Tropospheric ozone variations in the Arctic during January 1990

Abstract. The goal of the paper are to: (1) present tropospheric ozone (O3) climatologies in summer 2008 based on a large amount of measurements, during the International Polar Year when the Polar Study using Aircraft, Remote Sensing, Surface Measurements, and Models of Climate Chemistry, Aerosols, and Transport (POLARCAT) campaigns were conducted (2) investigate the processes that determine O3 concentrations in two different regions (Canada and Greenland) that were thoroughly studied using measurements from 3 aircraft and 7 ozonesonde stations. This paper provides an integrated analysis of these observations and the discussion of the latitudinal and vertical variability of tropospheric ozone north of 55° N during this period is performed using a regional model (WFR-Chem). Ozone, CO and potential vorticity (PV) distributions are extracted from the simulation at the measurement locations. The model is able to reproduce the O3 latitudinal and vertical variability but a negative O3 bias of 6–15 ppbv is found in the free troposphere over 4 km, especially over Canada. Ozone average concentrations are of the order of 65 ppbv at altitudes above 4 km both over Canada and Greenland, while they are less than 50 ppbv in the lower troposphere. The relative influence of stratosphere-troposphere exchange (STE) and of ozone production related to the local biomass burning (BB) emissions is discussed using differences between average values of O3, CO and PV for Southern and Northern Canada or Greenland and two vertical ranges in the troposphere: 0–4 km and 4–8 km. For Canada, the model CO distribution and the weak correlation (< 30 %) of O3 and PV suggests that stratosphere-troposphere exchange (STE) is not the major contribution to average tropospheric ozone at latitudes less than 70° N, due to the fact that local biomass burning (BB) emissions were significant during the 2008 summer period. Conversely over Greenland, significant STE is found according to the better O3 versus PV correlation (> 40 %) and the higher 75th PV percentile. A weak negative latitudinal summer ozone gradient −6 to −8 ppbv is found over Canada in the mid troposphere between 4 and 8 km. This is attributed to an efficient O3 photochemical production due to the BB emissions at latitudes less than 65° N, while STE contribution is more homogeneous in the latitude range 55° N to 70° N. A positive ozone latitudinal gradient of 12 ppbv is observed in the same altitude range over Greenland not because of an increasing latitudinal influence of STE, but because of different long range transport from multiple mid-latitude sources (North America, Europe and even Asia for latitudes higher than 77° N).

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Ozone variations in the Scandinavian sector of the Arctic during the AASE Campaign and 1989

Geophysical Research Letters ◽

10.1029/94gl01069 ◽

1994 ◽

Vol 21 (17) ◽

pp. 1775-1778 ◽

Cited By ~ 3

Author(s):

K. Henriksen ◽

S. H. H. Larsen ◽

O. I. Shumilov ◽

B. Thorkelsson

Keyword(s):

The Arctic ◽

Ozone Variations

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Lidar Measurements of Tropospheric Ozone in the Arctic

EPJ Web of Conferences ◽

10.1051/epjconf/201611920003 ◽

2016 ◽

Vol 119 ◽

pp. 20003

Author(s):

Jeffrey Seabrook ◽

James Whiteway

Keyword(s):

Tropospheric Ozone ◽

The Arctic ◽

Lidar Measurements

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Effect of stratospheric ozone variations on UV radiation and on tropospheric ozone at high latitudes

Journal of Geophysical Research Atmospheres ◽

10.1029/96jd02310 ◽

1997 ◽

Vol 102 (D1) ◽

pp. 1533-1539 ◽

Cited By ~ 31

Author(s):

Petteri Taalas ◽

Juhani Damski ◽

Esko Kyrö ◽

Maximo Ginzburg ◽

Gustavo Talamoni

Keyword(s):

Uv Radiation ◽

Tropospheric Ozone ◽

Stratospheric Ozone ◽

High Latitudes ◽

Ozone Variations

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The role of ozone atmosphere-snow gas exchange on polar, boundary-layer tropospheric ozone – a review and sensitivity analysis

