scholarly journals In-situ observation of Asian pollution transported into the Arctic lowermost stratosphere

2011 ◽  
Vol 11 (5) ◽  
pp. 16265-16310 ◽  
Author(s):  
A. Roiger ◽  
H. Schlager ◽  
A. Schäfler ◽  
H. Huntrieser ◽  
M. Scheibe ◽  
...  
Keyword(s):  
Dispersion Model ◽  
Anthropogenic Pollution ◽  
Conveyor Belt ◽  
Particle Dispersion ◽  
The Arctic ◽  
In Situ Observation ◽  
Air Mass ◽  
Mixing Ratios ◽  
The North

Abstract. On a research flight on 10 July 2008, the German research aircraft Falcon sampled an air mass with unusually high carbon monoxide (CO), peroxyacetyl nitrate (PAN) and water vapour (H2O) mixing ratios in the Arctic lowermost stratosphere. The air mass was encountered twice at an altitude of 11.3 km, ~800 m above the dynamical tropopause. In-situ measurements of ozone, NO, and NOy indicate that this layer was a mixed air mass containing both air from the troposphere and stratosphere. Backward trajectory and Lagrangian particle dispersion model analysis suggest that the Falcon sampled the top of a polluted air mass originating from the coastal regions of East Asia. The anthropogenic pollution plume experienced strong up-lift in a warm conveyor belt (WCB) located over the Russian east-coast. Subsequently the Asian air mass was transported across the North Pole into the sampling area, elevating the local tropopause by up to ~3 km. Mixing with surrounding Arctic stratospheric air most likely took place during the horizontal transport when the tropospheric streamer was stretched into long and narrow filaments. The mechanism illustrated in this study possibly presents an important pathway to transport pollution into the polar tropopause region.

scholarly journals In-situ observation of Asian pollution transported into the Arctic lowermost stratosphere

2011 ◽  
Vol 11 (21) ◽  
pp. 10975-10994 ◽  
Author(s):  
A. Roiger ◽  
H. Schlager ◽  
A. Schäfler ◽  
H. Huntrieser ◽  
M. Scheibe ◽  
...  
Keyword(s):  
Dispersion Model ◽  
Anthropogenic Pollution ◽  
Conveyor Belt ◽  
Particle Dispersion ◽  
The Arctic ◽  
In Situ Observation ◽  
Air Mass ◽  
Mixing Ratios ◽  
The North

Abstract. On a research flight on 10 July 2008, the German research aircraft Falcon sampled an air mass with unusually high carbon monoxide (CO), peroxyacetyl nitrate (PAN) and water vapour (H2O) mixing ratios in the Arctic lowermost stratosphere. The air mass was encountered twice at an altitude of 11.3 km, ~800 m above the dynamical tropopause. In-situ measurements of ozone, NO, and NOy indicate that this layer was a mixed air mass containing both air from the troposphere and stratosphere. Backward trajectory and Lagrangian particle dispersion model analysis suggest that the Falcon sampled the top of a polluted air mass originating from the coastal regions of East Asia. The anthropogenic pollution plume experienced strong up-lift in a warm conveyor belt (WCB) located over the Russian east-coast. Subsequently the Asian air mass was transported across the North Pole into the sampling area, elevating the local tropopause by up to ~3 km. Mixing with surrounding Arctic stratospheric air most likely took place during the horizontal transport when the tropospheric streamer was stretched into long and narrow filaments. The mechanism illustrated in this study possibly presents an important pathway to transport pollution into the polar tropopause region.

scholarly journals Temporal changes in the emissions of CH<sub>4</sub> and CO from China estimated from CH<sub>4</sub> / CO<sub>2</sub> and CO / CO<sub>2</sub> correlations observed at Hateruma Island

