Jae

    2017-04-01

    We investigate aerosol optical depth (AOD) and its relation to regional-scale circulations over Korea during the two recent field campaigns conducted in May-June of 2015 (MAPS-Seoul experiment) and May-June of 2016 (KORUS-AQ campaign), using satellite MODIS and AERONET measurement data. The monthly averaged MODIS AOD at 550 nm was estimated to about 0.35 in May and 0.50 in June during the MAPS-Seoul experiment, which was about 33% and 17% lower than that of 13-year averaged MODIS AOD. MODIS AOD during KORUS-AQ 2016 campaign was similarly about 8˜23% lower than those of 13-year averages, but slightly higher than those in 2015. The monthly averaged MODIS AOD was 0.40 in May and 0.56 in June, 2016. Consistently, ground-based AERONET sky radiometer measurements at Seoul showed AODs of about 0.35 (May) and 0.60 (June) at 500 nm during MAPS-Seoul experiment, which was approximately 32% and 20% lower than the averaged AODs (May - 0.51; June - 0.76) from 4-year measurements (2012, 2013, 2015, and 2016). Also, AOD during KORUS-AQ campaign in 2016 was about 0.43 in May and 0.71 in June, which was about 16% and 6% lower than 4-year mean AOD. This year-to-year variation of AOD in May-June over East Asia, including Korea, was closely linked with synoptic atmospheric circulations. Generally, aerosol optical depth (AOD) is high in May and June due to stagnant synoptic meteorological systems, as previously reported by Kim et al. (Atmospheric Environment, 2007). For example, in 2012, MODIS AOD over the Korean Peninsula was observed to be about 0.71 in May and 0.72 in June. This can be explained by the frequent occurrences of stagnant atmospheric conditions. However, the regional-scale circulations during MAPS-Seoul and KORUS-AQ campaigns were characterized by the fast-moving confluent flows over the Korean peninsula, formed between Siberian high pressure system located in North China and North Pacific high in South China. These results suggest that atmospheric circulations play a

  8. Final Technical Report for "Ice nuclei relation to aerosol properties: Data analysis and model parameterization for IN in mixed-phase clouds" (DOE/SC00002354)

    SciTech Connect

    Anthony Prenni; Kreidenweis, Sonia M.

    2012-09-28

    Clouds play an important role in weather and climate. In addition to their key role in the hydrologic cycle, clouds scatter incoming solar radiation and trap infrared radiation from the surface and lower atmosphere. Despite their importance, feedbacks involving clouds remain as one of the largest sources of uncertainty in climate models. To better simulate cloud processes requires better characterization of cloud microphysical processes, which can affect the spatial extent, optical depth and lifetime of clouds. To this end, we developed a new parameterization to be used in numerical models that describes the variation of ice nuclei (IN) number concentrations active to form ice crystals in mixed-phase (water droplets and ice crystals co-existing) cloud conditions as these depend on existing aerosol properties and temperature. The parameterization is based on data collected using the Colorado State University continuous flow diffusion chamber in aircraft and ground-based campaigns over a 14-year period, including data from the DOE-supported Mixed-Phase Arctic Cloud Experiment. The resulting relationship is shown to more accurately represent the variability of ice nuclei distributions in the atmosphere compared to currently used parameterizations based on temperature alone. When implemented in one global climate model, the new parameterization predicted more realistic annually averaged cloud water and ice distributions, and cloud radiative properties, especially for sensitive higher latitude mixed-phase cloud regions. As a test of the new global IN scheme, it was compared to independent data collected during the 2008 DOE-sponsored Indirect and Semi-Direct Aerosol Campaign (ISDAC). Good agreement with this new data set suggests the broad applicability of the new scheme for describing general (non-chemically specific) aerosol influences on IN number concentrations feeding mixed-phase Arctic stratus clouds. Finally, the parameterization was implemented into a regional

  9. Improvement of GOCI Yonsei Aerosol retrieval algorithm and validation during DRAGON campaign: Surface reflectance issue according to land, clear water and turbid water

    NASA Astrophysics Data System (ADS)

    Kim, Jhoon; Choi, Myungje; Lee, Jaehwa

    2015-04-01

    Aerosol optical properties (AOPs) over East Asia are retrieved hourly from the first Geostationary Ocean Color Imager (GOCI). GOCI Yonsei aerosol retrieval (YAER) algorithm was developed and improved continuously. Final products of GOCI YAER are aerosol optical depth (AOD), fine-mode fraction (FMF), single scattering albedo (SSA), Angstrom exponent (AE) and aerosol type in high spatial and temporal resolution. Previous aerosol retrieval algorithm over ocean adopts surface reflectance using cox and munk technique as fixed wind speed or the minimum reflectivity technique for continuous characteristics between ocean and land. This study adopt cox and munk technique using real time ECMWF wind speed data over clear water and the minimum reflectivity technique over turbid water. For detecting turbid water, TOA reflectance of 412, 660, and 865nm was used. Over the turbid water, TOA reflectance at 660nm increases more than 412 and 865nm. It also shows more sensitivity over turbid water than dust aerosol. We evaluated the accuracy of GOCI aerosol products using ground-based AERONET Level 2.0 products from total 38 East Asia sites and satellite-based MODIS-Aqua aerosol C6 products. The period of assessment is 3 months from March to May, 2012. Comparison results show that a correlation coefficient between the AODs at 550 nm of AERONET and GOCI is 0.884. Comparison results over ocean between GOCI and MODIS DT algorithm shows good agreement as R = 0.915.

  10. Measurements of aerosol absorption and scattering in the Mexico City Metropolitan Area during the MILAGRO field campaign: a comparison of results from the T0 and T1 sites

    NASA Astrophysics Data System (ADS)

    Marley, N. A.; Gaffney, J. S.; Castro, T.; Salcido, A.; Frederick, J.

    2008-07-01

    Measurements of aerosol absorption and scattering were obtained in Mexico City during the MILAGRO (Megacity Initiative: Local and Global Research Observations) field campaign in March 2006. A comparison of aerosol absorption and scattering was obtained in Mexico City at site T0 located in the northern part of Mexico City at the Instituto Mexicano del Petróleo Laboratories and at site T1 located at the Universidad Tecnológica de Tecamac, 18 miles northwest of T0. Hourly averages of aerosol absorption were similar at both sites, ranging from 6 93 Mm-1 with an average of 31 Mm-1 at T0; and from 2 104 Mm-1 with an average of 19 Mm-1 at T1. Aerosol scattering at T0 ranged from 16 344 Mm-1 with an average of 105 Mm-1; while the scattering values at T1 were lower than T0 ranging from 2 136 with an average of 53 Mm-1. Aerosol single scattering albedos (SSAs) were determined at both sites using these data. SSAs at T1 ranged from 0.44 0.90 with an average 0.75 as compared to hose at T0, range 0.51 0.93 with an average of 0.77. Broadband UV-B intensity was found to be higher at site T0, with an average of 64 μW/cm2 at solar noon, than at site T1, which had an average of 54 μW/cm2 at solar noon. Comparisons of clear-sky modeled UV-B intensities with the simultaneous UV-B measurements obtained at site T0 and at site T1 for cloudless days indicate a larger diffuse radiation field at site T0 than at site T1. The determination of aerosol scattering Ångstrom coefficient at T0 suggests the larger diffuse radiation is due to the predominance of submicron aerosols at T0 with aerosol scattering of UV-B radiation peaked in the forward direction, leading to the enhancement observed at ground level.

  11. Temporal consistency of lidar observables during aerosol transport events in the framework of the ChArMEx/ADRIMED campaign at Menorca Island in June 2013

    NASA Astrophysics Data System (ADS)

    Chazette, P.; Totems, J.; Ancellet, G.; Pelon, J.; Sicard, M.

    2015-11-01

    We performed synergetic daytime and night-time active and passive remote sensing observations at Menorca (Balearic Island, Spain), over more than 3 weeks during the Chemistry-Aerosol Mediterranean Experiment/Aerosol Direct Radiative Effect in the Mediterranean (ChArMEx/ADRIMED) special observation period (SOP 1a, June-July 2013). We characterized the aerosol optical properties and type in the low and middle troposphere using an automated procedure combining Rayleigh-Mie-Raman lidar (355, 387 and 407 nm) with depolarization (355 nm) and AERONET Cimel® sun-photometer data. Results show a high variability due to varying dynamical forcing. The mean column-averaged lidar backscatter-to-extinction ratio (BER) was close to 0.024 sr-1 (lidar ratio of ∼ 41.7 sr), with a large dispersion of ±33 % over the whole observation period due to changing atmospheric transport regimes and aerosol sources. The ground-based remote sensing measurements, coupled with satellite observations, allowed to document (i) dust particles up to 5 km a.s.l. in altitude originating from Morocco and Algeria from 15 to 18 June with a peak in aerosol optical thickness (AOT) of 0.25 ± 0.05 at 355 nm, (ii) a long-range transport of biomass burning aerosol (AOT = 0.18 ± 0.16) related to North American forest fires detected from 26 to 28 June 2013 by the lidar between 2 and 7 km and (iii) mixture of local sources including marine aerosol particles and pollution from Spain. During the biomass burning event, the high value of the particle depolarization ratio (8-14 %) may imply the presence of dust-like particles mixed with the biomass burning aerosols in the mid troposphere. We show also linearity with SEVIRI retrievals of the aerosol optical thickness within 35 % relative bias, which is discussed as a function of aerosol type.

  12. Vertical variability of aerosol single-scattering albedo and equivalent black carbon concentration based on in-situ and remote sensing techniques during the iAREA campaigns in Ny-Ålesund

    NASA Astrophysics Data System (ADS)

    Markowicz, K. M.; Ritter, C.; Lisok, J.; Makuch, P.; Stachlewska, I. S.; Cappelletti, D.; Mazzola, M.; Chilinski, M. T.

    2017-09-01

    This work presents a methodology for obtaining vertical profiles of aerosol single scattering properties based on a combination of different measurement techniques. The presented data were obtained under the iAREA (Impact of absorbing aerosols on radiative forcing in the European Arctic) campaigns conducted in Ny-Ålesund (Spitsbergen) during the spring seasons of 2015-2017. The retrieval uses in-situ observations of black carbon concentration and absorption coefficient measured by a micro-aethalometer AE-51 mounted onboard a tethered balloon, as well as remote sensing data obtained from sun photometer and lidar measurements. From a combination of the balloon-borne in-situ and the lidar data, we derived profiles of single scattering albedo (SSA) as well as absorption, extinction, and aerosol number concentration. Results have been obtained in an altitude range from about 400 m up to 1600 m a.s.l. and for cases with increased aerosol load during the Arctic haze seasons of 2015 and 2016. The main results consist of the observation of increasing values of equivalent black carbon (EBC) and absorption coefficient with altitude, and the opposite trend for aerosol concentration for particles larger than 0.3 μm. SSA was retrieved with the use of lidar Raman and Klett algorithms for both 532 and 880 nm wavelengths. In most profiles, SSA shows relatively high temporal and altitude variability. Vertical variability of SSA computed from both methods is consistent; however, some discrepancy is related to Raman retrieval uncertainty and absorption coefficient estimation from AE-51. Typically, very low EBC concentration in Ny-Ålesund leads to large error in the absorbing coefficient. However, SSA uncertainty for both Raman and Klett algorithms seems to be reasonable, e.g. SSA of 0.98 and 0.95 relate to an error of ±0.01 and ± 0.025, respectively.

  13. ORACLES and LASIC: New observational campaigns to improve understanding of the effects of Southern African Biomass Burning Aerosol on Radiation, Clouds and Climate.

    NASA Astrophysics Data System (ADS)

    Wood, R.; Redemann, J.; Zuidema, P.

    2016-12-01

    Southern Africa produces almost a third of the Earth's biomass burning (BB) aerosol particles. Particles lofted into the mid-troposphere are transported westward over the South-East Atlantic, home to one of the three permanent subtropical Stratocumulus (Sc) cloud decks in the world. The stratocumulus "climate radiators" are critical to the regional and global climate system. They interact with dense layers of BB aerosols that initially overlay the cloud deck, but later subside and are mixed into the clouds. These interactions include adjustments to aerosol-induced solar heating and microphysical effects, and their global representation in climate models remains one of the largest uncertainties in estimates of future climate. Hence, new observations over the SE Atlantic have significant implications for global climate change scenarios. ORACLES (ObseRvations of Aerosols above CLouds and their intEractionS) is a five-year investigation between 2015 and 2019 with three Intensive Observation Periods (IOP), recently funded by the NASA Earth-Venture Suborbital Program. ORACLES is designed to improve understanding of aerosol-radiation-cloud-climate interactions in the SE Atlantic. These interactions will be studied using aircraft observations from the NASA P-3 and ER-2 aircraft, which will provide key aerosol and cloud property information to improve process and large-scale models. LASIC (Layered Atlantic Smoke Interactions with Clouds) is a DOE deployment of the ARM Mobile Facility to Ascension Island (June 2016 - October 2017) that will provide ground-based in situ and remote sensing observations of aerosols and clouds from Ascension Island (8S, 14W). BB aerosols from Africa frequently advect to Ascension Island where they mix down into the trade wind boundary layer and interact with clouds. This presentation will describe "first-light" observations from the 2016 ORACLES and LASIC deployments, focusing upon the absorptive and cloud nucleating properties of aerosols

  14. Ganges valley aerosol experiment.

    SciTech Connect

    Kotamarthi, V.R.; Satheesh, S.K.

    2011-08-01

    In June 2011, the Ganges Valley Aerosol Experiment (GVAX) began in the Ganges Valley region of India. The objective of this field campaign is to obtain measurements of clouds, precipitation, and complex aerosols to study their impact on cloud formation and monsoon activity in the region.

  15. Observations and Modeling of the Green Ocean Amazon 2014/15: Transmission Electron Microscopy Analysis of Aerosol Particles Field Campaign Report

    SciTech Connect

    Buseck, Peter

    2016-03-01

    During two Intensive Operational Periods (IOP), we collected samples at 3-hour intervals for transmission electron microscopy analysis. The resulting transmission electron microscopy images and compositions were analyzed for the samples of interest. Further analysis will be done especially for the plume of interest. We found solid spherical organic particles from rebounded samples collected with Professor Scot Martin’s group (Harvard University). Approximately 30% of the rebounded particles at 95% relative humidity were spherical organic particles. Their sources and formation process are not known, but such spherical particles could be solid and will have heterogeneous chemical reactions. We observed many organic particles that are internally mixed with inorganic elements such as potassium and nitrogen. They are either homogeneously mixed or have inorganic cores with organic aerosol coatings. Samples collected from the Manaus, Brazil, pollution plume included many nano-size soot particles mixed with organic material and sulfate. Aerosol particles from clean periods included organic aerosol particles, sulfate, sea salt, dust, and primary biogenic aerosol particles. There was more dust, primary biogenic aerosol, and tar balls in samples taken during IOP1 than those taken during IOP2. Many dust particles were found between March 2 and 3.

  16. Aerosol plume transport and transformation in high spectral resolution lidar measurements and WRF-Flexpart simulations during the MILAGRO Field Campaign

    NASA Astrophysics Data System (ADS)

    de Foy, B.; Burton, S. P.; Ferrare, R. A.; Hostetler, C. A.; Hair, J. W.; Wiedinmyer, C.; Molina, L. T.

    2011-04-01

    The Mexico City Metropolitan Area (MCMA) experiences high loadings of atmospheric aerosols from anthropogenic sources, biomass burning and wind-blown dust. This paper uses a combination of measurements and numerical simulations to identify different plumes affecting the basin and to characterize transformation inside the plumes. The High Spectral Resolution Lidar on board the NASA LaRC B-200 King Air aircraft measured extinction coefficients and extinction to backscatter ratio at 532 nm, and backscatter coefficients and depolarization ratios at 532 and 1064 nm. These can be used to identify aerosol types. The measurement curtains are compared with particle trajectory simulations using WRF-Flexpart for different source groups. The good correspondence between measurements and simulations suggests that the aerosol transport is sufficiently well characterized by the models to estimate aerosol types and ages. Plumes in the basin undergo complex transport, and are frequently mixed together. Urban aerosols are readily identifiable by their low depolarization ratios and high lidar ratios, and dust by the opposite properties. Fresh biomass burning plumes have very low depolarization ratios which increase rapidly with age. This rapid transformation is consistent with the presence of atmospheric tar balls in the fresh plumes.

  17. Aerosol plume transport and transformation in high spectral resolution lidar measurements and WRF-Flexpart simulations during the MILAGRO Field Campaign

    NASA Astrophysics Data System (ADS)

    de Foy, B.; Burton, S. P.; Ferrare, R. A.; Hostetler, C. A.; Hair, J. W.; Wiedinmyer, C.; Molina, L. T.

