A. Engel

Goethe-Universität Frankfurt am Main, Frankfurt, Hesse, Germany

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Publications (138)378.14 Total impact

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    ABSTRACT: The three-dimensional quantification of small scale processes in the upper troposphere and lower stratosphere is one of the challenges of current atmospheric research and requires the development of new measurement strategies. This work presents first results from the newly developed Gimballed Limb Observer for Radiance Imaging of the Atmosphere (GLORIA) obtained during the ESSenCe and TACTS/ESMVal aircraft campaigns. The focus of this work is on the so-called dynamics mode data characterized by a medium spectral and a very high spatial resolution. The retrieval strategy for the derivation of two- and three-dimensional constituent fields in the upper troposphere and lower stratosphere is presented. Uncertainties of the main retrieval targets (temperature, O3, HNO3 and CFC-12) and their spatial resolution are discussed. During ESSenCe, high resolution two-dimensional cross-sections have been obtained. Comparisons to collocated remote-sensing and in-situ data indicate a good agreement between the data sets. During TACTS/ESMVal a tomographic flight pattern to sense an intrusion of stratospheric air deep into the troposphere has been performed. This filament could be reconstructed with an unprecedented spatial resolution of better than 500 m vertically and 20 km × 20 km horizontally.
    03/2014; 7(4).
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    ABSTRACT: The effects of chemical two-way mixing on the Extratropical Transition Layer (ExTL) near the subtropical jet (STJ) is investigated by stratospheric tracer-tracer correlations. To this end, in-situ measurements were performed west of Africa (25- 32°N) during the TACTS/ESMVal mission in August/September 2012. The Atmospheric chemical Ionization Mass Spectrometer AIMS sampling HCl and HNO3 was for the first time deployed on the new German High Altitude and LOng range research aircraft HALO. Measurements of O3, CO, ECMWF analysis and the tight correlation of the unambiguous tracer HCl to O3 and HNO3 in the lower stratosphere were used to quantify the stratospheric content of these species in the ExTL. With increasing distance from the tropopause the stratospheric content increased from 10% to 100% with differing profiles for HNO3 and O3. Tropospheric fractions of 20% HNO3 and 40% O3 were detected up to a distance of 30 K above the tropopause.
    Geophysical Research Letters. 03/2014;
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    ABSTRACT: In this work, we have revisited the spectroscopy of the R(6) manifold of the ν3 band of methane which is particularly suitable for in situ laser monitoring of CH4. For that purpose, a home-made Difference Frequency Generation (DFG) laser emitting at 3.24 µm has been coupled to a cryogenically-cooled optical cell to investigate the temperature dependences of the air-broadening, the air-narrowing and the air-mixing coefficients of these ν3 R(6) manifold transitions. The temperatures of the measurements range from 213.5 K to room temperature. These are typically the temperatures found in the troposphere and the lower stratosphere. Finally, the measured spectroscopic parameters have been used to process the in-situ methane absorption spectra recorded by a balloon-borne laser diode spectrometer.
