Global carbon tetrachloride distributions obtained from the Atmospheric Chemistry Experiment (ACE)

Abstract. The first study of the global atmospheric distribution of carbon tetrachloride (CCl4), as a function of altitude and latitude, was performed using solar occultation measurements obtained by the Atmospheric Chemistry Experiment (ACE) mission using Fourier transform spectroscopy. A total of 8703 profile measurements were taken in the upper troposphere and lower stratosphere between February 2004 and August 2007. The zonal distribution of carbon tetrachloride displays a slight hemispheric asymmetry and decreasing concentration with increasing altitude at all latitudes. Maximum carbon tetrachloride concentrations are situated below 10 km in altitude with VMR (Volume Mixing Ratio) values of 100–130 ppt (parts per trillion). The highest concentrations are located about the Equator and at mid-latitudes, particularly for latitudes in heavily industrialised regions (20–45° N), with values declining towards the poles. Global distributions obtained from ACE were compared with predictions from three chemistry transport models showing good agreement in terms of the vertical gradient despite an overall offset. The ACE dataset gives unique global and temporal coverage of carbon tetrachloride and its transport through the atmosphere. An estimated lifetime for carbon tetrachloride of 34±5 years was determined through correlation with CFC-11.

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ACE-FTS observations of acetonitrile in the lower stratosphere

Atmospheric Chemistry and Physics ◽

10.5194/acp-13-7405-2013 ◽

2013 ◽

Vol 13 (15) ◽

pp. 7405-7413 ◽

Cited By ~ 12

Author(s):

J. J. Harrison ◽

P. F. Bernath

Keyword(s):

Remote Sensing ◽

Atmospheric Chemistry ◽

Satellite Remote Sensing ◽

Lower Stratosphere ◽

Measurement Noise ◽

Fourier Transform Spectrometer ◽

Mixing Ratio ◽

Solar Occultation ◽

Retrieval Scheme ◽

Chemistry Experiment

Abstract. This work reports the first infrared satellite remote-sensing measurements of acetonitrile (CH3CN) in the Earth's atmosphere using solar occultation measurements made by the Atmospheric Chemistry Experiment Fourier transform spectrometer (ACE-FTS) between 2004 and 2011. The retrieval scheme uses new quantitative laboratory spectroscopic measurements of acetonitrile (Harrison and Bernath, 2012). Although individual ACE-FTS profile measurements are dominated by measurement noise, median profiles in 10° latitude bins show a steady decline in volume mixing ratio from ~150 ppt (parts per trillion) at 11.5 km to < 40 ppt at 25.5–29.5 km. These new measurements agree well with the scant available air- and balloon-borne data in the lower stratosphere. An acetonitrile stratospheric lifetime of 73 ± 20 yr has been determined.

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First carbon dioxide atmospheric vertical profiles retrieved from space observation using ACE-FTS solar occultation instrument

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-10-26473-2010 ◽

2010 ◽

Vol 10 (11) ◽

pp. 26473-26512

Author(s):

P. Y. Foucher ◽

A. Chédin ◽

R. Armante ◽

C. Boone ◽

C. Crevoisier ◽

...

Keyword(s):

Atmospheric Chemistry ◽

Atmospheric Transport ◽

Vertical Gradient ◽

Vertical Profiles ◽

Aircraft Measurements ◽

Transport Models ◽

Solar Occultation ◽

Chemistry Experiment ◽

Better Than

Abstract. Major limitations of our present knowledge of the global distribution of CO2 in the atmosphere are the uncertainty in atmospheric transport and the sparseness of in situ concentration measurements. Limb viewing spaceborne sounders such as the Atmospheric Chemistry Experiment Fourier transform spectrometer (ACE-FTS) offer a vertical resolution of a few kilometres for profiles, which is much better than currently flying or planned nadir sounding instruments can achieve. After having demonstrated the feasibility of obtaining CO2 vertical profiles in the 5–25 km altitude range with an accuracy of about 2 ppm in a previous study, we present here the results of five years of ACE-FTS observations in terms of monthly mean profiles of CO2 averaged over 10° latitude bands for northern mid-latitudes. These results are compared with in-situ aircraft measurements and with simulations from two different air transport models. Key features of the measured altitude distribution of CO2 are shown to be accurately reproduced by the ACE-FTS retrievals: variation in altitude of the seasonal cycle amplitude and extrema, seasonal change of the vertical gradient, and mean growth rate. We show that small but significant differences from model simulations could result from an over estimation of the model circulation strength during the northern hemisphere spring. Coupled with column measurements from a nadir viewing instrument, it is expected that occultation measurements will bring useful constraints to the surface carbon flux determination.

