C. A. M. Brenninkmeijer

Publications (158)174.21 Total impact

• Article: Quantifying the uncertainty in simulating global tropospheric composition due to the variability in global emission estimates of Biogenic Volatile Organic Compounds

  J E Williams, P F J Van Velthoven, C A M Brenninkmeijer
  [show abstract] [hide abstract]
  ABSTRACT: The emission of organic compounds from bio-genic processes acts as an important source of trace gases in remote regions away from urban conurbations, and is likely to become more important in future decades due to the further mitigation of anthropogenic emissions that af-fect air quality and climate forcing. In this study we exam-ine the contribution of biogenic volatile organic compounds (BVOCs) towards global tropospheric composition using the global 3-D chemistry transport model TM5 and the recently developed modified CB05 chemical mechanism. By compar-ing regional BVOC emission estimates we show that bio-genic processes act as dominant sources for many regions and exhibit a large variability in the annually and seasonally integrated emission fluxes. By performing sensitivity studies we find that the contribution of BVOC species containing be-tween 1 to 3 carbon atoms has an impact on the resident mix-ing ratios of tropospheric O 3 and CO, accounting for ∼2.5 % and ∼10.8 % of the simulated global distribution, respec-tively. This is approximately a third of the cumulative effect introduced by isoprene and the monoterpenes. By examining an ensemble of 3-D global chemistry transport simulations which adopt different global BVOC emission inventories we determine the associated uncertainty introduced towards sim-ulating the composition of the troposphere for the year 2000. By comparing the model ensemble values against a compos-ite of atmospheric measurements we show that the effects on tropospheric O 3 are limited to the lower troposphere (with an uncertainty between −2 % to 10 %), whereas that for tro-pospheric CO extends up to the upper troposphere (with an uncertainty of between 10 to 45 %). Comparing the mixing ratios for low molecular weight alkenes in TM5 against sur-face measurements taken in Europe implies that the cumu-lative emission estimates are too low, regardless of the cho-sen BVOC inventory. This variability in the global distribu-tion of CO due to BVOC emissions introduces an associ-ated uncertainty in the tropospheric CO burden of 11.4 %, which impacts strongly on the oxidative capacity of the tro-posphere, introducing an uncertainty in the atmospheric life-time of the greenhouse gas CH 4 of ∼3.3 %. This study thus identifies the necessity of placing further constraints on non-CH 4 global biogenic emission estimates in large-scale global atmospheric chemistry models.
  Atmospheric Chemistry and Physics 03/2013; 13:2857-2891.
• Article: Atmospheric CO along the Trans-Siberian Railroad and River Ob: source identification using isotope analysis

  O. A. Tarasova, C. A. M. Brenninkmeijer, S. S. Assonov, N. F. Elansky, T. Röckmann, M. A. Sofiev
  [show abstract] [hide abstract]
  ABSTRACT: The concentration, radiocarbon (14C) and stable isotope (13C and 18O) content of CO have been determined in air samples collected across Russia (about 8,500km) and along the Ob river during the summer of 1999 to study the CO sources and sinks. An instrumented carriage on the Trans-Siberian railway and a boat on the river Ob were used as atmospheric measurement platforms. In general, CO mixing ratios, CO stable isotope ratios, as well as the abundances of 14CO over West Siberia were similar to those found at remote northern hemispheric baseline monitoring stations. Identified sources of CO along the Ob appear to be connected to methane oxidation based on an inferred δ13Csource = −36.8 ± 0.6‰, while the value for δ18Osource = 9.0 ± 1.6‰ identifies it as burning. Thus flaring in the oil and gas production can be supposed to be a source. The extreme 13C depletion and concomitant 18O enrichment for two of the boat samples unambiguously indicates contamination by CO from combustion of natural gas (inferred values δ13Csource = −40.3‰ and δ18Osource = 17.5‰). For these two samples, that have strongly elevated 14CO concentrations, the industrial area near Tomsk is identified as a source area using meteorological calculations. Along the Trans-Siberian Railroad background CO was to various degrees contaminated with CO from methane combustion (δ13Csource = −35.7 ± 6.2‰ and δ18Osource = 10.3 ± 1.8‰). The impact of industrial burning was discernable in the vicinity of Perm-Kungur.
  Journal of Atmospheric Chemistry 04/2012; 57(2):135-152. · 0.99 Impact Factor
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  Available from: O. A. Tarasova

  Article: Application of stable isotope analysis for improved understanding of the methane budget: comparison of TROICA measurements with TM3 model simulations