    Journal of Quantitative Spectroscopy and Radiative Transfer 08/2013; · 2.38 Impact Factor
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    ABSTRACT: This work reassesses the global atmospheric budget of H2 with the TM5 model. The recent adjustment of the calibration scale for H2 translates into a change in the tropospheric burden. Furthermore, the ECMWF Reanalysis-Interim (ERA-Interim) data from the European Centre for Medium-Range Weather Forecasts (ECMWF) used in this study show slower vertical transport than the operational data used before. Consequently, more H2 is removed by deposition. The deposition parametrization is updated because significant deposition fluxes for snow, water, and vegetation surfaces were calculated in our previous study. Timescales of 1-2 h are asserted for the transport of H2 through the canopies of densely vegetated regions. The global scale variability of H2 and δ[DH2] is well represented by the updated model. H2 is slightly overestimated in the Southern Hemisphere because too little H2 is removed by dry deposition to rainforests and savannahs. The variability in H2 over Europe is further investigated using a high-resolution model subdomain. It is shown that discrepancies between the model and the observations are mainly caused by the finite model resolution. The tropospheric burden is estimated at 165±8 Tg H2. The removal rates of H2 by deposition and photochemical oxidation are estimated at 53±4 and 23±2 Tg H2/yr, resulting in a tropospheric lifetime of 2.2±0.2 year. Also accessible through Utrecht University repository: http://dspace.library.uu.nl/handle/1874/275776
    Journal of Geophysical Research 05/2013; · 3.17 Impact Factor
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    ABSTRACT: The atmospheric lifetime of a trace gas is defined as the ratio of its global atmospheric burden to its annually averaged global loss rate. Here, we are interested in the lifetimes of the dominant ozone-depleting substances (ODS), which are the prerequisite for the calculation of their ozone-depletion potentials (ODPs). Due to the fact that there is some evidence that the lifetimes for some important ODSs like CFC-11 may be somewhat longer than reported in past WMO assessments the re-evaluation of the dominant ODP lifetimes will be done in the framework of SPARC. Some of the most important ODSs, i.e. CFCs, have solely stratospheric sinks and their stratospheric equals their atmospheric lifetime. For these compounds, the use of tracer-tracer correlation as described by Volk et al. (1997) is the only way that allows to calculate stratospheric lifetimes from solely observations. We will present an evaluation of this method using the results of the GEOS Chemistry-Climate Model (CCM). Hereby, the modelled lifetime serves as an independent reference for the lifetime calculated from the tracer-tracer correlation consistently derived from the same model experiment. We will discuss the implications of these results on the validity and applicability of the method for lifetime calculations described by Volk et al. (1997). Volk, C. M., Elkins, J. W., Fahey, D. W., Dutton, G. S., Gilligan, J. M., Loewenstein, M., Podolske, J. R., Chan, K. R., and Gunson, M. R.: Evaluation of source gas lifetimes from stratospheric observations, J. Geophys. Res., 102, 25543-25564, 1997.
    04/2013;
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    ABSTRACT: EGU General Assembly 2013, Geophysical Research Abstracts, Vol. 15, EGU2013-9191, 2013
    Euopean Geosciences Uninon General Assembly, 7-12. April 2013; 04/2013
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    ABSTRACT: Dynamic and chemical processes modify the ozone (O3) budget of the upper troposphere/lower stratosphere, leading to locally variable O3 trends. In this region, O3 acts as a strong greenhouse gas with a net positive radiative forcing. It has been suggested, that the correlation of the stratospheric tracer hydrochloric acid (HCl) with O3 can be used to quantify stratospheric O3 in the UT/LS region (Marcy et al., 2004). The question is, whether the stratospheric contribution to the nitric acid (HNO3) budget in the UT/LS can be determined by a similar approach in order to differentiate between tropospheric and stratospheric sources of HNO3. To this end, we performed in situ measurements of HCl and HNO3 with a newly developed Atmospheric chemical Ionization Mass Spectrometer (AIMS) during the TACTS (Transport and Composition in the UTLS) / ESMVal (Earth System Model Validation) mission in August/September 2012. The linear quadrupole mass spectrometer deployed aboard the new German research aircraft HALO was equipped with a new discharge source generating SF5- reagent ions and an in-flight calibration allowing for accurate, spatially highly resolved trace gas measurements. In addition, sulfur dioxide (SO2), nitrous acid (HONO) and chlorine nitrate (ClONO2) have been simultaneously detected with the AIMS instrument. Here, we show trace gas distributions of HCl and HNO3 measured during a North-South transect from Northern Europe to Antarctica (68° N to 65° S) at 8 to 15 km altitude and discuss their latitude dependence. In particular, we investigate the stratospheric ozone contribution to the ozone budget in the mid-latitude UT/LS using correlations of HCl with O3. Differences in these correlations in the subtropical and Polar regions are discussed. A similar approach is used to quantify the HNO3 budget of the UT/LS. We identify unpolluted atmospheric background distributions and various tropospheric HNO3 sources in specific regions. Our observations can be compared to data from remote sensing instruments. Further, they will help to validate global chemistry-climate models to gain a better understanding of the trace gas distribution in the UT/LS. Marcy, T. P., Fahey, D. W., Gao, R. S., Popp, P. J., Richard, E. C., Thompson, T. L., Rosenlof, K. H., Ray, E. A., Salawitch, R. J., Atherton, C. S., Bergmann, D. J., Ridley, B. A., Weinheimer, A. J., Loewenstein, M., Weinstock, E. M., and Mahoney, M. J.: Quantifying stratospheric ozone in the upper troposphere with in situ measurements of HCl, Science, 304, 261-265, 2004.
    04/2013;
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    ABSTRACT: The Upper Troposphere / Lower Stratosphere (UTLS) represents an important region for the exchange of air between the stratosphere and the troposphere. Tropospheric gaseous compounds such as greenhouse gases and ozone depleting substances (ODS) are transported into the lower stratosphere on different pathways. Especially the two-way horizontal transport across the subtropical jet was further investigated during the "TACTS - Transport and Composition in the UT/LMS" campaign. We will present in-situ measurements of long-lived and very short-lived (VSLS) halocarbons and Sulfurhexafluoride (SF6) in the UTLS region. The measurements were performed with a sophisticated two channel in-situ instrument on board of the new German research aircraft for atmospheric science HALO (The High Altitude and LOng Range Research Aircraft) during the two campaigns TACTS and "ESMVal - Earth System Modell Validation". The first channel is a gas chromatography (GC) system coupled with mass spectrometer (MS) which operates in negative chemical ionization mode. This GC/MS channel is able to measure halocarbons in ambient air with a time resolution of four minutes. For the measurement of SF6 and CFC-12 the second channel provides its own GC system with an electron capture detector (ECD). With the GC/ECD we achieve a time resolution of 60 seconds. The dataset includes 13 flights with a total of 120 flight hours and a coverage from 80° N to 65° S with a maximum altitude of 15 km. The measurements include halogenated hydrocarbons with a wide span of chemical lifetimes reaching from 100 years for CFC-12 to 26 days for CHBr3. On the basis of this distribution we can improve our understanding of transport timescales, compositions and pathways in the UTLS region. Furthermore we discuss the distribution in respect of atmospheric transport and lifetimes.
    04/2013;
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    ABSTRACT: Intense vertical transport of air from the troposphere to the stratosphere occurs in the maritime continent-west Pacific in boreal winter (Fueglistaler et al., 2004). Convective uplift injects tropospheric air masses into the TTL, where strong radiative heating fosters further vertical transport to the stratosphere and the upper branch of the Brewer Dobson Circulation. Based on observations of very low tropospheric ozone made during the TransBrom-Cruise (Ridder et al., 2012), Rex et al. (2011) has hypothesized that tropospheric air in the western Pacific region should be rather depleted in OH - the main tropospheric oxidant - leading to significantly longer lifetimes of compounds carrying halogens (VSLS) and sulfur (SO2) in these air masses. We investigate this hypothesis and its possible impact on SO2 and VSLS transport to the stratosphere by looking at aircraft measurements made during the SCOUT-O3 field experiment in Darwin, Australia, in November and December 2005. Trajectory calculations show that tropospheric ozone mixing ratios below 15 ppb encountered during several flights are typically found in clean Pacific air masses that are also relatively low in CO. A slightly negative correlation between CO and SO2 in these air masses may indeed be caused by a longer lifetime due to low OH. However, the tropospheric SO2 concentrations observed during SCOUT-O3 are too low to represent a significant sulfur source to the stratosphere. Samples of several VSLS made in the TTL are also analyzed for a possible signature of enhanced tropospheric lifetimes. Fueglistaler, S., et al.: Tropical troposphere-to-stratosphere transport inferred from trajectory calculations, J. Geophys. Res., 109, 10.1029/2003jd004069, 2004. Rex, M., et al.: Is There a Hole in the Global OH Shield Over the Tropical Western Pacific Warm Pool?, NDACC symposium, Reunion Island, 2011. Ridder, T., et al.: Ship-borne FTIR measurements of CO and O3 in the Western Pacific from 43° N to 35° S: an evaluation of the sources, Atmos. Chem. Phys., 12, 815-828, 10.5194/acp-12-815-2012, 2012.
