institut d’astrophysique et de géophysique, université de ...¨ge_servais_cf.pdf · project...

International Foundation HFSJG Activity Report 2014

11

Name of research institute or organization: Institut d’Astrophysique et de Géophysique, Université de Liège Title of project: High resolution, solar infrared Fourier Transform spectrometry. Application to the study of the Earth atmosphere Part of this programme: NDACC, GAW, NORS Project leader and team: Christian Servais, project leader Whitney Bader, Benoît Bovy, Philippe Demoulin, Olivier Flock, Bruno Franco, Bernard Lejeune, Emmanuel Mahieu, Ginette Roland (em.), Vincent Van De Weerdt, Diane Zander, Rodolphe Zander (em.) Project description: The team’s objectives are essentially twofold: (i) improve the performance of the instrumentation and perform the observations, (ii) analyse the spectra in order to produce high-level geophysical parameters and valorize them.

Over the last years, significant efforts have been invested in the development and implementation of a reliable system allowing to remotely and safely control the whole instrumentation, among which the spectrometer itself, the cooling of the detectors, the suntracker and its protective lid. Nevertheless, local support from the custodians remains critical, e.g. to remove heavy snow from the lid, to fill in the LN2 Dewar flask. The remote control system led to a significant improvement of the observation statistics, taking advantage of most days with clear-sky conditions. In 2014, more than 1500 high resolution infrared solar spectra have been recorded on 92 days, including 32 days from a remote location.

Analysis of our spectra allows us to determine the abundance of an increasing number (currently more than 25) of constituents of the Earth’s atmosphere, playing a role in ozone depletion, climate change or affecting the air quality. Numerous target species are therefore relevant to the Montreal Protocol on substances that deplete stratospheric ozone (e.g. CFC-11, -12, HCFC-22, CCl4, HCl, ClONO2) and/or to the Kyoto Protocol (e.g. CO2, CH4, N2O, CF4, SF6). We present hereafter a selection of key results derived in 2014 from the scientific exploitation of our observational database.

Ethane (C2H6) Ethane is the most abundant non-methane hydrocarbon in the Earth’s atmosphere and has a large impact on tropospheric composition and air quality. Using an optimized retrieval strategy (Franco et al., submitted, 2014), we have produced a 20-year long-term time series of C2H6 abundance above Jungfraujoch from 1994 onwards (see Figure 1). After a 1994 – 2008 decrease of the C2H6 amounts, which is very consistent with prior major studies and with our understanding of global C2H6 emissions, trend analysis using a bootstrap resampling tool reveals a C2H6 upturn and statistically-significant sharp burden increase from 2009 onwards.

We hypothesize that this observed recent increase in C2H6 could affect the whole Northern Hemisphere and may be related to the recent massive growth in the exploitation of shale gas and tight oil reservoirs. This hypothesis is supported by measurements derived from solar occultation observations performed since 2004 by the Atmospheric Chemistry Experiment – Fourier Transform Spectrometer (ACE-FTS) instrument. Indeed, the recent trend characterizing the ACE-FTS version 3.5 partial columns above North America is consistent in magnitude and sign with the one derived from the FTIR measurements at Jungfraujoch.


12

Investigating both the cause and impact on air quality of the C2H6 upturn should be a high priority for the atmospheric chemistry community.

Figure 1. FTIR time series of daily-averaged C2H6 total columns and associated 1-σ standard deviation bars above Jungfraujoch from September 1994 to August 2014. The functions fitted to all available daily means (including seasonal modulation and trend component) over the 1994–2008 and 2009–2014 time periods using a bootstrap resampling tool are shown in blue. The green and red solid lines correspond to the linear trend components of these fitting functions. Ethylene (C2H4) Ethylene (C2H4) is a tropospheric pollutant source of formaldehyde and formic acid. Its retrieval from infrared spectra is very challenging, particularly from a remote and high altitude site like the Jungfraujoch. Nevertheless, a strategy has been set up and optimized, using a microwindow encompassing several lines of the ν7 band of ethylene and ranging from 949 to 952 cm-1. Panel A of Figure 2 shows a simulation of the individual absorptions of the target (multiplied by 10 for visibility purpose) and interfering species, for a solar zenith angle of 80º. Using a subset of Jungfraujoch solar spectra, we evaluated the impact of new line parameters (line intensities and self-broadening coefficients) for C2H4, based on laboratory measurements performed at the Université Libre de Bruxelles. We noted a systematic reduction of the total columns by 4.1% when compared to results using HITRAN 2012, but no effect on the fitting residuals. More information is available in Vander Auwera et al. (2014).