    2010-11-01

    The Mexico City Metropolitan Area (MCMA) experiences high loadings of atmospheric aerosols from anthropogenic sources, biomass burning and wind-blown dust. This paper uses a combination of measurements and numerical simulations to identify different plumes affecting the basin and to characterize transformation inside the plumes. The airborne High Spectral Resolution Lidar measures extinction coefficients and extinction to backscatter ratio at 532 nm, and backscatter coefficients and depolarization ratios at 532 and 1064 nm. These can be used to identify aerosol types. The measurement curtains are compared with particle trajectory simulations using WRF-Flexpart for different source groups. The good correspondence between measurements and simulations suggests that the aerosol transport is sufficiently well characterized by the models to estimate aerosol types and ages. Plumes in the basin undergo complex transport, and are frequently mixed together. Urban aerosols are readily identifiable by their low depolarization ratios and high lidar ratios, and dust by the opposite properties. Fresh biomass burning plumes have very low depolarization ratios which increase rapidly with age. This rapid transformation is consistent with the presence of atmospheric tar balls in the fresh plumes.

  18. Carbonaceous aerosols in the Western Mediterranean during summertime and their contribution to the aerosol optical properties at ground level: First results of the ChArMEx-ADRIMED 2013 intensive campaign in Corsica

    NASA Astrophysics Data System (ADS)

    Sciare, Jean; Dulac, Francois; Feron, Anais; Crenn, Vincent; Sarda Esteve, Roland; Baisnee, Dominique; Bonnaire, Nicolas; Hamonou, Eric; Mallet, Marc; Lambert, Dominique; Nicolas, Jose B.; Bourrianne, Thierry; Petit, Jean-Eudes; Favez, Olivier; Canonaco, Francesco; Prevot, Andre; Mocnik, Grisa; Drinovec, Luka; Marpillat, Alexandre; Serrie, Wilfrid

    2014-05-01

    As part of the Chemistry-Aerosol Mediterranean Experiment (ChArMEx, http://charmex.lsce.ipsl.fr/), the CORSiCA (http://www.obs-mip.fr/corsica) and the ANR-ADRIMED programs, a large set of real-time measurements of carbonaceous aerosols was deployed in June 2013 at the Cape Corsica atmospheric supersite (http://gaw.empa.ch/gawsis/reports.asp?StationID=2076203042). Submicron organic aerosols (OA) were monitored every 30 min using an Aerosol Chemical Speciation Monitor (ACSM; Aerodyne Res. Inc. MA, USA); Fine (PM2.5) Organic Carbon (OC) and Elemental Carbon (EC) were measured every 2h using an OCEC Sunset Field Instrument (Sunset Lab, OR, USA) and every 12h using a low-vol (Leckel) filter sampler running at 2.3m3/h. Equivalent Black Carbon (BC) was monitored using two Aethalometers (models AE31 and AE33, Magee Scientific, US & Aerosol d.o.o., Slovenia) and a MAAP instrument (Thermo). Quality control of this large dataset was performed through chemical mass closure studies (using co-located SMPS and TEOM-FDMS) and direct comparisons with other real-time instruments running in parallel (Particle-Into-Liquid-Sampler-Ion-Chromatograph for ions, filter sampling, ...). Source apportionment of OA was then performed using the SourceFinder software (SoFi v4.5, http://www.psi.ch/acsm-stations/me-2) allowing the distinction between hydrogen- and oxygen-like organic aerosols (HOA and OOA, respectively) and highlighting the major contribution of secondary OA in the Western Mediterranean during summer. Using this time-resolved chemical information, reconstruction of the optical aerosol properties were performed and compared with integrating nephelometer (Model 3563, TSI, US) and photoacoustic extinctiometer (PAX, DMT, US) measurements performed in parallel. Results of these different closure studies (chemical/physical/optical) are presented and discussed here in details. They highlight the central role of carbonaceous aerosols on the optical properties of aerosols at ground level

  19. Vertical Distribution and Columnar Optical Properties of Springtime Biomass-Burning Aerosols over Northern Indochina during the 7-SEAS/BASELInE field campaign

    NASA Astrophysics Data System (ADS)

    Lin, N. H.; Wang, S. H.; Welton, E. J.; Holben, B. N.; Tsay, S. C.; Giles, D. M.; Stewart, S. A.; Janjai, S.; Anh, N. X.; Hsiao, T. C.; Chen, W. N.; Lin, T. H.; Buntoung, S.; Chantara, S.; Wiriya, W.

    2015-12-01

    In this study, the aerosol optical properties and vertical distributions in major biomass-burning emission area of northern Indochina were investigated using ground-based remote sensing (i.e., four Sun-sky radiometers and one lidar) during the Seven South East Asian Studies/Biomass-burning Aerosols & Stratocumulus Environment: Lifecycles & Interactions Experiment conducted during spring 2014. Despite the high spatial variability of the aerosol optical depth (AOD; which at 500 nm ranged from 0.75 to 1.37 depending on the site), the temporal variation of the daily AOD demonstrated a consistent pattern among the observed sites, suggesting the presence of widespread smoke haze over the region. Smoke particles were characterized as small (Ångström exponent at 440-870 nm of 1.72 and fine mode fraction of 0.96), strongly absorbing (single-scattering albedo at 440 nm of 0.88), mixture of black and brown carbon particles (absorption Ångström exponent at 440-870 nm of 1.5) suspended within the planetary boundary layer (PBL). Smoke plumes driven by the PBL dynamics in the mountainous region reached as high as 5 km above sea level; these plumes subsequently spread out by westerly winds over northern Vietnam, southern China, and the neighboring South China Sea. Moreover, the analysis of diurnal variability of aerosol loading and optical properties as well as vertical profile in relation to PBL development, fire intensity, and aerosol mixing showed that various sites exhibited different variability based on meteorological conditions, fuel type, site elevation, and proximity to biomass-burning sources. These local factors influence the aerosol characteristics in the region and distinguish northern Indochina smoke from other biomass-burning regions in the world.

  20. Aerosol Activity and Hygroscopicity Combined with Lidar Data in the Urban Atmosphere of Athens, Greece in the Frame of the HYGRA_CD Campaign

    NASA Astrophysics Data System (ADS)

    Bougiatioti, Aikaterini; Papayannis, Alexandros; Vratolis, Stergios; Argyrouli, Athina; Mihalopoulos, Nikolaos; Tsagkaraki, Maria; Nenes, Athanasios; Eleftheriadis, Konstantinos

    2016-06-01

    Measurements of cloud condensation nuclei (CCN) concentrations between 0.2-1.0% supersaturation and aerosol size distribution were performed at an urban background site of Athens during HygrA-CD. The site is affected by local and long-range transported emissions as portrayed by the external mixing of the particles, as the larger ones appear to be more hygroscopic and more CCN-active than smaller ones. Activation fractions at all supersaturations exhibit a diurnal variability with minimum values around noon, which are considerably lower than unity. This reinforces the conclusion that the aerosol is mostly externally mixed between "fresher", less hygroscopic components with more aged, CCN active constituents.

  1. Impact of cloud processes on aerosol particle properties: results from two ATR-42 flights in an extended stratocumulus cloud layer during the EUCAARI campaign (2008)

    NASA Astrophysics Data System (ADS)

    Crumeyrolle, S.; Weigel, R.; Sellegri, K.; Roberts, G.; Gomes, L.; Stohl, A.; Laj, P.; Bourianne, T.; Etcheberry, J. M.; Villani, P.; Pichon, J. M.; Schwarzenboeck, A.

    2011-12-01

    Within the European Aerosol Cloud Climate and Air Quality Interactions (EUCAARI) project, the Meteo France research aircraft ATR-42 was operated from Rotterdam airport during May 2008, to perform scientific flights dedicated to the investigation of aerosol-cloud interactions. Therein, the objective of this study is to illustrate the impact of cloud processing on the aerosol particles physical and chemical properties. The presented results are retrieved from measurements during a double-flight mission from Rotterdam (Netherlands) to Newcastle (UK) and back using data measured with compact Time of Flight Aerosol Mass Spectrometer (cToF-AMS) and Scanning Mobility Particle Sizer (SMPS). Cloud-related measurements during these flights were performed over the North Sea within as well as in close vicinity of a marine stratocumulus cloud layer. Particle physical and chemical properties observed in the close vicinity (V), below and above the stratocumulus cloud show strong differences. Firstly, measurements at constant altitude above the cloud layer show decreasing mass concentrations with decreasing horizontal distance (210-0 km) to the cloud layer by a factor up to 7, whereas below the cloud and by same means of distance, the mass concentrations merely decrease by a factor of 2 on average. Secondly, the averaged aerosol size distributions, observed above and below the cloud layer, are of bimodal character with pronounced minima between Aitken and accumulation mode which is potentially the consequence of cloud processing. Finally, the chemical composition of aerosol particles is strongly dependent on the location relative to the cloud layer (vicinity or below/above cloud). In general, the nitrate and organic fractions decrease with decreasing distance to the cloud, in the transit from cloud-free conditions towards the cloud boundaries. The decrease of nitrate and organic compounds ranges at a factor of three to ten, affecting sulfate and ammonium compounds to be

  2. Measurements of the Size-Resolved Chemical Composition of Marine Boundary Layer Aerosols in Asian Outflow During the ACE-Asia Campaign

    NASA Astrophysics Data System (ADS)

    Guazzotti, S. A.; Sodeman, D. A.; Moffet, R.; Prather, K. A.

    2003-12-01

    The size and chemical composition of individual particles were evaluated with high temporal resolution during the Asian Pacific Regional Aerosol Chemical Characterization Experiment (ACE-Asia) using a transportable aerosol time-of-flight mass spectrometer (ATOFMS) aboard the NOAA Research Vessel Ronald H. Brown. ATOFMS allows characterization of the aerodynamic diameter and chemical composition of individual particles from a polydisperse aerosol. This technique couples aerodynamic particle sizing with time-of-flight mass spectrometry in a single instrument, providing both positive and negative ion mass spectra for each detected particle which are employed to classify the particles into different classes using criteria based searches and a neural network algorithm, ART-2a. Size-resolved chemical characteristics of sampled particles under different synoptic meteorological patterns and at various locations and distances from continental influences are discussed in detail, with special focus given to the associations among different species and the variability in the degrees of aging, reaction, and/or mixing, which can alter the optical properties of these particles. Changes in the aerosol chemical characteristics due to heterogeneous reactions are evidenced in the mass spectra of detected particles by the presence and intensity of specific ion markers (e.g., sulfate, nitrate). The ability to differentiate between particles that have undergone heterogeneous reactions is relevant since these reactions affect several aerosol attributes, such as hygroscopic, optical, and radiative properties. Particularly, heterogeneous reactions/ nucleation on sea-salt and dust particles are discussed together with results of comparison efforts with some relevant laboratory and source characterization studies that allow determination of corresponding ion markers, relative ratios among species, and probable sources from a single particle perspective.

  3. High Spectral Resolution Lidar and MPLNET Micro Pulse Lidar Aerosol Optical Property Retrieval Intercomparison During the 2012 7-SEAS Field Campaign at Singapore

    NASA Technical Reports Server (NTRS)

    Lolli, Simone; Welton, Ellsworth J.; Campbell, James R.; Eloranta, Edwin; Holben, Brent N.; Chew, Boon Ning; Salinas, Santo V.

    2014-01-01

    From August 2012 to February 2013 a High Resolution Spectral Lidar (HSRL; 532 nm) was deployed at that National University of Singapore near a NASA Micro Pulse Lidar NETwork (MPLNET; 527 nm) site. A primary objective of the MPLNET lidar project is the production and dissemination of reliable Level 1 measurements and Level 2 retrieval products. This paper characterizes and quantifies error in Level 2 aerosol optical property retrievals conducted through inversion techniques that derive backscattering and extinction coefficients from MPLNET elastic single-wavelength datasets. MPLNET Level 2 retrievals for aerosol optical depth and extinction/backscatter coefficient profiles are compared with corresponding HSRL datasets, for which the instrument collects direct measurements of each using a unique optical configuration that segregates aerosol and cloud backscattered signal from molecular signal. The intercomparison is performed, and error matrices reported, for lower (0-5km) and the upper (>5km) troposphere, respectively, to distinguish uncertainties observed within and above the MPLNET instrument optical overlap regime.

  4. High Spectral Resolution Lidar and MPLNET Micro Pulse Lidar aerosol optical property retrieval intercomparison during the 2012 7-SEAS field campaign at Singapore

    NASA Astrophysics Data System (ADS)

    Lolli, Simone; Welton, Ellsworth J.; Campbell, James R.; Eloranta, Edwin; Holben, Brent N.; Chew, Boom Ning; Salinas, Santo V.

    2014-10-01

    From August 2012 to February 2013 a High Resolution Spectral Lidar (HSRL; 532 nm) was deployed at that National University of Singapore near a NASA Micro Pulse Lidar NETwork (MPLNET; 527 nm) site. A primary objective of the MPLNET lidar project is the production and dissemination of reliable Level 1 measurements and Level 2 retrieval products. This paper characterizes and quantifies error in Level 2 aerosol optical property retrievals conducted through inversion techniques that derive backscattering and extinction coefficients from MPLNET elastic single-wavelength datasets. MPLNET Level 2 retrievals for aerosol optical depth and extinction/backscatter coefficient profiles are compared with corresponding HSRL datasets, for which the instrument collects direct measurements of each using a unique optical configuration that segregates aerosol and cloud backscattered signal from molecular signal. The intercomparison is performed, and error matrices reported, for lower (0-5km) and the upper (>5km) troposphere, respectively, to distinguish uncertainties observed within and above the MPLNET instrument optical overlap regime.

  5. High Spectral Resolution Lidar and MPLNET Micro Pulse Lidar Aerosol Optical Property Retrieval Intercomparison During the 2012 7-SEAS Field Campaign at Singapore

    NASA Technical Reports Server (NTRS)

    Lolli, Simone; Welton, Ellsworth J.; Campbell, James R.; Eloranta, Edwin; Holben, Brent N.; Chew, Boon Ning; Salinas, Santo V.

    2014-01-01

    From August 2012 to February 2013 a High Resolution Spectral Lidar (HSRL; 532 nm) was deployed at that National University of Singapore near a NASA Micro Pulse Lidar NETwork (MPLNET; 527 nm) site. A primary objective of the MPLNET lidar project is the production and dissemination of reliable Level 1 measurements and Level 2 retrieval products. This paper characterizes and quantifies error in Level 2 aerosol optical property retrievals conducted through inversion techniques that derive backscattering and extinction coefficients from MPLNET elastic single-wavelength datasets. MPLNET Level 2 retrievals for aerosol optical depth and extinction/backscatter coefficient profiles are compared with corresponding HSRL datasets, for which the instrument collects direct measurements of each using a unique optical configuration that segregates aerosol and cloud backscattered signal from molecular signal. The intercomparison is performed, and error matrices reported, for lower (0-5km) and the upper (>5km) troposphere, respectively, to distinguish uncertainties observed within and above the MPLNET instrument optical overlap regime.

  6. Capital Campaigns.

    ERIC Educational Resources Information Center

    Dalessandro, David; And Others

    1989-01-01

    Eight articles focus on capital campaigns including setting goals (D. Dalessandro), the lead gift (D. A. Campbell), motivating trustees (J. J. Ianolli, Jr.), alumni associations (W. B. Adams), role of public relations officers (R. L. Williams), special events( H.R. Gilbert), the campaign document (R. King), and case statements (D. R. Treadwell,…

  7. Capital Campaigns.

    ERIC Educational Resources Information Center

    Dalessandro, David; And Others

    1989-01-01

    Eight articles focus on capital campaigns including setting goals (D. Dalessandro), the lead gift (D. A. Campbell), motivating trustees (J. J. Ianolli, Jr.), alumni associations (W. B. Adams), role of public relations officers (R. L. Williams), special events( H.R. Gilbert), the campaign document (R. King), and case statements (D. R. Treadwell,…

  8. Water-soluble organic aerosol in the Los Angeles Basin and outflow regions: Airborne and ground measurements during the 2010 CalNex field campaign

    NASA Astrophysics Data System (ADS)

    Duong, Hanh T.; Sorooshian, Armin; Craven, Jill S.; Hersey, Scott P.; Metcalf, Andrew R.; Zhang, Xiaolu; Weber, Rodney J.; Jonsson, Haflidi; Flagan, Richard C.; Seinfeld, John H.

    2011-11-01

    A particle-into-liquid sampler coupled to a total organic carbon analyzer (PILS-TOC) quantified particulate water-soluble organic carbon (WSOC) mass concentrations during the May 2010 deployment of the Center for Interdisciplinary Remotely Piloted Aircraft Studies (CIRPAS) Twin Otter in the CalNex field study. WSOC data collected during 16 flights provide the first spatiotemporal maps of WSOC in the San Joaquin Valley, Los Angeles Basin, and outflow regions of the Basin. WSOC was consistently higher in concentration within the Los Angeles Basin, where sea breeze transport and Basin topography strongly influence the spatial distribution of WSOC. The highest WSOC levels were associated with fire plumes, highlighting the importance of both primary and secondary sources for WSOC in the region. Residual pollution layers enriched with WSOC are observed aloft up to an altitude of 3.2 km and the highest WSOC levels for each flight were typically observed above 500 m. Simultaneous ground WSOC measurements during aircraft overpasses in Pasadena and Riverside typically exhibit lower levels, especially when relative humidity (RH) was higher aloft suggestive of the influence of aerosol-phase water. This points to the underestimation of the radiative effects of WSOC when using only surface measurements. Reduced aerosol-phase water in the eastern desert outflow region likely promotes the re-partitioning of WSOC to the gas phase and suppression of processes to produce these species (partitioning, multiphase chemistry, photolytic production); as a result, WSOC is reduced relative to sulfate (but not as much as nitrate) as aerosol is advected from the Basin to the outflows.

