Improved ozone monitoring by ground-based FTIR spectrometry

Abstract. Accurate observations of atmospheric ozone (O3) are essential to monitor in detail the key role of O3 in the atmospheric chemistry. The present paper examines the performance of different O3 retrieval strategies from FTIR (Fourier Transform InfraRed) spectrometry by using the 20-year time series of the high-resolution solar spectra acquired from 1999 to 2018 at the subtropical Izaña Observatory (IZO, Spain) within NDACC (Network for the Detection of Atmospheric Composition Change). In particular, the effect of two of the most influential factors have been investigated: the spectral region used for O3 retrievals and inclusion of an atmospheric temperature profile fit. The theoretical and experimental quality assessments of the different FTIR O3 products (total column, TC, amounts and volume mixing ratio, VMR, profiles) provide consistent results. Combining an optimal selection of spectral O3 absorption lines and a simultaneous temperature retrieval results in superior FTIR O3 products, with a precision greater than 0.6–0.7 % for O3 TCs as compared to coincident NDACC Brewer observations used as reference. However, this improvement can be only achieved provided the FTIR spectrometer is properly characterised and stable over time. For unstable instruments, the temperature fit has been found to exhibit a strong negative influence on O3 retrievals by increasing the cross-interference between instrumental performance and temperature retrieval. This cross-interference becomes especially noticeable beyond the upper troposphere/lower stratosphere as documented theoretically, as well as experimentally by comparing FTIR O3 profiles to those measured using Electrochemical Concentration Cell (ECC) sondes within NDACC. Consequently, it should be taken into account for the reliable monitoring of O3 vertical distribution, especially on long-term timescales.

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Upper altitude limit for Rayleigh lidar

Annales Geophysicae ◽

10.5194/angeo-25-19-2007 ◽

2007 ◽

Vol 25 (1) ◽

pp. 19-25 ◽

Cited By ~ 6

Author(s):

P. S. Argall

Keyword(s):

Atmospheric Temperature ◽

Atmospheric Composition ◽

Retrieval Algorithm ◽

Temperature Profiles ◽

Basic Assumptions ◽

Photon Count ◽

Accurate Knowledge ◽

Signal Photon ◽

Rayleigh Lidar ◽

Temperature Retrieval

Abstract. It has long been assumed that Rayleigh lidar can be used to measure atmospheric temperature profiles up to about 90 or 100 km and that above this region the technique becomes invalid due to changes in atmospheric composition which affect basic assumptions on which Rayleigh lidar is based. Modern powerful Rayleigh lidars are able to measure backscatter from well above 100 km requiring a closer examination of the effects of the changing atmospheric composition on derived Rayleigh lidar temperature profiles. The NRLMSISE-00 model has been used to simulate lidar signal (photon-count) profiles, taking into account the effects of changing atmospheric composition, enabling a quantitative analysis of the biases and errors associated with extending Rayleigh lidar temperature measurements above 100 km. The biases associated with applying a nominal correction for the change in atmospheric composition with altitude has also been investigated. The simulations reported here show that in practice the upper altitude limit for Rayleigh lidar is imposed more by the accuracy of the temperature or pressure used to seed the temperature retrieval algorithm than by accurate knowledge of the atmospheric composition as has long been assumed.

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Clean air in the Anthropocene

Faraday Discussions ◽

10.1039/c7fd90032e ◽

2017 ◽

Vol 200 ◽

pp. 693-703 ◽

Cited By ~ 18

Author(s):

Jos Lelieveld

Keyword(s):

Air Pollution ◽

Sustainable Development ◽

Air Quality ◽

Human Health ◽

Atmospheric Chemistry ◽

Clean Energy ◽

Atmospheric Composition ◽

Anthropogenic Sources ◽

Years Of Life Lost ◽

Clean Air

In atmospheric chemistry, interactions between air pollution, the biosphere and human health, often through reaction mixtures from both natural and anthropogenic sources, are of growing interest. Massive pollution emissions in the Anthropocene have transformed atmospheric composition to the extent that biogeochemical cycles, air quality and climate have changed globally and partly profoundly. It is estimated that mortality attributable to outdoor air pollution amounts to 4.33 million individuals per year, associated with 123 million years of life lost. Worldwide, air pollution is the major environmental risk factor to human health, and strict air quality standards have the potential to strongly reduce morbidity and mortality. Preserving clean air should be considered a human right, and is fundamental to many sustainable development goals of the United Nations, such as good health, climate action, sustainable cities, clean energy, and protecting life on land and in the water. It would be appropriate to adopt “clean air” as a sustainable development goal.

