References of "Boone, C.D"
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See detailLong-term evolution and seasonal modulation above Jungfraujoch (46.5°N, 8.0°E): Optimisation of the retrieval strategy, comparison with model and independant observations
Bader, Whitney ULg; Stavrakou, T; Muller, J-F et al

in Atmospheric Measurement Techniques. Papers in Open Discussion (2014), 7

Methanol (CH3OH) is the second most abundant organic compound in the Earth's atmosphere after methane. In this work, we present the first long-term time series of methanol total, lower tropospheric and ... [more ▼]

Methanol (CH3OH) is the second most abundant organic compound in the Earth's atmosphere after methane. In this work, we present the first long-term time series of methanol total, lower tropospheric and upper tropospheric-lower stratospheric partial columns derived from the analysis of high resolution Fourier transform infrared solar spectra recorded at the Jungfraujoch station (46.5° N, 3580 m a.s.l.). The retrieval of methanol is very challenging due to strong absorptions of ozone in the region of the selected υ8 band of CH3OH. Two wide spectral intervals have been defined and adjusted in order to maximize the information content. Methanol does not exhibit a significant trend over the 1995–2012 time period, but a strong seasonal modulation characterized by maximum values and variability in June–July, minimum columns in winter and a peak-to-peak amplitude of 130%. In situ measurements performed at the Jungfraujoch and ACE-FTS occultations give similar results for the methanol seasonal variation. The total and lower tropospheric columns are also compared with IMAGESv2 model simulations. There is no systematic bias between the observations and IMAGESv2 but the model underestimates the peak-to-peak amplitude of the seasonal modulations. [less ▲]

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See detailLong-term evolution and seasonal modulation above Jungfraujoch (46.5°N, 8.0°E): Optimisation of the retrieval strategy, comparison with model and independant observations
Bader, Whitney ULg; Stavrakou, J; Muller, J-F et al

Poster (2014, May)

Methanol (CH3OH) is the second most abundant organic compound in the Earth’s atmosphere after methane. In this work, we present the first long-term time series of methanol total, lower tropospheric and ... [more ▼]

Methanol (CH3OH) is the second most abundant organic compound in the Earth’s atmosphere after methane. In this work, we present the first long-term time series of methanol total, lower tropospheric and upper tropospheric-lower stratospheric partial columns derived from the analysis of high resolution Fourier transform infrared solar spectra recorded at the Jungfraujoch station (46.5°N, 3580 m a.s.l.). The retrieval of methanol is very challenging due to strong absorptions of ozone in the region of the selected 8 band of CH3OH. Two wide spectral intervals have been defined and adjusted in order to maximize the information content. Methanol does not exhibit a significant trend over the 1995-2012 time period, but a strong seasonal modulation characterized by maximum values and variability in June-July, minimum columns in winter and a peak-to-peak amplitude of 130 %. In situ measurements performed at the Jungfraujoch and ACE-FTS occultations give similar results for the methanol seasonal variation. The total and lower tropospheric columns are also compared with IMAGESv2 model simulations. There is no systematic bias between the observations and IMAGESv2 but the model underestimates the peak-to-peak amplitude of the seasonal modulations. [less ▲]

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See detailAssessing the losses of HCFC-22 using ACE-FTS measurements
Kolonjari, F.; Walker, K.A.; Boone, C.D. et al

Scientific conference (2012, November 09)

The annual springtime minimum in stratospheric ozone over the Antarctic is primarily caused by catalytic reactions of ozone and chlorine. The Montreal Protocol on Substances that Deplete the Ozone Layer ... [more ▼]