  9. Aerosol particles collected on aircraft flights over the northwestern Pacific region during the ACE-Asia campaign: Composition and major sources of the organic compounds

    NASA Astrophysics Data System (ADS)

    Simoneit, Bernd R. T.; Kobayashi, Minoru; Mochida, Michihiro; Kawamura, Kimitaka; Huebert, Barry J.

    2004-10-01

    Atmospheric particulate matter, collected over the polluted east Asia/Pacific region in spring 2001 during research flights with the National Center for Atmospheric Research (NCAR) C-130 aircraft, was analyzed for different types of organic compounds using capillary gas chromatography-mass spectrometry. More than 70 organic species were detected in the aerosols and grouped into different compound classes on the basis of functional groups, including n-alkanes, polycyclic aromatic hydrocarbons, fatty acids, dehydroabietic acid, alkanols, water-soluble sugars (including glucose, sucrose, mycose, and levoglucosan), monocarboxylic and dicarboxylic acids, urea, and phthalates. Interestingly, the water-soluble compounds (72-133 ng m-3) were found to account for 16-50% (average 34%) of the total identified compound mass (TCM). Organic compounds were further categorized into several groups to suggest their sources. Fossil fuel combustion was recognized as the most significant source for the TCM (contributing 33-80% of TCM, average 50%), followed by soil resuspension (5-25%, average 19%) and secondary oxidation products (4-15%, average 9%). In contrast, the contribution of natural sources such as terrestrial plant wax and marine lipids (fatty acids and alkanols) was relatively small (3.4% and 9.4% on average, respectively). Biomass burning was suggested to contribute only a minor portion to the TCM of the Asian aerosols during the spring season (1.4% on average based on levoglucosan). However, levoglucosan may have been hydrolyzed and/or oxidized in part during long-range transport, and therefore this value represents a lower limit. The organic compound compositions of these samples are very different from those reported for aerosol particles of the Atlantic Ocean and from the earlier data for the mid-Pacific in terms of the abundant presence of water-soluble compounds consisting of saccharides, anhydrosaccharides, and the secondary dicarboxylic acids. This study

  10. VELETA 2002 Field Campaign.

    NASA Astrophysics Data System (ADS)

    Alados-Arboledas, L.; Veleta2002 Team

    2003-04-01

    Depletion of the Earth's ozone layer is considered responsible of an increase in the solar ultraviolet irradiance incoming at surface level (WMO, 1998). For this reason, it is important to know the amount of ultraviolet radiation received by plants and animal organisms to evaluate the potential impact of increased UV radiation on biological systems. During recent years several studies has investigated the differences in UV radiation between places located at different altitude. Depending on the choice of the experimental area altitudinal gradients in erythemal UV have been reported ranging from 0.08 to 0.40 at different regions. Rather high altitudinal gradients were obtained when the studies have been undertaken at sites with important tropospheric pollution or when snow cover was present in the high-level sites. In this sense, it seems of interest to study these altitudinal gradients including comprehensive observations of the environmental conditions relevant to the incoming UV irradiance in order to separate the different contributions to this altitudinal effect. This paper presents the field campaign VELETA2002 (eValuation of the Effects of eLevation and aErosols on the ultravioleT rAdiation), developed during the month of July 2002 in the area of Sierra Nevada (Spain). This field campaign was designed to obtain experimental data on elevation and atmospheric aerosol effects on the solar ultraviolet irradiance. For this purpose a set of radiometers and spectroradiometers has been installed at both slopes of Sierra Nevada Massif, from coastal to inland locations. The field stations include Motril, a coastal location at sea level, Pitres (1200 m a.s.l.) located in the South slope of Sierra Nevada Massif, the Veleta Peak (3398 m a.s.l.), Las Sabinas (2200 m a.s.l.) located on the north slope of the mountain range and Armilla (680 m a.s.l.) located in the valley. The principal feature of the locations is that they provide a strong altitudinal gradient considering

  11. Chemical composition, microstructure, and hygroscopic properties of aerosol particles at the Zotino Tall Tower Observatory (ZOTTO), Siberia, during a summer campaign

    DOE PAGES

    Mikhailov, E. F.; Mironov, G. N.; Pöhlker, C.; ...

    2015-03-16

    In this study we describe the hygroscopic properties of accumulation- and coarse-mode aerosol particles sampled at the Zotino Tall Tower Observatory (ZOTTO) in Central Siberia (61° N; 89° E) from 16 to 21 June 2013. The hygroscopic growth measurements were supplemented with chemical analyses of the samples, including inorganic ions and organic/elemental carbon. In addition, the microstructure and chemical composition of aerosol particles were analyzed by X-ray micro-spectroscopy (STXM-NEXAFS) and transmission electron microscopy (TEM). A mass closure analysis indicates that organic carbon accounted for 61 and 38% of PM in the accumulation mode and coarse mode, respectively. The water solublemore » fraction of organic matter was estimated to be 52 and 8% of PM in these modes. Sulfate, predominantly in the form of ammoniated sulfate, was the dominant inorganic component in both size modes: ~ 34% in the accumulation vs. ~ 47% in the coarse mode. The hygroscopic growth measurements were conducted with a filter-based differential hygroscopicity analyzer (FDHA) over the range of 5–99.4% RH in the hydration and dehydration operation modes. The FDHA study indicates that both accumulation and coarse modes exhibit pronounced water uptake approximately at the same RH, starting at ~ 70%, while efflorescence occurred at different humidities, i.e., at ~ 35% RH for submicron particles vs. ~ 50% RH for supermicron particles. This ~ 15% RH difference was attributed to higher content of organic material in the submicron particles, which suppresses water release in the dehydration experiments. The kappa mass interaction model (KIM) was applied to characterize and parameterize non-ideal solution behavior and concentration-dependent water uptake by atmospheric aerosol samples in the 5–99.4% RH range. Based on KIM, the volume-based hygroscopicity parameter, κv, was calculated. The κv, ws value related to the water soluble (ws) fraction was estimated to be ~ 0.15 for the

  12. Iceland Polar Vortex 2016 campaign: Winter and high-altitude dust size distributions with the balloon-borne Light Optical Aerosol Counter (LOAC)

    NASA Astrophysics Data System (ADS)

    Renard, Jean-Baptiste; Dagsson-Waldhauserova, Pavla; Olafsson, Haraldur; Arnalds, Olafur; Vignelles, Damien; Verdier, Nicolas

    2017-04-01

    Iceland has the largest area of volcaniclastic sandy desert on Earth where dust is originating from volcanic, but also glaciogenic sediments. Total Icelandic desert areas cover 44,000 km2 which makes Iceland the largest Arctic as well as European desert. The mean frequency of days with dust suspension was to 135 dust days annually in 1949-2011. The annual dust deposition was calculated as 31 - 40.1 million tons yr-1 affecting the area of > 500,000 km2. About 50% of the suspended PM10 are submicron particles. Icelandic dust is of volcanic origin; it is very dark in colour and contains sharp-tipped shards with bubbles. Such properties allow even large particles to be easily transported long distances as revealed on the satellite MODIS images with dust plumes traveling over 1000 km at times. There is a need to understand better the vertical distribution of such aerosols as well as their residence time in the atmosphere, especially during occasions such as polar vortex. Four LOAC flights were performed under meteorological balloons in Iceland in January 9-13 2016 when stratospheric polar vortex occurred above Iceland. LOAC is an optical aerosol counter that uses a new optical design to retrieve the size concentrations in 19 size classes between 0.2 and 100 micrometers, and to provide an estimate of the main nature of aerosols. Vertical profile of aerosol size distribution showed the presence of volcanic dust particles up to altitudes of 8 km for two of the flights (9-10 January). The MODIS satellite images confirmed a dust plume present above the southern coast from the deposits of September 2015 glacial outburst flood (jökulhlaup) while the rest of the country was covered by snow. These deposits had been actively suspended in November and December 2015. The ground PM10 mass concentration measurements in Reykjavik showed elevated PM measurements over 100 micrograms.m-3, confirming the particle presence 250 km far from the source. The number concentration exceeded 200

  13. Chemical composition, microstructure, and hygroscopic properties of aerosol particles at the Zotino Tall Tower Observatory (ZOTTO), Siberia, during a summer campaign

    NASA Astrophysics Data System (ADS)

    Mikhailov, E. F.; Mironov, G. N.; Pöhlker, C.; Chi, X.; Krüger, M. L.; Shiraiwa, M.; Förster, J.-D.; Pöschl, U.; Vlasenko, S. S.; Ryshkevich, T. I.; Weigand, M.; Kilcoyne, A. L. D.; Andreae, M. O.

    2015-08-01

    In this study we describe the hygroscopic properties of accumulation- and coarse-mode aerosol particles sampled at the Zotino Tall Tower Observatory (ZOTTO) in central Siberia (61° N, 89° E) from 16 to 21 June 2013. The hygroscopic growth measurements were supplemented with chemical analyses of the samples, including inorganic ions and organic/elemental carbon. In addition, the microstructure and chemical compositions of aerosol particles were analyzed by x-ray micro-spectroscopy (STXM-NEXAFS) and transmission electron microscopy (TEM). A mass closure analysis indicates that organic carbon accounted for 61 and 38 % of particulate matter (PM) in the accumulation mode and coarse mode, respectively. The water-soluble fraction of organic matter was estimated to be 52 and 8 % of PM in these modes. Sulfate, predominantly in the form of ammoniated sulfate, was the dominant inorganic component in both size modes: ~ 34 % in the accumulation mode vs. ~ 47 % in the coarse mode. The hygroscopic growth measurements were conducted with a filter-based differential hygroscopicity analyzer (FDHA) over the range of 5-99.4 % RH in the hydration and dehydration operation modes. The FDHA study indicates that both accumulation and coarse modes exhibit pronounced water uptake approximately at the same relative humidity (RH), starting at ~ 70 %, while efflorescence occurred at different humidities, i.e., at ~ 35 % RH for submicron particles vs. ~ 50 % RH for supermicron particles. This ~ 15 % RH difference was attributed to higher content of organic material in the submicron particles, which suppresses water release in the dehydration experiments. The kappa mass interaction model (KIM) was applied to characterize and parameterize non-ideal solution behavior and concentration-dependent water uptake by atmospheric aerosol samples in the 5-99.4 % RH range. Based on KIM, the volume-based hygroscopicity parameter, κv, was calculated. The κv,ws value related to the water-soluble (ws

  14. Chemical composition, microstructure, and hygroscopic properties of aerosol particles at the Zotino Tall Tower Observatory (ZOTTO), Siberia, during a summer campaign

    NASA Astrophysics Data System (ADS)

    Mikhailov, E. F.; Mironov, G. N.; Pöhlker, C.; Chi, X.; Krüger, M. L.; Shiraiwa, M.; Förster, J.-D.; Pöschl, U.; Vlasenko, S. S.; Ryshkevich, T. I.; Weigand, M.; Kilcoyne, A. L. D.; Andreae, M. O.

    2015-03-01

    In this study we describe the hygroscopic properties of accumulation- and coarse-mode aerosol particles sampled at the Zotino Tall Tower Observatory (ZOTTO) in Central Siberia (61° N; 89° E) from 16 to 21 June 2013. The hygroscopic growth measurements were supplemented with chemical analyses of the samples, including inorganic ions and organic/elemental carbon. In addition, the microstructure and chemical composition of aerosol particles were analyzed by X-ray micro-spectroscopy (STXM-NEXAFS) and transmission electron microscopy (TEM). A mass closure analysis indicates that organic carbon accounted for 61 and 38% of PM in the accumulation mode and coarse mode, respectively. The water soluble fraction of organic matter was estimated to be 52 and 8% of PM in these modes. Sulfate, predominantly in the form of ammoniated sulfate, was the dominant inorganic component in both size modes: ∼34% in the accumulation vs. ∼47% in the coarse mode. The hygroscopic growth measurements were conducted with a filter-based differential hygroscopicity analyzer (FDHA) over the range of 5-99.4% RH in the hydration and dehydration operation modes. The FDHA study indicates that both accumulation and coarse modes exhibit pronounced water uptake approximately at the same RH, starting at ∼70%, while efflorescence occurred at different humidities, i.e., at ∼35% RH for submicron particles vs. ∼50% RH for supermicron particles. This ∼15% RH difference was attributed to higher content of organic material in the submicron particles, which suppresses water release in the dehydration experiments. The kappa mass interaction model (KIM) was applied to characterize and parameterize non-ideal solution behavior and concentration-dependent water uptake by atmospheric aerosol samples in the 5-99.4% RH range. Based on KIM, the volume-based hygroscopicity parameter, κv, was calculated. The κv, ws value related to the water soluble (ws) fraction was estimated to be ∼0.15 for

  15. Estimation of mineral dust direct radiative forcing at the European Aerosol Research Lidar NETwork site of Lecce, Italy, during the ChArMEx/ADRIMED summer 2013 campaign: Impact of radiative transfer model spectral resolutions

    NASA Astrophysics Data System (ADS)

    Barragan, Ruben; Romano, Salvatore; Sicard, Michaël.; Burlizzi, Pasquale; Perrone, Maria Rita; Comeron, Adolfo

    2016-09-01

    A field campaign took place in the western and central Mediterranean basin on June-July 2013 in the framework of the ChArMEx (Chemistry-Aerosol Mediterranean Experiment, http://charmex.lsce.ipsl.fr/)/ADRIMED (Aerosol Direct Radiative Impact on the regional climate in the MEDiterranean region, http://adrimed.sedoo.fr/) project to characterize the aerosol direct radiative forcing (DRF) over the Mediterranean. This work focuses on the aerosol DRF estimations at Lecce (40.33°N; 18.11°E; 30 m above sea level) during the Saharan dust outbreak that affected southern Italy from 20 to 24 June 2013. The Global Atmospheric Model (GAME) and the Two-Stream (TS) model were used to calculate the instantaneous aerosol DRF in the short-wave (SW) and long-wave (LW) spectral ranges, at the surface and at the top of the atmosphere (TOA). The main differences between the two models were due to the different numerical methods to solve the radiative transfer (RT) equations and to the more detailed spectral resolution of GAME compared to that of TS. 167 and 115 subbands were used by GAME in the 0.3-4 and 4-37 µm spectral ranges, respectively. Conversely, the TS model used 8 and 11 subbands in the same spectral ranges, respectively. We found on 22 June that the SW-DRFs from the two models were in good agreement, both at the TOA and at the surface. The instantaneous SW-DRFs at the surface and at the TOA varied from -50 to -34 W m-2 and from -6 to +8 W m-2, respectively, while the surface and TOA LW-DRFs ranged between +3.5 and +8.0 W m-2 and between +1.7 and +6.9 W m-2, respectively. In particular, both models provided positive TOA SW-DRFs at solar zenith angles smaller than 25° because of the mixing of the desert dust with anthropogenic pollution during its transport to the study site. In contrast, the TS model overestimated the GAME LW-DRF up to about 5 and 7.5 times at the surface and at the TOA, respectively, when the dust particle contribution was largest. The low spectral

  16. Integrated campaign.

    PubMed

    2006-01-01

    Virginia Hospital Center launched a multiintegrated advertising campaign that centers around topic-specific medical issues through the use of provocative advertisements. For example, the first ad, which launched in September, focuses on abdominal hysterectomies.

  17. The stratospheric aerosol particle measurement by balloon at Syowa Station (69.00 deg S, 39.35 deg E): Outline of special sonde (rubber) campaign JARE 24

    NASA Technical Reports Server (NTRS)

    Iwasaka, Y.; Morita, T.; Itoh, T.; Shibazaki, K.; Makino, Y.; Tanaka, T.; Tsukamura, K.; Yano, T.; Kondoh, K.; Iwashita, G.

    1985-01-01

    During the period of AMA (Antarctic Middle Atmosphere), various style balloons were used to measure atmospheric parameters at Syowa Station (69.00 deg S, 39.35 deg E), Antarctica. The measurements which were made using balloons specially designed to monitor stratospheric aerosol particles are discussed. This type balloon was first used by JARE (Japan Antarctic Research Expedition) 24th Team in 1983. Until that time, the Japan Antarctic Research Expedition Team had been using only a large plastic balloon to monitor various minor constituents in the stratosphere. The plastic balloon was very useful, but it took a long time to arrange a balloon launching. Additionally, launching time strongly depended on weather conditions. A timely launching of the balloon was carried out with this specially designed sonde.

  18. Single-particle characterization of atmospheric aerosols collected at Gosan, Korea, during the Asian Pacific Regional Aerosol Characterization Experiment field campaign using low-Z (atomic number) particle electron probe X-ray microanalysis.