  O. A. Tarasova, S. Houweling, N. F. Elansky, C. A. M. Brenninkmeijer
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  ABSTRACT: Presented is a detailed comparison of CH4 and δ13C–CH4 measurements with simulations of the global transport model TM3. Experimental data were obtained during campaigns along the Trans-Siberian railroad in the framework of the TROICA project. Two summer (1999 and 2001) and one spring (2003) expeditions are evaluated. Model simulations include sensitivity tests to further investigate the isotopic composition of natural gas and emissions from Siberian wetlands. Comparison of the average mixing ratio of methane and its isotopic composition (δ13C) has been performed for different geographic zones, including the European part of Russia, Western Siberia and Central Siberia. Simulations are in reasonable agreement with the measurements for the European part of Russia and confirm a high contribution of natural gas to the observed methane levels. An increase of emission from bogs shifts the simulated methane isotopic composition closer to the observations. The relative importance of the Western Siberia emissions in current inventories is underestimated in comparison with other wetland regions in the former USSR. Simulated average mixing ratios are in a good agreement with the observations in Central Siberia, while 13C(CH4) values tend to be higher than measured in all considered scenarios. These results point to a bias in the modeled source mixture over Russia, which could be repaired by shifting emissions from isotopically heavy methane sources (e.g. coal, oil or biomass burning) to light sources (e.g. wetlands, ruminants, waste treatment). Alternatively, the average isotopic signature of Siberian wetlands may be lighter than expected.
  Journal of Atmospheric Chemistry 04/2012; · 0.99 Impact Factor
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  Available from: Anneke Batenburg

  Article: The stable isotopic composition of molecular hydrogen in the tropopause region probed by the CARIBIC aircraft

  A M Batenburg, T J Schuck, A K Baker, A Zahn, C A M Brenninkmeijer, T Röckmann
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  ABSTRACT: More than 450 air samples that were collected in the upper troposphere – lower stratosphere (UTLS) region by the CARIBIC aircraft (Civil Aircraft for the Regular Investi-gation of the atmosphere Based on an Instrument Container) have been analyzed for molecular hydrogen (H 2) mixing ra-tios (χ (H 2)) and H 2 isotopic composition (deuterium con-tent, δD). More than 120 of the analyzed samples contained air from the lowermost stratosphere (LMS). These show that χ(H 2) does not vary appreciably with O 3 -derived height above the thermal tropopause (TP), whereas δD does increase with height. The isotope enrichment is caused by H 2 production and destruction processes that enrich the stratospheric H 2 reservoir in deuterium (D); the exact shapes of the profiles are mainly determined by mixing of stratospheric with tro-pospheric air. Tight negative correlations are found between δD and the mixing ratios of methane (χ(CH 4)) and nitrous oxide (χ (N 2 O)), as a result of the relatively long lifetimes of these three species. The correlations are described by δD[‰] = −0.35 · χ(CH 4)[ppb]+768 and δD[‰] = −1.90 · χ(N 2 O)[ppb]+745. These correlations are similar to previ-ously published results and likely hold globally for the LMS. Samples that were collected from the Indian subcontinent up to 40 • N before, during and after the summer monsoon season show no significant seasonal change in χ(H 2), but δD is up to 12.3 ‰ lower in the July, August and Septem-ber monsoon samples. This δD decrease is correlated with the χ(CH 4) increase in these samples. The significant corre-lation with χ (CH 4) and the absence of a perceptible χ(H 2) increase that accompanies the δD decrease indicates that mi-crobial production of very D-depleted H 2 in the wet season may contribute to this phenomenon. Some of the samples have very high χ (H 2) and very low δD values, which indicates a pollution effect. Aircraft engine exhaust plumes are a suspected cause, since the effect mostly occurs in samples collected close to airports, but no similar signals are found in other chemical tracers to support this. The isotopic source signature of the H 2 pollution seems to be on the low end of the signature for fossil fuel burning.
  Atmospheric Chemistry and Physics 04/2012; 12:4633--4646.
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  Available from: O. A. Tarasova

  Chapter: Train-Based Platform for Observations of the Atmosphere Composition (TROICA Project)

  N.F. Elansky, I.B. Belikov, O.V. Lavrova, A.I. Skorokhod, R.A. Shumsky, C.A.M. Brenninkmeijer, O.A. Tarasova
  03/2012; , ISBN: 978-953-51-0424-7
• Article: Characterization of non-methane hydrocarbons in Asian summer monsoon outflow observed by the CARIBIC aircraft