    04/2013;
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    ABSTRACT: EGU General Assembly 2013, Geophysical Research Abstracts, Vol. 15, EGU2013-9191, 2013
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    ABSTRACT: We investigate the contribution of oceanic methyl iodide (CH3I) to the stratospheric iodine budget. Based on CH3I measurements during three tropical ship campaigns and the Lagrangian transport model FLEXPART we provide a detailed analysis of CH3I transport from the ocean surface to the cold point in the upper tropical tropopause layer (TTL). While average oceanic emissions differ by less than 50% from campaign to campaign, the measurements show much stronger variations within each campaign. A positive correlation between the oceanic CH3I emissions and the efficiency of CH3I troposphere-stratosphere transport has been identified for some cruise sections. The mechanism of strong horizontal surface winds triggering large emissions on the one hand and being associated with tropical convective systems, such as developing typhoons, on the other hand, could explain the identified correlations. As a result of the simultaneous occurrence of large CH3I emissions and strong vertical uplift, localized maximum mixing ratios of 0.6 ppt CH3I at the cold point have been determined for observed peak emissions during the SHIVA-Sonne campaign in the coastal West Pacific. The other two campaigns give considerable smaller maxima of 0.1 ppt CH3I for the TransBrom campaign in the open West Pacific and 0.03 ppt for emissions from the coastal East Atlantic during the DRIVE campaign. In order to assess the representativeness of the large local mixing ratios we use climatological emission scenarios to derive global upper air estimates of CH3I abundances. The model results are compared to available upper air measurements including data from the recent ATTREX and HIPPO2 aircraft campaigns. In the East Pacific region, the location of the available measurement campaigns in the upper TTL, the comparisons give a good agreement indicating that around 0.01 to 0.02 ppt of CH3I enter the stratosphere. However, other tropical regions, which are subject to stronger convective activity show larger CH3I entrainment, e.g., 0.08 ppt in the West Pacific. The strong variations in the geographical distribution of CH3I entrainment suggest that currently available upper air measurements are not representative of global estimates and further campaigns will be necessary in order to better understand the CH3I contribution to stratospheric iodine.
    Atmospheric Chemistry and Physics 04/2013; 13(4):11427-11471. · 4.88 Impact Factor
  • Andreas Engel, Harald Boenisch
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    ABSTRACT: The TACTS (Transport and Composition in the UTLS) mission is the first large atmospheric mission of the new German research aircraft HALO. TACTS aims at improving our understanding of the transport processes which determine the chemical composition in the UTLS with a special emphasis on the transition from summer to fall. The mission was flown in August and September 2012 with a fully equipped aircraft carrying 13 different instruments measuring a wide range of chemical tracers with different lifetimes and different source-sink characteristics. The payload consists of both in-situ and remote sensing instruments. In addition to TACTS the same payload was employed to measure the chemical composition during a large north-south transect as part of the ESMVal project. Data are available up to to altitudes above 15 km, potential temperatures above 400 K and covering the latitude range from 65°S to 80°N. Due to the large payload a very wide range of measurements allows for a very good characterisation of the chemical composition. All instruments performed well and close to complete data sets are available for all flights performed during both missions. We present an overview of the scientific aims of TACTS, the payload, the measurements performed and some selected first results.