    PubMed

    Geng, Hong; Cheng, Fangqin; Ro, Chul-Un

    2011-11-01

    A quantitative energy-dispersive electron probe X-ray microanalysis (ED-EPMA), namely low-Z (atomic number) particle EPMA, was used to characterize the chemical compositions of the individual aerosol particles collected at the Gosan supersite, Jeju Island, Korea, as a part of the Asian Pacific Regional Aerosol Characterization Experiment (ACE-Asia). On 4-10 April 2001 just before a severe dust storm arrived, seven sets of aerosol samples were obtained by a seven-stage May cascade impactor with a flow rate of 20 L/min. Overall 11,200 particles on stages 1-6 with cutoff diameters of 16, 8, 4, 2, 1, and 0.5 microm, respectively, were examined and classified based on their secondary electron images and X-ray spectra. In general, sea salt particles were the most frequently encountered, followed by mineral dust, organic carbon (OC)-like, (NH4)2SO4/NH4HSO4-containing, elemental carbon (EC)-like, Fe-rich, and K-rich particles. Sea salt and mineral dust particles had a higher relative abundance on stages 1-5, whereas OC-like, (NH4)2SO4/NH4HSO4-containing, Fe-rich, and K-rich particles were relatively abundant on stage 6. The analysis on relative number abundances of various particle types combined with 72-hr backward air mass trajectories indicated that a lot of reacted sea salt and reacted mineral dust (with airborne NOx and SO2 or their acidic products) and OC-like particles were carried by the air masses passing over the Yellow Sea (for sample "10 April") and many NH4HSO4/ (NH4)2SO4-containing particles were carried by the air masses passing over the Sea of Japan and Korea Strait (for samples "4-9 April"). It was concluded that the atmosphere over Jeju Island was influenced by anthropogenic SO2 and NOx, organic compounds, and secondary aerosols when Asian dust was absent.

  19. Original sounding and drifting balloon-borne measurements in the western Mediterranean with the aerosol counter/sizer LOAC during summer ChArMEx campaigns, with a focus on desert dust events

    NASA Astrophysics Data System (ADS)

    Renard, Jean-Baptiste; Dulac, François; Vignelles, Damien; Jeannot, Matthieu; Verdier, Nicolas; Chazette, Patrick; Crenn, Vincent; Sciare, Jean; Totems, Julien; Durand, Pierre; Barret, Brice; Jambert, Corinne; Mallet, Marc; Menut, Laurent; Mailler, Sylvain; Basart, Sara; Baldasano, José Maria

    2015-04-01

    LOAC (Light Optical Aerosol Counter) is a new small optical particle counter/sizer of ~250 grams designed to fly under all kinds of balloons. The measurements are conducted at two scattering angles (12° and 60°), allowing the determination of the aerosol particle concentrations in 19 size classes within a diameter range of ~0.2-100 µm and some identification of the nature of particles dominating different size classes. Following laboratory calibration, the sensor particularly discriminates wet or liquid particles, mineral dust, soot carbon particles and salts. Comparisons with other in situ sensors at the surface and with remote sensing measurements on the vertical were performed to give confidence in measurements. The instrument has been operated at the surface, under all kinds of balloons up to more than 35 km in altitude, including tethered, sounding, open stratospheric and new boundary-layer pressurized drifting balloons (BLPB) from CNES, and was tested on board a small UAV. Operations encompass a variety of environments including the Arctic (Reykjavik, Island, and Kiruna, Sweden), Brazil (Sao Paolo), the western Mediterranean Basin, southwestern France, peri-urban (Ile de France) and urban areas (Paris and Vienna). Presented results are focused on the LOAC balloon-borne measurements performed in the western Mediterranean basin during MISTRALS/ChArMEx campaigns (Mediterranean Integrated Studies aT Regional And Local Scales/the Chemistry-Aerosol Mediterranean Experiment; http://www.mistrals-hjome.org; http://charmex.lsce.ipsl.fr), with a focus on African dust events. Two test flights with a first version of LOAC under sounding balloons were first successfully performed in late June 2012 near Marseille during an intense dust event. In 2013, 19 LOAC flights have been performed under meteorological balloons and 12 under low altitude drifting balloons, most of them from Minorca Island (Spain) in June and early July and others from Levant Island (south of France

  20. Chemical composition, microstructure, and hygroscopic properties of aerosol particles at the Zotino Tall Tower Observatory (ZOTTO), Siberia, during a summer campaign

    SciTech Connect

    Mikhailov, E. F.; Mironov, G. N.; Pöhlker, C.; Chi, X.; Krüger, M. L.; Shiraiwa, M.; Förster, J. -D.; Pöschl, U.; Vlasenko, S. S.; Ryshkevich, T. I.; Weigand, M.; Kilcoyne, A. L. D.; Andreae, M. O.

    2015-03-16

    In this study we describe the hygroscopic properties of accumulation- and coarse-mode aerosol particles sampled at the Zotino Tall Tower Observatory (ZOTTO) in Central Siberia (61° N; 89° E) from 16 to 21 June 2013. The hygroscopic growth measurements were supplemented with chemical analyses of the samples, including inorganic ions and organic/elemental carbon. In addition, the microstructure and chemical composition of aerosol particles were analyzed by X-ray micro-spectroscopy (STXM-NEXAFS) and transmission electron microscopy (TEM). A mass closure analysis indicates that organic carbon accounted for 61 and 38% of PM in the accumulation mode and coarse mode, respectively. The water soluble fraction of organic matter was estimated to be 52 and 8% of PM in these modes. Sulfate, predominantly in the form of ammoniated sulfate, was the dominant inorganic component in both size modes: ~ 34% in the accumulation vs. ~ 47% in the coarse mode.

    The hygroscopic growth measurements were conducted with a filter-based differential hygroscopicity analyzer (FDHA) over the range of 5–99.4% RH in the hydration and dehydration operation modes. The FDHA study indicates that both accumulation and coarse modes exhibit pronounced water uptake approximately at the same RH, starting at ~ 70%, while efflorescence occurred at different humidities, i.e., at ~ 35% RH for submicron particles vs. ~ 50% RH for supermicron particles. This ~ 15% RH difference was attributed to higher content of organic material in the submicron particles, which suppresses water release in the dehydration experiments.

    The kappa mass interaction model (KIM) was applied to characterize and parameterize non-ideal solution behavior and concentration-dependent water uptake by atmospheric aerosol samples in the 5–99.4% RH range. Based on KIM, the volume-based hygroscopicity parameter, κv, was calculated. The κv, ws value related to the water soluble (ws) fraction was

  1. Spatial and temporal variabilities in vertical structure of the Marine Atmospheric Boundary Layer over Bay of Bengal during Winter Phase of Integrated Campaign for Aerosols, gases and Radiation Budget

    NASA Astrophysics Data System (ADS)

    Subrahamanyam, D. Bala; Anurose, T. J.; Kumar, N. V. P. Kiran; Mohan, Mannil; Kunhikrishnan, P. K.; John, Sherine Rachel; Prijith, S. S.; Dutt, C. B. S.

    2012-04-01

    Spatial and temporal variabilities in the vertical structure of Marine Atmospheric Boundary Layer (MABL) over the Bay of Bengal (BoB) are investigated through a ship-borne field experiment measurements pertaining to three different classes, namely: night, morning and afternoon conditions. High-resolution vertical profiles of meteorological parameters obtained through balloon-borne GPS Sondes during the Winter phase of Integrated Campaign for Aerosols, gases and Radiation Budget (W-ICARB) formed the primary database for the present investigation. The study advocates usage of wind shear profiles in association with virtual potential temperature (θv) and specific humidity (q) profiles for determination of the mixed layer heights (MLH). The mean values of turbulent flow thickness (TFT) obtained from the vertical profiles of Bulk Richardson Number (RiB) and MLH magnitudes for the entire cruise did not show any appreciable variations for three classes. During the entire cruise period, the MLH varied in a range from 450 m to 1500 m with a mean of about 900 m, whereas the TFT variations were confined between 125 m and 1475 m with a mean of about 581 m. The statistical means of TFT and MLH were similar for nighttime profiles, whereas they showed significant differences in the morning and afternoon conditions. Spatio-temporal variability in the MLH showed good correlation with the surface-layer sensible heat flux which is one of the driving mechanisms in mixing processes.

  2. Seasonal variation in the spatial distribution of aerosol black carbon over Bay of Bengal: A synthesis of multi-campaign measurements

    NASA Astrophysics Data System (ADS)

    Kompalli, Sobhan Kumar; Suresh Babu, S.; Krishna Moorthy, K.; Nair, Vijayakumar S.; Gogoi, Mukunda M.; Chaubey, Jai Prakash

    2013-01-01

    Synthesizing data from several cruise experiments over the Bay of Bengal (BoB), the seasonal characterization of aerosol black carbon (BC) mass concentration was made. The study indicated that the BC mass concentration (MBC) showed significant seasonal variation over the oceanic region with MBC being the highest during the winter season (˜2407 ± 1756 ng m-3) and lowest in summer monsoon (˜765 ± 235 ng m-3). The seasonal changes in the BC mass concentration were more prominent over the northern BoB (having an annual amplitude of ˜4) compared to southern BoB (amplitude ˜ 2). Significant spatial gradients in MBC, latitudinal as well as longitudinal, existed in all the seasons. Latitudinal gradients, despite being consistently increasing northwards, were found to be sharper during winter and weakest during summer monsoon with e-fold scaling distances of ˜7.7° and ˜15.6° during winter and summer monsoon seasons respectively. Longitudinally, BC concentrations tend to increase toward east during winter and premonsoon seasons, but an opposite trend was seen in monsoon season highlighting the seasonally changing source impacts on BC loading over BoB. Examination of the results in light of possible role of transport from adjoining landmasses, using airmass back trajectory cluster analysis, also supported spatially and temporally varying source influence on oceanic region.

  3. Sugars in Antarctic aerosol

    NASA Astrophysics Data System (ADS)

    Barbaro, Elena; Kirchgeorg, Torben; Zangrando, Roberta; Vecchiato, Marco; Piazza, Rossano; Barbante, Carlo; Gambaro, Andrea

    2015-10-01

    The processes and transformations occurring in the Antarctic aerosol during atmospheric transport were described using selected sugars as source tracers. Monosaccharides (arabinose, fructose, galactose, glucose, mannose, ribose, xylose), disaccharides (sucrose, lactose, maltose, lactulose), alcohol-sugars (erythritol, mannitol, ribitol, sorbitol, xylitol, maltitol, galactitol) and anhydrosugars (levoglucosan, mannosan and galactosan) were measured in the Antarctic aerosol collected during four different sampling campaigns. For quantification, a sensitive high-pressure anion exchange chromatography was coupled with a single quadrupole mass spectrometer. The method was validated, showing good accuracy and low method quantification limits. This study describes the first determination of sugars in the Antarctic aerosol. The total mean concentration of sugars in the aerosol collected at the "Mario Zucchelli" coastal station was 140 pg m-3; as for the aerosol collected over the Antarctic plateau during two consecutive sampling campaigns, the concentration amounted to 440 and 438 pg m-3. The study of particle-size distribution allowed us to identify the natural emission from spores or from sea-spray as the main sources of sugars in the coastal area. The enrichment of sugars in the fine fraction of the aerosol collected on the Antarctic plateau is due to the degradation of particles during long-range atmospheric transport. The composition of sugars in the coarse fraction was also investigated in the aerosol collected during the oceanographic cruise.

  4. Overview of the CINDI campaign

    NASA Astrophysics Data System (ADS)

    van Roozendael, Michel; Piters, Ankie; Boersma, Folkert; Wittrock, Folkard; Hains, Jennifer; Kroon, Mark; Roscoe, Howard

    2010-05-01

    The Cabauw Intercomparison Campaign of Nitrogen Dioxide measuring Instruments (CINDI) took place in June-July 2009 at the Cabauw meteorological observatory, a semi-rural site located in the Netherlands, 30 km South of Utrecht. Its main objective was to intercompare a broad range of NO2 measuring instruments that can be used in support of the validation of tropospheric NO2 column measurements from satellites with, as primary focus, the assessment of tropospheric NO2 column and profile measurements using the DOAS and MAXDOAS techniques. The campaign included a formal semi-blind exercise following standards from the Network for the Detection of Atmospheric Composition Change (NDACC), and was followed by a number of additional activities. In total measurements from 32 NO2 instruments, most of them of DOAS-type but also a NO2 Lidar, in-situ sensors and a new-developed NO2 sonde, were collected and intercompared. In addition, a number of other parameters were measured, among them aerosol, HCHO, CHOCHO and BrO. Measurements were also dedicated to the study of horizontal gradients in the NO2 field and their impact on remote-sensing observations. Various working groups were set up to analyse results, establish uncertainties and progress towards improved and standardized retrieval algorithms. The campaign should result in consolidated trace gas and aerosol data products from both remote-sensing and in-situ techniques, thereby contributing to fulfill the needs for improved vertically-resolved monitoring of the air quality.

  5. Teaching Health Campaigns by Doing Health Campaigns

    ERIC Educational Resources Information Center

    Neuberger, Lindsay

    2017-01-01

    Courses: Health Campaigns, Health Communication,Communication Campaigns, Public Relations Campaigns, Persuasion. Objectives: Students will demonstrate their ability to work effectively both individually and in teams to apply "health communication" theory to emerging, practical, on-campus health issues via formative research, multimodal…

  6. Recent development in aerosol devices for pulmonary vaccine delivery.

    PubMed

    Lu, Dong mei

    2012-10-18

    This review will discuss aerosol device technologies available for pulmonary vaccine deliveries. The possibilities of adopting aerosol-generation for the purpose of pulmonary immunization are described. Aerosol-generation systems might offer advantages in respect to vaccine stability and antigenicity. The noninvasive, relatively safe and low-cost net of pulmonary delivery may provide great benefits to the public health vaccination campaign.

  7. RACORO aerosol data processing

    SciTech Connect

    Elisabeth Andrews

    2011-10-31

    The RACORO aerosol data (cloud condensation nuclei (CCN), condensation nuclei (CN) and aerosol size distributions) need further processing to be useful for model evaluation (e.g., GCM droplet nucleation parameterizations) and other investigations. These tasks include: (1) Identification and flagging of 'splash' contaminated Twin Otter aerosol data. (2) Calculation of actual supersaturation (SS) values in the two CCN columns flown on the Twin Otter. (3) Interpolation of CCN spectra from SGP and Twin Otter to 0.2% SS. (4) Process data for spatial variability studies. (5) Provide calculated light scattering from measured aerosol size distributions. Below we first briefly describe the measurements and then describe the results of several data processing tasks that which have been completed, paving the way for the scientific analyses for which the campaign was designed. The end result of this research will be several aerosol data sets which can be used to achieve some of the goals of the RACORO mission including the enhanced understanding of cloud-aerosol interactions and improved cloud simulations in climate models.

  8. Field Campaign Guidelines

    SciTech Connect

    Voyles, J. W.; Chapman, L. A.

    2015-12-01

    This document establishes a common set of guidelines for the Atmospheric Radiation Measurement (ARM) Climate Research Facility for planning, executing, and closing out field campaigns. The steps that guide individual field campaigns are described in the Field Campaign Tracking System and are specifically tailored to meet the scope of each field campaign.

  9. The Aerosol Coarse Mode Initiative

    NASA Astrophysics Data System (ADS)

    Arnott, W. P.; Adhikari, N.; Air, D.; Kassianov, E.; Barnard, J.

    2014-12-01

    Many areas of the world show an aerosol volume distribution with a significant coarse mode and sometimes a dominant coarse mode. The large coarse mode is usually due to dust, but sea salt aerosol can also play an important role. However, in many field campaigns, the coarse mode tends to be ignored, because it is difficult to measure. This lack of measurements leads directly to a concomitant "lack of analysis" of this mode. Because, coarse mode aerosols can have significant effects on radiative forcing, both in the shortwave and longwave spectrum, the coarse mode -- and these forcings -- should be accounted for in atmospheric models. Forcings based only on fine mode aerosols have the potential to be misleading. In this paper we describe examples of large coarse modes that occur in areas of large aerosol loading (Mexico City, Barnard et al., 2010) as well as small loadings (Sacramento, CA; Kassianov et al., 2012; and Reno, NV). We then demonstrate that: (1) the coarse mode can contribute significantly to radiative forcing, relative to the fine mode, and (2) neglecting the coarse mode may result in poor comparisons between measurements and models. Next we describe -- in general terms -- the limitations of instrumentation to measure the coarse mode. Finally, we suggest a new initiative aimed at examining coarse mode aerosol generation mechanisms; transport and deposition; chemical composition; visible and thermal IR refractive indices; morphology; microphysical behavior when deposited on snow and ice; and specific instrumentation needs. Barnard, J. C., J. D. Fast, G. Paredes-Miranda, W. P. Arnott, and A. Laskin, 2010: Technical Note: Evaluation of the WRF-Chem "Aerosol Chemical to Aerosol Optical Properties" Module using data from the MILAGRO campaign, Atmospheric Chemistry and Physics, 10, 7325-7340. Kassianov, E. I., M. S. Pekour, and J. C. Barnard, 2012: Aerosols in Central California: Unexpectedly large contribution of coarse mode to aerosol radiative forcing

  10. Transport, Chemistry, and Blowing Snow: Antarctic Aerosol sources and processes

    NASA Astrophysics Data System (ADS)

    DeCarlo, P. F.; Giordano, M.; Kalnajs, L.