The annual springtime minimum in stratospheric ozone over the Antarctic is primarily caused by catalytic reactions of ozone and chlorine. The Montreal Protocol on Substances that Deplete the Ozone Layer (with its subsequent amendments) restricts the emissions of ozone depleting substances. HCFC-22 has been the primary replacement for both CFC-11 and CFC-12, which has led to an increase in its atmospheric abundance. The Atmospheric Chemistry Experiment (ACE) is a mission on-board the Canadian satellite SCISAT. The primary instrument on SCISAT is a highresolution infrared Fourier Transform Spectrometer (ACE-FTS). With its wide spectral range, the ACE-FTS is capable of measuring an extensive range of gases including key CFC and HCFC species. The altitude distribution from the ACE-FTS profiles provides information that is complementary to the ground-based measurements that have been used to monitor these species. The ACE-FTS measurements compare well with surface in situ and balloon measurements. A preliminary validation of HCFC-22 using ground-based FTSs is discussed. The zonal mean distribution of HCFC-22 as observed by ACE-FTS is presented. The global distributions of HCFC-22 have been compared to the Global Modelling Initiative (GMI) Combined Stratospheric-Tropospheric Model, a chemistry and transport model. Large differences between the model and ACE-FTS measurements of HCFC-22 reveal issues with the boundary value mixing ratios. The comparison of stratospheric measurements with GMI suggest that there may be a missing loss process in the stratosphere, some issues with transport circulation and polar cap averaging in the current run, or a combination of the two processes. We propose the reaction of HCFC-22 with atomic chlorine as a potentially important loss process in the lowermost stratosphere and the lower stratosphere. [less ▲]

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See detailValidation of ACE-FTS using ground-based FTIR measurements of CFC-11, CFC-12 and HCFC-22
Kolonjari, F.; Mahieu, Emmanuel ULg; Walker, K.A. et al

Poster (2012, July 24)

Satellite data can be an effective global monitoring tool for long-lived compounds in the atmosphere. The Atmospheric Chemistry Experiment (ACE) is a mission on-board the Canadian satellite SCISAT. The ... [more ▼]

Satellite data can be an effective global monitoring tool for long-lived compounds in the atmosphere. The Atmospheric Chemistry Experiment (ACE) is a mission on-board the Canadian satellite SCISAT. The primary instrument on SCISAT is a high-resolution infrared Fourier Transform Spectrometer (ACE-FTS) which is capable of measuring a wide range of gases including key chlorofluorocarbon (CFC) and hydrochlorofluorocarbon (HCFC) species. These families of species are of interest because of their significant contribution to anthropogenic ozone depletion and to global warming. To assess the quality of data derived from satellite measurements, validation using other data sources is critical. Ground-based Fourier transform infrared spectrometers (FTIRs) are particularly useful for this purpose. In this study, five FTIRs located at four sites around the world are used to validate the CFC- 11, CFC-12, and HCFC-22 data products from ACE-FTS. These species are related; HCFC-22 was the primary replacement for CFC-11 and CFC-12 in refrigerant and propellant applications. The five FTIR instruments used in this study record solar absorption spectra at Eureka, Canada, Jungfraujoch, Switzerland, Poker Flat, USA, and Toronto, Canada. Details on the instrumentation at each site will be provided. The retrieval of CFC-11, CFC-12, and HCFC-22 are not standard products for many of these FTIRs, and as such, the initial stage of this study is to develop the retrieval of each species. Harmonization of retrieval parameters between the sites is an important step in this process. The development of these retrievals and preliminary results will be presented. Additionally, a new method for the validation of ACE-FTS measurements will be discussed. [less ▲]

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See detailMeasurements of HCFC-22 and validation update
Kolonjari, F.; Walker, K.A.; Mahieu, Emmanuel ULg et al

Scientific conference (2012, May 24)

This talk reports about global HCFC-22 measurements derived from ACE-FTS occultation observations recorded from 2004 onwards. It further provides information on the validation of ACE-FTS products for CFC ... [more ▼]

This talk reports about global HCFC-22 measurements derived from ACE-FTS occultation observations recorded from 2004 onwards. It further provides information on the validation of ACE-FTS products for CFC-11, -12 and HCFC-22 with ground-based FTIR instruments operated at four sites: Eureka, Poker Flat, Toronto and Jungfraujoch. [less ▲]

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See detailTrend of lower stratospheric methane (CH4) from Atmospheric Chemistry Experiment (ACE) and Atmospheric Trace Molecule Spectroscopy (ATMOS) measurements
Rinsland, Curtis P.; Chiou, Linda S.; Boone, C. D. et al

in Journal of Quantitative Spectroscopy & Radiative Transfer (2009), 110(13), 1066-1071

The long-term trend of methane (CH4) in the lower stratosphere has been estimated for the 1985 to 2008 time period by combining spaceborne solar occultation measurements recorded with high spectral ... [more ▼]

