ACP Atmospheric Chemistry and Physics ACP 1680-7324 Copernicus GmbH Göttingen, Germany 10.5194/acp-11-4163-2011 Carbon balance of South Asia constrained by passenger aircraft CO<sub>2</sub> measurements Patra P. K. 1 Niwa Y. 2 Schuck T. J. 3 Brenninkmeijer C. A. M. 3 Machida T. 4 Matsueda H. 2 Sawa Y. 2 Research Institute for Global Change, JAMSTEC, Yokohama 236 001, Japan Meteorological Research Institute, Tsukuba, Ibaraki, 305-0052 Japan Max Planck Institute for Chemistry, 55128 Mainz, Germany National Institute for Environmental Studies, Tsukuba, Ibaraki, 305-0052 Japan 06 05 2011 11 9 4163 4175 This is an open-access article ditributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. This article is available from http://www.atmos-chem-phys.net/11/4163/2011/acp-11-4163-2011.html The full text article is available as a PDF file from http://www.atmos-chem-phys.net/11/4163/2011/acp-11-4163-2011.pdf

Quantifying the fluxes of carbon dioxide (CO<sub>2</sub>) between the atmosphere and terrestrial ecosystems in all their diversity, across the continents, is important and urgent for implementing effective mitigating policies. Whereas much is known for Europe and North America for instance, in comparison, South Asia, with 1.6 billion inhabitants and considerable CO<sub>2</sub> fluxes, remained terra incognita in this respect. We use regional measurements of atmospheric CO<sub>2</sub> aboard a Lufthansa passenger aircraft between Frankfurt (Germany) and Chennai (India) at cruise altitude, in addition to the existing network sites for 2008, to estimate monthly fluxes for 64-regions using Bayesian inversion and transport model simulations. The applicability of the model's transport parameterization is confirmed using SF<sub>6</sub>, CH<sub>4</sub> and N<sub>2</sub>O simulations for the CARIBIC datasets. The annual amplitude of carbon flux obtained by including the aircraft data is twice as large as the fluxes simulated by a terrestrial ecosystem model that was applied to prescribe the fluxes used in the inversions. It is shown that South Asia sequestered carbon at a rate of 0.37 ± 0.20 Pg C yr<sup>−1</sup> (1 Pg C = 10<sup>15</sup> g of carbon in CO<sub>2</sub>) for the years 2007 and 2008. The seasonality and the strength of the calculated monthly fluxes are successfully validated using independent measurements of vertical CO<sub>2</sub> profiles over Delhi and spatial variations at cruising altitude over Asia aboard Japan Airlines passenger aircraft.

 References Assonov,~S S., Brenninkmeijer,~C A M., Schuck,~T J., and Taylor,~P.: Analysis of \chem^13C and \chem^18O isotope data of \chemCO_2 in CARIBIC aircraft samples as tracers of upper troposphere/lower stratosphere mixing and the global carbon cycle, Atmos. Chem. Phys., 10, 8575–8599, http://dx.doi.org/10.5194/acp-10-8575-2010doi:10.5194/acp-10-8575-2010, 2010. Bhattacharya,~S K., Borole,~D V., Francey,~R J., Allison,~C E., Steele,~L P., Krummel,~P., Langenfelds,~R., Masarie,~K A., Tiwari,~Y K., and Patra,~P K.: Trace gases and \chemCO_2 isotope records from Cabo de Rama, India, Curr. Sci., 97, 1336–1344, 2009. Beer, C., Reichstein, M., Tomelleri, E., Ciais, P., Jung, M., Carvalhais, N., Rödenbeck, C., Arain, M. A., Baldocchi, D., Bonan, G. B., Bondeau, A., Cescatti, A., Lasslop, G., Lindroth, A., Lomas, M., Luyssaert, S., Margolis, H., Oleson, K. W., Roupsard, O., Veenendaal, E., Viovy, N., Williams, C., Woodward, F. I., and Papale, D.: Terrestrial