Concentration of trace gases in the lower troposphere, simultaneously recorded at neighboring mountain stations Part II: Ozone

1987 ◽  
Vol 37 (1) ◽  
pp. 27-47 ◽  
Author(s):  
R. Reiter ◽  
R. Sladkovic ◽  
H. -J. Kanter
Author(s):  
Paul I Palmer

We have been observing the Earth's upper atmosphere from space for several decades, but only over the past decade has the necessary technology begun to match our desire to observe surface air pollutants and climate-relevant trace gases in the lower troposphere, where we live and breathe. A new generation of Earth-observing satellites, capable of probing the lower troposphere, are already orbiting hundreds of kilometres above the Earth's surface with several more ready for launch or in the planning stages. Consequently, this is one of the most exciting times for the Earth system scientists who study the countless current-day physical, chemical and biological interactions between the Earth's land, ocean and atmosphere. First, I briefly review the theory behind measuring the atmosphere from space, and how these data can be used to infer surface sources and sinks of trace gases. I then present some of the science highlights associated with these data and how they can be used to improve fundamental understanding of the Earth's climate system. I conclude the paper by discussing the future role of satellite measurements of tropospheric trace gases in mitigating surface air pollution and carbon trading.


2019 ◽  
Vol 19 (10) ◽  
pp. 7073-7103 ◽  
Author(s):  
Yoichi Inai ◽  
Ryo Fujita ◽  
Toshinobu Machida ◽  
Hidekazu Matsueda ◽  
Yousuke Sawa ◽  
...  

Abstract. To investigate the seasonal characteristics of trace gas distributions in the extratropical upper troposphere and lower stratosphere (ExUTLS) as well as stratosphere–troposphere exchange processes, origin fractions of air masses originating in the stratosphere, tropical troposphere, midlatitude lower troposphere (LT), and high-latitude LT in the ExUTLS are estimated using 10-year backward trajectories calculated with European Centre for Medium-Range Weather Forecasts (ECMWF) ERA-Interim data as the meteorological input. Time series of trace gases obtained from ground-based and airborne observations are incorporated into the trajectories, thus reconstructing spatiotemporal distributions of trace gases in the ExUTLS. The reconstructed tracer distributions are analyzed with the origin fractions and the stratospheric age of air (AoA) estimated using the backward trajectories. The reconstructed distributions of SF6 and CO2 in the ExUTLS are linearly correlated with those of AoA because of their chemically passive behavior and quasi-stable increasing trends in the troposphere. Distributions of CH4, N2O, and CO are controlled primarily by chemical decay along the transport path from the source region via the stratosphere and subsequent mixing of such stratospheric air masses with tropospheric air masses in the ExUTLS.


2020 ◽  
Vol 20 (11) ◽  
pp. 6973-6990 ◽  
Author(s):  
Jianzhong Ma ◽  
Steffen Dörner ◽  
Sebastian Donner ◽  
Junli Jin ◽  
Siyang Cheng ◽  
...  

Abstract. Mt. Waliguan Observatory (WLG) is a World Meteorological Organization (WMO) Global Atmosphere Watch (GAW) global baseline station in China. WLG is located at the northeastern part of the Tibetan Plateau (36∘17′ N, 100∘54′ E, 3816 m a.s.l.) and is representative of the pristine atmosphere over the Eurasian continent. We made long-term ground-based multi-axis differential optical absorption spectroscopy (MAX-DOAS) measurements at WLG during the period 2012–2015. In this study, we retrieve the differential slant column densities (dSCDs) and estimate the tropospheric background mixing ratios of different trace gases, including NO2, SO2, HCHO, and BrO, using the measured spectra at WLG. Averaging of 10 original spectra is found to be an “optimum option” for reducing both the statistical error of the spectral retrieval and systematic errors in the analysis. The dSCDs of NO2, SO2, HCHO, and BrO under clear-sky and low-aerosol-load conditions are extracted from measured spectra at different elevation angles at WLG. By performing radiative transfer simulations with the model TRACY-2, we establish approximate relationships between the trace gas dSCDs at 1∘ elevation angle and the corresponding average tropospheric background volume mixing ratios. Mixing ratios of these trace gases in the lower troposphere over WLG are estimated to be in a range of about 7 ppt (January) to 100 ppt (May) for NO2, below 0.5 ppb for SO2, between 0.4 and 0.9 ppb for HCHO, and lower than 0.3 ppt for BrO. The chemical box model simulations constrained by the NO2 concentration from our MAX-DOAS measurements show that there is a little net ozone loss (−0.8 ppb d−1) for the free-tropospheric conditions and a little net ozone production (0.3 ppb d−1) for the boundary layer conditions over WLG during summertime. Our study provides valuable information and data sets for further investigating tropospheric chemistry in the background atmosphere and its links to anthropogenic activities.