Hydrogen chloride (HCl) Hydrogen chloride is the most abundant reservoir of chlorine in the stratosphere, in the absence of chlorine activation. It is therefore an excellent indicator of the success of the Montreal Protocol, an international treaty which banned the CFCs and other important chlorine-bearing organic source gases in the 1980s, on substances that deplete ozone. Time series of HCl monitored at stations of the Network for the Detection of Atmospheric Composition Change are therefore scrutinized to characterize the evolution of the HCl loading in the Earth’s atmosphere, and successive studies have reported about a stabilization of HCl in the atmosphere around the mid-1990s and of its subsequent decrease (Mahieu et al., 2014b and references therein).


13

Figure 2. Simulation of the main absorptions in the microwindow used for the retrieval of ethylene from the Jungfraujoch (panel A). Panel B shows the mean fitting residuals when retrieving C2H4 (see colour key) or assuming no ethylene in the atmosphere (Vander Auwera et al., 2014).

However, a recent and unexpected upturn in HCl has been detected, using Jungfraujoch and satellite data. This observation stimulated a study involving several NDACC stations, a merged satellite data set (GOZCARDS, combining data from HALOE, ACE-FTS and Aura/MLS) and two state-of-the-art chemistry transport models (KASIMA and SLIMCAT) to characterize this recent upturn and identify its cause.

The paper reporting about these investigations has recently been published in Nature (Mahieu et al., 2014b). Figure 3 shows the recent evolutions of HCl (red curve) at three NDACC sites, Ny-Ålesund (79ºN), Jungfraujoch (47ºN) and Lauder (45ºS). It can be seen that after a period of decrease, the HCl started to increase again from July 2007 onwards in the Northern Hemisphere. In contrast, a continuous decrease is observed for Lauder in the Southern Hemisphere. A good agreement is found with SLIMCAT model simulations (green curve) using ERA-Interim meteorology and surface source gas mixing ratios from the WMO A1 scenario. In contrast, the SLIMCAT run S2000 (light green curve) using 6-hourly winds of 2000 from 2000 onwards does not produce the HCl increase. Hence atmospheric circulation changes and variability are responsible for the HCl increase. It was further possible to identify that a slowing of the Northern Hemisphere atmospheric circulation which occurred over a few years after 2005-2006 caused the recent rise in HCl. In the Southern Hemisphere, a rather constant speedup was diagnosed.


14

Figure 3. Recent evolution of HCl at three NDACC stations (Mahieu et al., doi: 10.1038/nature13857, 2014b). The main conclusion of this study is that unidentified or unreported emissions of chlorinated source gases are not responsible for the recent rise in HCl in the Northern Hemisphere stratosphere. Hence, the Montreal Protocol is well on track and will lead to the reduction of the chlorine loading in the stratosphere, allowing ozone recovery in the next decades. Key words: Earth atmosphere, climate change, greenhouse gases, ozone layer, long-term monitoring, infrared spectroscopy, atmospheric circulation Internet data bases: General website: http://girpas.astro.ulg.ac.be Consolidated geophysical data are available from NDACC: ftp://ftp.cpc.ncep.noaa.gov/ndacc/station/jungfrau/ Rapid delivery data are also available from: ftp://ftp.cpc.ncep.noaa.gov/ndacc/RD/jungfrau/hdf/ftir Collaborating partners/networks: Main collaborations: BIRA-IASB (Institut d’Aéronomie Spatiale de Belgique) NDACC (Network for the Detection of Atmospheric Composition Change; http://www.ndacc.org) GAW-CH / partners of the EC-project NORS (http://nors.aeronomie.be) / ACE science team NASA JPL / EMPA / University of Leeds / IMK (Forschungszentrum Karlsruhe) satellite experiments: IASI, AURA, OMI, ENVISAT / … Scientific publications and public outreach 2014: The complete list of GIRPAS publications can be found at http://girpas.astro.ulg.ac.be/girpas/publi03e.htm and http://girpas.astro.ulg.ac.be/girpas/Communic.htm