The long-term trend of methane (CH4) in the lower stratosphere has been estimated for the 1985 to 2008 time period by combining spaceborne solar occultation measurements recorded with high spectral resolution Fourier transform spectrometers (FTSs). Volume mixing ratio (VMR) FTS measurements from the ATMOS (Atmospheric Trace Molecule Spectroscopy) FTS covering 120-10 hPa (~16 to 30 km altitude) at 25°N-35°N latitude from 1985 and 1994 have been combined with Atmospheric Chemistry Experiment (ACE) SCISAT-1 FTS measurements covering the same latitude and pressure range from 2004 to 2008. The CH4 trend was estimated by referencing the VMRs to those measured for the long-lived constituent N2O to account for the dynamic history of the sampled airmasses. The combined measurement set shows that the VMR increase measured by ATMOS has been replaced by a leveling off during the ACE measurement time period. Our conclusion is consistent with both remote sensing and in situ measurements of the CH4 trend obtained over the same time span. [less ▲]

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See detailTime series of 12CO and 13CO at northern mid-latitudes: Determination of Partial Column and δ13C seasonal and interannual variations
Mahieu, Emmanuel ULg; Duchatelet, Pierre ULg; Rinsland, C. P. et al

in Geophysical Research Abstracts (2009, April), 11(EGU2009-10017-1),

Carbon monoxide (CO) is an important reactive gas in the troposphere. It is emitted at the ground level by fossil fuel combustion and biomass burning. Biogenic sources and oceans as well as oxidation of ... [more ▼]

Carbon monoxide (CO) is an important reactive gas in the troposphere. It is emitted at the ground level by fossil fuel combustion and biomass burning. Biogenic sources and oceans as well as oxidation of methane and nonmethane hydrocarbons complete the emissions budget. Large uncertainties still affect the relative contributions of the identified anthropogenic and natural sources. Destruction by the hydroxyl radical (OH) is the main removal process for CO in both the troposphere and the stratosphere. The resulting average tropospheric lifetime of CO varies from several weeks to a few months. Two approaches have been developed and optimized to independently retrieve abundances of 12CO and 13CO from high-resolution ground-based infrared solar spectra, using sets of carefully selected lines and the SFIT-2 (v3.91) algorithm which implements the optimal estimation method. The corresponding products will be described and characterized in terms of error budget and information content. These strategies have allowed us to produce partial column time series of 12CO and 13CO, using spectra recorded on a regular basis at the Jungfraujoch station (46.5ºN, 8.0ºE, 3580 m asl, Swiss Alps), a site of the Network for the Detection of Atmospheric Composition Change (NDACC). The seasonal and interannual changes observed in the 12CO,13CO and δ13C (13C/12C) data sets will be presented and discussed. Complementary zonal mean time series derived from occultation measurements collected by the ACE-FTS instrument onboard the Canadian SCISAT-1 platform since 2004 will also be included and analyzed, focusing on the upper troposphere-lower stratosphere region of the atmosphere. Finally, we will use GEOS-Chem 3-D chemistry transport model results to help in the interpretation of the short and long-term variations characterizing the ground-based and satellite data sets, focusing on the factors influencing the partitioning between the two CO isotopologues. [less ▲]

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See detailRetrievals of C2H2 from high-resolution FTIR solar spectra recorded at the Jungfraujoch station (46.5ºN) and comparison with ACE-FTS observations
Mahieu, Emmanuel ULg; Duchatelet, Pierre ULg; Bernath, P. F. et al

in Geophysical Research Abstracts (2008), 10

Acetylene (C2H2) is among the nonmethane hydrocarbons (NMHCs) accessible to infrared remote sensing technique. As a product of combustion and biomass burning, it is emitted at the Earth’s surface and ... [more ▼]