2011 ◽  
Vol 11 (9) ◽  
pp. 4491-4503 ◽  
Author(s):  
J. Worden ◽  
D. Noone ◽  
J. Galewsky ◽  
A. Bailey ◽  
K. Bowman ◽  
...  

Abstract. The Aura satellite Tropospheric Emission Spectrometer (TES) instrument is capable of measuring the HDO/H2O ratio in the lower troposphere using thermal infrared radiances between 1200 and 1350 cm−1. However, direct validation of these measurements is challenging due to a lack of in situ measured vertical profiles of the HDO/H2O ratio that are spatially and temporally co-located with the TES observations. From 11 October through 5 November 2008, we undertook a campaign to measure HDO and H2O at the Mauna Loa observatory in Hawaii for comparison with TES observations. The Mauna Loa observatory is situated at 3.1 km above sea level or approximately 680 hPa, which is approximately the altitude where the TES HDO/H2O observations show the most sensitivity. Another advantage of comparing in situ data from this site to estimates derived from thermal IR radiances is that the volcanic rock is heated by sunlight during the day, thus providing significant thermal contrast between the surface and atmosphere; this thermal contrast increases the sensitivity to near surface estimates of tropospheric trace gases. The objective of this inter-comparison is to better characterize a bias in the TES HDO data, which had been previously estimated to be approximately 5 % too high for a column integrated value between 850 hPa and 500 hPa. We estimate that the TES HDO profiles should be corrected downwards by approximately 4.8 % and 6.3 % for Versions 3 and 4 of the data respectively. These corrections must account for the vertical sensitivity of the TES HDO estimates. We estimate that the precision of this bias correction is approximately 1.9 %. The accuracy is driven by the corrections applied to the in situ HDO and H2O measurements using flask data taken during the inter-comparison campaign and is estimated to be less than 1 %. Future comparisons of TES data to accurate vertical profiles of in situ measurements are needed to refine this bias estimate.


2021 ◽  
Author(s):  
Sebastian Donner ◽  
Steffen Dörner ◽  
Joelle Buxmann ◽  
Steffen Beirle ◽  
David Campbell ◽  
...  

<p>Multi-AXis (MAX)-Differential Optical Absorption Spectroscopy (DOAS) instruments record spectra of scattered sun light under different elevation angles. From such measurements tropospheric vertical column densities (VCDs) and vertical profiles of different atmospheric trace gases and aerosols can be determined for the lower troposphere. These measurements allow a simultaneous observation of multiple trace gases, e.g. formaldehyde (HCHO), glyoxal (CHOCHO) and nitrogen dioxide (NO<sub>2</sub>), with the same measurement setup. Since November 2018, a MAX-DOAS instrument has been operating at Bayfordbury Observatory, which is located approximately 30 km north of London. This measurement site is operated by the University of Hertfordshire and equipped with an AERONET station, a LIDAR and multiple instruments to measure meteorological quantities and solar radiation. Depending on the prevailing wind direction the air masses at the measurement site can be dominated by the pollution of London (SE to SW winds) or rather pristine air (northerly winds).</p><p>First results already showed that the highest formaldehyde and glyoxal columns are observed for southerly to southeasterly winds indicating the influence of the anthropogenic emissions of London. However, the detailed patterns of the different trace gases were found to be more complex. Therefore, this measurement site is well suited to study the influence of anthropogenic pollution on the atmospheric composition and chemistry at a rather pristine location in the vicinity of London, a major European capital with about 10 million inhabitants and 4 major international airports.</p><p>In this study, trace gas and aerosol profiles are retrieved using the MAinz Profile Algorithm (MAPA) with a focus on tropospheric HCHO which plays an important role in tropospheric chemistry. The HCHO results are combined with the results of other trace species such as NO<sub>2</sub>, CHOCHO and aerosols in order to identify pollution levels, emission sources and different chemical regimes.</p>


2020 ◽  
Author(s):  
Sebastian Donner ◽  
Steffen Dörner ◽  
Joelle Buxmann ◽  
Steffen Beirle ◽  
David Campbell ◽  
...  