Atmospheric Chemistry and Physics ◽

10.5194/acp-7-15-2007 ◽

2007 ◽

Vol 7 (1) ◽

pp. 15-30 ◽

Cited By ~ 45

Author(s):

D. Helmig ◽

L. Ganzeveld ◽

T. Butler ◽

S. J. Oltmans

Keyword(s):

Sensitivity Analysis ◽

Gas Exchange ◽

Tropospheric Ozone ◽

The Arctic ◽

Tracer Transport ◽

Model Calculations ◽

Substantial Impact ◽

Ozone Deposition ◽

Wide Range ◽

Ozone Fluxes

Abstract. Recent research on snowpack processes and atmosphere-snow gas exchange has demonstrated that chemical and physical interactions between the snowpack and the overlaying atmosphere have a substantial impact on the composition of the lower troposphere. These observations also imply that ozone deposition to the snowpack possibly depends on parameters including the quantity and composition of deposited trace gases, solar irradiance, snow temperature and the substrate below the snowpack. Current literature spans a remarkably wide range of ozone deposition velocities (vdO3); several studies even reported positive ozone fluxes out of the snow. Overall, published values range from ~–3<vdO3<2 cm s−1, although most data are within 0<vdO3<0.2 cm s−1. This literature reveals a high uncertainty in the parameterization and the magnitude of ozone fluxes into (and possibly out of) snow-covered landscapes. In this study a chemistry and tracer transport model was applied to evaluate the applicability of the published vdO3 and to investigate the sensitivity of tropospheric ozone towards ozone deposition over Northern Hemisphere snow-covered land and sea-ice. Model calculations using increasing vdO3 of 0.0, 0.01, 0.05 and 0.10 cm s−1 resulted in general ozone sensitivities up to 20–30% in the Arctic surface layer, and of up to 130% local increases in selected Northern Latitude regions. The simulated ozone concentrations were compared with mean January ozone observations from 18 Arctic stations. Best agreement between the model and observations, not only in terms of absolute concentrations but also in the hourly ozone variability, was found by applying an ozone deposition velocity in the range of 0.00–0.01 cm s−1, which is smaller than most literature data and also significantly lower compared to the value of 0.05 cm s−1 that is commonly applied in large-scale atmospheric chemistry models. This sensitivity analysis demonstrates that large errors in the description of the wintertime tropospheric ozone budget stem from the uncertain magnitude of ozone deposition rates and the inability to properly parameterize ozone fluxes to snow-covered landscapes.

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Late-Spring and Summertime Tropospheric Ozone and NO<sub>2</sub> in Western Siberia and the Russian Arctic: Regional Model Evaluation and Sensitivities

10.5194/acp-2020-426 ◽

2020 ◽

Author(s):

Thomas Thorp ◽

Stephen R. Arnold ◽

Richard J. Pope ◽

Dominic V. Spracklen ◽

Luke Conibear ◽

...

Keyword(s):

