Tropospheric CH4 signals as observed by NDACC FTIR at global
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TitleTropospheric CH4 signals as observed by NDACC FTIR at globally distributed sites and comparison to GAW surface in situ measurementsAbstractWe present lower/middle tropospheric column-averaged CH4 mole fraction time series measured by nine globally distributed ground-based FTIR (Fourier transform infrared) remote sensing experiments of the Network for the Detection of Atmospheric Composition Change (NDACC). We show that these data are well representative of the tropospheric regional-scale CH4 signal, largely independent of the local surface small-scale signals, and only weakly dependent on upper tropospheric/lower stratospheric (UTLS) CH4 variations. In order to achieve the weak dependency on the UTLS, we use an a posteriori correction method. We estimate a typical precision for daily mean values of about 0.5% and a systematic error of about 2.5%. The theoretical assessments are complemented by an extensive empirical study. For this purpose, we use surface in situ CH4 measurements made within the Global Atmosphere Watch (GAW) network and compare them to the remote sensing data. We briefly discuss different filter methods for removing the local small-scale signals from the surface in situ data sets in order to obtain the in situ regional-scale signals. We find good agreement between the filtered in situ and the remote sensing data. The agreement is consistent for a variety of timescales that are interesting for CH4 source/sink research: day-to-day, monthly, and inter-annual. The comparison study confirms our theoretical estimations and proves that the NDACC FTIR measurements can provide valuable data for investigating the cycle of CH4. Copyright Author(s) 2014.AcknowledgementsWe would like to thank the many different technicians, PhD students, postdocs, and scientists from the different research groups that have been involved in the NDACC-FTIR activities during the last two decades. Thanks to their excellent work (maintenance, calibration, observation activities, etc.) high quality long-term data sets can be generated. The Eureka measurements were made at the Polar Environment Atmospheric Research Laboratory (PEARL) by the Canadian Network for the Detection of Atmospheric Change (CANDAC), led by James R. Drummond, and in part by the Canadian Arctic ACE Validation Campaigns, led by Kaley A. Walker. They were supported by the AIF/NSRIT, CFI, CFCAS, CSA, EC, GOC-IPY, NSERC, NSTP, OIT, PCSP, and ORF. The authors wish to thank Rebecca Batchelor, Rodica Lindenmaier, PEARL site manager Pierre F. Fogal, the CANDAC operators, and the staff at Environment Canadaś Eureka weather station for their contributions to data acquisition, and logistical and on-site support. We thank the Alfred Wegener Institute Bremerhaven for support in using the AWIPEV research base, Spitsbergen, Norway. We would like acknowledge funding from the EU-Project InGOS and the Senate of Bremen for supporting the measurement programme at Bremen. We would like to thank Uwe Raffalski and Peter Völger for technical support at IRF Kiruna. Measurements at Wollongong are supported by the Australian Research Council, grant DP110103118. We would like to thank Antarctica New Zealand and the Scott Base staff for providing logistical support for the NDACC-FTIR measurement and in situ programme at Arrival Heights. The NIWA measurements at Lauder and Arrival Heights is core funded through the Ministry of Business, Innovation and Employment. The authors would like to thank Dr Vanessa Sherlock for her input and helpful comments. The Advanced Global Atmospheric Gases Experiment (AGAGE) is funded by NASA grant NNX11AF17G to MIT. Funding for AGAGE measurements at Mace Head, Ireland comes from the above NASA grant to MIT and the UK Department of Energy and Climate Change. AGAGE measurements at Cape Grim, Tasmania are supported by the above NASA grant to MIT and by the Australian Bureau of Meteorology and CSIRO Marine and Atmospheric Research. Flask measurements from Cape Ferguson, Australia are funded by CSIRO Marine and Atmospheric Research. In situ CH4 measurements at Jungfraujoch are run by Empa in collaboration with the Swiss Federal Office for the Environment (FOEN). Empa and FOEN acknowledge the International Foundation High Altitude Research Station Jungfraujoch and Gornergrat (HFSJG) for providing access to Jungfraujoch facilities. The Izana in situ GAW measurements have been carried out and financed by the Izana Atmospheric Research Center (AEMET). At Nyalesund and Izana, the FTIR work has received funding from the European Communityś Seventh Framework Programme ([FP7/2007--2013]) under grant agreement no. 284421 (see Article II.30. of the Grant Agreement). At Izaña has also received funding from the Ministerio de Economia and Competitividad from Spain for the project CGL2012-37505 (NOVIA project). This study has strongly benefited from work made in the framework of the project MUSICA, which is funded by the European Research Council under the European Communityś Seventh Framework Programme (FP7/2007--2013)/ERC grant agreement number 256961. E. Sepulveda enjoyed a pre-doctoral fellowship thanks to the Spanish Ministry of Education.Funding DetailsDP110103118, ARC, Antarctica New Zealand; CFCAS, Antarctica New Zealand; CFI, Antarctica New Zealand; CSA, Antarctica New Zealand; EC, Antarctica New Zealand; NSERC, Antarctica New Zealand; Antarctica New Zealand; CSIRO, Antarctica New Zealand; 256961, ERC, Antarctica New Zealand; NNX11AF17G, NASA, Antarctica New Zealand
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1st AuthorSepulveda, E.AuthorSepulveda, E.Schneider, M.Hase, F.Barthlott, S.Dubravica, D.Garcia, O.Gomez-Pelaez, A.Gonzalez, Y.Guerra, J.Gisi, M.Kohlhepp, R.Dohe, S.Blumenstock, T.Strong, K.Weaver, D.Palm, M.Sadeghi, A.Deutscher, N.Warneke, T.Notholt, J.Jones, N.Griffith, D.Smale, D.Brailsford, G.Robinson, J.Meinhardt, F.Steinbacher, M.Aalto, T.Worthy, D.Year2014JournalAtmospheric Measurement TechniquesVolume7Number7Pages2337-2360DOI10.5194/amt-7-2337-2014URLhttps://www.scopus.com/inward/recor.....3eb84c07504f2aa90028cb169Keywordsrank5
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TypeArticleCitationSepulveda, E., Schneider, M., Hase, F., Barthlott, S., Dubravica, D., Garcia, O., Gomez-Pelaez, A., Gonzalez, Y., Guerra, J., Gisi, M., Kohlhepp, R., Dohe, S., Blumenstock, T., Strong, K., Weaver, D., Palm, M., Sadeghi, A., Deutscher, N., Warneke, T., Notholt, J., Jones, N., Griffith, D., Smale, D., Brailsford, G., Robinson, J., Meinhardt, F., Steinbacher, M., Aalto, T. and Worthy, D. (2014). Tropospheric CH4 signals as observed by NDACC FTIR at globally distributed sites and comparison to GAW surface in situ measurements. Atmospheric Measurement Techniques, 7(7): 2337-2360 IdentifierSepulveda2014Relevancerank5
Worthy, D., Tropospheric CH4 signals as observed by NDACC FTIR at global , [Sepulveda2014]. Antarctica NZ, accessed 02/08/2026, https://adam.antarcticanz.govt.nz/nodes/view/63759, 10.5194/amt-7-2337-2014