  A. K. Baker, T. J. Schuck, Slemr F, P. van Velthoven, Zahn A, C. A. M. Brenninkmeijer
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  ABSTRACT: Between April and December 2008 the CARIBIC commercial aircraft conducted monthly measurement flights between Frankfurt, Germany and Chennai, India. These flights covered the period of the Asian summer monsoon (June–September), during which enhancements in a number of atmospheric species were observed in the upper troposphere over southwestern Asia. In addition to in situ measurements of trace gases and aerosols, whole air samples were collected during the flights, and these were subsequently analyzed for a suite of trace gases that included a number of C2–C8 non-methane hydrocarbons. Non-methane hydrocarbons are relatively short-lived compounds and the large enhancements in their mixing ratios in the upper troposphere over southwestern Asia during the monsoon, sometimes more than double their spring and fall means, provides qualitative evidence for the influence of convectively uplifted boundary layer air. The particularly large enhancements of the combustion tracers benzene and ethyne, along with the similarity of their ratios with carbon monoxide and emission ratios from the burning of household biofuels, indicate a strong influence of biofuel burning to NMHC emissions in this region. Conversely, the ratios of ethane and propane to carbon monoxide, along with the ratio between i-butane and n-butane, indicate a significant source of these compounds from the use of fossil fuels, and comparison to previous campaigns suggests that this source could be increasing. Photochemical aging patterns of NMHCs showed that the CARIBIC samples were collected in two distinctly different regions of the monsoon circulation: a southern region where air masses had been recently influenced by low level contact and a northern region, where air parcels had spent substantial time in transit in the upper troposphere before being probed. Estimates of age using ratios of individual NMHCs have ranges of 3–6 days in the south and 9–12 days in the north.
  Atmospheric Chemistry and Physics. 01/2011;
• Article: SO2 and BrO observation in the plume of the Eyjafjallajökull volcano 2010: CARIBIC and GOME-2 retrievals

  K.-P. Heue, C. A. M. Brenninkmeijer, A. K. Baker, A. Rauthe-Schöch, D. Walter, T. Wagner, C. Hörmann, H. Sihler, B. Dix, U. Frieß, U. Platt, B. G. Martinsson, P. F. J. van Velthoven, M. Hermann, A. Zahn, R. Ebinghaus
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  ABSTRACT: The ash cloud of the Eyjafjallajökull1 volcano on Iceland caused closure of large parts of European airspace in April and May 2010. For the validation and improvement of the European volcanic ash forecast models several research flights were performed. Also the CARIBIC (Civil Aircraft for the Regular Investigation of the atmosphere Based on an Instrument Container) flying laboratory, which routinely measures at cruise altitude (≈11 km) performed three dedicated measurements flights through sections of the ash plume. Although the focus of these flights was on the detection and quantification of the volcanic ash, we report here on sulphur dioxide (SO2) and bromine monoxide (BrO) measurements with the CARIBIC DOAS (Differential Optical Absorption Spectroscopy) instrument during the second of these special flights on 16 May 2010. As the BrO and the SO2 observations coincide, we assume the BrO to have been formed inside the volcanic plume. Both SO2 and BrO observations agree well with simultaneous satellite (GOME-2) observations. SO2 column densities retrieved from satellite observations are often used as an indicator for volcanic ash. For SO2 some additional information on the local distribution can be derived from a~comparison of forward and back scan GOME-2 data. More details on the local plume size and position are retrieved by combining CARIBIC and GOME-2 data. 1Also referred to as: Eyjafjalla (e.g. Schumann et al., 2010), Eyjafjöll or Eyjafjoll (e.g. Ansmann et al., 2010).
  Atmospheric Chemistry and Physics 11/2010; 10:29631-29682. · 4.88 Impact Factor
• Article: Regional Impact on Pollution Event in the Upper Troposphere during CARIBIC Flights between South China and the Philippines

  S. C. Lai, A. R. Baker, T. J. Schuck, P. van Velthoven, D. E. Oram, A. Zahn, M. Hermann, A. Weigelt, S. Slemr, C. A. M. Brenninkmeijer
  [show abstract] [hide abstract]
  ABSTRACT: The research project CARIBIC (Civil Aircraft for the Regular Investigation of the atmosphere Based on an Instrumented Container, phase II) is designed to conduct regular, long-term and detailed observations of the free troposphere and UT/LS regions where passenger aircraft happen to cruise. A fully-automated measurement container (1.5 tons) was equipped onboard an Airbus 340-600 operated by Lufthansa Airlines during regular passenger flights to conduct real time trace gas and aerosol measurements and to collect aerosol and air samples on a near monthly basis. During May 2005 - March 2008, CARIBIC observations have been performed along the flight tracks of Frankfurt-Guangzhou-Manila. Data have been collected in the upper troposphere during a total of 81 flights over the region between South China and the Philippines. Carbon monoxide was used an indicator to identify the pollution events and to access the regional impacts of fossil fuel burning and biomass/biofuel burning on upper tropospheric air. Five regions, i.e. Northeast Asia, South China, Indochina Peninsula, India and Indonesia/Philippines, are identified as the major source regions to be related to the observed pollution events. The characteristics of the events from these regions are investigated. The contributions of different source categories are also estimated.
  04/2010; 12:7235.
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  Available from: caribic.de