Dry Deposition ◽

Tropospheric Ozone ◽

Western Siberia ◽

Surface Ozone ◽

Late Spring ◽

The Arctic ◽

Transport Sector ◽

Anthropogenic Emissions ◽

Negative Bias ◽

Russian Arctic

Abstract. We use a regional chemistry transport model (WRF-Chem) in conjunction with surface observations of tropospheric ozone and Ozone Monitoring Instrument (OMI) satellite retrievals of tropospheric column NO2 to evaluate processes controlling the regional distribution of tropospheric ozone over Western Siberia for late-spring and summer in 2011. This region hosts a range of anthropogenic and natural ozone precursor sources, and serves as a gateway for near-surface transport of Eurasian pollution to the Arctic. However, there is a severe lack of in-situ observations to constrain tropospheric ozone sources and sinks in the region. We show widespread negative bias in WRF-Chem tropospheric column NO2 when compared to OMI satellite observations from May – August, which is reduced when using ECLIPSE v5a emissions (FMB= -0.82 to -0.73) compared with the EDGAR-HTAP-2 emissions data (FMB= -0.80 to -0.70). Despite the large negative bias, the spatial correlations between model and observed NO2 columns suggest that the spatial pattern of NOx sources in the region is well represented. Based on ECLIPSE v5a emissions, we assess the influence of the two dominant anthropogenic emission sectors (transport and energy) and vegetation fires on surface NOx and ozone over Siberia and the Russian Arctic. Our results suggest regional ozone is more sensitive to anthropogenic emissions, particularly from the transport sector, and the contribution from fire emissions maximises in June and is largely confined to latitudes south of 60° N. Large contributions to surface ozone from energy emissions are simulated in April north of 60° N, due to emissions associated with oil and gas extraction. Ozone dry deposition fluxes from the model simulations show that the dominant ozone dry deposition sink in the region is to forest, averaging 6.0 Tg of ozone per month, peaking at 9.1 Tg of ozone deposition during June. The impact of fires on ozone dry deposition within the domain is small compared to anthropogenic emissions, and is negligible north of 60° N. Overall, our results suggest that surface ozone in the region is controlled by an interplay between seasonality in atmospheric transport patterns, vegetation dry deposition, and a dominance of transport and energy sector emissions.

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Vertical structure of Antarctic tropospheric ozone depletion events: characteristics and broader implications

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-10-8189-2010 ◽

2010 ◽

Vol 10 (3) ◽

pp. 8189-8246 ◽

Cited By ~ 2

Author(s):

A. E. Jones ◽

P. S. Anderson ◽

E. W. Wolff ◽

H. K. Roscoe ◽

G. J. Marshall ◽

...

Keyword(s):

High Altitude ◽

Ozone Depletion ◽

Tropospheric Ozone ◽

Large Scale ◽

Field Experiments ◽

Strong Association ◽

Vertical Component ◽

Low Pressure ◽

The Arctic ◽

Low Pressure Systems

Abstract. The majority of tropospheric ozone depletion event (ODE) studies have focussed on time-series measurements, with comparatively few studies of the vertical component. Those that exist have almost exclusively used free-flying balloon-borne ozonesondes and almost all have been conducted in the Arctic. Here we use measurements from two separate Antarctic field experiments to examine the vertical profile of ozone during Antarctic ODEs. We use tethersonde data to probe details in the lowest few hundred meters and find considerable structure in the profiles associated with complex atmospheric layering. The profiles were all measured at wind speeds less than 7 ms−1, and on each occasion the lowest inversion height lay between 10 m and 40 m. We also use data from a free-flying ozonesonde study to select events where ozone depletion was recorded at altitudes >1 km above ground level. Using ERA-40 meteorological charts, we find that on every occasion the high altitude depletion was preceded by an atmospheric low pressure system. An examination of limited published ozonesonde data from other Antarctic stations shows this to be a consistent feature. Given the link between BrO and ODEs, we also examine ground-based and satellite BrO measurements, and find a strong association between enhanced BrO and atmospheric low pressure systems. The results suggest that, in Antarctica, such depressions are responsible for driving high altitude ODEs and for generating the large-scale BrO clouds observed from satellites. In the Arctic, the prevailing meteorology differs from that in Antarctica, but we show that major low pressure systems in the Arctic, when they occur, can also generate BrO clouds. Such depressions thus appear to be fundamental when considering the broader influence of ODEs, particularly in Antarctica, such as halogen export and the radiative influence of ozone-depleted air masses.

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Stratospheric impact on the Northern Hemisphere winter and spring ozone interannual variability in the troposphere

10.5194/acp-2019-825 ◽

2019 ◽

Author(s):

Junhua Liu ◽

Jose M. Rodriguez ◽

Luke D. Oman ◽

Anne R. Douglass ◽

Mark A. Olsen ◽

...

