70 results on '"Kloss, Corinna"'
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52. Reply to Michael Fromm
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Kloss, Corinna, primary
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- 2019
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53. Sampling bias adjustment for sparsely sampled satellite measurements applied to ACE-FTS carbonyl sulfide observations
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Kloss, Corinna, primary, von Hobe, Marc, additional, Höpfner, Michael, additional, Walker, Kaley A., additional, Riese, Martin, additional, Ungermann, Jörn, additional, Hassler, Birgit, additional, Kremser, Stefanie, additional, and Bodeker, Greg E., additional
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- 2019
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54. Transport of the 2017 Canadian wildfire plume to the tropics and global stratosphere via the Asian monsoon circulation
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Kloss, Corinna, primary, Berthet, Gwenaël, additional, Sellitto, Pasquale, additional, Ploeger, Felix, additional, Bucci, Silvia, additional, Khaykin, Sergey, additional, Jégou, Fabrice, additional, Taha, Ghassan, additional, Thomason, Larry W., additional, Barret, Brice, additional, Le Flochmoen, Eric, additional, von Hobe, Marc, additional, Bossolasco, Adriana, additional, Bègue, Nelson, additional, and Legras, Bernard, additional
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- 2019
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55. Response to RC 2
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Kloss, Corinna, primary
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- 2018
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56. Response to RC 1
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Kloss, Corinna, primary
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- 2018
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57. Carbonyl Sulfide in the Stratosphere: airborne instrument development and satellite based data analysis
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Kloss, Corinna
- Subjects
ddc:5:54:540 ,500 Naturwissenschaften und Mathematik » 540 Chemie » 540 Chemie und zugeordnete Wissenschaften ,Fakultät für Mathematik und Naturwissenschaften » Chemie » Dissertationen - Abstract
Carbonylsulfid (OCS) hat einen großen Einfluss auf den globalen Schwefelkreislauf und damit auch auf das globale Klima. In Zeiten geringer vulkanischer Aktivität ist OCS das dominierende Schwefelgas in der Atmosphäre. In der Stratosphäre wird OCS über Schwefeldioxid zu Aerosol umgewandelt. Stratosphärisches Aerosol hat einen kühlenden Effekt auf das Klima. Im Rahmen dieser Dissertation wird ein Beitrag zum Verständnis von OCS und dessen Rolle in atmosphärischen Prozessen, in der oberen Troposphäre und unteren Stratosphäre geleistet. Hierzu wurden Satellitendaten analysiert und ein neues Messgerät AMICA (Airborne Mid-Infrared Cavity enhanced Absorption spectrometer), für Einsätze auf stratosphärischen Forschungsflugzeugen entwickelt. Mit dem Satelliten Datenprodukt von ACE-FTS wurde die Gesamtmenge an stratosphärischem OCS bestimmt, der sog. stratosphärische "Burden". Dieser beträgt 524 Gg, was gut mit der OCS Repräsentierung eines Schwefelkreislauf Modells übereinstimmt und entspricht etwa 10 % der gesamten atmosphärischen OCS Masse. Im gesamten bisherigen ACE-FTS Messzeitraum von 2004 bis 2016 ist kein signifikanter Trend zu beobachten. Wegen der lückenhaften, globalen Abtastung von ACE-FTS entsteht ein systematischer Fehler bei der Berechnung von klimatologischen Mittlungen über Breitengrad- und Zeitbereiche. Um diesen Fehler zu korrigieren wurde in dieser Arbeit eine Methode entwickelt, die auf einer mathematischen Interpolation basiert. Für eine Einschätzung der Größe und Signifikanz dieser Abweichung wurde diese Methode erprobt und Grenzen aufgezeigt. Signifikant erhöhte OCS- (CO- und HCN-) Konzentrationen werden in der Antizyklone des asiatischen Monsuns, der als wichtiger Transportweg von dem Treibhausgas- verschmutzen asiatischen Raum in die Stratosphäre gilt, mit dem ACE-FTS Datensatz nachgewiesen. Ein HCN:OCS Vergleich unterstützt die Annahme, dass Luftmassen aus der Bay of Bengal Region eher südlich der Antizyklone des asiatischen Monsuns transportiert werden und die Antizyklone eher von kontinentaler Konvektion gespeist wird. Der asiatische Monsun soll mit hochaufgelösten in-situ Messungen genauer untersucht werden. Ein hochauflösendes, in-situ Messgerät AMICA für den Einsatz auf Flugzeug-Messkampagnen, wurde im Rahmen dieser Arbeit entwickelt und charakterisiert. AMICA ist ein hochauflösendes in-situ Spektrometer, entwickelt für den Einsatz auf Forschungsflugzeugen. Unter die Entwicklung und Erprobung einzelner Komponenten des Messinstruments fallen zum Beispiel ein druckdichtes Gehäuse für die Messapparatur, ein Flusssystem zur Regulierung eines konstanten Drucks in den Messzellen (bei Schwankungen des Außendrucks während eines Messflugs) und ein geeignetes OCS Kalibrierungssystem. Während der ersten Messkampagne in Kalamata, Griechenland im Sommer 2016, hat AMICA erfolgreich gemessen. Messungen zeigen, dass OCS, wie angenommen in der Stratosphäre abnimmt. In der oberen Troposphäre und unteren Stratosphäre (UTLS) zeigen die OCS Messungen eine höhere Variabilität als erwartet. Das AMICA CO Datenprodukt wurde der StratoClim Gemeinschaft zur Verfügung gestellt. Ein Vergleich mit einem nahe gelegenem ACE-FTS Messprofil zeigt eine gute übereinstimmung mit AMICA OCS- und CO-Werten in der Stratosphäre. Ein Vergleich mit ACE-FTS OCS und CO Messungen zeigt eine gute übereinstimmung der beiden Messinstrumente in der Stratosphäre. Weitere geplante Messflüge mit AMICA werden zu einem besseren Verständnis der gemessenen OCS Variabilität in der UTLS beitragen, was zu einer besseren Parameterisierung von OCS in globalen Klimamodellen führen kann. Carbonyl sulfide plays a crucial role in the global atmospheric sulfur cycle and therefore for the global climate. It is the most abundant sulfur containing gas in the atmosphere during volcanic quiescence and is converted to aerosol in the stratosphere, which has a cooling effect on the climate. This work contributes to a better understanding of the role of OCS in the upper troposphere and lower stratosphere. Satellite based data were analyzed and a new instrument AMICA (Airborne Mid-Infrared Cavity enhanced Absorption spectrometer) for in-situ OCS measurements on stratospheric research aircraft was developed. Using the OCS data set from the satellite based instrument ACE-FTS, the stratospheric OCS burden was calculated to be 524 Gg, which is 10 % of the total atmospheric OCS budget and is in agreement with a sulfur cycle model. No trend in the global burden is observed between 2004 and 2016. Due to the sparse spacial coverage of the data set of ACE-FTS, a sampling bias arises when computing climatological averages over seasons and latitude bands. This sampling bias is corrected for with a newly developed procedure, using a mathematical interpolation. To estimate the significance and magnitude of the bias for each data point, the performance of the interpolation method was tested and some limitations identified. Additionally, with the ACE-FTS data set, a significant increase in OCS (CO and HCN) mixing ratios is observed in the Asian monsoon anticyclone, a pathway from the highest polluted region on earth into the stratosphere. An analysis of the HCN:OCS ratios supports the suggestion of a transport from the Bay of Bengal region outside to the southern border of the anticyclone with air masses in the Asian monsoon anticyclone mostly originating from continental convection. The Asian monsoon and the features seen with the ACE-FTS data set will be investigated in detail with the new in-situ, high resolution instrument AMICA during the EU-project StratoClim. AMICA has been developed and tested as part of this thesis. Important tests were made that contributed to the mechanical design and measurement set up in the final AMICA instrument. Key components include a box-shaped pressure tight enclosure, a flow system that regulates the cavity pressure over a wide ambient pressure range, spanning the full altitude range of available research aircraft, and the establishment of an OCS calibration system. AMICA successfully measured OCS as well as CO, CO2 and H2O during its first campaign that comprised three flights from Kalamata, Greece in summer 2016. OCS measurements show decreasing mixing ratios in the stratosphere as expected and a larger variability in the UTLS region than expected. The complete data set of the important tropospheric tracer CO was provided to the StratoClim community. A comparison with a nearby ACE-FTS profile shows a reasonably good agreement between AMICA and ACE-FTS in the stratosphere. Further measurement flights in the UTLS region will help understand the detected higher variability of OCS in the UTLS. This can improve the representation of OCS in global climate models.