15

Refereed journal articles and their internet access Bader, W., T. Stavrakou, J.-F. Muller, S. Reimann, C.D. Boone, J.J. Harrison, O. Flock, B. Bovy, B. Franco, B. Lejeune, C. Servais, and E. Mahieu, Long-term evolution and seasonal modulation of methanol above Jungfraujoch (46.5° N, 8.0° E): optimisation of the retrieval strategy, comparison with model simulations and independent observations, Atmospheric Measurement Techniques, 7, 11, 3861–3872, doi: 10.5194/amt-7-3861-2014, 2014. http://hdl.handle.net/2268/168055 Barthlott, S., M. Schneider, F. Hase, A. Wiegele, E. Christner, Y. González, T. Blumenstock, S. Dohe, O.E. García, E. Sepúlveda, K. Strong, J. Mendonca, D. Weaver, M. Palm, N.M. Deutscher, T. Warneke, J. Notholt, B. Lejeune, E. Mahieu, N. Jones, D.W.T. Griffith, V.A. Velazco, D. Smale, J. Robinson, R. Kivi, P. Heikkinen, and U. Raffalski, Using XCO2 retrievals for assessing the long-term consistency of NDACC/FTIR data sets, Atmospheric Measurement Techniques Discussions, 7, 10, 10513–10558, doi: 10.5194/amtd-7-10513-2014, 2014. http://hdl.handle.net/2268/173087 Franco, B., F. Hendrick, M. Van Roozendael, J.-F. Müller, T. Stavrakou, E.A. Marais, B. Bovy, W. Bader, C. Fayt, C. Hermans, B. Lejeune, G. Pinardi, C. Servais, and E. Mahieu, Retrievals of formaldehyde from ground-based FTIR and MAX-DOAS observations at the Jungfraujoch station and comparisons with GEOS-Chem and IMAGES model simulations, Atmospheric Measurement Techniques Discussions, 7, 10, 10715–10770, doi: 10.5194/amtd-7-10715-2014, 2014. http://hdl.handle.net/2268/154767 Mahieu, E., M.P. Chipperfield, J. Notholt, T. Reddmann, J. Anderson, P.F. Bernath, T. Blumenstock, M.T. Coffey, S.S. Dhomse, W. Feng, B. Franco, L. Froidevaux, D.W.T. Griffith, J.W. Hannigan, F. Hase, R. Hossaini, N.B. Jones, I. Morino, I. Murata, H. Nakajima, M. Palm, C. Paton-Walsh, J.M. Russell, M. Schneider, C. Servais, D. Smale, and K.A. Walker, Recent Northern Hemisphere stratospheric HCl increase due to atmospheric circulation changes, Nature, 515 ,7525, 104–107, doi: 10.1038/nature13857, 2014a. http://dx.doi.org/10.1038/nature13857 Mahieu, E., R. Zander, G.C. Toon, M.K. Vollmer, S. Reimann, J. Mühle, W. Bader, B. Bovy, B. Lejeune, C. Servais, P. Demoulin, G. Roland, P.F. Bernath, C.D. Boone, K.A. Walker, and P. Duchatelet, Spectrometric monitoring of atmospheric carbon tetrafluoride (CF4) above the Jungfraujoch station since 1989: evidence of continued increase but at a slowing rate, Atmospheric Measurement Techniques, 7, 1, 333–344, doi: 10.5194/amt-7-333-2014, 2014b. http://hdl.handle.net/2268/154767 Scheepmaker, R. A., C. Frankenberg, N.M. Deutscher, M. Schneider, S. Barthlott, T. Blumenstock, O.E. Garcia, F. Hase, N. Jones, E. Mahieu, J. Notholt, V. Velazco, J. Landgraf, and I. Aben, Validation of SCIAMACHY HDO/H2O measurements using the TCCON and NDACC-MUSICA networks, Atmospheric Measurement Techniques Discussions, 7, 11, 11799–11851, doi: 10.5194/amtd-7-11799-2014, 2014. http://hdl.handle.net/2268/174484 Van Geffen, J. H. G. M., K.F. Boersma, M. Van Roozendael, F. Hendrick, E. Mahieu, I. De Smedt, M. Sneep, and J.P. Veefkind, Improved spectral fitting of nitrogen dioxide from OMI in the 405–465 nm window, Atmospheric Measurement Techniques Discussions, 7, 10, 10619–10671, doi: 10.5194/amtd-7-10619-2014, 2014. http://hdl.handle.net/2268/173258 Vander Auwera, J., A. Fayt, M. Tudorie, M. Rotger, V. Boudon, B. Franco, and E. Mahieu, Self-broadening coefficients and improved line intensities for the ν7 band of ethylene near 10.5 μm, and impact on ethylene retrievals from Jungfraujoch solar spectra, Journal of Quantitative Spectroscopy and Radiative Transfer, 148, 177–185, doi: 10.1016/j.jqsrt.2014.07.003, 2014. http://hdl.handle.net/2268/169909 Vigouroux, C., T. Blumenstock, M. Coffey, Q. Errera, O. García, N.B. Jones, J.W. Hannigan, F. Hase, B. Liley, E. Mahieu, J. Mellqvist, J. Notholt, M. Palm, G. Persson, M. Schneider, C. Servais, D. Smale, L. Thölix, and M. De Mazière, Trends of ozone total columns and vertical distribution from FTIR observations at 8 NDACC stations around the globe, Atmospheric Chemistry and Physics Discussions, 14, 17, 24623–24666, doi: 10.5194/acpd-14-24623-2014, 2014. http://hdl.handle.net/2268/172277