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The excitation of atmospheric oscillations

Proceedings of the Royal Society of London Series A - Mathematical and Physical Sciences ◽

10.1098/rspa.1963.0116 ◽

1963 ◽

Vol 274 (1356) ◽

pp. 91-121 ◽

Cited By ~ 59

Keyword(s):

Large Scale ◽

Ground Level ◽

Atmospheric Temperature ◽

Direct Absorption ◽

Pressure Oscillations ◽

Thermal Mechanism ◽

Atmospheric Temperature Profile ◽

Water Vapour Absorption ◽

The Vertical Distribution ◽

Quiet Day

An investigation is made into the excitation of large-scale atmospheric oscillations by the direct absorption of incoming solar radiation by atmospheric ozone. The atmospheric temperature profile is chosen to agree favourably with the main features of the observed temperature distribution, particularly as regards the maximum around the 50 km height; this distribution is shown to be non-resonant as far as the solar semidiurnal component is concerned. The excited solar diurnal, semidiurnal and terdiurnal pressure oscillations are computed and we find that although the largest Fourier component in the heating is the diurnal term , the tide it excites is small in keeping with observation. On the other hand, the excited semidiurnal oscillation is much larger than that due to any previously considered thermal mechanism . It is found that the main semidiurnal and terdiurnal tides generated by the direct absorption of insolation by ozone as calculated in the present work, together with published results regarding water vapour absorption, can adequately account for the observed values at ground level. The seasonal variations of the semi and terdiurnal tides are also calculated and these agree extremely well with observation. Finally, the change of phase of 180° in the vertical distribution of the solar semidiurnal oscillation, which is expected from the analysis of the quiet day magnetic variation, is accounted for in the present work.

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Observing the climate impact of large wildfires on stratospheric temperature

Scientific Reports ◽

10.1038/s41598-021-02335-7 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Matthias Stocker ◽

Florian Ladstädter ◽

Andrea K. Steiner

Keyword(s):

Lower Stratosphere ◽

Volcanic Eruptions ◽

Satellite Observation ◽

Atmospheric Temperature ◽

Climate Impact ◽

Atmospheric Composition ◽

Temperature Structure ◽

Climate Trends ◽

Short Term ◽

Climate Signal

AbstractWildfires are expected to become more frequent and intense in the future. They not only pose a serious threat to humans and ecosystems, but also affect Earth’s atmosphere. Wildfire plumes can reach into the stratosphere, but little is known about their climate impact. Here, we reveal observational evidence that major wildfires can have a severe impact on the atmospheric temperature structure and short-term climate in the stratosphere. Using advanced satellite observation, we find substantial warming of up to 10 K of the lower stratosphere within the wildfire plumes during their early development. The short-term climate signal in the lower stratosphere lasts several months and amounts to 1 K for the Northern American wildfires in 2017, and up to striking 3.5 K for the Australian wildfires in 2020. This is stronger than any signal from recent volcanic eruptions. Such extreme events affect atmospheric composition and climate trends, underpinning their importance for future climate.

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A comparison of atmospheric composition using the Carbon Bond and Regional Atmospheric Chemistry Mechanisms

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-13-6923-2013 ◽

2013 ◽

Vol 13 (3) ◽

pp. 6923-6969 ◽

Cited By ~ 2

Author(s):

G. Sarwar ◽

J. Godowitch ◽

B. Henderson ◽

K. Fahey ◽

G. Pouliot ◽

...

Keyword(s):

Hydrogen Peroxide ◽

Atmospheric Chemistry ◽

Production Efficiency ◽

Fine Particles ◽

Secondary Organic Aerosols ◽

Organic Aerosols ◽

Ozone Production ◽

Atmospheric Composition ◽

Organic Nitrate ◽

Carbon Bond

Abstract. We incorporate the recently developed Regional Atmospheric Chemistry Mechanism (version 2, RACM2) into the Community Multiscale Air Quality modeling system for comparison with the existing 2005 Carbon Bond mechanism with updated toluene chemistry (CB05TU). Compared to CB05TU, RACM2 enhances the domain-wide monthly mean hydroxyl radical concentrations by 46% and nitric acid by 26%. However, it reduces hydrogen peroxide by 2%, peroxyacetic acid by 94%, methyl hydrogen peroxide by 19%, peroxyacetyl nitrate by 40%, and organic nitrate by 41%. RACM2 predictions generally agree better with the observed data than the CB05TU predictions. RACM2 enhances ozone for all ambient levels leading to higher bias at low (< 60 ppbv) concentrations but improved performance at high (>70 ppbv) concentrations. The RACM2 ozone predictions are also supported by increased ozone production efficiency that agrees better with observations. Compared to CB05TU, RACM2 enhances the domain-wide monthly mean sulfate by 10%, nitrate by 6%, ammonium by 10%, anthropogenic secondary organic aerosols by 42%, biogenic secondary organic aerosols by 5%, and in-cloud secondary organic aerosols by 7%. Increased inorganic and organic aerosols with RACM2 agree better with observed data. While RACM2 enhances ozone and secondary aerosols by relatively large margins, control strategies developed for ozone or fine particles using the two mechanisms do not differ appreciably.