2013 ◽  
Vol 13 (8) ◽  
pp. 22893-22930 ◽  
Author(s):  
Y. Tohjima ◽  
M. Kubo ◽  
C. Minejima ◽  
H. Mukai ◽  
H. Tanimoto ◽  
...  
Keyword(s):  
Fossil Fuel ◽  
Dispersion Model ◽  
Temporal Changes ◽  
Particle Dispersion ◽  
Anthropogenic Sources ◽  
In Situ Observation ◽  
Mixing Ratios ◽  
Increasing Trend ◽  
Concentration Footprint

Abstract. In-situ observation of the atmospheric CO2, CH4, and CO mixing ratios at Hateruma Island (HAT, 24.05° N, 123.80° E) often show synoptic-scale variations with correlative elevations during winter, associated with air transport from the East Asian countries. We examine winter (November–March) trends in ΔCH4 / ΔCO2, ΔCO / ΔCO2, and ΔCO / ΔCH4 observed at Hateruma over the period 1999 to 2010. Although the ratios ΔCH4 / ΔCO2 and ΔCO / ΔCO2 both show an overall gradual decrease over the study period due to a recent rapid increase in fossil fuel consumption in China, we note that ΔCH4 / ΔCO2 and ΔCO / ΔCO2 remains relatively flat (no trend) during 2005–2010 and 1999–2004, respectively. The CO/CH4 slope on the other hand shows an increasing trend during 1999–2004 but a decrease during 2005–2010. Calculation of the concentration footprint for the atmospheric observation at HAT by using the FLEXPART Lagrangian particle dispersion model indicates that most of the short-term variations are caused by emission variations from North and East China. Combined with a set of reported emission maps, we have estimated the temporal changes in the annual CH4 and CO emissions from China under the assumption that the estimate of the fossil fuel-derived CO2 emissions based on the energy statistics is accurate. The estimated annual CH4 emissions, corresponding to non-seasonal sources or anthropogenic sources without rice fields, show a nearly constant value of 39 ± 6 TgCH4 yr−1 during 1998–2002, and then gradually increases to 46 ± 7 TgCH4 yr−1 in 2009/2010. The estimated annual CO emissions increase from 134 ± 26 TgCO yr−1 in 1998/1999 to 182 ± 33 TgCO yr−1 in 2004/2005, level off after 2005, and then slightly decrease to less than 160 TgCO yr−1 in 2008–2010.

scholarly journals Boundary layer and free-tropospheric dimethyl sulfide in the Arctic spring and summer

2017 ◽  
Vol 17 (14) ◽  
pp. 8757-8770 ◽  
Author(s):  
Roghayeh Ghahremaninezhad ◽  
Ann-Lise Norman ◽  
Betty Croft ◽  
Randall V. Martin ◽  
Jeffrey R. Pierce ◽  
...  
Keyword(s):  
Dimethyl Sulfide ◽  
Transport Model ◽  
Dispersion Model ◽  
Open Water ◽  
Particle Dispersion ◽  
The Arctic ◽  
Chemical Transport Model ◽  
Model Simulations ◽  
Baffin Bay ◽  
Mixing Ratios

Abstract. Vertical distributions of atmospheric dimethyl sulfide (DMS(g)) were sampled aboard the research aircraft Polar 6 near Lancaster Sound, Nunavut, Canada, in July 2014 and on pan-Arctic flights in April 2015 that started from Longyearbyen, Spitzbergen, and passed through Alert and Eureka, Nunavut, and Inuvik, Northwest Territories. Larger mean DMS(g) mixing ratios were present during April 2015 (campaign mean of 116  ±  8 pptv) compared to July 2014 (campaign mean of 20  ±  6 pptv). During July 2014, the largest mixing ratios were found near the surface over the ice edge and open water. DMS(g) mixing ratios decreased with altitude up to about 3 km. During April 2015, profiles of DMS(g) were more uniform with height and some profiles showed an increase with altitude. DMS reached as high as 100 pptv near 2500 m. Relative to the observation averages, GEOS-Chem (www.geos-chem.org) chemical transport model simulations were higher during July and lower during April. Based on the simulations, more than 90 % of the July DMS(g) below 2 km and more than 90 % of the April DMS(g) originated from Arctic seawater (north of 66° N). During April, 60 % of the DMS(g), between 500 and 3000 m originated from Arctic seawater. During July 2014, FLEXPART (FLEXible PARTicle dispersion model) simulations locate the sampled air mass over Baffin Bay and the Canadian Arctic Archipelago 4 days back from the observations. During April 2015, the locations of the air masses 4 days back from sampling were varied: Baffin Bay/Canadian Archipelago, the Arctic Ocean, Greenland and the Pacific Ocean. Our results highlight the role of open water below the flight as the source of DMS(g) during July 2014 and the influence of long-range transport (LRT) of DMS(g) from further afield in the Arctic above 2500 m during April 2015.