  Article: Analysis of accurate ¹³C and ¹⁸O isotope measurements of CO₂ in CARIBIC aircraft air samples from the tropical troposphere, and the upper troposphere/lowermost stratosphere

  S. S. Assonov, C. A. M. Brenninkmeijer, T. J. Schuck, Taylor P
  [show abstract] [hide abstract]
  ABSTRACT: The project CARIBIC ( http://caribic-atmospheric.com ) aims to study atmospheric chemistry and transport by regularly measuring many compounds in the free troposphere (FT) and the upper troposphere/lowermost stratosphere (UT/LMS) by using passenger aircraft. Here CO₂ concentrations and highly accurate isotope results are presented in detail together with supporting trace gas data. 509 CARIBIC-2 samples (highest precision and accuracy δ¹³C(CO₂) and δ¹⁸O(CO₂) data) from June 2007 until March 2009, together with CARIBIC-1 samples (flights between November 1999 and April 2002, 350 samples in total, 270 for NH, mostly δ¹³C(CO₂) data) give a fairly extensive, unique data set for the NH free troposphere and the UT/LMS region. To compare data from different years a de-trending is applied. In the UT/LMS region δ¹³C(CO₂), δ¹⁸O(CO₂) and CO₂ are found to correlate well with stratospheric tracers, in particular N₂O. These correlations are in good agreement with current understanding of stratospheric circulation. δ¹⁸O(CO₂) appears to be a useful, hitherto unused, tracer of atmospheric transport in the UT/LMS region. By filtering out the LMS data (based on N₂O distribution), the isotope variations for the free and upper troposphere are obtained. These show however little latitudinal gradient, if any, and are in good agreement with the data of selected NOAA stations in NH tropics. Correlations between δ¹³C(CO₂) and CO₂ are observed both within single flight(s) covering long distances and for certain seasons. The overall variability in de-trended δ¹³C(CO₂) and CO₂ for CARIBIC-1 and CARIBIC-2 are similar and basically agree with each other, which also underscores the high quality of measurement. Based on all correlations, we discuss that CO₂ distribution in the NH FT and UT (at CARIBIC flight routes) is regulated by uplift and pole-wards transport of tropical air up to approximately 50° N. The main reasons for variability of signals in FT and UT (which is larger for the high spatial resolution sampling during CARIBIC-2) is mixing of different tropospheric air masses affected by CO₂ sources and sinks. The effect of stratospheric flux appears to be limited. All in all it is demonstrated that CARIBIC produced new important and reliable data sets for little explored regions of the atmosphere. A logical next step will be global scale modeling of δ¹³C and especially δ¹⁸O, which is linked to the hydrological cycle.
  Atmospheric Chemistry and Physics Discussions. 01/2010;
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  Available from: atmos-chem-phys.org

  Article: Analysis of ¹³C and ¹⁸O isotope data of CO₂ in CARIBIC aircraft samples as tracers of upper troposphere/lower stratosphere mixing and the global carbon cycle

  S. S. Assonov, C. A. M. Brenninkmeijer, T. J. Schuck, Taylor P
  [show abstract] [hide abstract]
  ABSTRACT: The project CARIBIC (http://caribic-atmospheric.com) aims to study atmospheric chemistry and transport by regularly measuring many compounds in the free troposphere and the upper troposphere/lowermost stratosphere (UT/LMS) by using passenger aircraft. Here we present CO2 concentrations and isotope results, and analyze the data together with supporting trace gas data. 509 CARIBIC-2 samples (highest precision and accuracy δ13C(CO2) and δ18O(CO2) data) from June 2007 until March 2009, together with CARIBIC-1 samples (flights between November 1999 and April 2002, 350 samples in total, 270 for NH, mostly δ13C(CO2) data) give a fairly extensive, unique data set for the NH free troposphere and the UT/LMS region. Total uncertainty of the data is the same as reported for the global monitoring program by NOAA-ESRL. To compare data from different years a de-trending is applied. In the UT/LMS region δ13C(CO2), δ18O(CO2) and CO2 are found to correlate well with stratospheric tracers, in particular N2O; δ18O(CO2) appears to be a useful, hitherto unused, tracer of atmospheric transport in the UT/LMS region and also inter-hemispheric mixing. By filtering out the LMS data (based on N2O distributions), the isotope variations for the free and upper troposphere are obtained. These variations have only small latitudinal gradients, if any, and are in good agreement with the data of selected NOAA stations in NH tropics. Correlations between δ13C(CO2) and CO2 are observed both within single flight(s) covering long distances and during certain seasons. The overall variability in de-trended δ13C(CO2) and CO2 for CARIBIC-1 and CARIBIC-2 are similar and are generally in agreement, which underscores agreement between high and low resolution sampling. Based on all correlations, we infer that the CO2 distribution in the NH troposphere along CARIBIC flight routes is chiefly regulated by uplift and pole-wards transport of tropical air up to approximately 50° N. The main reason for variability of signals in the troposphere (which is larger for the higher resolution sampling during CARIBIC-2) is mixing of different tropospheric air masses affected by different CO2 sources and sinks. The effect of stratospheric flux appears to be limited. All in all it is demonstrated that CARIBIC produced new important and reliable data sets for little explored regions of the atmosphere. A logical next step will be global scale modeling of 13C and especially 18O, which is linked to the hydrological cycle.
  Atmospheric Chemistry and Physics. 01/2010;
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  Available from: Emmanuel Witrant