    2016-12-01

    Due to access to the southernmost continent and the harsh environment, Antarctic aerosol remains one of the least studied aerosol populations. Observations are necessary to understand the sources and evolution of the Antarctic aerosol population. The 2ODIAC (2-Season Ozone Depletion and Interaction with Aerosols Campaign) field campaign saw the first ever deployment of a real-time, high resolution aerosol mass spectrometer (AMS) to the continent. Using the AMS with a suite of other meteorological, aerosol, and gas phase instrumentation provided novel measurements on the size and composition of the coastal Antarctic aerosol population as a function of season. This presentation will discuss the role of long range transport, atmospheric chemistry, and blowing snow in shaping the aerosol composition and population in this region from two field measurement seasons.

  11. Campaign datasets for Biomass Burning Observation Project (BBOP)

    DOE Data Explorer

    Kleinman,Larry; Mei,Fan; Arnott,William; Buseck,Peter; Chand,Duli; Comstock,Jennifer; Dubey,Manvendra; Lawson,Paul; Long,Chuck; Onasch,Timothy; Sedlacek,Arthur; Senum,Gunnar; Shilling,John; Springston,Stephen; Tomlinson,Jason; Wang,Jian

    2014-04-24

    This field campaign will address multiple uncertainties in aerosol intensive properties, which are poorly represented in climate models, by means of aircraft measurements in biomass burning plumes. Key topics to be investigated are: 1. Aerosol mixing state and morphology 2. Mass absorption coefficients (MACs) 3. Chemical composition of non-refractory material associated with light-absorbing carbon (LAC) 4. Production rate of secondary organic aerosol (SOA) 5. Microphysical processes relevant to determining aerosol size distributions and single scattering albedo (SSA) 6. CCN activity. These topics will be investigated through measurements near active fires (0-5 hours downwind), where limited observations indicate rapid changes in aerosol properties, and in biomass burning plumes aged >5 hours. Aerosol properties and their time evolution will be determined as a function of fire type, defined according to fuel and the mix of flaming and smoldering combustion at the source.

  12. Collision Repair Campaign

    EPA Pesticide Factsheets

    The Collision Repair Campaign targets meaningful risk reduction in the Collision Repair source category to reduce air toxic emissions in their communities. The Campaign also helps shops to work towards early compliance with the Auto Body Rule.

  13. The "Know Stroke" Campaign

    MedlinePlus

    ... Current Issue Past Issues Special Section The "Know Stroke" Campaign Past Issues / Summer 2007 Table of Contents ... campaign for the U.S. Hispanic community. 1 Know Stroke A stroke occurs when the blood supply to ...

  14. The Effect of Aerosol Hygroscopicity and Volatility on Aerosol Optical Properties During Southern Oxidant and Aerosol Study

    NASA Astrophysics Data System (ADS)

    Khlystov, A.; Grieshop, A. P.; Saha, P.; Subramanian, R.

    2014-12-01

    Secondary organic aerosol (SOA) from biogenic sources can influence optical properties of ambient aerosol by altering its hygroscopicity and contributing to light absorption directly via formation of brown carbon and indirectly by enhancing light absorption by black carbon ("lensing effect"). The magnitude of these effects remains highly uncertain. A set of state-of-the-art instruments was deployed at the SEARCH site near Centerville, AL during the Southern Oxidant and Aerosol Study (SOAS) campaign in summer 2013 to measure the effect of relative humidity and temperature on aerosol size distribution, composition and optical properties. Light scattering and absorption by temperature- and humidity-conditioned aerosols was measured using three photo-acoustic extinctiometers (PAX) at three wavelengths (405 nm, 532 nm, and 870 nm). The sample-conditioning system provided measurements at ambient RH, 10%RH ("dry"), 85%RH ("wet"), and 200 C ("TD"). In parallel to these measurements, a long residence time temperature-stepping thermodenuder (TD) and a variable residence time constant temperature TD in combination with three SMPS systems and an Aerosol Chemical Speciation Monitor (ACSM) were used to assess aerosol volatility and kinetics of aerosol evaporation. We will present results of the on-going analysis of the collected data set. We will show that both temperature and relative humidity have a strong effect on aerosol optical properties. SOA appears to increase aerosol light absorption by about 10%. TD measurements suggest that aerosol equilibrated fairly quickly, within 2 s. Evaporation varied substantially with ambient aerosol loading and composition and meteorology.

  15. Who Runs Presidential Campaigns?

    ERIC Educational Resources Information Center

    Kindsvatter, Peter S.

    Presidential campaigns in the last decade have provided evidence of the rising influence of the mass media campaign and of campaign consultants. The media, through their power of access to the people, manipulate the public's recognition of a candidate by the amount of coverage given. Newspaper endorsements and the reporting of media-conducted…

  16. Who Runs Presidential Campaigns?

    ERIC Educational Resources Information Center

    Kindsvatter, Peter S.

    Presidential campaigns in the last decade have provided evidence of the rising influence of the mass media campaign and of campaign consultants. The media, through their power of access to the people, manipulate the public's recognition of a candidate by the amount of coverage given. Newspaper endorsements and the reporting of media-conducted…

  17. Diversity: A Corporate Campaign

    ERIC Educational Resources Information Center

    Akiyama, Diana D.

    2008-01-01

    In this article, the author calls for a "campaign" because she believes there is a need to build upon the successes of diversity initiatives with renewed commitment, in much the same way as capital campaigns build upon past successes and refocus campuses on their work. Just as a capital campaign invests in financial stability by stimulating…

  18. Dual Wavelength Lidar Observation of Tropical High-Altitude Cirrus Clouds During the ALBATROSS 1996 Campaign

    NASA Technical Reports Server (NTRS)

    Beyerle, G.; Schafer, J.; Neuber, R.; Schrems, O.; McDermid, I. S.

    1998-01-01

    Dual wavelength aerosol lidar observations of tropical high-altitude cirrus clouds were performed during the ALBATROSS 1996 campaign aboard the research vessel POLARSTERN on the Atlantic ocean in October-November 1996.

  19. Pre-Cloud Aerosol, Cloud Droplet Concentration, and Cloud Condensation Nuclei from the VAMOS Ocean-Cloud-Atmosphere Land Study (VOCALS) Field Campaign First Quarter 2010 ASR Program Metric Report

    SciTech Connect

    Kleinman, LI; Springston, SR; Daum, PH; Lee, Y-N; Sedlacek, AJ; Senum, G; Wang, J

    2011-08-31

    In this, the first of a series of Program Metric Reports, we (1) describe archived data from the DOE G-1 aircraft, (2) illustrate several relations between sub-cloud aerosol, CCN, and cloud droplets pertinent to determining the effects of pollutant sources on cloud properties, and (3) post to the data archive an Excel spreadsheet that contains cloud and corresponding sub-cloud data.

  20. Organic aerosols

    SciTech Connect

    Penner, J.E.

    1994-01-01

    Organic aerosols scatter solar radiation. They may also either enhance or decrease concentrations of cloud condensation nuclei. This paper summarizes observed concentrations of aerosols in remote continental and marine locations and provides estimates for the sources of organic aerosol matter. The anthropogenic sources of organic aerosols may be as large as the anthropogenic sources of sulfate aerosols, implying a similar magnitude of direct forcing of climate. The source estimates are highly uncertain and subject to revision in the future. A slow secondary source of organic aerosols of unknown origin may contribute to the observed oceanic concentrations. The role of organic aerosols acting as cloud condensation nuclei (CCN) is described and it is concluded that they may either enhance or decrease the ability of anthropogenic sulfate aerosols to act as CCN.

  1. Formation of highly oxygenated organic aerosol in the atmosphere: Insights from the Finokalia Aerosol Measurement Experiments

    NASA Astrophysics Data System (ADS)

    Hildebrandt, Lea; Kostenidou, Evangelia; Mihalopoulos, Nikos; Worsnop, Douglas R.; Donahue, Neil M.; Pandis, Spyros N.

    2010-12-01

    Aged organic aerosol (OA) was measured at a remote coastal site on the island of Crete, Greece during the Finokalia Aerosol Measurement Experiments (FAME-08 and FAME-09), which were part of the EUCAARI intensive campaigns. Quadrupole aerosol mass spectrometers (Q-AMSs) were employed to measure the size-resolved chemical composition of non-refractory submicron aerosol (NR-PM1), and to estimate the extent of oxidation of the OA. The experiments provide unique insights into ambient oxidation of aerosol by measuring at the same site but under different photochemical conditions. NR-PM1 concentrations were about a factor of three lower during FAME-09 (winter) than during FAME-08 (summer). The OA sampled was significantly less oxidized and more variable in composition during the winter than during the early summer. Lower OH concentrations in the winter were the main difference between the two campaigns, suggesting that atmospheric formation of highly oxygenated OA is associated with homogeneous photochemical aging.

  2. Measurements of Semi-volatile Aerosol and Its Effect on Aerosol Optical Properties During Southern Oxidant and Aerosol Study

    NASA Astrophysics Data System (ADS)

    Khlystov, A.; Grieshop, A. P.; Saha, P.; Subramanian, R.

    2013-12-01

    Semi-volatile compounds, including particle-bound water, comprise a large part of aerosol mass and have a significant influence on aerosol lifecycle and its optical properties. Understanding the properties of semi-volatile compounds, especially those pertaining to gas/aerosol partitioning, is of critical importance for our ability to predict concentrations and properties of ambient aerosol. A set of state-of-the-art instruments was deployed at the SEARCH site near Centerville, AL during the Southern Oxidant and Aerosol Study (SOAS) campaign in summer 2013 to measure the effect of temperature and relative humidity on aerosol size distribution, composition and optical properties. Light scattering and absorption by temperature- and humidity-conditioned aerosols was measured using three photo-acoustic extinctiometers (PAX) at three wavelengths (405 nm, 532 nm, and 870 nm). In parallel to these measurements, a long residence time temperature-stepping thermodenuder and a variable residence time constant temperature thermodenuder in combination with three SMPS systems and an Aerosol Chemical Speciation Monitor (ACSM) were used to assess aerosol volatility and kinetics of aerosol evaporation. It was found that both temperature and relative humidity have a strong effect on aerosol optical properties. The variable residence time thermodenuder data suggest that aerosol equilibrated fairly quickly, within 2 s, in contrast to other ambient observations. Preliminary analysis show that approximately 50% and 90% of total aerosol mass evaporated at temperatures of 100 C and 180C, respectively. Evaporation varied substantially with ambient aerosol loading and composition and meteorology. During course of this study, T50 (temperatures at which 50% aerosol mass evaporates) varied from 60 C to more than 120 C.

  3. An overview of the AROMAT campaigns

    NASA Astrophysics Data System (ADS)

    Merlaud, Alexis; Dekemper, Emmanuel; Van Roozendael, Michel; Constantin, Daniel; Georgescu, Lucian; Meier, Andreas; Richter, Andreas; Den Hoed, Mirjam; Allaart, Marc; Boscornea, Andreea; Vajaiac, Sorin; Bellegante, Livio; Nemuc, Anca; Nicolae, Doina; Shaifangar, Reza; Dörner, Steffen; Wagner, Thomas; Stebel, Kerstin; Schuettemeyer, Dirk

    2016-04-01

    The Airborne ROmanian Measurements of Aerosols and Trace gases (AROMAT) campaign and its follow-up AROMAT-2 were held in September 2014 and August 2015, respectively. Both campaigns focused on two geophysical targets: the city of Bucharest and the large power plants of the Jiu Valley, which are located in a rural area 170 km West of Bucharest. These two areas are complementary in terms of emitted chemical species and their spatial distributions. The objectives of the AROMAT campaigns were (i) to test recently developed airborne observation systems dedicated to air quality satellite validation studies such as the AirMAP imaging DOAS system (University of Bremen), the NO2 sonde (KNMI), and the compact SWING whiskbroom imager (BIRA), and (ii) to prepare the validation programme of the future Atmospheric Sentinels, starting with Sentinel-5 Precursor (S5P) to be launched in early summer 2016. We present results from the different airborne instrumentations and from coincident ground-based measurements (lidar, in-situ, and mobile DOAS systems) performed during both campaigns. The AROMAT dataset addresses several of the mandatory products of TROPOMI/S5P, in particular NO2 and SO2 (horizontal distribution and profile from aircraft, plume image with ground-based SO2 and NO2 cameras, transects with mobile DOAS, in-situ), H2CO (mobile MAX-DOAS), and aerosols (lidar, airborne FUBISS-ASA2 sun-photometer, and aircraft in-situ). We investigate the information content of the AROMAT dataset for satellite validation studies based on co-located OMI and GOME-2 data, and simulations of TROPOMI measurements. The experience gained during AROMAT and AROMAT-2 will be used in support of a large-scale TROPOMI/S5P validation campaign in Romania scheduled for summer 2017.

  4. Comparison of MADE3-simulated and observed aerosol distributions with a focus on aerosol vertical profiles

    NASA Astrophysics Data System (ADS)

    Kaiser, Christopher; Hendricks, Johannes; Righi, Mattia; Jöckel, Patrick

    2016-04-01

    The reliability of aerosol radiative forcing estimates from climate models depends on the accuracy of simulated global aerosol distribution and composition, as well as on the models' representation of the aerosol-cloud and aerosol-radiation interactions. To help improve on previous modeling studies, we recently developed the new aerosol microphysics submodel MADE3 that explicitly tracks particle mixing state in the Aitken, accumulation, and coarse mode size ranges. We implemented MADE3 into the global atmospheric chemistry general circulation model EMAC and evaluated it by comparison of simulated aerosol properties to observations. Compared properties include continental near-surface aerosol component concentrations and size distributions, continental and marine aerosol vertical profiles, and nearly global aerosol optical depth. Recent studies have shown the specific importance of aerosol vertical profiles for determination of the aerosol radiative forcing. Therefore, our focus here is on the evaluation of simulated vertical profiles. The observational data is taken from campaigns between 1990 and 2011 over the Pacific Ocean, over North and South America, and over Europe. The datasets include black carbon and total aerosol mass mixing ratios, as well as aerosol particle number concentrations. Compared to other models, EMAC with MADE3 yields good agreement with the observations - despite a general high bias of the simulated mass mixing ratio profiles. However, BC concentrations are generally overestimated by many models in the upper troposphere. With MADE3 in EMAC, we find better agreement of the simulated BC profiles with HIPPO data than the multi-model average of the models that took part in the AeroCom project. There is an interesting difference between the profiles from individual campaigns and more "climatological" datasets. For instance, compared to spatially and temporally localized campaigns, the model simulates a more continuous decline in both total

  5. The STAR Grants Contribution to the SOAS Campaign

    EPA Science Inventory

    The Southern Oxidant and Aerosol Study (SOAS) is a community-led field campaign that was part of the Southeast Atmosphere Study (SAS). As one of the largest field studies in decades to characterize air quality in the Southeastern United States, SAS is a collaborative project invo...

  6. The STAR Grants Contribution to the SOAS Campaign

    EPA Science Inventory

    The Southern Oxidant and Aerosol Study (SOAS) is a community-led field campaign that was part of the Southeast Atmosphere Study (SAS). As one of the largest field studies in decades to characterize air quality in the Southeastern United States, SAS is a collaborative project invo...

  7. Real Time Detection of Sodium in Size-Segregated Marine Aerosols

    DTIC Science & Technology

    2002-09-30

    Real Time Measurement of Sea- Salt Aerosol during the SEAS Campaign: Comparison of Emission based Sodium Detection with an Aerosol Volatility Technique. Submitted to the Journal of Atmospheric and Oceanic Technology. ...Real Time Detection of Sodium in Size-Segregated Marine Aerosols Anthony J. Hynes Rosenstiel School of Marine and Atmospheric Science 4600...this capability for sodium and a prototype has been deployed as part of an ONR-sponsored field campaign (SEAS). The ultimate goal of the project is to

  8. Sun photometer aerosol retrievals during SALTRACE

    NASA Astrophysics Data System (ADS)

    Toledano, Carlos; Torres, Benjamin; Althausen, Dietrich; Groß, Silke; Freudenthaler, Volker; Weinzierl, Bernadett; Gasteiger, Josef; Ansmann, Albert; Wiegner, Matthias; González, Ramiro; Cachorro, Victoria

    2015-04-01

    The Saharan Aerosol Long-range Transport and Aerosol-Cloud-Interaction Experiment (SALTRACE), aims at investigating the long-range transport of Saharan dust across the Atlantic Ocean. A large set of ground-based and airborne aerosol and meteorological instrumentation was used for this purpose during a 5-week campaign that took place during June-July 2013. Several Sun photometers were deployed at Barbados Island during this campaign. Two Cimels included in AERONET and the Sun and Sky Automatic Radiometer (SSARA) were co-located with the ground-based lidars BERTHA and POLIS. A set of optical and microphysical aerosol properties derived from Sun and Sky spectral observations (principal plane and almucantar configurations) in the range 340-1640nm are analyzed, including aerosol optical depth (AOD), volume size distribution, complex refractive index, sphericity and single scattering albedo. The Sun photometers include polarization capabilities, therefore apart from the inversion of sky radiances as it is routinely done in AERONET, polarized radiances are also inverted. Several dust events are clearly identified in the measurement period, with moderated AOD (500nm) in the range 0.3 to 0.6. The clean marine background was also observed during short periods. The retrieved aerosol properties are compared with the lidar and in-situ observations carried out within SALTRACE, as well as with data collected during the SAMUM campaigns in Morocco and Cape Verde, in order to investigate possible changes in the dust plume during the transport.