Conference papers Bader, W., B. Bovy, K. Wecht, F. Hase, and E. Mahieu, Seeking for causes of recent methane increase: comparison between GEOS-Chem tagged simulations and FTIR column measurements above Jungfraujoch, poster presentation at the joint NDACC-IRWG and TCCON meeting, Bad Sulza, Germany, May 12-16, 2014. http://orbi.ulg.ac.be/handle/2268/167947 Bader, W., T. Stavrakou, J.-F. Müller, S. Reimann, C.D. Boone, J.J. Harrison, O. Flock, B. Bovy, B. Franco, B. Lejeune, C. Servais, and E. Mahieu, Long-term evolution and seasonal modulation of methanol above Jungfraujoch (46.5ºN, 8.0ºE): Optimisation of the retrieval strategy, comparison with model simulations and independent observations, poster presentation at the joint NDACC-IRWG and TCCON meeting, Bad Sulza, Germany, May 12-16, 2014. http://orbi.ulg.ac.be/handle/2268/167946


16

Chipperfield, M. P., E. Mahieu, J. Notholt, and the Stratospheric HCl Team, Recent Increases in Stratospheric HCl: Stratospheric Dynamics versus the Montreal Protocol, oral presentation at the “EGU 2014 General Assembly”, Vienna, Austria, April 27 – May 2, 2014. http://hdl.handle.net/2268/173839 Franco, B., F. Hendrick, M. Van Roozendael, J.-F. Müller, T. Stavrakou, E. Marais, B. Bovy, W. Bader, C. Fayt, C. Hermans, B. Lejeune, G. Pinardi, C. Servais, and E. Mahieu, Retrievals of formaldehyde from ground-based FTIR and MAX-DOAS observations at the Jungfraujoch station and comparisons with GEOS-Chem and IMAGES model simulations, oral presentation at the “NORS/NDACC/GAW workshop”, Brussels, Belgium, November 5-7, 2014. http://orbi.ulg.ac.be/handle/2268/174023 Hendrick, F., C. Fayt, B. Franco, C. Gielen, C. Hermans, E. Mahieu, J.-F. Müller, G. Pinardi, T. Stavrakou, and M. Van Roozendael, Retrieval of HCHO from MAX-DOAS measurements at the high-altitude station of Jungfraujoch (46.5°N, 8.0°E), oral presentation at the “EGU 2014 General Assembly”, Vienna, Austria, April 27 – May 2, 2014. http://hdl.handle.net/2268/166588 Mahieu, E., Recent results from long-term FTIR monitoring activities at Jungfraujoch: some unexpected trends and new target species, oral presentation at the meeting “Spawning the atmosphere measurements of Jungfraujoch, Schneefernerhaus and Sonnblick”, Bern, Switzerland, January 22-23, 2014. http://hdl.handle.net/2268/162780 Mahieu, E., M.P. Chipperfield, J. Notholt, T. Reddmann, J. Anderson, P.F. Bernath, T. Blumenstock, M.T. Coffey, S.S. Dhomse, W. Feng, B. Franco, L. Froidevaux, D.W.T. Griffith, J.W. Hannigan, F. Hase, R. Hossaini, N.B. Jones, I. Morino, I. Murata, H. Nakajima, M. Palm, C. Paton-Walsh, J.M. Russell, M. Schneider, C. Servais, D. Smale, and K.A. Walker, Increase in northern hemisphere stratospheric hydrogen chloride over recent years, poster presentation at the “Reklim Conference 2014: Our Climate – Our Future”, Berlin, Germany, October 6-9, 2014. Petri, C., T. Blumenstock, F. Hase, M. De Mazière, B. Langerock, E. Mahieu, B. Franco, and J. Notholt, Carbon monoxide retrieved from ground-based FTIR remote-sensing in the mid- and near infrared spectral region, oral presentation