Keyword(s):

North America ◽

Tropospheric Ozone ◽

Interannual Variation ◽

Stratospheric Ozone ◽

Lower Troposphere ◽

The Arctic ◽

Vertical Extent ◽

Pinatubo Eruption ◽

Tropospheric O3 ◽

The Impact

Abstract. In this study we use O3 and stratospheric O3 tracer simulations from the high-resolution Goddard Earth Observing System, Version 5 (GEOS-5) Replay run (MERRA-2 GMI at 0.5° model resolution ~ 50 km) and observations from ozonesondes to investigate the interannual variation and vertical extent of the stratospheric ozone impact on tropospheric ozone. Our work focuses on the winter and spring seasons over North America and Europe. The model reproduces the observed interannual variation of tropospheric O3, except for the Pinatubo period from 1991 to 1995 over the region of North America. Ozonesonde data show a negative ozone anomaly in 1992–1994 following the Pinatubo eruption, with recovery thereafter. The simulated anomaly is only half the magnitude of that observed. Our analysis suggests that the simulated Stratosphere-troposphere exchange (STE) flux deduced from the analysis might be too strong over the North American (50° N–70° N) region after the Mt. Pinatubo eruption in the early 1990s, masking the impact of lower stratospheric O3 concentration on tropospheric O3. European ozonesonde measurements show a similar but weaker O3 depletion after the Mt. Pinatubo eruption, which is fully reproduced by the model. Analysis based on a stratospheric O3 tracer (StratO3) identifies differences in strength and vertical extent of stratospheric ozone influence on the tropospheric ozone interannual variation (IAV) between North America and Europe. Over North America, the StratO3 IAV has a significant impact on tropospheric O3 from the upper to lower troposphere and explains about 60 % and 66 % of simulated O3 IAV at 400 hPa, ~ 11 % and 34 % at 700 hPa in winter and spring respectively. Over Europe, the influence is limited to the middle to upper troposphere, and becomes much smaller at 700 hPa. The stronger and deeper stratospheric contributions in the tropospheric O3 IAV over North America shown by the model is likely related to ozonesondes' being closer to the polar vortex in winter with lower geopotential height, lower tropopause height, and stronger coupling to the Arctic Oscillation in the lower troposphere (LT) than over Europe.

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Biomass burning influence on high latitude tropospheric ozone and reactive nitrogen in summer 2008: a multi-model analysis based on POLMIP simulations

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-14-24573-2014 ◽

2014 ◽

Vol 14 (17) ◽

pp. 24573-24621 ◽

Cited By ~ 9

Author(s):

S. R. Arnold ◽

L. K. Emmons ◽

S. A. Monks ◽

K. S. Law ◽

D. A. Ridley ◽

...

Keyword(s):

Biomass Burning ◽

High Latitude ◽

Tropospheric Ozone ◽

Transport Model ◽

Chemical Transport ◽

Ozone Production ◽

The Arctic ◽

Vertical Position ◽

Chemical Transport Model ◽

Fire Emissions

Abstract. We have evaluated tropospheric ozone enhancement in air dominated by biomass burning emissions at high laititudes (> 50˚ N) in July 2008, using 10 global chemical transport model simulations from the POLMIP multi-model comparison exercise. In model air masses dominated by fire emissions, Δ O3/ΔCO values ranged between 0.039 and 0.196 ppbv ppbv−1 (mean: 0.113 ppbv ppbv−1) in freshly fire-influenced air, and between 0.140 and 0.261 ppbv ppbv−1 (mean: 0.193 ppbv) in more aged fire-influenced air. These values are in broad agreement with the range of observational estimates from the literature. Model ΔPAN/ΔCO enhancement ratios show distinct groupings according to the meteorological data used to drive the models. ECMWF-forced models produce larger ΔPAN/ΔCO values (4.44–6.28 pptv ppbv−1) than GEOS5-forced models (2.02–3.02 pptv ppbv−1), which we show is likely linked to differences efficiency of vertical transport during poleward export from mid-latitude source regions. Simulations of a large plume of biomass burning and anthropogenic emissions exported from Asia towards the Arctic using a Lagrangian chemical transport model show that 4 day net ozone change in the plume is sensitive to differences in plume chemical composition and plume vertical position among the POLMIP models. In particular, Arctic ozone evolution in the plume is highly sensitive to initial concentrations of PAN, as well as oxygenated VOCs (acetone, acetaldehyde), due to their role in producing the peroxyacetyl radical PAN precursor. Vertical displacement is also important due to its effects on the stability of PAN, and subsequent effect on NOx abundance. In plumes where net ozone production is limited, we find that the lifetime of ozone in the plume is sensitive to hydrogen peroxide loading, due to the production of HO2 from peroxide photolysis, and the key role of HO2 + O3 in controlling ozone loss. Overall, our results suggest that emissions from biomass burning lead to large-scale photochemical enhancement in high latitude tropospheric ozone during summer.