gross carbon dioxide uptake: global distribution and covariation with climate, Science, 329, 834–838, 2010. Boden,~T A., Marland,~G., and Andres,~R J.: Global \chemCO_2 Emissions from Fossil-Fuel Burning, Cement Manufacture, and Gas Flaring: 1751–2006, Carbon Dioxide Inf. Anal. Cent., Oak Ridge Natl. Lab., Oak Ridge, Tenn., 2010. Bouwman,~A F., van der Hoek,~K W., and Olivier,~J G J.: Uncertainties in the global source distribution of nitrous oxide, J Geophys. Res., 100(D2), 2785–2800, 1995. Brenninkmeijer,~C A M., Crutzen,~P., Boumard,~F., Dauer,~T., Dix,~B., Ebinghaus,~R., Filippi,~D., Fischer,~H., Franke,~H., Frieß,~U., Heintzenberg,~J., Helleis,~F., Hermann,~M., Kock,~H H., Koeppel,~C., Lelieveld,~J., Leuenberger,~M., Martinsson,~B G., Miemczyk,~S., Moret,~H P., Nguyen,~H N., Nyfeler,~P., Oram,~D., O'Sullivan,~D., Penkett,~S., Platt,~U., Pupek,~M., Ramonet,~M., Randa,~B., Reichelt,~M., Rhee,~T S., Rohwer,~J., Rosenfeld,~K., Scharffe,~D., Schlager,~H., Schumann,~U., Slemr,~F., Sprung,~D., Stock,~P., Thaler,~R., Valentino,~F., van Velthoven,~P., Waibel,~A., Wandel,~A., Waschitschek,~K., Wiedensohler,~A., Xueref-Remy,~I., Zahn,~A., Zech,~U., and Ziereis,~H.: Civil Aircraft for the regular investigation of the atmosphere based on an instrumented container: The new CARIBIC system, Atmos. Chem. Phys., 7, 4953–4976, http://dx.doi.org/10.5194/acp-7-4953-2007doi:10.5194/acp-7-4953-2007, 2007. Castaldi,~S., de Grandcourt,~A., Rasile,~A., Skiba,~U., and Valentini,~R.: \chemCO_2, \chemCH_4 and \chemN_2O fluxes from soil of a~burned grassland in Central Africa, Biogeosciences, 7, 3459–3471, http://dx.doi.org/10.5194/bg-7-3459-2010doi:10.5194/bg-7-3459-2010, 2010. EDGAR4: Emission Database for Global Atmospheric Research (EDGAR), release version 4.0, European Commission, Joint Research Centre (JRC)/Netherlands Environmental Assessment Agency (PBL), available at: http://edgar.jrc.ec.europa.eu (last access: 23~June~2009), 2009. Fung,~I., John,~J., Lerner,~J., Matthews,~E., Prather,~M., Steele,~L P., and Fraser,~P J.: Three- dimensional model synthesis of the global methane cycle, J Geophys. Res., 96, 13033–13065, 1991. GLOBALVIEW-\chemCO_2: Cooperative Atmospheric Data Integration Project – Carbon Dioxide, CD-ROM, NOAA CMDL, Boulder, Colorado, anonymous FTP to ftp.cmdl.noaa.gov, path: ccq/CO2/GLOBALVIEW (last access: 30~October 2009), 2009. Gurney, K. R., Law, R. M., Denning, A. S., Rayner, P. J., Pak, B. C., Baker, D., Bousquet, P., Bruhwiler, L., Chen, Y.-H., Ciais, P., Fung, I. Y., Heimann, M., John, J., Maki, T., Maksyutov., S., Peylin, P., Prather, M., and Taguchi, S.: Transcom~3 inversion intercomparison: model mean results for the estimation of seasonal carbon sources and sinks, Global Biogeochem. Cy., 18, GB1010, http://dx.doi.org/10.1029/2003GB002111doi:10.1029/2003GB002111, 2004. Iguchi,~T., Kozu,~T., Meneghini,~R., Awaka,~J., and Okamoto,~K.: Rain-profiling algorithm for the TRMM precipitation radar, J Appl. Meteorol., 39, 2038–2052, 2000. INCCA, Indian Network for Climate Change Assessment, India: Greenhouse Gas Emissions 2007, Ministry of Environment and Forests, Government of India, New Delhi, May, 2010. Ishijima,~K., Patra,~P K., Takigawa,~M., Machida,~T., Matsueda,~H., Sawa,~Y., Steele,~L P., Krummel,~P B., Langenfelds,~R L., Aoki,~S., and Nakazawa,~T.: Stratospheric influence on the seasonal cycle of nitrous oxide in the troposphere as deduced from aircraft observations and model simulations, J Geophys. Res., 115, D20308, http://dx.doi.org/10.1029/2009JD013322doi:10.1029/2009JD013322, 2010. Janssens, I. A., Freibauer, A., Ciais, P., Smith, P., Nabuurs, G., Schlamadinger, B., Hutjes, R., Schulze, E., Ceulemans, E., Valentini, R., and Dolman, J.: Europe's terrestrial biosphere absorbs 7 to 12 % of European anthropogenic \chemCO_2 emissions, Science, 300, 1538–1542, 2003. Kanamitsu, M., Ebisuzaki, W., Woollen, J., Yang, S.