    04/2013;
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    ABSTRACT: Halogenated hydrocarbons play a major role as precursors for stratospheric ozone depletion. Released from the surface in the troposphere, the halocarbons reach the stratosphere via transport through the tropical tropopause layer. Measurements of stratospheric BrO indicate an existing gap between the abundance of long lived brominated halocarbons, such as Halons and methyl bromide (CH3Br), and the abundance of inorganic bromine in the stratosphere. Recently, it has been realized that in addition to these long-lived substances so called very short-lived substances (VSLS) can also contribute significantly to the stratospheric halogen loading. The VSLS have lifetimes less than half a year and are predominantly emitted from climate-sensitive natural sources, e.g. marine macro-algae. A main source region for those emissions is the Western Pacific where sea surface temperatures are high and air masses from the surface can be transported rapidly into the TTL (Tropical Tropopause Layer) by deep convective systems. In this work, we present results derived by our measurement data from the field campaign which was part of the SHIVA (Stratospheric Halogens in a Varying Atmosphere) Project. One aspect of this campaign, which took place in November and December 2011, was the deployment of the German research aircraft "Falcon" in the Western Pacific at Miri in Malaysia. From there we performed sixteen local flights in total; these flights covered a spatial range from the boundary layer up to 11km altitude around the area of Borneo. Our contribution to the campaign was the deployment of a newly developed GC/MS system operated in negative chemical ionization mode for the fast analysis of halogenated hydrocarbons in ambient air onboard the aircraft. The long lived halocarbons H1301, H1211, H1202, H2402 as well as CH3Br and the very short lived substances CHBr3, CH2Br2, CHBr2Cl, CHBrCl2 and CHBrCl were be analyzed with the instrument. We derive a detailed budget of total organic bromine in this tropical region from more than 500 measurements of ambient air. Observations in the boundary layer as well as data from survey flights in the free upper troposphere are discussed. Furthermore, the results are compared and discussed with other studies from this region.
    04/2013; 14(4):10605-.
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    ABSTRACT: This paper briefl y summarizes the activities and observations made during the SHIVA (Stratospheric Ozone: Halogen Impacts in a Varying Atmosphere) Western Pacific campaign in fall 2011, here referred to as the SHIVA South China Sea (SCS) campaign. The campaign addressed investigation of emissions of so-called halogenated very short-lived substances (VSLS) from the South China Sea (SCS), their atmospheric transport and transformation, their contribution to the budget of ozone destroying halogens in the stratosphere. Key fi ndings of the SHIVA campaign are that, (a) the SCS is indeed a prominent emission region for halogenated VSLS, mostly due to the emissions of micro- and macro-algae, (b) in the boundary layer of the marine atmosphere typical VSLS mixing ratios were 3.6 – 13.3 ppt and in the upper troposphere 4.1±0.6 ppt, which may well explained a total source gas (SG) and product gas (PG) injection of [VSLS] = 4 – 5 ppt into the global stratosphere.
    Malaysian Journal of Science 01/2013; 32:141-148.
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    ABSTRACT: The International Halocarbons in Air Comparison Experiment (IHALACE) was conducted to document relationships between calibration scales among various laboratories that measure atmospheric greenhouse and ozone depleting gases. Six stainless steel cylinders containing natural and modified natural air samples were circulated among 19 laboratories. Results from this experiment reveal relatively good agreement among commonly used calibration scales for a number of trace gases present in the unpolluted atmosphere at pmol mol<sup>−1</sup> (parts per trillion) levels, such as chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), and hydrofluorocarbons (HFCs). Some scale relationships were found to be consistent with those derived from bi-lateral experiments or from analysis of atmospheric data, while others revealed discrepancies. The transfer of calibration scales among laboratories was found to be problematic in many cases, meaning that measurements tied to a common scale may not, in fact, be compatible. These results reveal substantial improvements in calibration over previous comparisons. However there is room for improvement in communication and coordination of calibration activities with respect to the measurement of halogenated and related trace gases.