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Carbon dioxide atmospheric vertical profiles retrieved from space observation using ACE-FTS solar occultation instrument

Atmospheric Chemistry and Physics ◽

10.5194/acp-11-2455-2011 ◽

2011 ◽

Vol 11 (6) ◽

pp. 2455-2470 ◽

Cited By ~ 44

Author(s):

P. Y. Foucher ◽

A. Chédin ◽

R. Armante ◽

C. Boone ◽

C. Crevoisier ◽

...

Keyword(s):

Atmospheric Chemistry ◽

Atmospheric Transport ◽

Vertical Gradient ◽

Vertical Profiles ◽

Aircraft Measurements ◽

Transport Models ◽

Solar Occultation ◽

Chemistry Experiment ◽

Better Than

Abstract. Major limitations of our present knowledge of the global distribution of CO2 in the atmosphere are the uncertainty in atmospheric transport and the sparseness of in situ concentration measurements. Limb viewing spaceborne sounders such as the Atmospheric Chemistry Experiment Fourier transform spectrometer (ACE-FTS) offer a vertical resolution of a few kilometres for profiles, which is much better than currently flying or planned nadir sounding instruments can achieve. After having demonstrated the feasibility of obtaining CO2 vertical profiles in the 5–25 km altitude range with an accuracy of about 2 ppm in a previous study, we present here the results of five years of ACE-FTS observations in terms of monthly mean profiles of CO2 averaged over 10° latitude bands for northern mid-latitudes. These results are compared with in-situ aircraft measurements and with simulations from two different air transport models. Key features of the measured altitude distribution of CO2 are shown to be accurately reproduced by the ACE-FTS retrievals: variation in altitude of the seasonal cycle amplitude and extrema, seasonal change of the vertical gradient, and mean growth rate. We show that small but significant differences from model simulations could result from an over estimation of the model circulation strength during the northern hemisphere spring. Coupled with column measurements from a nadir viewing instrument, it is expected that occultation measurements will bring useful constraints to the surface carbon flux determination.

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Validation of water vapour profiles from the Atmospheric Chemistry Experiment (ACE)

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-8-4499-2008 ◽

2008 ◽

Vol 8 (2) ◽

pp. 4499-4559 ◽

Cited By ~ 50

Author(s):

M. R. Carleer ◽

C. D. Boone ◽

K. A. Walker ◽

P. F. Bernath ◽

K. Strong ◽

...

Keyword(s):

Water Vapour ◽

Atmospheric Chemistry ◽

Near Infrared ◽

Mixing Ratio ◽

Solar Occultation ◽

Key Species ◽

Uv Visible ◽

Ground Based Lidar ◽

Chemistry Experiment ◽

Better Than

Abstract. The Atmospheric Chemistry Experiment (ACE) mission was launched in August 2003 to sound the atmosphere by solar occultation. Water vapour (H2O), one of the most important molecules for climate and atmospheric chemistry, is one of the key species provided by the two principal instruments, the infrared Fourier Transform Spectrometer (ACE-FTS) and the MAESTRO UV-Visible spectrometer (ACE-MAESTRO). The first instrument performs measurements on several lines in the 1362–2137 cm−1 range, from which vertically resolved H2O concentration profiles are retrieved, from 7 to 90 km altitude. ACE-MAESTRO measures profiles using the water absorption band in the near infrared part of the spectrum at 926.0–969.7 nm. This paper presents a comprehensive validation of the ACE-FTS profiles. We have compared the H2O volume mixing ratio profiles with space-borne (SAGE II, HALOE, POAM III, MIPAS, SMR) observations and measurements from balloon-borne frostpoint hygrometers and a ground based lidar. We show that the ACE-FTS measurements provide H2O profiles with small retrieval uncertainties in the stratosphere (better than 5% from 15 to 70 km, gradually increasing above). The situation is unclear in the upper troposphere, due mainly to the high variability of the water vapour volume mixing ratio in this region. A new water vapour data product from the ACE-MAESTRO (Measurement of Aerosol Extinction in the Stratosphere and Troposphere Retrieved by Occultation) is also presented and initial comparisons with ACE-FTS are discussed.

