Anthropogenic plumes from metropolitan areas and biomass burning emissions in West Africa during DACCIWA - airborne measurements on board the DLR Falcon 20

International audienceThe DACCIWA (Dynamics-Aerosol-Chemistry-Cloud Interactions over West Africa) airborne field campaign was conducted in Southern West Africa in June/July 2016. Three European research aircraft (DLR - Falcon 20, SAFIRE - ATR 42 and BAS - Twin Otter) were deployed from Lomé/Togo and conducted research flights across Ivory Coast, Ghana, Togo and Benin. On board the DLR Falcon O3, SO2, CO, NO2 and aerosol fine mode particle number concentration and size distribution were measured during a total of 12 scientific flights. Until now only few airborne trace gas measurements were conducted in Southern West Africa. Therefore, this field experiment contributes to the knowledge of the chemical composition of the lower troposphere between 0 - 4 km. During several flights pollution plumes from major population centers - Lomé/Togo, Accra/Ghana, Kumasi/Ghana, and Abidjan/Ivory Coast - were probed below, inside and above clouds. Here, enhanced trace gas and particle concentrations were observed. In addition, plumes from biomass burning emissions were detected which were transported to West Africa. The composition of the pollution plumes are presented as well as transport pathways using HYSPLIT (Hybrid Single-Particle Lagrangian Integrated Trajectories) trajectory calculations. Ozone enhancements in the biomass burning pollution plumes of up to 70 ppb were observed compared to background concentrations of 30-40 ppb. Furthermore, HYSPLIT atmospheric dispersion simulations are used to estimate anthropogenic SO2 city emissions

Anthropogenic plumes from metropolitan areas and biomass burning emissions in West Africa during DACCIWA - airborne measurements on board the DLR Falcon 20

International audienceThe DACCIWA (Dynamics-Aerosol-Chemistry-Cloud Interactions over West Africa) airborne field campaign was conducted in Southern West Africa in June/July 2016. Three European research aircraft (DLR - Falcon 20, SAFIRE - ATR 42 and BAS - Twin Otter) were deployed from Lomé/Togo and conducted research flights across Ivory Coast, Ghana, Togo and Benin. On board the DLR Falcon O3, SO2, CO, NO2 and aerosol fine mode particle number concentration and size distribution were measured during a total of 12 scientific flights. Until now only few airborne trace gas measurements were conducted in Southern West Africa. Therefore, this field experiment contributes to the knowledge of the chemical composition of the lower troposphere between 0 - 4 km. During several flights pollution plumes from major population centers - Lomé/Togo, Accra/Ghana, Kumasi/Ghana, and Abidjan/Ivory Coast - were probed below, inside and above clouds. Here, enhanced trace gas and particle concentrations were observed. In addition, plumes from biomass burning emissions were detected which were transported to West Africa. The composition of the pollution plumes are presented as well as transport pathways using HYSPLIT (Hybrid Single-Particle Lagrangian Integrated Trajectories) trajectory calculations. Ozone enhancements in the biomass burning pollution plumes of up to 70 ppb were observed compared to background concentrations of 30-40 ppb. Furthermore, HYSPLIT atmospheric dispersion simulations are used to estimate anthropogenic SO2 city emissions

SPECIES: a multi-channel infrared laser spectrometer with optical-feedback cavity-enhanced absorption for in-situ balloon-borne and airborne measurements

International audienceOver the last decades, thanks to significant technological advances in measurement techniques, our understanding of the chemistry and dynamics of the upper troposphere and stratosphere has progressed significantly. However some key questions remain unsolved and new ones arise in the climate change context. The full recovery of the ozone layer in a period of halogens decrease and N2O increase (and the delay of this recovery), the impact of the climate change on the stratosphere and the role of this one as a feedback are very uncertain. To address these challenges, one needs instruments able to measure a wide variety of trace gases simultaneously with a wide vertical range, combined to chemical and dynamical modelling at different scales. LPC2E and LIPHY laboratories are developing a new balloon-borne and airborne instrument: SPECIES (SPECtromètre Infrarouge à lasErs in Situ). Based on the Optical Feedback Cavity Enhanced Spectroscopy (OF-CEAS) technique combined with mid-infrared quantum or interband cascade lasers (QCLs or ICLs), this instrument will offer unprecedented performances in terms of vertical extent of the measurements, from ground to the middle stratosphere, and number of molecular species simultaneously measured with sub-ppb detection limits (e.g. O3, N2O, HNO3, NH3, H2O2, HCl, HOCl,CF2O, CH4, CH2O, CO, CO2, OCS, SO2). Due to high frequency measurement (>0.5 Hz) it shall offer very high spatial resolution (a few meters)