    Atmospheric Measurement Techniques 01/2013; 6(4):8021-8069. · 3.21 Impact Factor
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    ABSTRACT: Estimates of the recovery time of stratospheric ozone heavily rely on the exact knowledge of the processes that lead to the decomposition of the relevant halogenated source gases. Crucial parameters in this context are Fractional Release Factors (FRFs) as well as stratospheric lifetimes and Ozone Depletion Potentials (ODPs). We here present data from the analysis of air samples collected between 2009 and 2011 on board research aircraft flying in the mid- and high latitudinal stratosphere and infer the above-mentioned parameters for ten major source gases:CFCl3 (CFC-11), CF2Cl2 (CFC-12), CF2ClCFCl2(CFC-113), CCl4 (carbon tetrachloride),CH3CCl3 (methyl chloroform), CHF2Cl (HCFC-22), CH3CFCl2 (HCFC-141b), CH3CF2Cl (HCFC-142b), CF2ClBr (H-1211), and CF3Br (H-1301). The inferred correlations of their FRFs with mean ages of air reveal less decomposition as compared to previous studies for most compounds. When using the calculated set of FRFs to infer equivalent stratospheric chlorine we find a reduction of more than 20% as compared to the values inferred in the most recent Scientific Assessment of Ozone Depletion by the World Meteorological Organisation (WMO, 2011). We also note that FRFs and their correlations with mean age are not generally time-independent as often assumed. The stratospheric lifetimes were calculated relative to that of CFC-11. Within our uncertainties the inferred ratios between lifetimes agree with those between stratospheric lifetimes from recent WMO reports except for CFC-11, CFC-12 and CH3CCl3. Finally we calculate lower ODPs than WMO for six out of ten compounds with changes most pronounced for the three HCFCs. Collectively these newly calculated values may have important implications for the severity and recovery time of stratospheric ozone loss.
    Atmospheric Chemistry and Physics 10/2012; 12(10):28525-28557. · 4.88 Impact Factor
  • H. Boenisch, A. Engel
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    ABSTRACT: The atmospheric lifetime of a trace gas is defined as the ratio of its global atmospheric burden to its annually averaged global loss rate and it can be used to predict the future evolution of the specie. Here, we are interested in the lifetimes of the dominant ozone-depleting substances (ODS), which are the prerequisite for the calculation of their ozone-depletion potentials (ODPs). Due to the fact that there is some evidence that the lifetimes for some important ODSs like CFC-11 may be somewhat longer than reported in past assessments (WMO, 2011) re-evaluation of the dominant ODP lifetimes will be done in the framework of SPARC. Some of the most important of the ODSs, i.e. CFCs and halons, have solely stratospheric sinks and their stratospheric equals their atmospheric lifetime. For these compounds the best reference is still the work of Volk et al. (1997) which is based upon the theoretical work of Plumb and Ko (1992) and Plumb (1996). In this work, we will discuss the implications of seasonality, tropospheric trends, latitudinal tropospheric tracer gradients and quasi-horizontal transport between the tropics and the extratropics on the validity and applicability of the two methods for lifetime calculations described by Volk et al. (1997). Plumb, R. A., and Ko, M. K. W.: Interrelationships between Mixing Ratios of Long Lived Stratospheric Constituents, J. Geophys. Res., 97, 10145-10156, 1992. Plumb, R. A.: A 'tropical pipe' model of stratospheric transport, J. Geophys. Res., 101, 3957-3972, 1996. Volk, C. M., Elkins, J. W., Fahey, D. W., Dutton, G. S., Gilligan, J. M., Loewenstein, M., Podolske, J. R., Chan, K. R., and Gunson, M. R.: Evaluation of source gas lifetimes from stratospheric observations, J. Geophys. Res., 102, 25543-25564, 1997.