  Article: Rapid growth of HFC-227ea (1,1,1,2,3,3,3-Heptafluoropropane) in the atmosphere

  J. C. Laube, Martinerie P, Witrant E, Blunier T, Schwander J, C. A. M. Brenninkmeijer, T. J. Schuck, Bolder M, Röckmann T, C. van der Veen, Bönisch H, Engel A, G. P. Mills, M. J. Newland, D. E. Oram, C. E. Reeves, W. T. Sturges
  [show abstract] [hide abstract]
  ABSTRACT: We report the first measurements of 1,1,1,2,3,3,3-heptafluoropropane (HFC-227ea), a substitute for ozone depleting compounds, in remote regions of the atmosphere and present evidence for its rapid growth. Observed mixing ratios ranged from below 0.01 ppt in deep firn air to 0.59 ppt in the northern mid-latitudinal upper troposphere. Firn air samples collected in Greenland were used to reconstruct a history of atmospheric abundance. Year-on-year increases were deduced, with acceleration in the growth rate from 0.026 ppt per year in 2000 to 0.057 ppt per year in 2007. Upper tropospheric air samples provide evidence for a continuing growth until late 2009. Furthermore we calculated a stratospheric lifetime of 370 years from measurements of air samples collected on board high altitude aircraft and balloons. Emission estimates were determined from the reconstructed atmospheric trend and suggest that current "bottom-up" estimates of global emissions for 2005 are too high by more than a factor of three.
  Atmospheric Chemistry and Physics Discussions. 01/2010;
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  Available from: Klaus-Peter Heue

  Article: A comparison of DOAS observations by the CARIBIC aircraft and the GOME-2 satellite of the 2008 Kasatochi volcanic SO₂ plume

  Heue K.-P, C. A. M. Brenninkmeijer, Wagner T, Mies K, Dix B, Frieß U, B. G. Martinsson, Slemr F, P. F. J. van Velthoven
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  ABSTRACT: The 2008 Kasatochi volcanic eruption emitted ≈1.5–2.5 Tg SO₂ into the upper troposphere and lower stratosphere. Parts of the main volcanic plume (gases and particles) reached central Europe a week after the eruption and were detected there by the CARIBIC (Civil Aircraft for Regular investigation of the Atmosphere based on an Instrument Container) flying observatory. The plume was also observed by the GOME-2 satellite instrument, only a few hours after the CARIBIC aircraft had crossed the plume, thus giving a unique opportunity to compare results. Trajectories and local wind speeds are investigated in detail using the GOME-2 and CARIBIC observations for better comparison of the results from these two observational systems. A comparison of the spatial pattern with the local observations of the wind speed and the trajectory model TRAJKS showed a slight discrepancy, which has to be considered for satellite validation. Hence, it appears that detailed analyses of wind speeds are required. Emitted and secondary particles, partly measured and sampled by the CARIBIC in situ instruments, affected the DOAS SO₂ measurements, of both CARIBIC and GOME-2. Overall GOME-2 and the CARIBIC SO₂ measurements agree very well. The major uncertainties remain the actual wind speed needed to properly correct for the advection of the plume between the different overpass times, and to smaller degree the effect of aerosol. The good agreement can be seen as validation for both GOME-2 and CARIBIC DOAS observations and is also a basis for future common projects.
  Atmospheric Chemistry and Physics Discussions. 01/2010;
• Article: Greenhouse gas relationships in the Indian summer monsoon plume measured by the CARIBIC passenger aircraft