at the joint NDACC-IRWG and TCCON meeting, Bad Sulza, Germany, May 14, 2014. Schibig, M., M. Leuenberger, P. Nyfeler, and E. Mahieu, Comparison of continuous background in-situ and column integrated CO2 observations at Jungfraujoch with an urban site in the city of Bern, poster presentation at the “EGU 2014 General Assembly”, Vienna, Austria, April 27 – May 2, 2014. http://hdl.handle.net/2268/166589 Vander Auwera, J., A. Fayt, M. Tudorie, M. Rotger, V. Boudon, B. Franco, and E. Mahieu, Self broadening coefficients and improved line intensities for the ν7 band of ethylene near 10.5 µm, and impact on ethylene retrievals from Jungfraujoch spectra, poster presentation at the PAMO-JSM meeting, Reims, France, July 7-10, 2014. http://hdl.handle.net/2268/170533 Vander Auwera, J., A. Fayt, M. Tudorie, M. Rotger, V. Boudon, B. Franco, and E. Mahieu, Self broadening coefficients and improved line intensities for the ν7 band of ethylene near 10.5 µm, and impact on ethylene retrievals from Jungfraujoch spectra, poster presentation at the 23rd International Conference on High Resolution Molecular Spectroscopy, Bologna, Italy, September 2-6, 2014. http://hdl.handle.net/2268/172155

Magazine and Newspapers articles “Is there a new threat to the ozone layer?”, Reflexions, November 5, 2014. “Ozone-destroying chemical making comeback, scientists find”, The Globe and Mail, November 5, 2014. “Increase in ozone-destroying substances, but Montreal Protocol on track”, Science Daily, November 5, 2014. “Circulation blips caused rise in reservoir for ozone destroyer”, Environmental Research Web, November 6, 2014. “Nature: Konzentration ozonzerstörender Stoffe steigt wieder an”, Ad Hoc News, November 6, 2014. “Research reveals recent increase in ozone-depleting atmospheric hydrogen chloride”, AzoCleantech, November 7, 2014.

Radio and television “Substance dangereuse pour l’ozone”, TV interview with Emmanuel Mahieu, ULg, La Une RTBF, “Le 15 minutes”, August 21, 2014. “Le CCl4 ne diminue pas comme prévu”, radio interview with Emmanuel Mahieu, ULg, La Première, “Matin Première”, August 22, 2014. “Ozonschicht Folgen früherer Sünden”, radio interview with Emmanuel Mahieu, ULg, Deutschlandfunk, Forschung Aktuell, November 6, 2014.


17

Address: Institut d’Astrophysique et de Géophysique Université de Liège Allée du 6 août, 17 – Bâtiment B5a B-4000 Sart Tilman (Liège, Belgique) Contacts: Whitney Bader +32 4 366 9789 [email protected] Benoît Bovy +32 4 366 9789 [email protected] Olivier Flock +32 4 366 9790 [email protected] Bruno Franco +32 4 366 9785 [email protected] Bernard Lejeune +32 4 366 9788 [email protected] Emmanuel Mahieu +32 4 366 9786 [email protected] Ginette Roland +32 4 342 2594 [email protected] Christian Servais +32 4 366 9784 [email protected] Vincent Van De Weerdt +32 4 366 9767 [email protected] Diane Zander +32 4 366 9770 [email protected] Rodolphe Zander +32 4 366 9786 [email protected] Fax: +32 4 366 9747 URL: http://girpas.astro.ulg.ac.be

institut d’astrophysique et de géophysique, université de ...¨ge_servais_cf.pdf · project...

Documents