scholarly journals In situ measurements of aerosol optical properties and number size distributions in a coastal region of Norway during the summer of 2008

2012 ◽  
Vol 12 (13) ◽  
pp. 5841-5857 ◽  
Author(s):  
S. Mogo ◽  
V. E. Cachorro ◽  
J. F. Lopez ◽  
E. Montilla ◽  
B. Torres ◽  
...  
Keyword(s):  
The Arctic ◽  
Size Distributions ◽  
Aerosol Optical Properties ◽  
Air Mass ◽  
Mean Values ◽  
Air Masses ◽  
The North ◽  
Microphysical Parameters ◽  
The One

Abstract. In situ measurements of aerosol optical properties and particle size distributions were made in the summer of 2008 at the ALOMAR station facility (69°16' N, 16°00' E), located in a rural site in the north of the island of Andøya (Vesterålen archipelago), approximately 300 km north of the Arctic Circle. The extended three-month campaign was part of the POLARCAT Project (Polar Study using Aircraft, Remote Sensing, Surface Measurements and Models, of Climate, Chemistry, Aerosols, and Transport) of the International Polar Year (IPY-2007-2008). Our goal was to characterize the aerosols of this sub-Arctic area, which are frequently transported to the Arctic region. Data from 13 June to 26 August 2008 were available and the statistical data for all instruments were calculated based on the hourly averages. The overall data coverage was approximately 72%. The hourly mean values of the light-scattering coefficient, σs, and the light-absorption coefficient, σa, at 550 nm were 5.41 Mm−1 (StD = 3.55 Mm−1) and 0.40 Mm−1 (StD = 0.27 Mm−1), respectively. The scattering/absorption Ångström exponents, αs,a, were used in a detailed analysis of the variations of the spectral shape of σs,a. While αs indicates the presence of two particle sizes corresponding to two types of aerosols, αa indicates only one type of absorbing aerosol particle. αa values greater than 1 were not observed. The single-scattering albedo, ω0, ranged from 0.62 to 0.99 (mean = 0.91, StD = 0.05), and the relationships between this parameter and the absorption/scattering coefficients and the Ångström exponents are presented. Any absorption value may lead to the lowest values of ω0, whereas only the lowest scattering values were observed in the lowest range of ω0. For a given absorption value, lower ω0 were observed for smaller αs. The submicrometer, micrometer and total concentrations of the particles presented hourly mean values of 1277 cm−3 (StD = 1563 cm−3), 1 cm−3 (StD = 1 cm−3) and 2463 cm−3 (StD = 4251 cm−3), respectively, and the modal correlations were also investigated. The optical and microphysical parameters, as well as their relationship with each other, are reported. σs correlated strongly with the number concentration of accumulation mode particles and more strongly with the micrometer fraction of particles, but weak correlations were observed for the Aitken and nucleation modes. The origins and pathways of the air masses were examined, and based on sector classification, a relationship between the air mass origin, the optical parameters and the size distributions was established. The low values of the optical and microphysical parameters indicate that the predominant regional aerosol is mostly clean and the shape of the size distribution is characterized by bimodal median size distributions. However, the relationships between the air mass origins and the parameters studied allow us to describe two characteristic situations: the one of the northern and western air masses, which were predominantly composed of marine aerosols and presented the lowest optical and microphysical values observed, indicating predominantly non-absorbent and coarser particles; and the one of the eastern and southern air masses, in which continental aerosols were predominant and exhibited higher values for all parameters, indicating the presence of smaller absorbent particles. The north-northeastern air masses presented the strongest Aitken mode, indicating more recently formed particles, and the southeastern air masses presented the strongest accumulation mode (however, the southeastern air masses were the least common, accounting for only 3% of occurrences).