SPECIES: a multi-channel infrared laser spectrometer with optical-feedback cavity-enhanced absorption for in-situ balloon-borne and airborne measurements

International audienceOver the last decades, thanks to significant technological advances in measurement techniques, our understanding of the chemistry and dynamics of the upper troposphere and stratosphere has progressed significantly. However some key questions remain unsolved and new ones arise in the climate change context. The full recovery of the ozone layer in a period of halogens decrease and N2O increase (and the delay of this recovery), the impact of the climate change on the stratosphere and the role of this one as a feedback are very uncertain. To address these challenges, one needs instruments able to measure a wide variety of trace gases simultaneously with a wide vertical range, combined to chemical and dynamical modelling at different scales. LPC2E and LIPHY laboratories are developing a new balloon-borne and airborne instrument: SPECIES (SPECtromètre Infrarouge à lasErs in Situ). Based on the Optical Feedback Cavity Enhanced Spectroscopy (OF-CEAS) technique combined with mid-infrared quantum or interband cascade lasers (QCLs or ICLs), this instrument will offer unprecedented performances in terms of vertical extent of the measurements, from ground to the middle stratosphere, and number of molecular species simultaneously measured with sub-ppb detection limits (e.g. O3, N2O, HNO3, NH3, H2O2, HCl, HOCl,CF2O, CH4, CH2O, CO, CO2, OCS, SO2). Due to high frequency measurement (>0.5 Hz) it shall offer very high spatial resolution (a few meters)

SPECIES: a balloon-borne and airborne instrument coupling infrared lasers with Optical Feedback Cavity Enhanced Absorption Spectroscopy technique for atmospheric in-situ trace-gas measurements

International audienceThe balloon-borne and airborne instrument SPECIES (SPECtromètre Infrarouge à lasErs in Situ) recently built in our laboratory will be described. This is a mid-infrared absorption spectrometer, including four channels by coupling Interband or Quantum Cascade Lasers (ICLs or QCLs) to Optical-Feedback Cavity-Enhanced Absorption Spectroscopy (OF-CEAS). Using cavities of 50 cm length, this leads to very high resolution ( 5 km) and thus, low detection limits for the trace gases to be measured. It can contribute to the detailed description and understanding of the functioning of the free troposphere and stratosphere in terms of composition, chemical reactivity and circulation of air masses by carrying out fast ( 4 days). High accuracies are obtained when calibration in flight, or at ground before and after the flight, is performed against standards. In addition to providing reference measurements for calibration/validation of space missions, these performances can lead to in-depth characterization of particular atmospheric processes

SPECIES: a multi-channel infrared laser spectrometer with optical-feedback cavity-enhanced absorption for in-situ balloon-borne and airborne measurements

International audienceOver the last decades, thanks to significant technological advances in measurement techniques, our understanding of the chemistry and dynamics of the upper troposphere and stratosphere has progressed significantly. However some key questions remain unsolved and new ones arise in the climate change context. The full recovery of the ozone layer in a period of halogens decrease and N2O increase (and the delay of this recovery), the impact of the climate change on the stratosphere and the role of this one as a feedback are very uncertain. To address these challenges, one needs instruments able to measure a wide variety of trace gases simultaneously with a wide vertical range, combined to chemical and dynamical modelling at different scales. LPC2E and LIPHY laboratories are developing a new balloon-borne and airborne instrument: SPECIES (SPECtromètre Infrarouge à lasErs in Situ). Based on the Optical Feedback Cavity Enhanced Spectroscopy (OF-CEAS) technique combined with mid-infrared quantum or interband cascade lasers (QCLs or ICLs), this instrument will offer unprecedented performances in terms of vertical extent of the measurements, from ground to the middle stratosphere, and number of molecular species simultaneously measured with sub-ppb detection limits (e.g. O3, N2O, HNO3, NH3, H2O2, HCl, HOCl,CF2O, CH4, CH2O, CO, CO2, OCS, SO2). Due to high frequency measurement (>0.5 Hz) it shall offer very high spatial resolution (a few meters)

On the use of hyperpectral infrared imagers for studying volcano plumes: IMAGETNA campaign