  9. The 1971 Literacy Campaign.

    ERIC Educational Resources Information Center

    Hall, Budd L., Ed.

    Results of a study of the campaigns to eliminate illiteracy in five districts of Tanzania are reported. Using case study methods, researchers from the Institute of Adult Education followed a common outline in collecting data from the Mafia, Ukerewe, Masasi, Kilimanjaro, and Pare Districts regarding their literacy campaigns. The outline was 1.…

  10. Aerosol optical properties in the ABL over arctic sea ice from airborne aerosol lidar measurements

    NASA Astrophysics Data System (ADS)

    Schmidt, Lukas; Neuber, Roland; Ritter, Christoph; Maturilli, Marion; Dethloff, Klaus; Herber, Andreas

    2014-05-01

    Between 2009 and 2013 aerosols, sea ice properties and meteorological variables were measured during several airborne campaigns covering a wide range of the western Arctic Ocean. The campaigns were carried out with the aircraft Polar 5 of the German Alfred-Wegener-Institute (AWI) during spring and summer periods. Optical properties of accumulation mode aerosol and clouds were measured with the nadir looking AMALi aerosol lidar covering the atmospheric boundary layer and the free troposphere up to 3000m, while dropsondes provided coincident vertical profiles of meteorological quantities. Based on these data we discuss the vertical distribution of aerosol backscatter in and above the atmospheric boundary layer and its dependence on relative humidity, dynamics and underlying sea ice properties. We analyze vertical profiles of lidar and coincident dropsonde measurements from various locations in the European and Canadian Arctic from spring and summer campaigns. Sea ice cover is derived from modis satellite and aircraft onboard camera images. The aerosol load in the arctic atmospheric boundary layer shows a high variability. Various meteorological parameters and in particular boundary layer properties are discussed with their respective influence on aerosol features. To investigate the effect of the frequency and size of open water patches on aerosol properties, we relate the profiles to the sea ice properties influencing the atmosphere in the upwind region.

  11. Influence of crustal dust and sea spray supermicron particle concentrations and acidity on inorganic NO3− aerosol during the 2013 Southern Oxidant and Aerosol Study

    DOE PAGES

    Allen, H. M.; Draper, D. C.; Ayres, B. R.; ...

    2015-09-25

    Inorganic aerosol composition was measured in the southeastern United States, a region that exhibits high aerosol mass loading during the summer, as part of the 2013 Southern Oxidant and Aerosol Study (SOAS) campaign. Measurements using a Monitor for AeRosols and GAses (MARGA) revealed two periods of high aerosol nitrate (NO3−) concentrations during the campaign. These periods of high nitrate were correlated with increased concentrations of supermicron crustal and sea spray aerosol species, particularly Na+ and Ca2+, and with a shift towards aerosol with larger (1 to 2.5 μm) diameters. We suggest this nitrate aerosol forms by multiphase reactions of HNO3more » and particles, reactions that are facilitated by transport of crustal dust and sea spray aerosol from a source within the United States. The observed high aerosol acidity prevents the formation of NH4NO3, the inorganic nitrogen species often dominant in fine-mode aerosol at higher pH. In addition, calculation of the rate of the heterogeneous uptake of HNO3 on mineral aerosol supports the conclusion that aerosol NO3− is produced primarily by this process, and is likely limited by the availability of mineral cation-containing aerosol surface area. Modeling of NO3− and HNO3 by thermodynamic equilibrium models (ISORROPIA II and E-AIM) reveals the importance of including mineral cations in the southeastern United States to accurately balance ion species and predict gas–aerosol phase partitioning.« less

  12. Pride Campaign Overcomes Vandalism.

    ERIC Educational Resources Information Center

    Lucas, Donald W.

    1984-01-01

    A San Jose high school's campaign to develop student pride in the school and its appearance includes publicity measures, painting garbage cans in school colors, and cafeteria supervision. Results in diminishing acts of vandalism have been encouraging. (MJL)

  13. Automated campaign system

    NASA Astrophysics Data System (ADS)

    Vondran, Gary; Chao, Hui; Lin, Xiaofan; Beyer, Dirk; Joshi, Parag; Atkins, Brian; Obrador, Pere

    2006-02-01

    To run a targeted campaign involves coordination and management across numerous organizations and complex process flows. Everything from market analytics on customer databases, acquiring content and images, composing the materials, meeting the sponsoring enterprise brand standards, driving through production and fulfillment, and evaluating results; all processes are currently performed by experienced highly trained staff. Presented is a developed solution that not only brings together technologies that automate each process, but also automates the entire flow so that a novice user could easily run a successful campaign from their desktop. This paper presents the technologies, structure, and process flows used to bring this system together. Highlighted will be how the complexity of running a targeted campaign is hidden from the user through technologies, all while providing the benefits of a professionally managed campaign.

  14. A Global Data Assimilation System for Atmospheric Aerosol

    NASA Technical Reports Server (NTRS)

    daSilva, Arlindo

    1999-01-01

    We will give an overview of an aerosol data assimilation system which combines advances in remote sensing of atmospheric aerosols, aerosol modeling and data assimilation methodology to produce high spatial and temporal resolution 3D aerosol fields. Initially, the Goddard Aerosol Assimilation System (GAAS) will assimilate TOMS, AVHRR and AERONET observations; later we will include MODIS and MISR. This data assimilation capability will allows us to integrate complementing aerosol observations from these platforms, enabling the development of an assimilated aerosol climatology as well as a global aerosol forecasting system in support of field campaigns. Furthermore, this system provides an interactive retrieval framework for each aerosol observing satellites, in particular TOMS and AVHRR. The Goddard Aerosol Assimilation System (GAAS) takes advantage of recent advances in constituent data assimilation at DAO, including flow dependent parameterizations of error covariances and the proper consideration of model bias. For its prognostic transport model, GAAS will utilize the Goddard Ozone, Chemistry, Aerosol, Radiation and Transport (GOCART) model developed at NASA/GSFC Codes 916 and 910.3. GOCART includes the Lin-Rood flux-form, semi-Langrangian transport model with parameterized aerosol chemistry and physical processes for absorbing (dust and black carbon) and non-absorbing aerosols (sulfate and organic carbon). Observations and model fields are combined using a constituent version of DAO's Physical-space Statistical Analysis System (PSAS), including its adaptive quality control system. In this talk we describe the main components of this assimilation system and present preliminary results obtained by assimilating TOMS data.

  15. Aerosol Remote Sensing from AERONET, the Ground-Based Satellite

    NASA Technical Reports Server (NTRS)

    Holben, Brent N.

    2012-01-01

    Atmospheric particles including mineral dust, biomass burning smoke, pollution from carbonaceous aerosols and sulfates, sea salt, impact air quality and climate. The Aerosol Robotic Network (AERONET) program, established in the early 1990s, is a federation of ground-based remote sensing aerosol networks of Sun/sky radiometers distributed around the world, which provides a long-term, continuous and readily accessible public domain database of aerosol optical (e.g., aerosol optical depth) and microphysical (e.g., aerosol volume size distribution) properties for aerosol characterization, validation of satellite retrievals, and synergism with Earth science databases. Climatological aerosol properties will be presented at key worldwide locations exhibiting discrete dominant aerosol types. Further, AERONET's temporary mesoscale network campaign (e.g., UAE2, TIGERZ, DRAGON-USA.) results that attempt to quantify spatial and temporal variability of aerosol properties, establish validation of ground-based aerosol retrievals using aircraft profile measurements, and measure aerosol properties on compatible spatial scales with satellite retrievals and aerosol transport models allowing for more robust validation will be discussed.

  16. Free Speech and Campaign Reform.

    ERIC Educational Resources Information Center

    Sharp, Harry, Jr.

    The Federal Election Campaign Act of 1971, a political campaign reform measure, was enacted to limit campaign contributions and independent expenditures, to mandate disclosure of contributors, and to establish public financing of campaigns, all to minimize the opportunity for political corruption. Unfortunate implications of such reform on the…

  17. Campaigning for change.

    PubMed

    Hirschhorn, Larry

    2002-07-01

    Most organizations must change if they're to stay alive. Change is tough to accomplish, but it's not impossible and can be systematized. The author, who has been involved in change initiatives at scores of companies, believes that the success of such programs has more to do with execution than with conceptualization. The successful change programs he observed had one thing in common: They employed three distinct but linked campaigns--political, marketing, and military. The author cites examples from such companies as Hewlett-Packard, Bristol-Myers Squibb, and Saturn to illustrate how effective such campaigns can be. A political campaign creates a coalition strong enough to support and guide the initiative. Sometimes, coalitions arise from changes to a company's formal structure. But they may come out of the informal structure, or they could stem from a temporary counterstructure. A marketing campaign must go beyond simply publicizing the initiative's benefits. It focuses on listening to ideas that bubble up from the field as well as on working with lead customers to design the initiative. A clearly articulated theme for the transformation program must also be developed. A military campaign deploys executives' scarce resources of attention and time. Successful executives secure their supply lines by, for instance, piggybacking onto initiatives that have already captured people's interests or already exist as bootleg projects. These managers also set up pilot projects that turn into beachheads because the projects expose them to the difficult dynamics they will ultimately face. Successful executives launch all three campaigns simultaneously. The three always feed on one another, and if any one campaign is not properly implemented, the change initiative is bound to fail.

  18. ENCAPSULATED AEROSOLS

    DTIC Science & Technology

    acetate, polymerized rapidly and produced some polymer film encapsulation of the aerosol droplets. A two-stage microcapsule generator was designed...encapsulating material, the generator also produced microcapsules of dibutyl phosphite in polyethylene, nitrocellulose, and natural rubber.

  19. Note: Design and development of wireless controlled aerosol sampling network for large scale aerosol dispersion experiments

    SciTech Connect

    Gopalakrishnan, V.; Subramanian, V.; Baskaran, R.; Venkatraman, B.

    2015-07-15

    Wireless based custom built aerosol sampling network is designed, developed, and implemented for environmental aerosol sampling. These aerosol sampling systems are used in field measurement campaign, in which sodium aerosol dispersion experiments have been conducted as a part of environmental impact studies related to sodium cooled fast reactor. The sampling network contains 40 aerosol sampling units and each contains custom built sampling head and the wireless control networking designed with Programmable System on Chip (PSoC™) and Xbee Pro RF modules. The base station control is designed using graphical programming language LabView. The sampling network is programmed to operate in a preset time and the running status of the samplers in the network is visualized from the base station. The system is developed in such a way that it can be used for any other environment sampling system deployed in wide area and uneven terrain where manual operation is difficult due to the requirement of simultaneous operation and status logging.

  20. Note: Design and development of wireless controlled aerosol sampling network for large scale aerosol dispersion experiments.

    PubMed

    Gopalakrishnan, V; Subramanian, V; Baskaran, R; Venkatraman, B

    2015-07-01

    Wireless based custom built aerosol sampling network is designed, developed, and implemented for environmental aerosol sampling. These aerosol sampling systems are used in field measurement campaign, in which sodium aerosol dispersion experiments have been conducted as a part of environmental impact studies related to sodium cooled fast reactor. The sampling network contains 40 aerosol sampling units and each contains custom built sampling head and the wireless control networking designed with Programmable System on Chip (PSoC™) and Xbee Pro RF modules. The base station control is designed using graphical programming language LabView. The sampling network is programmed to operate in a preset time and the running status of the samplers in the network is visualized from the base station. The system is developed in such a way that it can be used for any other environment sampling system deployed in wide area and uneven terrain where manual operation is difficult due to the requirement of simultaneous operation and status logging.

  1. Note: Design and development of wireless controlled aerosol sampling network for large scale aerosol dispersion experiments

    NASA Astrophysics Data System (ADS)

    Gopalakrishnan, V.; Subramanian, V.; Baskaran, R.; Venkatraman, B.

    2015-07-01

    Wireless based custom built aerosol sampling network is designed, developed, and implemented for environmental aerosol sampling. These aerosol sampling systems are used in field measurement campaign, in which sodium aerosol dispersion experiments have been conducted as a part of environmental impact studies related to sodium cooled fast reactor. The sampling network contains 40 aerosol sampling units and each contains custom built sampling head and the wireless control networking designed with Programmable System on Chip (PSoC™) and Xbee Pro RF modules. The base station control is designed using graphical programming language LabView. The sampling network is programmed to operate in a preset time and the running status of the samplers in the network is visualized from the base station. The system is developed in such a way that it can be used for any other environment sampling system deployed in wide area and uneven terrain where manual operation is difficult due to the requirement of simultaneous operation and status logging.

  2. Japanese respond to campaign.

    PubMed

    1994-08-01

    A unique campaign launched by JOICFP in August 1993 had by the end of June 1994 netted US $41,200 to support activities of the integrated Project (IP) in developing countries. Under the campaign, the public, institutions, organizations, and businesses have been sending in used prepaid cards for sale to collectors in Japan and abroad. Prepaid cards are widely used throughout Japan for phones, subways, railways and highways. Nippon Telegraph and Telephone Corporation (NTT) alone issues 20 million cards annually. The campaign, which has been widely featured in the media, has proved effective for drawing attention to JOICFP and to population and family planning issues. Gaining the understanding of the Japanese public about population issues has grown in importance since the government's announcement of the new Global Issues Initiative (GII). Word about the campaign was carried by radio, television, newspapers, and magazines nationwide. The number of cards sent in escalated with the attention. By the end of June, JOICFP had received around 700,000 cards, of which 550,000 have been exchanged for cash. The funds generated by the card sales have been allocated to support grassroots IP activities and encourage the self-reliance of projects in China, Ghana, Guatemala, Nepal, Tanzania, and Zambia. Responses to the campaign have come from individuals as well as local governments, hospitals, enterprises, and educational institutions. Many of these have initiated their own card-collection system and information-dissemination activities to support JOICFP. Over 5000 different organizations are now collaborating with JOICFP for the campaign, including Tenmaya Department Store in Okayama City.

  3. Overview of atmospheric aerosol studies in Malaysia: Known and unknown

    NASA Astrophysics Data System (ADS)

    Kanniah, Kasturi Devi; Kaskaoutis, Dimitris G.; San Lim, Hwee; Latif, Mohd Talib; Kamarul Zaman, Nurul Amalin Fatihah; Liew, Juneng

    2016-12-01

    Atmospheric aerosols particularly those originated from anthropogenic sources can affect human health, air quality and the regional climate system of Southeast Asia (SEA). Population growth, and rapid urbanization associated with economic development in the SEA countries including Malaysia have resulted in high aerosol concentrations. Moreover, transboundary smoke plumes add more aerosols to the atmosphere in Malaysia. Nevertheless, the aerosol monitoring networks and/or field studies and research campaigns investigating the various aerosol properties are not so widespread over Malaysia. In the present work, we summarize and discuss the results of previous studies that investigated the aerosol properties over Malaysia by means of various instrumentation and techniques, focusing on the use of remote sensing data to examine atmospheric aerosols. Furthermore, we identify gaps in this research field and recommend further studies to bridge these knowledge gaps. More specifically gaps are identified in (i) monitoring aerosol loading and composition over urban areas, (ii) examining the influence of dust, (iii) assessing radiative effects of aerosols, (iv) measuring and modelling fine particles and (v) quantifying the contribution of long range transport of aerosols. Such studies are crucial for understanding the optical, physical and chemical properties of aerosols and their spatio-temporal characteristics over the region, which are useful for modelling and prediction of aerosols' effects on air quality and climate system.

  4. District heating campaign in Sweden

    SciTech Connect

    Stalebrant, R.E.

    1995-09-01

    During the fall of 1994 a district heating campaign was conducted in Sweden. The campaign was initiated because the Swedish district heating companies agreed that it was time to increase knowledge and awareness of district heating among the general public, especially among potential customers. The campaign involved many district heating companies and was organized as a special project. Advertising companies, media advisers, consultants and investigators were also engaged. The campaign was conducted in two stages, a national campaign followed by local campaign was conducted in two stages, a national campaign followed by local campaigns. The national campaign was conducted during two weeks of November 1994 and comprised advertising on commercial TV and in the press.