scholarly journals Arctic smoke – record high air pollution levels in the European Arctic due to agricultural fires in Eastern Europe

2006 ◽  
Vol 6 (5) ◽  
pp. 9655-9722 ◽  
Author(s):  
A. Stohl ◽  
T. Berg ◽  
J. F. Burkhart ◽  
A. M. Fjæraa ◽  
C. Forster ◽  
...  
Keyword(s):  
Air Pollution ◽  
Eastern Europe ◽  
Dispersion Model ◽  
Spatial Scales ◽  
Agricultural Waste ◽  
Particle Dispersion ◽  
The Arctic ◽  
Aerosol Size Distribution ◽  
Radiative Processes ◽  
European Arctic

Abstract. In spring 2006, the European Arctic was abnormally warm, setting new historical temperature records. During this warm period, smoke from agricultural fires in Eastern Europe intruded into the European Arctic and caused the most severe air pollution episodes ever recorded there. This paper confirms that biomass burning (BB) was indeed the source of the observed air pollution, studies the transport of the smoke into the Arctic, and presents an overview of the observations taken during the episode. Fire detections from the MODIS instruments aboard the Aqua and Terra satellites were used to estimate the BB emissions. The FLEXPART particle dispersion model was used to show that the smoke was transported to Spitsbergen and Iceland, which was confirmed by MODIS retrievals of the aerosol optical depth (AOD) and AIRS retrievals of carbon monoxide (CO) total columns. Concentrations of halocarbons, carbon dioxide and CO, as well as levoglucosan and potassium, measured at Zeppelin mountain near Ny Ålesund, were used to further corroborate the BB source of the smoke at Spitsbergen. The ozone (O3) and CO concentrations were the highest ever observed at the Zeppelin station, and gaseous elemental mercury was also enhanced. A new O3 record was also set at a station on Iceland. The smoke was strongly absorbing – black carbon concentrations were the highest ever recorded at Zeppelin –, and strongly perturbed the radiation transmission in the atmosphere: aerosol optical depths were the highest ever measured at Ny Ålesund. We furthermore discuss the aerosol chemical composition, obtained from filter samples, as well as the aerosol size distribution during the smoke event. Photographs show that the snow at a glacier on Spitsbergen became discolored during the episode and, thus, the snow albedo was reduced. Samples of this polluted snow contained strongly enhanced levels of potassium, sulphate, nitrate and ammonium ions, thus relating the discoloration to the deposition of the smoke aerosols. This paper shows that, to date, BB has been underestimated as a source of aerosol and air pollution for the Arctic, relative to emissions from fossil fuel combustion. Given its significant impact on air quality over large spatial scales and on radiative processes, the practice of agricultural waste burning should be banned in the future.

scholarly journals In situ observation of atmospheric oxygen and carbon dioxide in the North Pacific using a cargo ship

2018 ◽  
Vol 18 (13) ◽  
pp. 9283-9295 ◽  
Author(s):  
Yu Hoshina ◽  
Yasunori Tohjima ◽  
Keiichi Katsumata ◽  
Toshinobu Machida ◽  
Shin-ichiro Nakaoka
Keyword(s):  
Carbon Dioxide ◽  
Mole Fraction ◽  
North Pacific ◽  
Atmospheric Oxygen ◽  
The United States ◽  
In Situ Observation ◽  
Airflow Rate ◽  
The North ◽  
The North Pacific