  T. J. Schuck, C. A. M. Brenninkmeijer, A. K. Baker, Slemr F, P. F. J. von Velthoven, Zahn A
  [show abstract] [hide abstract]
  ABSTRACT: During the Indian summer monsoon period 2008, regular measurement flights were performed by the CARIBIC aircraft between Germany and India. Measurements included whole air sampling and subsequent analysis for greenhouse gases (CH4, CO2, N2O, SF6) and in-situ measurements of CO, O3, and H2O. For all these tracers a distinct monsoon signature was observed in the longitude range 50–80° E south of 40° N at flight altitudes 8–12.5 km. The formation of a monsoon plume with enhanced mixing ratios was observed for CH4, N2O, SF6, CO and H2O. The plume began to develop in May and persisted through September, and maximum mixing ratios and maximum spatial extension of the plume were observed in August. For CO2 and O3 a minimum was observed. The amplitude of the CO2 seasonal cycle was larger than at comparable latitudes outside the monsoon region, and the CO2 spring maximum was observed with a delay of one month. Different tracer relationships show strong spatial variations across the plume. The comparison with NOAA ground station data shows a clear enhancement for CH4, N2O, SF6 and CO and a decrease in CO2 mixing ratios. Assuming seasonally invariant SF6 emissions based on the EDGAR 4.0 inventory, monthly emissions were estimated for the period June–September for CH4, N2O, and CO, and the CO2 uptake was estimated. While for N2O an emission decrease during the monsoon period was derived, emissions of CH4 were highest in September indicating a different seasonal cycle of emissions. Net CO2 uptake by the vegetation was largest in September.
  Atmospheric Chemistry and Physics. 01/2010;
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  Available from: Peter van Velthoven

  Article: Pollution events observed during CARIBIC flights in the upper troposphere between South China and the Philippines

  S. C. Lai, A. K. Baker, T. J. Schuck, P. van Velthoven, D. E. Oram, Zahn A, Hermann M, Weigelt A, Slemr F, C. A. M. Brenninkmeijer, Ziereis H
  [show abstract] [hide abstract]
  ABSTRACT: A strong pollution episode in the upper troposphere between South China and the Philippines was observed during CARIBIC flights in April 2007. Five pollution events were observed, where enhancements in aerosol and trace gas concentrations including CO, CO2, CH4, non-methane hydrocarbons (NMHCs) and halocarbons were observed along the flight tracks during four sequential flights. The importance of the contribution of biomass/biofuel burning was investigated using chemical tracers, emission factor analysis, back-trajectory analysis and satellite images. The Indochinese peninsula was identified as the probable source region of biomass/biofuel burning. However, enhancements in the urban/industrial tracer C2Cl4 during the events also indicate a substantial contribution from urban anthropogenic emissions. An estimation of the contribution of fossil fuel versus biomass/biofuel to the CO enhancement was made, indicating a biomass/biofuel burning contribution of ~54 to ~92% of the observed CO enhancements. Biomass/biofuel burning was found to be the most important source category during the sampling period.
  Atmospheric Chemistry and Physics. 01/2010;
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  Available from: Angela K Baker

  Article: Greenhouse gas relationships in the Indian summer monsoon plume measured by the CARIBIC passenger aircraft

  T. J. Schuck, C. A. M. Brenninkmeijer, A. K. Baker, Slemr F, P. F. J. v. Velthoven, Zahn A
  [show abstract] [hide abstract]
  ABSTRACT: During the Indian summer monsoon period 2008, regular measurement flights were performed by the CARIBIC aircraft between Germany and India. Measurements included whole air sampling and subsequent analysis for greenhouse gases (CH4, CO2, N2O, SF6) and in-situ measurements of CO, O3, and H2O. For all these tracers a distinct monsoon signature was observed in the longitude range 50–80° E south of 40° N at flight altitudes 8–12.5 km. The formation of a monsoon plume with enhanced mixing ratios was observed for CH4, N2O, SF6, CO and H2O. The plume began to develop in May and persisted through September, and maximum mixing ratios and maximum spatial extension of the plume were observed in August. For CO2 and O3 a minimum was observed. The amplitude of the CO2 seasonal cycle was larger than at comparable latitudes outside the monsoon region, and the CO2 spring maximum was observed with a delay of one month. Different tracer relationships show strong spatial variations across the plume. The comparison with NOAA ground station data shows a clear enhancement for CH4, N2O, SF6 and CO and a decrease in CO2 mixing ratios. Assuming seasonally invariant SF6 emissions based on the EDGAR 4.0 inventory, monthly emissions were estimated for the period June–September for CH4, N2O, and CO, and the CO2 uptake was estimated. While for N2O an emission decrease during the monsoon period was derived, emissions of CH4 were highest in September indicating a different seasonal cycle of emissions. Net CO2 uptake by the vegetation was largest in September.
  Atmospheric Chemistry and Physics Discussions. 01/2010;
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  Available from: Angela K Baker