  5. Synchronised Aerosol Mass Spectrometer Measurements across Europe

    NASA Astrophysics Data System (ADS)

    Nemitz, Eiko

    2010-05-01

    Up to twelve Aerodyne Aerosol Mass Spectrometers (AMSs) were operated simultaneously at rural and background stations (EMEP and EUSAAR sites) across Europe. Measurements took place during three intensive periods, in collaboration between the European EUCAARI IP and the EMEP monitoring activities under the UNECE Convention for Long-Range Transboundary Air Pollution (CLRTAP) during three contrasting months (May 2008, Sep/Oct 2008, Feb/Mar 2009). These measurements were conducted, analysed and quality controlled carefully using a unified protocol, providing the largest spatial database of aerosol chemical composition measured with a unified online technique to date, and a unique snapshots of the European non-refractory submicron aerosol climatology. As campaign averages over all active monitoring sites, organics represent 28 to 43%, sulphate 18 to 25%, ammonium 13 to 15% and nitrate 15 to 36% of the resolved aerosol mass, with the highest relative nitrate contribution during the Feb/Mar campaign. The measurements demonstrate that in NW Europe (e.g. Ireland, UK, The Netherlands, Germany, Switzerland) the regional submicron aerosol tends to be neutralised and here nitrates make a major contribution to the aerosol mass. By contrast, periods with low nitrate and acidic aerosol were observed at sites in S and E Europe (e.g. Greece, Finland), presumably due to a combination of larger SO2 point sources in Easter Europe, smaller local NH3 sources and, in the case of Greece, higher temperatures. While at the more marine and remote sites (Ireland, Scotland, Finland) nitrate concentrations were dominated by episodic transport phenomena, at continental sites (Switzerland, Germany, Hungary) nitrate followed a clear diurnal cycle, reflecting the thermodynamic behaviour of ammonium nitrate. The datasets clearly shows spatially co-ordinated, large-scale pollution episodes of organics, sulphate and nitrate, the latter being most pronounced during the Feb/Mar campaign. At selected

  6. Seasonality of Aerosols the Southeastern United States

    NASA Astrophysics Data System (ADS)

    Ford, B. J.; Heald, C. L.

    2012-12-01

    Previous studies have suggested that increases in atmospheric aerosols of biogenic origin may have caused regional cooling over the southeastern United States in recent decades. Understanding the sources and behaviors of these aerosols is important for determining their role in a changing climate and managing their air quality impacts. In this study, we investigate the strong seasonality in aerosol optical depth (AOD) observed by MODIS, MISR, and CALIOP instruments over the southeastern United States and show that this is not simulated by a chemical transport model (GEOS-Chem). However, the model does reproduce surface PM 2.5 concentrations in the region as reported by the IMPROVE and Southeastern Aerosol Research and Characterization (SEARCH) networks, as well as the muted seasonality of these concentrations. In addition, these surface measurements show that organic aerosol makes up a small fraction of total PM 2.5 and has relatively little seasonality, which calls into question the importance of biogenic aerosol as a driver for climate change in the region. Sounding profiles and ground observations of relative humidity suggest that the magnitude of seasonality in AOD cannot be explained by seasonal differences in the hygroscopic growth of aerosols. CALIOP measurements of the vertical profile of aerosol extinction confirm that the likely reconciliation of the differences in seasonality between the surface PM 2.5 and AOD observations is the formation of aerosol aloft, a process not captured by the model. These findings provide initial insights for the Southern Oxidant and Aerosol Study (SOAS) campaign in 2013 which aims to investigate the anthropogenic influence on biogenic aerosol formation in the Southeastern US and elucidate the impact on regional climate and air quality.

  7. The STAR Grants Contribution to the SOAS Campaign

    NASA Astrophysics Data System (ADS)

    Hunt, S.

    2013-12-01

    The Southern Oxidant and Aerosol Study (SOAS) is a community-led field campaign that was part of the Southeast Atmosphere Study (SAS). As one of the largest field studies in decades to characterize air quality in the Southeastern United States, SAS is a collaborative project involving the US Environmental Protection Agency (EPA), the National Science Foundation (NSF), the National Oceanic and Atmospheric Administration (NOAA), the Electric Power Research Institute (EPRI) and dozens of domestic and international research institutions. In 2013, the EPA's Science to Achieve Results (STAR) grants program funded fourteen projects, resulting in a research portfolio addressing a number of scientific needs outlined in the solicitation. These projects fall into two categories: field measurements of key chemical species and supporting laboratory experiments and model development. Awardees participating in the SOAS campaign are studying key chemical species (including volatile organic compounds, formaldehyde, reactive nitrogen species, reactive oxidant species, organonitrates and organosulfates) for understanding the interactions between anthropogenic and biogenic emissions. Measurements were made by instruments both on the ground and from aircrafts. Additionally, projects characterized and investigated the climatically-relevant properties of aerosol from the field site. Work also includes several chamber experiments that will result in a detailed analysis of secondary organic aerosol components and precursors. Certain species measured in the field campaign will be analyzed and characterized in a laboratory setting. Finally, three projects focus on improving air quality and climate models, particularly in areas dealing with cloud droplets, aqueous chemistry, and organic aerosol mixtures. This poster will provide an overview of the STAR grants program's contribution to the SAS and SOAS campaign and highlight some of the challenges and benefits of leveraging funds in this way.

  8. Remote Sensing of Aerosol Properties during CARES

    SciTech Connect

    Kassianov, Evgueni I.; Barnard, James C.; Pekour, Mikhail S.; Flynn, Connor J.; Ferrare, R.; Hostetler, Chris A.; Hair, John; Jobson, Bertram Thomas

    2011-10-01

    One month of MFRSR data collected at two sites in the central California (USA) region during the CARES campaign are processed and the MFRSR-derived AODs at 500 nm wavelength are compared with available AODs provided by AERONET measurements. We find that the MFRSR and AERONET AODs are small ({approx}0.05) and comparable. A reasonable quantitative agreement between column aerosol size distributions (up to 2 um) from the MFRSR and AERONET retrievals is illustrated as well. Analysis of the retrieved (MFRSR and AERONET) and in situ measured aerosol size distributions suggests that the contribution of the coarse mode to aerosol optical properties is substantial for several days. The results of a radiative closure experiment performed for the two sites and one-month period show a favorable agreement between the calculated and measured broadband downwelling irradiances (bias does not exceed about 3 Wm-2), and thus imply that the MFRSR-derived aerosol optical properties are reasonable.

  9. Campaign Finance: Reporter Guide

    ERIC Educational Resources Information Center

    Wieder, Ben

    2014-01-01

    Campaign finance might seem like the exclusive province of political reporters, but there are many good reasons why authors should be paying attention--both in races for education positions and in other key races at the local, state, and federal levels with implications for education. Basic math is a necessary skill and familiarity with a…

  10. Campaign Drama, Classroom Lessons

    ERIC Educational Resources Information Center

    Manzo, Kathleen Kennedy

    2008-01-01

    The hoopla surrounding the New Hampshire presidential primaries earlier this month stirred some students at Timberlane High School to watch the candidates' debates, read news coverage, attend rallies, and even volunteer in local campaign offices. That interest, in turn, stimulated discussions in Bob Dawson's government classes at the school,…

  11. Singapore's Speak Mandarin Campaign.

    ERIC Educational Resources Information Center

    Newman, John

    1988-01-01

    Reviews the "Speak Mandarin Campaign," that is intended to persuade the Singaporean ethnic Chinese to use Mandarin in place of Chinese dialects. The purported educational, cultural, and practical advantages are discussed, and the support of higher education and the media is evaluated. (Author/CB)

  12. Campaign Drama, Classroom Lessons

    ERIC Educational Resources Information Center

    Manzo, Kathleen Kennedy

    2008-01-01

    The hoopla surrounding the New Hampshire presidential primaries earlier this month stirred some students at Timberlane High School to watch the candidates' debates, read news coverage, attend rallies, and even volunteer in local campaign offices. That interest, in turn, stimulated discussions in Bob Dawson's government classes at the school,…

  13. Antipiracy Campaign Exasperates Colleges

    ERIC Educational Resources Information Center

    Rampell, Catherine

    2008-01-01

    This article reports on the withdrawal of some universities' support of a music industry's campaign against music piracy on their campuses. Talk to the chief information officer at just about any American university, and he will probably say that his institution has bent over backward to help the Recording Industry Association of America curb…

  14. Stratospheric ozone intercomparison campaign (STOIC) 1989: Overview

    SciTech Connect

    Margitan, J.J.; McDermid, I.S.; Walsh, T.D.

    1995-05-20

    The NASA Upper Atmosphere Research Program organized a Stratospheric Ozone Intercomparison Campaign (STOIC) held in July-August 1989 at the Table Mountain Facility (TMF) of the Jet Propulsion Laboratory (JPL). The primary instruments participating in this campaign were several that had been developed by NASA for the Network for the Detection of Stratospheric Change: the JPL ozone lidar at TMF, the Goddard Space Flight Center trailer-mounted ozone lidar which was moved to TMF for this comparison, and the Millitech/LaRC microwave radiometer. To assess the performance of these new instruments, a validation/intercomparison campaign was undertaken using established techniques: balloon ozonesondes launched by personnel from the Wallops Flight Facility and from NOAA Geophysical Monitoring for Climate Change (GMCC) (now Climate Monitoring and Diagnostics Laboratory), a NOAA GMCC Dobson spectrophotometer, and a Brewer spectrometer from the Atmospheric Environment Service of Canada, both being used for column as well as Umkehr profile retrievals. All of these instruments were located at TMF and measurements were made as close together in time as possible to minimize atmospheric variability as a factor in the comparisons. Daytime rocket measurements of ozone were made by Wallops Flight Facility personnel using ROCOZ-A instruments launched from San Nicholas Island. The entire campaign was conducted as a blind intercomparison, with the investigators not seeing each others data until all data had been submitted to a referee and archived at the end of the 2-week period (July 20 to August 2, 1989). Satellite data were also obtained from the Stratospheric aerosol and Gas Experiment (SAGE II) aboard the Earth Radiation Budget Satellite and the total ozone mapping spectrometer (TOMS) aboard Nimbus 7. An examination of the data has found excellent agreement among the techniques, especially in the 20- to 40-km range. 37 refs., 5 figs., 3 tabs.

  15. Tropospheric Aerosols

    NASA Astrophysics Data System (ADS)

    Buseck, P. R.; Schwartz, S. E.

    2003-12-01

    It is widely believed that "On a clear day you can see forever," as proclaimed in the 1965 Broadway musical of the same name. While an admittedly beautiful thought, we all know that this concept is only figurative. Aside from Earth's curvature and Rayleigh scattering by air molecules, aerosols - colloidal suspensions of solid or liquid particles in a gas - limit our vision. Even on the clearest day, there are billions of aerosol particles per cubic meter of air.Atmospheric aerosols are commonly referred to as smoke, dust, haze, and smog, terms that are loosely reflective of their origin and composition. Aerosol particles have arisen naturally for eons from sea spray, volcanic emissions, wind entrainment of mineral dust, wildfires, and gas-to-particle conversion of hydrocarbons from plants and dimethylsulfide from the oceans. However, over the industrial period, the natural background aerosol has been greatly augmented by anthropogenic contributions, i.e., those produced by human activities. One manifestation of this impact is reduced visibility (Figure 1). Thus, perhaps more than in other realms of geochemistry, when considering the composition of the troposphere one must consider the effects of these activities. The atmosphere has become a reservoir for vast quantities of anthropogenic emissions that exert important perturbations on it and on the planetary ecosystem in general. Consequently, much recent research focuses on the effects of human activities on the atmosphere and, through them, on the environment and Earth's climate. For these reasons consideration of the geochemistry of the atmosphere, and of atmospheric aerosols in particular, must include the effects of human activities. (201K)Figure 1. Impairment of visibility by aerosols. Photographs at Yosemite National Park, California, USA. (a) Low aerosol concentration (particulate matter of aerodynamic diameter less than 2.5 μm, PM2.5=0.3 μg m-3; particulate matter of aerodynamic diameter less than 10

  16. Cloud Physics Lidar Measurements During the SAFARI-2000 Field Campaign

    NASA Technical Reports Server (NTRS)

    McGill, Matthew; Hlavka, Dennis; Hart, William; Spinhirne, James; Scott, Stan; Starr, David OC. (Technical Monitor)

    2001-01-01

    A new remote sensing instrument, the Cloud Physics Lidar (CPL) has been built for use on the ER-2 aircraft. The first deployment for CPL was the SAFARI-2000 field campaign during August-September 2000. The CPL is a three-wavelength lidar designed for studies of cirrus, subvisual cirrus, and boundary layer aerosols. The CPL utilizes a high repetition rate, low pulse energy laser with photon counting detectors. A brief description of the CPL instrument will be given, followed by examples of CPL data products. In particular, examples of aerosol backscatter, including boundary layer smoke and cirrus clouds will be shown. Resulting optical depth estimates derived from the aerosol measurements will be shown. Comparisons of the CPL optical depth and optical depth derived from microPulse Lidar and the AATS-14 sunphotomer will be shown.

  17. Coordinated Field Campaigns in Chesapeake Bay and Gulf of Mexico

    NASA Technical Reports Server (NTRS)

    Mannino, Antonio; Novak, Michael; Tzortziou, Maria A.

    2015-01-01

    NASA's GEOstationary Coastal and Air Pollution Events (GEO-CAPE) mission concept recommended by the U.S. National Research Council (2007) focuses on measurements of atmospheric trace gases and aerosols and aquatic coastal ecology and biogeochemistry from geostationary orbit (35,786 km altitude). Two GEO-CAPE-sponsored multi-investigator ship-based field campaigns were conducted to coincide with the NASA Earth Venture Suborbital project DISCOVER-AQ (Deriving Information on Surface conditions from Column and Vertically Resolved Observations Relevant to Air Quality) field campaigns: (1) Chesapeake Bay in July 2011 and (2) northwestern Gulf of Mexico in September 2013. Goal: to evaluate whether GEO-CAPE coastal mission measurement and instrument requirements are optimized to address science objectives while minimizing ocean color satellite sensor complexity, size and cost - critical mission risk reduction activities. NASA continues to support science studies related to the analysis of data collected as part of these coordinated field campaigns and smaller efforts.

  18. Korea-United States Air Quality (KORUS-AQ) Campaign

    NASA Technical Reports Server (NTRS)

    Castellanos, Patricia; Da Silva, Arlindo; Longo-De Freitas, Karla

    2017-01-01

    The Korea-United States Air Quality (KORUS-AQ) campaign was an international cooperative field study based out of Osan Air Base, Songtan, South Korea (about 60 kilometers south of Seoul) in April-June 2016. A comprehensive suite of instruments capable of measuring atmospheric composition was deployed around the Korean peninsula on aircrafts, ships, and at ground sites in order to characterize local and transboundary pollution. The NASA Goddard Earth Observing System, version 5 (GEOS-5) forecast model was used for near real time meteorological and aerosol forecasting and flight planning during the KORUS-AQ campaign. Evaluation of GEOS-5 against observations from the campaign will help to identify inaccuracies in the models physical and chemical processes in this region within East Asia and lead to further developments of the modeling system.

  19. Thermodynamic characterization of Mexico City aerosol during MILAGRO 2006

    NASA Astrophysics Data System (ADS)

    Fountoukis, C.; Nenes, A.; Sullivan, A.; Weber, R.; Vanreken, T.; Fischer, M.; Matías, E.; Moya, M.; Farmer, D.; Cohen, R. C.

    2007-06-01

    Fast measurements of aerosol and gas-phase constituents coupled with the ISORROPIA-II thermodynamic equilibrium model are used to study the partitioning of semivolatile inorganic species and phase state of Mexico City aerosol sampled at the T1 site during the MILAGRO 2006 campaign. Overall, predicted semivolatile partitioning agrees well with measurements. PM2.5 is insensitive to changes in ammonia but is to acidic semivolatile species. Semi-volatile partitioning equilibrates on a timescale between 6 and 20 min. When the aerosol sulfate-to-nitrate molar ratio is less than 1, predictions improve substantially if the aerosol is assumed to follow the deliquescent phase diagram. Treating crustal species as "equivalent sodium" (rather than explicitly) in the thermodynamic equilibrium calculations introduces important biases in predicted aerosol water uptake, nitrate and ammonium; neglecting crustals further increases errors dramatically. This suggests that explicitly considering crustals in the thermodynamic calculations are required to accurately predict the partitioning and phase state of aerosols.

  20. Improvement in AOD retrieval from geostationary measurement over the ASIA with obtained AOP from DRAGON-2012 campaign

    NASA Astrophysics Data System (ADS)

    Choi, M.; KIM, M.; Kim, J.; Lee, J.

    2013-12-01

    The long-term aerosol monitoring from ground-based sun photometer such as AERONET has variously used to obtain optimized aerosol optical properties (AOPs) for assumed aerosol type and to validate aerosol optical depth (AOD) retrieved from satellite. Additionally, the meso-scale network campaign such as DRAGON ASIA-2012 is suitable to monitor the aerosol characteristic over localized area. Thus, this study focused on the improvement of AOPs over the East Asia by using the DRAGON ASIA-2012 campaign dataset for two geostationary AOD retrieval algorithms. The algorithms were developed for Geostationary Ocean Color Imager (GOCI) and Meteorological Imager (MI) onboarding the Communication, Ocean, and Meteorological Satellite (COMS), which was launched in June, 2010. GOCI has 8 channels in visible and near IR. Using these multi-spectral bands, we retrieved aerosol optical properties such as AOD, fine-mode fraction (FMF), single scattering albedo (SSA) and aerosol type. In this study, we consider dynamic aerosol models categorized by FMF and SSA from East Asia AERONET data including DRAGON campaign data. Using these aerosol data, AOPs are upgraded for LUT calculation and re-retrieved from GOCI. The validation with AERONET shows the improved results after AOP upgrade. On the other hand, a single channel algorithm developed for MI assumed seasonal aerosol property variation due the algorithm has limitation in select aerosol type. The seasonally analyzed SSAs at 675 nm from the AERONET measurement over the East Asia including the campaign data are 0.92, 0.94, 0.92, and 0.91 for spring (MAM), summer (JJA), autumn (SON), and winter (DJF), respectively, and slightly higher then the originally used values. By using those newly analyzed AOP, the comparison result between retrieved AOD and measured value from AERONET shows the increase of correlation coefficient from 0.551 to 0.702 and the increase of regression slope from 0.538 to 0.615 during months from May to Dec. in 2011.