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Tropospheric Ozone Depletion Events in the Arctic Spring of 2009: Modeling and Observations

10.5194/egusphere-egu2020-5035 ◽

2020 ◽

Author(s):

Maximilian Herrmann ◽

Holger Sihler ◽

Ulrich Platt ◽

Eva Gutheil

Keyword(s):

Chemical Reactions ◽

Ozone Depletion ◽

Tropospheric Ozone ◽

Vertical Direction ◽

Arctic Region ◽

Sea Salt ◽

The Arctic ◽

Parameter Study ◽

Atmospheric Pollutant ◽

The Arctic Region

<p>Ozone is an important atmospheric pollutant in the troposphere due to its high oxidation potential. In the Arctic troposphere, ozone mainly originates from transport and photo-chemical reactions involving nitrogen oxides and volatile organic compounds, resulting in a background mixing ratio of 30 to 50 nmol/mol. During polar spring, so-called tropospheric ozone depletion events (ODEs) are regularly observed, in which ozone mixing ratios in the boundary layer drop to almost zero levels coinciding with a surge in reactive bromine levels on the time scale of hours to days. The source of the reactive bromine is sea salt, i.e. aerosol and deposits on the ice. However, it is not fully understood how the salt bromide is oxidized and reactive bromine is released into the air. The most widely accepted emission mechanism is autocatalytic and termed &#8220;bromine explosion&#8221;. ODEs strongly change the lifetime of ozone and organic gases, they cause the removal and deposition of mercury as well as the transport of reactive bromine into the free troposphere. In order to model ODEs, the software package WRF-Chem is employed to simulate the meteorology and the emission, the transport, mixing, chemical reactions of trace gases as well as aerosols. For this purpose, the MOZART chemical reaction mechanism coupled with the MOSAIC aerosol model is extended to include bromine and chlorine chemistry. A resolution of 20 km for a 5,000 km x 5,000 km region in horizontal directions is employed, enabling the comparison of the simulation results to satellite GOME-2 BrO with a larger resolution. In vertical direction, 64 non-linear grid cells are used with a finer resolution near the ground. The simulation domain is centered north of Barrow (Utqia&#289;vik), Alaska and covers most of the Arctic region. The time from February 1 to May 1, 2009 is simulated. Improvements and differences to existing models include more complex bromine chemistry, the inclusion of chlorine chemistry, MOSAIC aerosols, and nudging of meteorological fields to ERA-INTERIM data.The simulations reveal that the first bromine explosions occur in early February in the Bering Sea and then extend to the Beaufort Sea in the middle of February, with further bromine explosions in the Arctic region through the end of the simulation. Simulations results are compared with the GOME-2 BrO measurements and in-situ ozone observations at Barrow (Utqia&#289;vik), Alaska. The comparison shows good agreement with respect to occurrence and location of ODEs. The simulations indicate that the existence and replenishment of bromine in the sea ice is necessary for the ODEs to occur throughout the observation time. Inclusion of direct release of bromine by the deposition of ozone is essential for the proper prediction of the frequent recurrence of ODEs as found through observations. The largest uncertainty in the model is the strength of the bromine deposition and emission from the ice/snow surface as well as the amount of available bromine in the sea salt, which is varied in a parameter study.</p>

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