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ACE-FTS observations of acetonitrile in the lower stratosphere

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-13-3323-2013 ◽

2013 ◽

Vol 13 (2) ◽

pp. 3323-3344 ◽

Cited By ~ 2

Author(s):

J. J. Harrison ◽

P. F. Bernath

Keyword(s):

Remote Sensing ◽

Atmospheric Chemistry ◽

Satellite Remote Sensing ◽

Lower Stratosphere ◽

Measurement Noise ◽

Fourier Transform Spectrometer ◽

Mixing Ratio ◽

Solar Occultation ◽

Retrieval Scheme ◽

Chemistry Experiment

Abstract. This work reports the first infrared satellite remote-sensing measurements of acetonitrile (CH3CN) in the Earth's atmosphere using solar occultation measurements made by the Atmospheric Chemistry Experiment Fourier transform spectrometer (ACE-FTS) between 2004 and 2011. The retrieval scheme uses new quantitative laboratory spectroscopic measurements of acetonitrile (Harrison and Bernath, 2012). Although individual ACE-FTS profile measurements are dominated by measurement noise, median profiles in 10° latitude bins show a steady decline in volume mixing ratio from ~150 ppt at 11.5 km to <40 ppt at 25.5–29.5 km. These new measurements agree well with the scant available air- and balloon-borne data in the lower stratosphere. An acetonitrile stratospheric lifetime of 73 ± 20 yr has been determined.

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Line-of-Sight Winds and Doppler Effect Smearing in ACE-FTS Solar Occultation Measurements

Atmosphere ◽

10.3390/atmos12060680 ◽

2021 ◽

Vol 12 (6) ◽

pp. 680

Author(s):

Chris D. Boone ◽

Johnathan Steffen ◽

Jeff Crouse ◽

Peter F. Bernath

Keyword(s):

Atmospheric Chemistry ◽

Doppler Effect ◽

Line Of Sight ◽

Measured Signal ◽

Mixing Ratio ◽

Model Calculations ◽

Doppler Shifts ◽

Solar Occultation ◽

Wide Range ◽

Wind Profiles

Line-of-sight wind profiles are derived from Doppler shifts in infrared solar occultation measurements from the Atmospheric Chemistry Experiment Fourier transform spectrometers (ACE-FTS), the primary instrument on SCISAT, a satellite-based mission for monitoring the Earth’s atmosphere. Comparisons suggest a possible eastward bias from 20 m/s to 30 m/s in ACE-FTS results above 80 km relative to some datasets but no persistent bias relative to other datasets. For instruments operating in a limb geometry, looking through a wide range of altitudes, smearing of the Doppler effect along the line of sight can impact the measured signal, particularly for saturated absorption lines. Implications of Doppler effect smearing are investigated for forward model calculations and volume mixing ratio retrievals. Effects are generally small enough to be safely ignored, except for molecules having a large overhang in their volume mixing ratio profile, such as carbon monoxide.

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Model – TCCON comparisons of column-averaged methane with a focus on the stratosphere

10.5194/amt-2016-90 ◽

2016 ◽

Author(s):

Andreas Ostler ◽

Ralf Sussmann ◽

Prabir K. Patra ◽

Sander Houweling ◽

Marko De Bruine ◽

...

Keyword(s):

Atmospheric Chemistry ◽

Transport Model ◽

Meteorological Data ◽

Michelson Interferometer ◽

Total Carbon ◽

Data Sets ◽

Transport Models ◽

Improved Model ◽

The Impact ◽

Chemistry Experiment

Abstract. The distribution of methane (CH4) in the stratosphere can be a major driver of spatial variability in the dry-air column-averaged CH4 mixing ratio (XCH4), which is being measured increasingly for the assessment of CH4 surface emissions. Chemistry-transport models (CTMs) therefore need to simulate the tropospheric and stratospheric fractional columns of XCH4 accurately for estimating surface emissions from XCH4. Simulations from three CTMs are tested against XCH4 observations from the Total Carbon Column Network (TCCON). We analyze how the model-TCCON agreement in XCH4 depends on the model representation of stratospheric CH4 distributions. Model equivalents of TCCON XCH4 are computed with stratospheric CH4 fields from both the model simulations and from satellite-based CH4 distributions from MIPAS (Michelson Interferometer for Passive Atmospheric Sounding) and MIPAS CH4 fields adjusted to ACE-FTS (Atmospheric Chemistry Experiment Fourier Transform Spectrometer) observations. In comparison to simulated model fields we find an improved model-TCCON XCH4 agreement for all models with MIPAS-based stratospheric CH4 fields. For the Atmospheric Chemistry Transport Model (ACTM) the average XCH4 bias is significantly reduced from 38.1 ppb to 13.7 ppb, whereas small improvements are found for the models TM5 (Transport Model, version 5; from 8.7 ppb to 4.3 ppb), and LMDz (Laboratoire de Météorologie Dynamique model with Zooming capability; from 6.8 ppb to 4.3 ppb), respectively. MIPAS stratospheric CH4 fields adjusted to ACE-FTS reduce the average XCH4 bias for ACTM (3.3 ppb), but increase the average XCH4 bias for TM5 (10.8 ppb) and LMDz (20.0 ppb). These findings imply that the range of satellite-based stratospheric CH4 is insufficient to resolve a possible stratospheric contribution to differences in total column CH4 between TCCON and TM5 or LMDz. Applying transport diagnostics to the models indicates that model-to-model differences in the simulation of stratospheric transport, notably the age of stratospheric air, can largely explain the inter-model spread in stratospheric CH4 and, hence, its contribution to XCH4. This implies that there is a need to better understand the impact of individual model transport components (e.g., physical parameterization, meteorological data sets, model horizontal/vertical resolution) on modeled stratospheric CH4.