-K., Hnilo, J. J., Fiorino, M., and Potter, G. L.: NCEP-DOE AMIP-II reanalysis (R-2), B Am. Meteorol. Soc., 83, 1631–1643, 2002. Le Quéré, C., Raupach, M. R., Canadell, J. G., Marland, G., Bopp, L., Ciais, P., Conway, T. J., Doney, S. C., Feely, R. A., Foster, P., Friedlingstein, P., Gurney, K., Houghton, R. A., House, J. I., Huntingford, C., Levy, P. E., Lomas, M. R., Majkut, J., Metzl, N., Ometto, J. P., Peters, G. P., Prentice, I. C., Randerson, J. T., Running, S. W., Sarmiento, J. L., Schuster, U., Sitch, S., Takahashi, T., Viovy, N., van der Werf, G. R., and Woodward, F. I.: Trends in the sources and sinks of carbon dioxide, Nat. Geosci., 2, 831–836, 2009. Levin,~I., Naegler,~T., Heinz,~R., Osusko,~D., Cuevas,~E., Engel,~A., Ilmberger,~J., Langenfelds,~R L., Neininger,~B., Rohden,~C. v., Steele,~L P., Weller,~R., Worthy,~D E., and Zimov,~S A.: The global \chemSF_6 source inferred from long-term high precision atmospheric measurements and its comparison with emission inventories, Atmos. Chem. Phys., 10, 2655–2662, http://dx.doi.org/10.5194/acp-10-2655-2010doi:10.5194/acp-10-2655-2010, 2010. Lokupitiya,~E., Denning,~S., Paustian,~K., Baker,~I., Schaefer,~K., Verma,~S., Meyers,~T., Bernacchi,~C J., Suyker,~A., and Fischer,~M.: Incorporation of crop phenology in Simple Biosphere Model (SiBcrop) to improve land-atmosphere carbon exchanges from croplands, Biogeosciences, 6, 969–986, http://dx.doi.org/10.5194/bg-6-969-2009doi:10.5194/bg-6-969-2009, 2009. Machida,~T., Matsueda,~H., Sawa,~Y., Nakagawa,~Y., Hirotani,~K., Kondo,~N., Goto,~K., Nakazawa,~T., Ishikawa,~K., and Ogawa,~T.: Worldwide measurements of atmospheric \chemCO_2 and other trace gas species using commercial airlines, J Atmos. Ocean. Tech., 25, 1744–1754, 2008. Machida,~T., Katsumata,~K., Tohjima,~Y., Watai,~T., and Mukai,~H.: Preparing and maintaining of \chemCO_2 calibration scale, in: National Institute for Environmental Studies – NIES 95 \chemCO_2 Scale, WMO/GAW Report No 186, edited by: by: Laurila, T., Geneva, 26–29, 2009. Malhi, Y., Saatchi, S., Girardin, C., and Aragao, L. E. O. C.: The production, storage, and flow of carbon in Amazonian forests, in: Amazonia and Global Change, Geophysical Monograph Series, edited by: Keller, M., Bustamante, M., Gash, J., and Silva Dias, P., American Geophysical Union, Washington DC, USA, 186, 355–372, 2009. Masarie,~K., Langenfelds,~R L., Allison,~C E., Conway,~T J., Dlugokencky,~E J., Francey,~R J., Novelli,~P C., Steele,~L P., Tans,~P P., Vaughn,~B., and White,~J W C.: NOAA/CSIRO flask air intercomparison experiment: a~strategy for directly assessing consistency among atmospheric measurements made by independent laboratories, J Geophys. Res., 106(D17), 20445–20464, 2001. Matsueda,~H., Inoue,~H Y., and Ishii,~M.: Aircraft observation of carbon dioxide at 8–13 km altitude over the Western Pacific from 1993 to 1999, Tellus B, 54, 1–21, 2002. Matsueda,~H., Machida,~T., Sawa,~Y., Nakagawa,~Y., Hirotani,~K., Ikeda,~H., Kondo,~N., and Goto,~K.: Evaluation of atmospheric \chemCO_2 measurements from new flask air sampling of JAL airliner observations, Pap. Meteorol. Geophys., 59, 1–17, 2008. Nevison,~C D., Weiss,~R F., and Erickson III,~D J.: Global oceanic emissions of nitrous oxide, J Geophys. Res., 100(C8), 15809–15820, 1995. Niwa,~Y., Patra,~P K., Sawa,~Y., Machida,~T., Matsueda,~H., Belikov,~D., Maki,~T., Ikegami,~M., Imasu,~R., Maksyutov,~S., Oda,~T., Satoh,~M., and Takigawa,~M.: Three dimemsional variations of atmospheric \chemCO_2: aircraft measurements and multi-transport model simulations, Atmos. Chem. Phys. Discuss., 11, 12805–12848, http://dx.doi.org/10.5194/acpd-11-12805-2011doi:10.5194/acpd-11-12805-2011, 2011. Numaguti,~A., Takahashi,~M., Nakajima,~T., and Sumi,~A.: Development of CCSR/NIES atmospheric general circulation model, in: Reports of a~New Program for Creative Basic Research Studies, CGERs Supercomput. Monogr. Rep., 3, CGER, Tsukuba, Ibaraki, 1–48, 1997. Olivier,~J G J. and Berdowski,~J J M.: Global emissions sources and sinks, in: The Climate System, edited by: Berdowski,~J., Guicherit,~R., and Heij,~B J., A A Balkema Publishers/Swets and Zeitlinger Pub., Lisse, The Netherlands, ISBN 9058092550, 33–78, 2001. Pacala, S. W., Hurtt, G. C., Baker, D., Peylin, P., Houghton, R. A., Birdsey, R. A., Heath, L., Sundquist, E. T., Stallard, R. F., Ciais, P., Moorcroft, P., Caspersen, J. P., Shevliakova, E., Moore, B., Kohlmaie, G., Holland, E., Gloor, M., Harmon, M. E., Fan, S.- M., Sarmiento, J. L., Goodale, C. L., Schimel, D., and Field, C. B.: Consistent land- and atmosphere-based US carbon sink estimates, Science, 292, 2316–2320, 2001. Park, M., Randel, W. J., Gettelman, A., Massie, S. T., and Jiang, J. H.: Transport above the Asian summer monsoon anticyclone inferred from Aura Microwave Limb Sounder tracers, J. Geophys. Res., 112, D16309, http://dx.doi.org/10.1029/2006JD008294doi:10.1029/2006JD008294, 2007. Parthasarathy,~B., Munot,~A A., and Kothawale,~D R.: All-India monthly and seasonal rainfall series: 1871–1993, Theor. Appl. Climatol., 49, 217–224, 1994. Patra, P. K., Ishizawa, M., Maksyutov, S., Nakazawa, T., and Inoue, G.: Role of biomass burning and climate anomalies for land-atmosphere carbon fluxes based on inverse modeling of atmospheric \chemCO_2, Global Biogeochem. Cy., 19, GB3005, http://dx.doi.org/10.1029/2004GB002258doi:10.1029/2004GB002258, 2005. Patra, P. K., Takigawa, M., Dutton, G. S., Uhse, K., Ishijima, K., Lintner, B. R., Miyazaki, K., and Elkins, J. W.: Transport mechanisms for synoptic, seasonal and interannual SF$_6$ variations and "age" of air in troposphere, Atmos. Chem. Phys., 9, 1209–1225, http://dx.doi.org/10.5194/acp-9-1209-2009doi:10.5194/acp-9-1209-2009, 2009a. Patra, P. K., Takigawa, M., Ishijima, K., Choi, B.-C., Cunnold, D., Dlugokencky, E. J., Fraser, P., Gomez-Pelaez, A.J., Goo, T.-Y., Kim, J.-S., Krummel, P., Langenfelds, R., Meinhardt, F., Mukai, H., O'Doherty, S., Prinn, R. G., Simmonds, P., Steele, P., Tohjima, Y., Tsuboi, K., Uhse, K., Weiss, R., Worthy, D., and Nakazawa, T.: Growth rate, seasonal, synoptic, diurnal variations and budget of methane in lower atmosphere, J. Meteorol. Soc. Jpn., 87, 635–663, 2009b. Piao,~S L., Fang,~J., Ciais,~P., Peylin,~P., Huang,~Y., Sitch,~S., and Wang,~T.: The carbon balance of terrestrial ecosystems in China, Nature, 458, 1009–1013, 2009. Pisharoty,~P R. and Desai,~B N.: Western disturbances and Indian weather, Indian~J. Meteorol. Geophys., 8, 333–338, 