  Article: Analysis of non-methane hydrocarbons in air samples collected aboard the CARIBIC passenger aircraft

  A. K. Baker, Slemr F, C. A. M. Brenninkmeijer
  [show abstract] [hide abstract]
  ABSTRACT: The CARIBIC project (Civil Aircraft for the Regular Investigation of the atmosphere Based on an Instrument Container) is a long-term monitoring program making regular atmospheric measurements from an instrument container installed monthly aboard a passenger aircraft. Typical cruising altitudes of the aircraft allow for the study of the free troposphere and the extra-tropical upper troposphere as well as the lowermost stratosphere. CARIBIC measurements include a number of real time analyses as well as the collection of aerosol and whole air samples. These whole air samples are analyzed post-flight for a suite of trace gases, which includes non-methane hydrocarbons (NMHC). The NMHC measurement system and its analytical performance are described here. Precision was found to vary slightly by compound, and is less than 2% for the C2–C6 alkanes and ethyne, and between 1% and 6% for C7–C8 alkanes and aromatic compounds. Preliminary results from participation in a Global Atmospheric Watch (WMO) VOC audit indicate accuracies within the precision of the system. Limits of detection are 1 pptv for most compounds, and up to 3 pptv for some aromatics. These are sufficiently low to measure mixing ratios typically observed in the upper troposphere and lowermost stratosphere for the longer-lived NMHC, however, in air samples from these regions many of the compounds with shorter lifetimes (<5 days) were frequently below the detection limit. Observed NMHC concentrations span several orders of magnitude, dependent on atmospheric region and air mass history, with concentrations typically decreasing with shorter chemical lifetimes.
  Atmospheric Measurement Techniques. 01/2010;
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  Available from: Klaus-Peter Heue

  Article: SO₂ and BrO observation in the plume of the Eyjafjallajökull volcano 2010: CARIBIC and GOME-2 retrievals

  Heue K.-P, C. A. M. Brenninkmeijer, A. K. Baker, Rauthe-Schöch A, Walter D, Wagner T, Hörmann C, Sihler H, Dix B, Frieß U, Platt U, B. G. Martinsson, P. F. J. van Velthoven, Hermann M, Zahn A, Ebinghaus R
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  ABSTRACT: The ash cloud of the Eyjafjallajökull1 volcano on Iceland caused closure of large parts of European airspace in April and May 2010. For the validation and improvement of the European volcanic ash forecast models several research flights were performed. Also the CARIBIC (Civil Aircraft for the Regular Investigation of the atmosphere Based on an Instrument Container) flying laboratory, which routinely measures at cruise altitude (≈11 km) performed three dedicated measurements flights through sections of the ash plume. Although the focus of these flights was on the detection and quantification of the volcanic ash, we report here on sulphur dioxide (SO2) and bromine monoxide (BrO) measurements with the CARIBIC DOAS (Differential Optical Absorption Spectroscopy) instrument during the second of these special flights on 16 May 2010. As the BrO and the SO2 observations coincide, we assume the BrO to have been formed inside the volcanic plume. Both SO2 and BrO observations agree well with simultaneous satellite (GOME-2) observations. SO2 column densities retrieved from satellite observations are often used as an indicator for volcanic ash. For SO2 some additional information on the local distribution can be derived from a~comparison of forward and back scan GOME-2 data. More details on the local plume size and position are retrieved by combining CARIBIC and GOME-2 data. 1Also referred to as: Eyjafjalla (e.g. Schumann et al., 2010), Eyjafjöll or Eyjafjoll (e.g. Ansmann et al., 2010).
  Atmospheric Chemistry and Physics Discussions. 01/2010;
• Article: Transport of NMHCs and halocarbons observed by CARIBIC: A case study