  1. Black carbon in aerosol during BIBLE B

    NASA Astrophysics Data System (ADS)

    Liley, J. Ben; Baumgardner, D.; Kondo, Y.; Kita, K.; Blake, D. R.; Koike, M.; Machida, T.; Takegawa, N.; Kawakami, S.; Shirai, T.; Ogawa, T.

    2003-02-01

    The Biomass Burning and Lightning Experiment (BIBLE) A and B campaigns over the tropical western Pacific during springtime deployed a Gulfstream-II aircraft with systems to measure ozone and numerous precursor species. Aerosol measuring systems included a MASP optical particle counter, a condensation nucleus (CN) counter, and an absorption spectrometer for black carbon. Aerosol volume was very low in the middle and upper troposphere during both campaigns, and during BIBLE A, there was little aerosol enhancement in the boundary layer away from urban areas. In BIBLE B, there was marked aerosol enhancement in the lowest 3 km of the atmosphere. Mixing ratios of CN in cloud-free conditions in the upper troposphere were in general higher than in the boundary layer, indicating new particle formation from gaseous precursors. High concentrations of black carbon were observed during BIBLE B, with mass loadings up to 40 μg m-3 representing as much as one quarter of total aerosol mass. Strong correlations with hydrocarbon enhancement allow the determination of a black carbon emission ratio for the fires at that time. Expressed as elemental carbon, it is about 0.5% of carbon dioxide and 6% of carbon monoxide emissions from the same fires, comparable to methane production, and greater than that of other hydrocarbons.

  2. Black carbon in aerosol during BIBLE B

    NASA Astrophysics Data System (ADS)

    Liley, J. Ben; Baumgardner, D.; Kondo, Y.; Kita, K.; Blake, D. R.; Koike, M.; Machida, T.; Takegawa, N.; Kawakami, S.; Shirai, T.; Ogawa, T.

    2002-02-01

    The Biomass Burning and Lightning Experiment (BIBLE) A and B campaigns over the tropical western Pacific during springtime deployed a Gulfstream-II aircraft with systems to measure ozone and numerous precursor species. Aerosol measuring systems included a MASP optical particle counter, a condensation nucleus (CN) counter, and an absorption spectrometer for black carbon. Aerosol volume was very low in the middle and upper troposphere during both campaigns, and during BIBLE A, there was little aerosol enhancement in the boundary layer away from urban areas. In BIBLE B, there was marked aerosol enhancement in the lowest 3 km of the atmosphere. Mixing ratios of CN in cloud-free conditions in the upper troposphere were in general higher than in the boundary layer, indicating new particle formation from gaseous precursors. High concentrations of black carbon were observed during BIBLE B, with mass loadings up to 40 μg m-3 representing as much as one quarter of total aerosol mass. Strong correlations with hydrocarbon enhancement allow the determination of a black carbon emission ratio for the fires at that time. Expressed as elemental carbon, it is about 0.5% of carbon dioxide and 6% of carbon monoxide emissions from the same fires, comparable to methane production, and greater than that of other hydrocarbons.

  3. Presidential Transitions during Capital Campaigns

    ERIC Educational Resources Information Center

    Nehls, Kimberly

    2008-01-01

    In the past few decades, capital campaigns at institutions of higher education have increased in duration, while collegiate presidential tenures have been doing just the opposite. Turnover in the top post was frequent, even during major fundraising campaigns. Before this study, presidential transitions during campaigns had not been previously…

  4. Leadership Transitions during Fundraising Campaigns

    ERIC Educational Resources Information Center

    Nehls, Kimberly

    2012-01-01

    Capital campaigns are intense efforts to build the financial assets of an institution in a specified amount of time. This study provides an empirical view of how changes in leadership affected concomitant capital campaigns at ten colleges and universities. The transitions during these 10 campaigns influenced morale on campus, altered timing of the…

  5. Leadership Transitions during Fundraising Campaigns

    ERIC Educational Resources Information Center

    Nehls, Kimberly

    2012-01-01

    Capital campaigns are intense efforts to build the financial assets of an institution in a specified amount of time. This study provides an empirical view of how changes in leadership affected concomitant capital campaigns at ten colleges and universities. The transitions during these 10 campaigns influenced morale on campus, altered timing of the…

  6. Campaigns in Agricultural Extension Programs.

    ERIC Educational Resources Information Center

    Spaven, John W.

    A booklet designed to aid those who use agricultural campaigns in their educational and advisory programs is presented. It is pointed out that a good campaign works as a chain reaction, inciting enthusiasm among workers and planners. The five steps in a well-organized campaign are: (1) planning, (2) preparing people for their jobs, (3) producing…

  7. Influences of upwind emission sources and atmospheric processing on aerosol chemistry and properties at a rural location in the Northeastern U.S.: URBAN INFLUENCE ON RURAL AEROSOL

    SciTech Connect

    Zhou, Shan; Collier, Sonya; Xu, Jianzhong; Mei, Fan; Wang, Jian; Lee, Yin-Nan; Sedlacek, Arthur J.; Springston, Stephen R.; Sun, Yele; Zhang, Qi

    2016-05-19

    Continuous real-time measurements of atmospheric aerosol with an Aerodyne High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-AMS) coupled with a fast temperature-stepping thermodenuder were carried out in summer 2011 at Brookhaven National Laboratory (BNL, 40.871°N, 72.89°W) during the DOE Aerosol Life Cycle Intensive Operational Period (ALC-IOP) campaign.

  8. ACTS mobile propagation campaign

    NASA Technical Reports Server (NTRS)

    Goldhirsh, Julius; Vogel, Wolfhard J.; Torrence, Geoffrey W.

    1994-01-01

    Preliminary results are presented for three propagation measurement campaigns involving a mobile receiving laboratory and 20 GHz transmissions from the Advanced Communications Technology Satellite (ACTS). Four 1994 campaigns were executed during weekly periods in and around Austin, Texas in February and May, in Central Maryland during March, and in Fairbanks, Alaska and environs in June. Measurements tested the following effects at 20 GHz: (1) attenuation due to roadside trees with and without foliage, (2) multipath effects for scenarios in which line-of-sight paths were unshadowed, (3) fades due to terrain and roadside obstacles, (4) fades due to structures in urban environs, (5) single tree attenuation, and (6) effects of fading at low elevation angles (8 deg in Fairbanks, Alaska) and high elevation angles (55 deg in Austin, Texas). Results presented here cover sampled measurements in Austin, Texas for foliage and non-foliage cases and in Central Maryland for non-foliage runs.

  9. Spectral radiation balance of absorbing aerosols over clouds

    NASA Astrophysics Data System (ADS)

    Stammes, Piet; de Graaf, Martin; Deneke, Hartwig

    2017-04-01

    Absorption by aerosols, like smoke and desert dust, may lead to strong atmospheric warming, surface cooling, and cloud dynamical responses. Therefore, detection of absorbing aerosols and assessment of their radiative effects is important. However, absorbing aerosols are difficult to detect, especially in cloudy scenes. Here we use a satellite detection technique which can be used to determine the spectral absorption effects of smoke aerosols over clouds, using the fact that aerosols have a much stronger effect at UV and visible wavelengths than at longer wavelengths. We also analyse the shortwave radiative balance of absorbing aerosols over clouds. We have developed a technique of measuring aerosols from their absorption effect using multi-spectral satellite data (De Graaf et al., JGR, 2012). Using a wide spectral range, from the UV (300-400 nm) up to the shortwave (SW) IR (1000-1750 nm), it is possible to distinguish the absorption by aerosols from the scattering by clouds. No microphysical assumptions are needed for the aerosols, except that their absorption must vanish at long wavelengths. With this method, called the Differential Aerosol Absorption (DAA) technique, which was applied to SCIAMACHY satellite data, we measured the direct radiative effect of absorbing biomass burning aerosols over clouds in the South-East Atlantic. We measured instantaneous direct radiative effects by the aerosols of the order of 100 W/m2 at top-of-atmosphere. The spectral radiation balance at both top-of-atmosphere and surface is needed to estimate the amount of absorption inside the aerosol layer. We therefore perform a simulation study, using accurate spectral RT modelling, in which we compute the profile of absorption in the aerosol layer. We find that the atmospheric absorption characteristics cannot be measured only from satellite by using reflected light, also the transmission at the surface has to be measured. Therefore, field campaigns are needed in addition to satellite

  10. Correlation of aerosol mass near the ground with aerosol optical depth during two seasons in Munich

    NASA Astrophysics Data System (ADS)

    Schäfer, Klaus; Harbusch, Andreas; Emeis, Stefan; Koepke, Peter; Wiegner, Matthias

    2008-06-01

    Relations of the aerosol optical depth (AOD) with aerosol mass concentration near the ground, particulate matter (PM), have been studied on the basis of measurements. The objective is with respect to possible remote sensing methods to get information on the spatial and temporal variation of aerosols which is important for human health effects. Worldwide the AOD of the atmospheric column is routinely monitored by sun-photometers and accessible from satellite measurements also. It is implied here that the AOD is caused mainly by attenuation processes within the mixing layer because this layer includes nearly all atmospheric aerosols. Thus the mixing layer height (MLH) is required together with the AOD, measured by ground-based sun-photometers (around 560 nm), to get information about aerosols near the ground. MLH is determined here from surface-based remote sensing. Investigations were performed during two measurement campaigns in and near Munich in May and November/December 2003 on the basis of daily mean values. Using AOD and MLH measurements the aerosol extinction coefficient of the mixing layer has been calculated. This quantity was correlated with the measured PM10, PM2.5 and PM1 mass concentrations near the ground by performing a linear regression and thus providing a mass extinction efficiency giving squares of the correlation coefficients (R2) between 0.48 (PM1 during summer campaign) and 0.90 (PM2.5 during winter campaign). These correlations suggest that the derived mass extinction efficiencies represent a statistically significant relation between the aerosol extinction coefficients and the surface-based PM mass concentrations mainly during winter conditions.

  11. The Influence of Free Tropospheric Aerosol on the Boundary Layer Aerosol Budget in the Arctic

    NASA Astrophysics Data System (ADS)

    Igel, A. L.; Ekman, A.; Leck, C.; Savre, J.; Tjernstrom, M. K. H.; Sedlar, J.

    2015-12-01

    Large-eddy simulations of the summertime high Arctic boundary layer with mixed-phase stratus clouds have been performed based on observations taken during the ASCOS[1] campaign. The model includes a prognostic aerosol scheme where accumulation mode aerosol particles can be activated into cloud droplets, impaction scavenged, and regenerated upon cloud droplet evaporation or ice crystal sublimation. Two sets of simulations were performed, one with a constant aerosol concentration in the boundary layer and free troposphere, and one with enhanced free tropospheric concentrations based on observed aerosol concentration profiles. We find that the rate of aerosol depletion in the boundary layer is an order of magnitude larger than the median surface emission rates measured over the open water, indicating that for the present case the surface emissions are unlikely to compensate for aerosol loss due to interactions with clouds. In this case study, when the enhanced free troposphere aerosol concentrations are included, the entrainment of these particles into the boundary layer is able to offset the loss of particles from aerosol-cloud interactions. These results suggest that enhanced levels of accumulation mode particles, if located at the cloud top, may be an important source of accumulation mode particles in the Arctic boundary layer. [1] The Arctic Summer Cloud Ocean Study (ASCOS) was conducted in 2008 with the overall aim to improve our understanding of stratus cloud formation and possible climate feedback processes over the central Arctic Ocean. Tjernström et al., 2014 give more details.

  12. Measurements of atmospheric aerosol vertical distributions above Svalbard, Norway, using unmanned aerial systems (UAS)

    NASA Astrophysics Data System (ADS)

    Bates, T. S.; Quinn, P. K.; Johnson, J. E.; Corless, A.; Brechtel, F. J.; Stalin, S. E.; Meinig, C.; Burkhart, J. F.

    2013-08-01

    Atmospheric aerosol vertical distributions were measured above Svalbard, Norway, in April 2011 during the Cooperative Investigation of Climate-Cryosphere Interactions campaign (CICCI). Measurements were made of the particle number concentration and the aerosol light absorption coefficient at three wavelengths. A filter sample was collected on each flight at the altitude of maximum particle number concentration. The filters were analyzed for major anions and cations. The aerosol payload was flown in a NOAA/PMEL MANTA Unmanned Aerial System (UAS). A total of 18 flights were flown during the campaign totaling 38 flight hours. The data show frequent aerosol layers aloft with high particle number concentration (1000 cm-3) and enhanced aerosol light absorption (1 Mm-1). Air mass histories of these aerosol layers were assessed using FLEXPART particle dispersion modeling. The data contribute to an assessment of sources of BC to the Arctic and potential climate impacts.

  13. Measurements of atmospheric aerosol vertical distributions above Svalbard, Norway using unmanned aerial systems

    NASA Astrophysics Data System (ADS)

    Bates, T.; Quinn, P.; Johnson, J. E.; Stalin, S.; Meinig, C.; Burkhart, J. F.

    2011-12-01

    Atmospheric aerosol vertical distributions were measured above Svalbard, Norway in April 2011 during the Coordinated Investigation of Climate-Cryosphere Interactions campaign (CICCI). Measurements were made of particle number concentration and aerosol light absorption at three wavelengths. A filter sample was collected on each flight at the altitude of maximum particle number concentration. The filters were analyzed for major anions and cations. The aerosol payload was flown in a NOAA/PMEL MANTA Unmanned Aerial System (UAS). A total of 18 flights were flown during the campaign totaling 38 flight hours. The data show frequent aerosol layers aloft with high particle number concentration (1000 cm-3) and enhanced aerosol light absorption (1 Mm-1). Transport of these aerosol layers was assessed using FLEXPART particle dispersion models. The data contribute to an assessment of sources of BC to the Arctic and potential climate impacts.

  14. Measurements of atmospheric aerosol vertical distributions above Svalbard, Norway using unmanned aerial systems (UAS)

    NASA Astrophysics Data System (ADS)

    Bates, T. S.; Quinn, P. K.; Johnson, J. E.; Corless, A.; Brechtel, F. J.; Stalin, S. E.; Meinig, C.; Burkhart, J. F.

    2013-03-01

    Atmospheric aerosol vertical distributions were measured above Svalbard, Norway in April 2011 during the Cooperative Investigation of Climate-Cryosphere Interactions campaign (CICCI). Measurements were made of the particle number concentration and the aerosol light absorption coefficient at three wavelengths. A filter sample was collected on each flight at the altitude of maximum particle number concentration. The filters were analyzed for major anions and cations. The aerosol payload was flown in a NOAA/PMEL MANTA Unmanned Aerial System (UAS). A total of 18 flights were flown during the campaign totaling 38 flight hours. The data show frequent aerosol layers aloft with high particle number concentration (1000 cm-3 and enhanced aerosol light absorption (1 Mm-1). Air mass histories of these aerosol layers were assessed using FLEXPART particle dispersion modeling. The data contribute to an assessment of sources of BC to the Arctic and potential climate impacts.

  15. LASE measurements of aerosols and water vapor during TARFOX

    NASA Technical Reports Server (NTRS)

    Ferrare, Richard A.; Ismail, Syed; Browell, Edward V.; Brackett, Vincent G.; Kooi, Susan A.; Clayton, Marian B.; Melfi, Harvey; Whiteman, David N.; Schwenner, Geary; Evans, Keith D.; Hobbs, Peter V.; Veefkind, J. Pepijn; Russell, Philip B.; Livingston, John M.; Hignett, Philip; Holben, Brent N.; Remer, Lorraine A.

    1998-01-01

    The TARFOX (Tropospheric Aerosol Radiative Forcing Observational Experiment) intensive field campaign was designed to reduce uncertainties in estimates of the effects of anthropogenic aerosols on climate by measuring direct radiative effects and the optical, physical, and chemical properties of aerosols [1]. TARFOX was conducted off the East Coast of the United States between July 10-31, 1996. Ground, aircraft, and satellite-based sensors measured the sensitivity of radiative fields at various atmospheric levels to aerosol optical properties (i.e., optical thickness, phase function, single-scattering albedo) and to the vertical profile of aerosols. The LASE (Lidar Atmospheric Sensing Experiment) instrument, which was flown on the NASA ER-2 aircraft, measured vertical profiles of total scattering ratio and water vapor during a series of 9 flights. These profiles were used in real-time to help direct the other aircraft to the appropriate altitudes for intensive sampling of aerosol layers. We have subsequently used the LASE aerosol data to derive aerosol backscattering and extinction profiles. Using these aerosol extinction profiles, we derived estimates of aerosol optical thickness (AOT) and compared these with measurements of AOT from both ground and airborne sun photometers and derived from the ATSR-2 (Along Track and Scanning Radiometer 2) sensor on ERS-2 (European Remote Sensing Satellite-2). We also used the water vapor mixing ratio profiles measured simultaneously by LASE to derive precipitable water vapor