Abstract. Atmospheric oxygen (O2) and carbon dioxide (CO2) variations in the North Pacific were measured aboard a cargo ship, the New Century 2 (NC2), while it cruised between Japan and the United States between December 2015 and November 2016. A fuel cell analyzer and a nondispersive infrared analyzer were used for the measurement of O2 and CO2, respectively. To achieve parts-per-million precision for the O2 measurements, we precisely controlled the flow rates of the sample and reference air introduced into the analyzers and the outlet pressure. A relatively low airflow rate (10 cm3 min−1) was adopted to reduce the consumption rate of the reference gases. In the laboratory, the system achieved measurement precisions of 3.8 per meg for δ(O2 ∕ N2), which is commonly used to express atmospheric O2 variation, and 0.1 ppm for the CO2 mole fraction. After the in situ observation started aboard NC2, we found that the ship's motion caused false wavy variations in the O2 signal with an amplitude of more than several tens of ppm and a period of about 20 s. Although we have not resolved the problem at this stage, hourly averaging considerably suppressed the variation associated with ship motion. Comparison between the in situ observation and flask sampling of air samples aboard NC2 showed that the averaged differences (in situ–flask) and the standard deviations (±1σ) are −2.8 ± 9.4 per meg for δ(O2 ∕ N2) and −0.02 ± 0.33 ppm for the CO2 mole fraction. We compared 1 year of in situ data for atmospheric potential oxygen (APO; O2 +1.1×CO2) obtained from the broad middle-latitude region (140∘ E–130∘ W, 29∘ N–45∘ N) with previous flask sampling data from the North Pacific. This comparison showed that longitudinal differences in the seasonal amplitude of APO, ranging from 51 to 73 per meg, were smaller than the latitudinal differences.

scholarly journals Development of CarbonTracker Europe-CH<sub>4</sub> – Part 2: global methane emission estimates and their evaluation for 2000–2012

2016 ◽  
Author(s):  
Aki Tsuruta ◽  
Tuula Aalto ◽  
Leif Backman ◽  
Janne Hakkarainen ◽  
Ingrid T. van der Laan-Luijkx ◽  
...  
Keyword(s):  
North American ◽  
Transport Model ◽  
Vertical Mixing ◽  
Total Carbon ◽  
In Situ Observation ◽  
Convection Scheme ◽  
Temperate Region ◽  
Northern Latitude ◽  
The North

Abstract. Gobal methane emissions were estimated for 2000–2012 using the CarbonTracker Europe-CH4 (CTE-CH4) data assimilation system. In CTE-CH4, the anthropogenic and biosphere emissions of CH4 are simultaneously constrained by global atmospheric in-situ methane mole fraction observations. We use three configurations developed in Tsuruta et al. (2016) to assess the sensitivity of the CH4 flux estimates to (a) the number of unknown flux scaling factors to be optimized which in turn depends on the choice of underlying land-ecosystem map, and (b) on the parametrization of vertical mixing in the 30 atmospheric transport model TM5. The posterior emission estimates were evaluated by comparing simulations to surface in-situ observation sites, to profile observations made by aircraft, to dry air total column-averaged mole fractions (XCH4) observations from the Total Carbon Column Observing Network (TCCON), and to XCH4 retrievals from the Greenhouse gases Observing SATellite (GOSAT). Our estimated posterior mean global total emissions during 2000–2012 are 516 ± 51 Tg CH4 yr−1, and emission estimates during 2007–2012 are 18 Tg CH4 yr−1 greater than those from 2001–2006, mainly driven by an 35 increase in emissions from the south America temperate region, the Asia temperate region and Asia tropics. The sensitivity of the flux estimates to the underlying ecosystem map was large for the Asia temperate region and Australia, but not significant in the northern latitude regions, i.e. the north American boreal region, the north American temperate region and Europe. Instead, the posterior estimates for the northern latitude regions show larger sensitivity to the choice of convection scheme in TM5. The Gregory et al. (2000) mixing scheme with faster interhemispheric exchange leads to higher estimated CH4 emissions at northern latitudes, and lower emissions in southern latitudes, compared to the estimates using Tiedtke (1989) convection scheme. Our evaluation with non-assimilated observations showed that posterior mole fractions were better matched with the 5 observations when Gregory et al. (2000) convection scheme was used.