    04/2012;
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    ABSTRACT: Chlorine isotope fractionation in CFC-12 reflects the latitude dependence of stratospheric chemistry and transport rates
    04/2012;
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    ABSTRACT: In this work, we present measurement data from the field campaign "SHIVA - Stratospheric Halogens in a Varying Atmosphere". One part of this campaign was the deployment of the German research aircraft "Falcon" in the Western Pacific at Miri/Malaysia, performing research flights from the boundary layer up to 11km altitude. The dataset we present was obtained by a total amount of sixteen local flights in the area of Borneo in November and December 2011. Onboard the aircraft we used a sophisticated in-situ GC/MS system operated in negative chemical ionization mode for the fast analysis of halogenated hydrocarbons in ambient air. Halogenated hydrocarbons play a major role as precursors for stratospheric ozone depletion. Released from the surface in the troposphere, the halocarbons reach the stratosphere via transport through the Tropical Tropopause Layer (TTL). Measurements of stratospheric BrO indicate an existing gap between the abundance of long lived brominated halocarbons, such as Halons and methyl bromide (CH3Br), and the abundance of inorganic bromine in the stratosphere. Recently, it has been realized that in addition to these long-lived substances so called very short-lived substances (VSLS) can also contribute significantly to the stratospheric halogen loading. The VSLS have lifetimes less than half a year and are predominantly emitted from climate-sensitive natural sources, e.g. marine macro-algae. A main source region for those emissions is the Western Pacific where sea surface temperatures are high and air masses from the surface can be transported rapidly into the TTL by deep convective systems. Our main goal during SHIVA was to improve the understanding of emissions, atmospheric transport and the chemical degradation of halogenated VSLS. Detailed measurements in the boundary layer as well as data from survey flights in the free upper troposphere are used to deflect a local budget bromine species in this tropical region. Measurements in areas of convective outflow can be used to gather information about the vertical transport of VSLS-emissions by shallow and deep convection over the rainforest and over coastal regions. Furthermore we will investigate the emission ratios of different substances like CHBr3, CH2Br2 and CHBr2Cl.
    04/2012;
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    ABSTRACT: Halogenated trace gases are large contributors to the anthropogenic greenhouse effect with chlorine- and bromine-containing species also catalysing ozone-depletion in the stratosphere. In order to quantify these impacts knowledge of the respective atmospheric lifetimes is crucial. For many of these compounds the stratospheric lifetime is very influential, in the case of chlorofluorocarbons (CFCs) it is even equivalent to the total atmospheric lifetime as CFCs have only negligible sink reactions in the troposphere. Published lifetime estimates based on various experimental and modelling-based approaches show considerable spread which results in significant uncertainty ranges. We here present an analysis of a data set based on mass spectrometric measurements of stratospheric whole-air samples. These samples originate from the tropical, mid-latitudinal, and polar stratosphere from aircraft and balloon campaigns in 2005, 2006, 2008, 2009, 2010, and 2011. Implications for the stratospheric lifetimes of a variety of halocarbons including CFCs, halons, hydrochlorofluorocarbons, and hydrofluorocarbons (HFCs) are being derived and discussed.
    04/2012;

Publication Stats

2k Citations
378.14 Total Impact Points

Institutions

  • 1998–2014
    • Goethe-Universität Frankfurt am Main
      • Institute of Atmosphere and Environment
      Frankfurt, Hesse, Germany
  • 2010
    • University of East Anglia
      • School of Environmental Sciences
      Norwich, ENG, United Kingdom
  • 2005–2010
    • University Hospital Frankfurt
      Frankfurt, Hesse, Germany
  • 1994–2001
    • Forschungszentrum Jülich
      • Institute of Energy and Climate Research (IEK)
      Jülich, North Rhine-Westphalia, Germany