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New Results on the Composition of the Outer Planets and Titan

Highlights of Astronomy ◽

10.1017/s1539299600017421 ◽

2005 ◽

Vol 13 ◽

pp. 891-893

Author(s):

Thierry Fouchet

Keyword(s):

Solar System ◽

Atmospheric Chemistry ◽

Recent Progress ◽

Giant Planets ◽

Atmospheric Composition ◽

Solar System Formation ◽

Outer Planets ◽

System Formation ◽

The Impact

AbstractIn this brief summary, I present recent progress on our knowledge of the Giant Planets and Titan atmospheric composition, as well as the impact of this progress on our understanding of Solar System formation, and atmospheric chemistry.

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A method to determine the atmospheric temperature profile from in situ pressure data: Application to Titan

Planetary and Space Science ◽

10.1016/j.pss.2007.06.001 ◽

2007 ◽

Vol 55 (14) ◽

pp. 2071-2076

Author(s):

J. Leinonen ◽

T. Mäkinen ◽

A.-M. Harri

Keyword(s):

Temperature Profile ◽

Atmospheric Temperature ◽

Pressure Data ◽

Data Application ◽

Atmospheric Temperature Profile

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Complexities of communicating atmospheric composition and its impacts during the COVID-19 public health crisis in 2020

10.5194/egusphere-egu21-2195 ◽

2021 ◽

Author(s):

Claudia Volosciuk

Keyword(s):

Public Health ◽

Carbon Dioxide ◽

Greenhouse Gases ◽

Atmospheric Chemistry ◽

Stratospheric Ozone ◽

Scientific Information ◽

Atmospheric Composition ◽

Physical Parameters ◽

Health Crisis ◽

Public Health Crisis

The Global Atmosphere Watch (GAW) Programme of the World Meteorological Organization (WMO) is driven by the need to understand the variability and trends in atmospheric composition and the related physical parameters, and to assess the consequences thereof. GAW provides reliable scientific information for a broad spectrum of users, including policymakers, on topics related to atmospheric chemical composition. The programme supports international environmental and climate agreements and improves our understanding of climate change and long-range transboundary air pollution through its work on greenhouse gases, aerosols, reactive gases, atmospheric deposition, stratospheric ozone, and ultraviolet radiation. GAW provides information based on combinations of observations, data analysis and modelling activities, and supports a number of applications at the global, regional and urban scale. This implies a variety of target groups and communication vectors. Due to the complexity and interrelations of the different constituents in atmospheric chemistry and the diversity of the target audience, communication of the related issues represents a substantial challenge. Some examples are questions like &#8220;If greenhouse gas emissions are falling, why do concentrations not decrease?&#8221;, &#8220;if satellite data show pollution reductions, why can&#8217;t we say that it is due to emission reductions?&#8221; etc. &#160;To sustain the credibility and increase the visibility of GAW within the WMO community and other national/international bodies, the broader scientific and policy communities, as well as the general public, increasing efforts towards &#8220;communicating GAW&#8221; are taken. The global pandemic related to COVID-19 was the dominating topic around the globe in 2020. This required adjustments to communication efforts. Due to in-person meetings being impossible, all communication efforts required delivery and engagement through virtual formats.While emissions of carbon dioxide (among others) have decreased temporarily in 2020 due to COVID-19 restrictions, concentrations have continued to increase. This has led to confusion among many non-scientists who were surprised that the restrictions they were experiencing did not even have the effect of decreasing atmospheric concentrations of carbon dioxide. Thereby, the crisis has provided an opportunity to explain the difference between emissions and concentrations, emphasizing that carbon dioxide (and other greenhouse gases) are long-lived and remain in the atmosphere for a long time, and highlighting the importance to reach net-zero emissions. Similar confusion was related to the interpretation of the pollution levels and also required additional communication efforts.Reflections on communication of atmospheric composition in the framework of WMO/GAW, including challenges and opportunities during the public health crisis will be presented.

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