<p>Multi-AXis (MAX)-DOAS instruments record spectra of scattered sun light under different elevation angles. From such measurements tropospheric vertical column densities (VCDs) and vertical profiles of different atmospheric trace gases and aerosols can be determined for the lower troposphere. These measurements allow a simultaneous observation of multiple trace gases (e.g. HCHO, CHOCHO, NO<sub>2</sub>, etc.) with the same measurement setup. Since November 2018, a MAX-DOAS instrument is operated at the Bayfordbury Observatory, which is located approximately 30 km north of London. This measurement site is operated by the University of Hertfordshire and equipped with an AERONET station, a LIDAR and multiple instruments to measure meteorological quantities and solar radiation. Depending on the prevailing wind direction the air masses at the measurement site can be dominated by the pollution of London (SE to SW winds) or rather pristine air (northerly winds). Therefore, this measurement site is well suited to study the influence of anthropogenic pollution on the atmospheric composition and chemistry at a rather pristine location in the vicinity of London, a major European capital with 9.8 million inhabitants and 4 major international airports.</p><p>In this study, trace gas and aerosol profiles are retrieved using the MAinz Profile Algorithm MAPA (Beirle et al., 2018) with a focus on tropospheric formaldehyde (HCHO) which plays an important role in tropospheric chemistry. The HCHO results are combined with the results of other trace species such as NO<sub>2</sub>, CHOCHO and aerosols in order to identify different chemical regimes and pollution levels.</p>


2009 ◽  
Vol 9 (9) ◽  
pp. 3011-3025 ◽  
Author(s):  
Q. Liang ◽  
A. R. Douglass ◽  
B. N. Duncan ◽  
R. S. Stolarski ◽  
J. C. Witte

Abstract. We used the seasonality of a combination of atmospheric trace gases and idealized tracers to examine stratosphere-to-troposphere transport and its influence on tropospheric composition in the Arctic. Maximum stratosphere-to-troposphere transport of CFCs and O3 occurs in April as driven by the Brewer-Dobson circulation. Stratosphere-troposphere exchange (STE) occurs predominantly between 40° N to 80° N with stratospheric influx in the mid-latitudes (30–70° N) accounting for 67–81% of the air of stratospheric origin in the Northern Hemisphere extratropical troposphere. Transport from the lower stratosphere to the lower troposphere (LT) takes three months on average, one month to cross the tropopause, the second month to travel from the upper troposphere (UT) to the middle troposphere (MT), and the third month to reach the LT. During downward transport, the seasonality of a trace gas can be greatly impacted by wet removal and chemistry. A comparison of idealized tracers with varying lifetimes suggests that when initialized with the same concentrations and seasonal cycles at the tropopause, trace gases that have shorter lifetimes display lower concentrations, smaller amplitudes, and earlier seasonal maxima during transport to the LT. STE contributes to O3 in the Arctic troposphere directly from the transport of O3 and indirectly from the transport of NOy. Direct transport of O3 from the stratosphere accounts for 78% of O3 in the Arctic UT with maximum contributions occurring from March to May. The stratospheric contribution decreases significantly in the MT/LT (20–25% of total O3) and shows a very weak March–April maximum. Our NOx budget analysis in the Arctic UT shows that during spring and summer, the stratospheric injection of NOy-rich air increases NOx concentrations above the 20 pptv threshold level, thereby shifting the Arctic UT from a regime of net photochemical ozone loss to one of net production with rates as high as +16 ppbv/month.


Chemosphere ◽  
1983 ◽  
Vol 12 (3) ◽  
pp. 371-375 ◽  
Author(s):  
R.A. Rasmussen ◽  
M.A.K. Khalil

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