International audienceKnowledge of the composition and the spatial evolution of volcanic plumes provides insights to processes occurring in the Earth's interior. On the other hand, quantification of gaseous emission fluxes is also a fundamental task in the framework of climate change in order to refine the contribution of natural emissions. UV cameras allow us to image volcanic plumes and evaluate SO2 fluxes, although can be subject to uncertainties in the retrieval. Another technique of imaging is now available in the infra-red. Such infrared hyperspectral imager (pixel-by-pixel spectra) might represent a major step forward in volcanology due to its potential to allow SO2 flux measurements during the night and gives access to additional relevant species but has to be tested and validated as a first step. In June 2015 a campaign of measurements - IMAGETNA - was performed at Mt Etna (Pizzi Deneri Volcano Observatory) with the intent to explore the application of these techniques for volcanic gas measurements all together. Over five days the volcanic plume was remotely observed simultaneously by employing three different hyperspectral imagers (commercial and under development), FTIR instrument, UV LWIR cameras, and radiometer. Results gathered from the different instruments will be compared and by performing sensitivity tests on the retrieval codes the reliability of applying these techniques to volcanic gas observations will be evaluated. The campaign, the characteristics of the different instruments involved as well as the instrumental deployment strategy will be presented. Direct comparisons of spectral radiance in the infrared obtained by the different infrared instruments will be shown for several selected fields of view. First results for SO2 from UV and in the infrared imagers will be shown, as well as first investigations on other species detected in the infrared

On the use of hyperpectral infrared imagers for studying volcano plumes: IMAGETNA campaign

International audienceKnowledge of the composition and the spatial evolution of volcanic plumes provides insights to processes occurring in the Earth's interior. On the other hand, quantification of gaseous emission fluxes is also a fundamental task in the framework of climate change in order to refine the contribution of natural emissions. UV cameras allow us to image volcanic plumes and evaluate SO2 fluxes, although can be subject to uncertainties in the retrieval. Another technique of imaging is now available in the infra-red. Such infrared hyperspectral imager (pixel-by-pixel spectra) might represent a major step forward in volcanology due to its potential to allow SO2 flux measurements during the night and gives access to additional relevant species but has to be tested and validated as a first step. In June 2015 a campaign of measurements - IMAGETNA - was performed at Mt Etna (Pizzi Deneri Volcano Observatory) with the intent to explore the application of these techniques for volcanic gas measurements all together. Over five days the volcanic plume was remotely observed simultaneously by employing three different hyperspectral imagers (commercial and under development), FTIR instrument, UV LWIR cameras, and radiometer. Results gathered from the different instruments will be compared and by performing sensitivity tests on the retrieval codes the reliability of applying these techniques to volcanic gas observations will be evaluated. The campaign, the characteristics of the different instruments involved as well as the instrumental deployment strategy will be presented. Direct comparisons of spectral radiance in the infrared obtained by the different infrared instruments will be shown for several selected fields of view. First results for SO2 from UV and in the infrared imagers will be shown, as well as first investigations on other species detected in the infrared

On the use of hyperpectral infrared imagers for studying volcano plumes: IMAGETNA campaign

International audienceKnowledge of the composition and the spatial evolution of volcanic plumes provides insights to processes occurring in the Earth's interior. On the other hand, quantification of gaseous emission fluxes is also a fundamental task in the framework of climate change in order to refine the contribution of natural emissions. UV cameras allow us to image volcanic plumes and evaluate SO2 fluxes, although can be subject to uncertainties in the retrieval. Another technique of imaging is now available in the infra-red. Such infrared hyperspectral imager (pixel-by-pixel spectra) might represent a major step forward in volcanology due to its potential to allow SO2 flux measurements during the night and gives access to additional relevant species but has to be tested and validated as a first step. In June 2015 a campaign of measurements - IMAGETNA - was performed at Mt Etna (Pizzi Deneri Volcano Observatory) with the intent to explore the application of these techniques for volcanic gas measurements all together. Over five days the volcanic plume was remotely observed simultaneously by employing three different hyperspectral imagers (commercial and under development), FTIR instrument, UV LWIR cameras, and radiometer. Results gathered from the different instruments will be compared and by performing sensitivity tests on the retrieval codes the reliability of applying these techniques to volcanic gas observations will be evaluated. The campaign, the characteristics of the different instruments involved as well as the instrumental deployment strategy will be presented. Direct comparisons of spectral radiance in the infrared obtained by the different infrared instruments will be shown for several selected fields of view. First results for SO2 from UV and in the infrared imagers will be shown, as well as first investigations on other species detected in the infrared