  A. K. Baker, C. A. M. Brenninkmeijer, D. E. Oram, D. A. O'Sullivan, T. J. Schuck, F. Slemr
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  ABSTRACT: The CARIBIC project (Civil Aircraft for the Regular Investigation of the Atmosphere Based on an Instrument Container) involves the monthly deployment of an instrument container equipped to make atmospheric measurements from onboard a long-range commercial airliner. Since December 2004, flights for the second phase of CARIBIC have been aboard a Lufthansa Airbus A340-600 traveling between Frankfurt, Germany and destinations in Asia, North America and South America. The instrument package housed in the container is fully automated and during each flight carries out a variety of real-time trace gas and aerosol measurements, and also collects 28 air samples, which are analyzed upon return to the laboratory. Routine measurements made from the sampling flasks include greenhouse gases, nonmethane hydrocarbons (NMHCs), and halocarbons; results of air sample analysis form the basis for the data discussed here. While the majority of CARIBIC samples represent background free tropospheric air and air representative of the upper troposphere/lower stratosphere, the aircraft also, less frequently, encounters air parcels influenced by more recent emissions. Here we present a case study of a round-trip flight between Frankfurt and Toronto, Canada during September 2007. During this flight, different air masses of unique origin were encountered; a number of samples were influenced by transport from the Gulf of Mexico, while others had source regions in Central and Southeast Asia. Samples from the Gulf of Mexico exhibited enhancements in C3-C6 alkanes, as well as a number of halogenated compounds with oceanic sources, such as methyl iodide and bromoform, while Asian samples had enhanced levels of combustion products (CO, acetylene, benzene) and anthropogenic halocarbons (methlyene chloride, chloroform, perchloroethylene). Additionally, a number of samples also showed stratospheric influence, and these samples were characterized by relatively depleted levels of many of the compounds measured. Characterization of the different air masses will be discussed, and these results will be compared to samples collected during other CARIBIC flights, which are representative of both background air and air masses influenced by similar source regions.
  03/2009; 11:12329.
• Article: CARIBIC measurements of methane and other trace gases in the easterly outflow of the Indian summer monsoon

  T. Rhee, C. A. M. Brenninkmeijer, T. J. Schuck, F. Slemr, A. Zahn
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  ABSTRACT: Indian monsoon is one of the most important global meteorological phenomena in the tropics. In particular during Indian summer monsoon, deep convection occurring in Intertropical Convergence Zone located in the Indian subcontinent brings the polluted surface air to high altitude, perturbing clean free troposphere and/or the lowermost stratosphere. CARIBIC (Civil Aircraft for the Regular Investigation of the atmosphere Based on an Instrument Container, www.caribic-atmosphere.com) conducted atmospheric chemical composition measurements at 8-11 km using an automated instrumental package. Monthly regular flights between Germany and the Maldives or Sri Lanka from November 1997 until April 2001 provides an opportunity to investigate spatial and temporal variation of a variety of atmospheric chemical composition. In summer large enhancement of CH4 was observed in the easterly jet flowing from northern Indian subcontinent between 20°N and 30°N. At the same latitudes, other trace gases (CO, O3, NHMCs, CH3Cl) also show an increase, suggesting the influence of surface air masses driven by deep convection to the chemical composition at high altitude. Seasonal variation of CH4 reveals clear enhancement in summer which is opposite to background observations in the marine boundary layer. This reflects the impact of Indian summer monsoon to the chemical composition of free troposphere. Aided by temporal and spatial variation of other trace gases measured in CARIBIC, we will discuss the source regions of this CH4 plume and estimate the amount of trace gases delivered to the flight altitudes during Indian summer monsoon.
  03/2009; 11:8057.
• Source

  Available from: caribic.de

  Article: CO2 isotope analyses using large air samples collected on intercontinental flights by the CARIBIC Boeing 767.

  S S Assonov, C A M Brenninkmeijer, C Koeppel, T Röckmann
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  ABSTRACT: Analytical details for 13C and 18O isotope analyses of atmospheric CO2 in large air samples are given. The large air samples of nominally 300 L were collected during the passenger aircraft-based atmospheric chemistry research project CARIBIC and analyzed for a large number of trace gases and isotopic composition. In the laboratory, an ultra-pure and high efficiency extraction system and high-quality isotope ratio mass spectrometry were used. Because direct comparison with other laboratories was practically impossible, the extraction and measurement procedures were tested in considerable detail. Extracted CO2 was measured twice vs. two different working reference CO2 gases of different isotopic composition. The two data sets agree well and their distributions can be used to evaluate analytical errors due to isotope measurement, ion corrections, internal calibration consistency, etc. The calibration itself is based on NBS-19 and also verified using isotope analyses on pure CO2 gases (NIST Reference Materials (RMs) and NARCIS CO2 gases). The major problem encountered could be attributed to CO2-water exchange in the air sampling cylinders. This exchange decreased over the years. To exclude artefacts due to such isotopic exchange, the data were filtered to reject negative delta18O(CO2) values. Examples of the results are given.
  Rapid Communications in Mass Spectrometry 03/2009; 23(6):822-30. · 2.79 Impact Factor