scholarly journals Long-path measurements of pollutants and micrometeorology over Highway 401 in Toronto

2017 ◽  
Author(s):  
Yuan You ◽  
Ralf M. Staebler ◽  
Samar G. Moussa ◽  
Yushan Su ◽  
Tony Munoz ◽  
...  
Keyword(s):  
Dispersion Model ◽  
Urban Air Pollution ◽  
Forecast Model ◽  
Emission Factors ◽  
Ammonia Nitrogen ◽  
Traffic Emissions ◽  
Mixing Ratios ◽  
Air Quality Forecast ◽  
Traffic Volumes

Abstract. Traffic emissions contribute significantly to urban air pollution. Measurements were conducted over Highway 401 in Toronto, Canada, with a long-path Fourier Transform Infra-Red Spectrometer (FTIR) combined with a suite of micrometeorological instruments, to identify and quantify a range of air pollutants. Results were compared with simultaneous in-situ observations at a roadside monitoring station, and with output from a special version of the operational Canadian air quality forecast model (GEM-MACH). Elevated mixing ratios of ammonia (0–23 ppb) were observed, of which 76 % were associated with traffic emissions. Hydrogen cyanide was identified at mixing ratios between 0 and 4 ppb. Using a simple dispersion model, an integrated emission factor of on average 2.6 g km−1 carbon monoxide was calculated for this defined section of Highway 401, which agreed well with estimates based on vehicular emission factors and observed traffic volumes. Based on the same dispersion calculations, vehicular average emission factors of 0.04, 0.36 and 0.15 g km−1 were calculated for ammonia, nitrogen oxide, and methanol respectively.

scholarly journals The Coastal Observing System for Northern and Arctic Seas (COSYNA)

Ocean Science ◽  
2017 ◽  
Vol 13 (3) ◽  
pp. 379-410 ◽  
Author(s):  
Burkard Baschek ◽  
Friedhelm Schroeder ◽  
Holger Brix ◽  
Rolf Riethmüller ◽  
Thomas H. Badewien ◽  
...  
Keyword(s):  
Real Time ◽  
The Arctic ◽  
Arctic Seas ◽  
The Public ◽  
The North ◽  
Data Products ◽  
The North Sea ◽  
Arctic Coast ◽  
The Impact

Abstract. The Coastal Observing System for Northern and Arctic Seas (COSYNA) was established in order to better understand the complex interdisciplinary processes of northern seas and the Arctic coasts in a changing environment. Particular focus is given to the German Bight in the North Sea as a prime example of a heavily used coastal area, and Svalbard as an example of an Arctic coast that is under strong pressure due to global change.The COSYNA automated observing and modelling system is designed to monitor real-time conditions and provide short-term forecasts, data, and data products to help assess the impact of anthropogenically induced change. Observations are carried out by combining satellite and radar remote sensing with various in situ platforms. Novel sensors, instruments, and algorithms are developed to further improve the understanding of the interdisciplinary interactions between physics, biogeochemistry, and the ecology of coastal seas. New modelling and data assimilation techniques are used to integrate observations and models in a quasi-operational system providing descriptions and forecasts of key hydrographic variables. Data and data products are publicly available free of charge and in real time. They are used by multiple interest groups in science, agencies, politics, industry, and the public.

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