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Sunset–sunrise difference in solar occultation ozone measurements (SAGE II, HALOE, and ACE–FTS) and its relationship to tidal vertical winds

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-14-16043-2014 ◽

2014 ◽

Vol 14 (11) ◽

pp. 16043-16083

Author(s):

T. Sakazaki ◽

M. Shiotani ◽

M. Suzuki ◽

D. Kinnison ◽

J. M. Zawodny ◽

...

Keyword(s):

Atmospheric Chemistry ◽

Seasonal Variations ◽

Climate Model ◽

Transport Model ◽

Stratospheric Aerosol ◽

Chemical Transport Model ◽

Latitude Range ◽

Solar Occultation ◽

Vertical Winds ◽

Chemistry Experiment

Abstract. This paper contains a comprehensive investigation of the sunset–sunrise difference (SSD; i.e., the sunset-minus-sunrise value) of the ozone mixing ratio in the latitude range of 10° S–10° N. SSD values were determined from solar occultation measurements based on data obtained from the Stratospheric Aerosol and Gas Experiment (SAGE) II, the Halogen Occultation Experiment (HALOE), and the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS). The SSD was negative at altitudes of 20–30 km (–0.1 ppmv at 25 km) and positive at 30–50 km (+0.2 ppmv at 40–45 km) for HALOE and ACE–FTS data. SAGE II data also showed a qualitatively similar result, although the SSD in the upper stratosphere was two times larger than those derived from the other datasets. On the basis of an analysis of data from the Superconducting Submillimeter Limb Emission Sounder (SMILES), and a nudged chemical-transport model (the Specified Dynamics version of the Whole Atmosphere Community Climate Model: SD–WACCM), we conclude that the SSD can be explained by diurnal variations in the ozone concentration, particularly those caused by vertical transport by the atmospheric tidal winds. All datasets showed significant seasonal variations in the SSD; the SSD in the upper stratosphere is greatest from December through February, while that in the lower stratosphere reaches a maximum twice: during the periods March–April and September–October. Based on an analysis of SD–WACCM results, we found that these seasonal variations follow those associated with the tidal vertical winds.

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Aerosol extinction profiles at 525 nm and 1020 nm derived from ACE imager data: comparisons with GOMOS, SAGE II, SAGE III, POAM III, and OSIRIS

Atmospheric Chemistry and Physics ◽

10.5194/acp-8-2027-2008 ◽

2008 ◽

Vol 8 (7) ◽

pp. 2027-2037 ◽

Cited By ~ 16

Author(s):

F. Vanhellemont ◽

C. Tetard ◽

A. Bourassa ◽

M. Fromm ◽

J. Dodion ◽

...

Keyword(s):

Atmospheric Chemistry ◽

Trace Gas ◽

Aerosol Extinction ◽

Optical Extinction ◽

Solar Occultation ◽

Comparison Results ◽

Stellar Occultation ◽

Relative Differences ◽

Atmospheric Trace Gas ◽

Chemistry Experiment

Abstract. The Canadian ACE (Atmospheric Chemistry Experiment) mission is dedicated to the retrieval of a large number of atmospheric trace gas species using the solar occultation technique in the infrared and UV/visible spectral domain. However, two additional solar disk imagers (at 525 nm and 1020 nm) were added for a number of reasons, including the retrieval of aerosol and cloud products. In this paper, we present first comparison results for these imager aerosol/cloud optical extinction coefficient profiles, with the ones derived from measurements performed by 3 solar occultation instruments (SAGE II, SAGE III, POAM III), one stellar occultation instrument (GOMOS) and one limb sounder (OSIRIS). The results indicate that the ACE imager profiles are of good quality in the upper troposphere/lower stratosphere, although the aerosol extinction for the visible channel at 525 nm contains a significant negative bias at higher altitudes, while the relative differences indicate that ACE profiles are almost always too high at 1020 nm. Both problems are probably related to ACE imager instrumental issues.

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