1956. Rayner, P. J., Law, R. M., Allison, C. E., Francey, R. J., Trudinger, C. M., and Pickett-Heaps, C.: Interannual variability of the global carbon cycle (1992–2005) inferred by inversion of atmospheric \chemCO_2 and \chem^13CO_2 measurements, Global Biogeochem. Cy., 22, GB3008, http://dx.doi.org/10.1029/2007GB003068doi:10.1029/2007GB003068, 2008. Randerson,~J., Thompson,~M., Conway,~T., Fung,~I., and Field,~C.: The contribution of terrestrial sources and sinks to trends in the seasonal cycle of atmospheric carbon dioxide, Global Biogeochem. Cy., 11(4), 535–560, 1997. Sander, S. P., Friedl, R. R., Golden, D. M., Kurylo, M. J., Moortgat, G. K., Keller-Rudek, H., Wine, P. H., Ravishankara, A. R., Kolb, C. E., Molina, M. J., Finlayson-Pitts, B. J., Huie, R. E., and Orkin, V. L.: Chemical Kinetics and Photochemical Data for Use in Atmospheric Studies: Evaluation Number 15, JPL Publ. 06-2, Jet Propul. Lab., Calif. Inst. of Technol., Pasadena, USA, 2006. Schuck,~T J., Brenninkmeijer,~C A M., Slemr,~F., Xueref-Remy,~I., and Zahn,~A.: Greenhouse gas analysis of air samples collected onboard the CARIBIC passenger aircraft, Atmos. Meas. Tech., 2, 449–464, http://dx.doi.org/10.5194/amt-2-449-2009doi:10.5194/amt-2-449-2009, 2009. Schuck,~T J., Brenninkmeijer,~C A M., Baker,~A K., Slemr,~F., von Velthoven,~P F J., and Zahn,~A.: Greenhouse gas relationships in the Indian summer monsoon plume measured by the CARIBIC passenger aircraft, Atmos. Chem. Phys., 10, 3965–3984, http://dx.doi.org/10.5194/acp-10-3965-2010doi:10.5194/acp-10-3965-2010, 2010. Schulze, E. D., Ciais, P., Luyssaert, S., Schrumpf, M., Janssens, I. A., Thiruchittampalam, B., Theloke, J., Saurat, M., Bringeze, S., Lelieveld, J., Lohila, A., Rebmann, C., Jung, M., Bastviken, D., Abril, G., Grassi, G., Leip, A., Freibauer, A., Kutsch, W., Don, A., Nieschulze, J., Borner, A., Gash, J. H., and Dolman, A. J.: The European carbon balance, Part 4: Integration of carbon and other trace-gas fluxes, Glob. Change Biol., 16, 1451–1469, 2010. Stephens, B. B., Gurney, K. R., Tans, P. P., Sweeney, C., Peters, W., Bruhwiler, L., Ciais, P., Ramonet, M., Bousquet, P., Nakazawa, T., Aoki, S., Machida, T., Inoue, G., Vinnichenko, N., Lloyd, J., Jordan, A., Heimann, M., Shibistova, O., Langenfelds, R. L., Steele, L. P., Francey, R. J., and Denning, A. S.: Weak northern and strong tropical land carbon uptake from vertical profiles of atmospheric \chemCO_2, Science, 316, 1732–1735, 2007. Takahashi,~T., Sutherland,~S C., Sweeney,~C., Poisson,~A., Metzl,~N., Tilbrook,~B., Bates,~N., Wanninkhof,~R., Feely,~R A., Sabine,~C., Olafsson,~J., and Nojiri,~Y.: Global sea-air \chemCO_2 flux based on climatological surface ocean $p$\chemCO_2, and seasonal biological and temperature effects, Deep-Sea Res. Pt II, 49, 1601–1622, 2002. WDCGG: WMO World Data Centre for Greenhouse Gases, Japan Meteorological Agency, Tokyo, available online at: http://gaw.kishou.go.jp, (last access: 19~April~2010), 2010. Xiong,~X., Houweling,~S., Wei,~J., Maddy,~E., Sun,~F., and Barnet,~C.: Methane plume over south Asia during the monsoon season: satellite observation and model simulation, Atmos. Chem. Phys., 9, 783–794, http://dx.doi.org/10.5194/acp-9-783-2009doi:10.5194/acp-9-783-2009, 2009. Yang,~X., Richardson,~T K., and Jain,~A K.: Contributions of secondary forest and nitrogen dynamics to terrestrial carbon uptake, Biogeosciences, 7, 3041–3050, http://dx.doi.org/10.5194/bg-7-3041-2010doi:10.5194/bg-7-3041-2010, 2010.