Acetylene (C2H2) is among the nonmethane hydrocarbons (NMHCs) accessible to infrared remote sensing technique. As a product of combustion and biomass burning, it is emitted at the Earth’s surface and further transported and mixed into the troposphere. Destruction by OH is the main removal process. The average tropospheric lifetime of C2H2 is estimated at about 1 month on the global scale; at mid-latitudes, it varies between 20 days in summer to 160 days in winter. This compound is appropriate to study tropospheric pollution and transport, and is often used in conjunction with other tracers of fires. C2H2 presents exploitable infrared absorption features near 3 and 15 μm, where weak isolated lines of the nu5 and the nu2 + nu4 + nu5 bands are found, respectively. Several of these lines can be used to retrieve abundances of C2H2 from high-resolution groundbased infrared solar spectra. Typical observations recorded at the Jungfraujoch station (46.5ºN, 8.0ºE, 3580m asl, Swiss Alps) by the NDACC (Network for the Detection of Atmospheric Composition Change)-affiliated Bruker instrument have been fitted with the OEM-SFIT-2 (v3.91) algorithm. Various approaches and combination of lines have been tested, seeking for the optimum inversion strategy. The HITRAN-2004 spectroscopic line parameters including the August 2006 updates for water vapor have been adopted in the retrievals. These approaches will be presented and critically compared, with the help of error budget and information content analyses, taking into account the impact of major interferences such as water vapor. The time series of C2H2 tropospheric column abundances above Jungfraujoch will also be presented, including determination of its long-term trend and strong seasonal cycle. The ground-based results will further be compared with zonal mean observations performed by the ACE-FTS space-based instrument since early 2004. [less ▲]

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See detailRetrievals of HCN from high-resolution FTIR solar spectra recorded at the Jungfraujoch station
Mahieu, Emmanuel ULg; Duchatelet, Pierre ULg; Demoulin, Philippe ULg et al

in Geophysical Research Abstracts (2007, April)

Recent investigations have resulted in the revision of the lifetime of hydrogen cyanide (HCN) from 2.5 years to 2-5 months, more in line with its important and well documented variability in the ... [more ▼]

Recent investigations have resulted in the revision of the lifetime of hydrogen cyanide (HCN) from 2.5 years to 2-5 months, more in line with its important and well documented variability in the troposphere. The main HCN source is believed to be biomass burning, making this species a useful tracer of fires, e.g. the widespread and intense 2004 boreal fires. Oxidation by the OH radical is among the identified sinks, while uptake by oceans has been hypothesized as the dominant sink. As shown by previous investigations, several lines from the nu3 fundamental HCN band at 3 μm can be used to retrieve information on vertical distribution of hydrogen cyanide from high-resolution FTIR solar absorption spectra. The major interfering gas in this region is water vapor. A series of typical observations recorded at the Jungfraujoch station (46.5ºN, 8.0ºE, 3580m asl, Swiss Alps) by the NDACC (Network for the Detection of Atmospheric Composition Change)-affiliated Bruker instrument have been fitted using various approaches to determine the optimum strategy to be used for HCN retrievals at that site, even under very wet conditions. The selected approach is made of 7 windows encompassing 5 HCN lines. The a priori information (HCN vertical distribution and covariance matrix) is based on ACE-FTS measurements performed over northern midlatitudes. The HITRAN-2004 spectroscopic line parameters including the August 2006 updates for water vapor have been adopted in the retrievals performed with the OEM-SFIT-2 (v3.91) algorithm. This contribution will give a full description of the adopted retrieval approach, including error budget and information content analysis. Tropospheric column time series of HCN from 1994 onwards will also be presented and discussed. [less ▲]

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See detailOn the line parameters for the X 1sigma+g (1–0) infrared quadrupolar transitions of 14N2
Goldman, Aaron; Tipping, R.H.; Ma, Q. et al

in Journal of Quantitative Spectroscopy & Radiative Transfer (2007), 103

Re-examination of the 14N2 X 1sigma+g (1–0) line parameters in the HITRAN database showed that the vibration–rotation interaction effect on the line intensities has been neglected, and that the halfwidths ... [more ▼]

Re-examination of the 14N2 X 1sigma+g (1–0) line parameters in the HITRAN database showed that the vibration–rotation interaction effect on the line intensities has been neglected, and that the halfwidths are not compatible with experimental and theoretical studies. New line parameters have been generated, which improve the consistency and accuracy in individual N2 line retrievals from atmospheric spectra. Unresolved line shape issues require further studies. [less ▲]

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See detailOptimisation of retrieval strategies using Jungfraujoch high-resolution FTIR observations for long-term trend studies and satellite validation.
Mahieu, Emmanuel ULg; Servais, Christian ULg; Duchatelet, Pierre ULg et al

in Burrows, J.; Borrell, P. (Eds.) Observing Tropospheric Trace Constituents from Space. (2007)

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