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- 2017
58. Atmospheric Abundances, Trends and Emissions of CFC-216ba, CFC-216ca and HCFC-225ca
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Kloss, Corinna, Newland, Mike, Oram, Dave, Fraser, Paul J., Brenninkmeijer, Carl A. M., Röckmann, Thomas, and Laube, Johannes
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lifetime ,ozone depletion ,CFC-216ba ,HCFC-225ca ,ODP ,emission ,lcsh:Meteorology. Climatology ,Montreal Protocol ,lcsh:QC851-999 ,CFC-216ca ,fractional release - Abstract
The first observations of the feedstocks, CFC-216ba (1,2-dichlorohexafluoropropane) and CFC-216ca (1,3-dichlorohexafluoropropane), as well as the CFC substitute HCFC-225ca (3,3-dichloro-1,1,1,2,2-pentafluoropropane), are reported in air samples collected between 1978 and 2012 at Cape Grim, Tasmania. Present day (2012) mixing ratios are 37.8 ± 0.08 ppq (parts per quadrillion; 1015) and 20.2 ± 0.3 ppq for CFC-216ba and CFC-216ca, respectively. The abundance of CFC-216ba has been approximately constant for the past 20 years, whilst that of CFC-216ca is increasing, at a current rate of 0.2 ppq/year. Upper tropospheric air samples collected in 2013 suggest a further continuation of this trend. Inferred annual emissions peaked 421 at 0.18 Gg/year (CFC-216ba) and 0.05 Gg/year (CFC-216ca) in the mid-1980s and then decreased sharply as expected from the Montreal Protocol phase-out schedule for CFCs. The atmospheric trend of CFC-216ca and CFC-216ba translates into continuing emissions of around 0.01 Gg/year in 2011, indicating that significant banks still exist or that they are still being used. HCFC-225ca was not detected in air samples collected before 1992. The highest mixing ratio of 52 ± 1 ppq was observed in 2001. Increasing annual emissions were found in the 1990s (i.e., when HCFC-225ca was being introduced as a replacement for CFCs). Emissions peaked around 1999 at about 1.51 Gg/year. In accordance with the Montreal Protocol, restrictions on HCFC consumption and the short lifetime of HCFC-225ca, mixing ratios declined after 2001 to 23.3 ± 0.7 ppq by 2012.
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- 2014
59. Upward transport into and within the Asian monsoon anticyclone as inferred from StratoClim trace gas observations.
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von Hobe, Marc, Ploeger, Felix, Konopka, Paul, Kloss, Corinna, Ulanowski, Alexey, Yushkov, Vladimir, Ravegnani, Fabrizio, Volk, C. Michael, Pan, Laura L., Honomichl, Shawn B., Tilmes, Simone, Kinnison, Douglas E., Garcia, Rolando R., and Wright, Jonathon S.
- Abstract
Every year during the Asian summer monsoon season from about mid-June to early September, a stable anticyclonic circulation system forms over the Himalayans. This Asian summer monsoon (ASM) anticyclone has been shown to promote transport of air into the stratosphere from the Asian troposphere, which contains large amounts of anthropogenic pollutants. Essential details of Asian monsoon transport, such as the exact time scales of vertical transport, the role of convection in cross-tropopause exchange, and the main location and level of export from the confined anticyclone to the strato sphere are still not fully resolved. Recent airborne observations from campaigns near the ASM anticyclone edge and centre in 2016 and 2017 respectively show a steady decrease in carbon monoxide (CO) and increase in ozone (O
3 ) with height starting from tropospheric values of 80-100 ppb CO and 30-50 ppb O3 at about 365 K potential temperature. CO mixing ratios reach stratospheric background values of ~20 ppb at about 420 K and do not show a significant vertical gradient at higher levels, while ozone continues to increase throughout the altitude range of the aircraft measurements. Nitrous oxide (N2 O) remains at or only marginally below its 2017 tropospheric mixing ratio of 326 ppb up to about 400 K, which is above the local tropopause. A decline in N2O mixing ratios that indicates a significant contribution of stratospheric air is only visible above this level. Based on our observations, we draw the following picture of vertical transport and confinement in the ASM anticyclone: rapid convective uplift transports air to near 16 km in altitude, corresponding to potential temperatures up to about 370 K. Although this main convective outflow layer extends above the level of zero radiative heating (LZRH), our observations of CO concentration show little to no evidence of convection actually penetrating the tropopause. Rather, further ascent occurs more slowly, consistent with isentropic vertical velocities of 0.3 - 0.8 K day-1. For gases not subject to microphysical processes, neither the lapse rate tropopause (LRT) around 380 K nor the cold point tropopause (CPT) around 390 K marks the strong discontinuity of the key tracers (CO, O3 , and N2 O). Up to about 10 to 20 K above the CPT, isolation of air inside the ASM anticyclone prevents significant in-mixing of stratospheric air. The observed changes in CO and O3 likely result from in-situ chemical processing. Above about 420 K, mixing processes become more significant and the air inside the anticyclone is exported vertically and horizontally into the surrounding stratosphere. [ABSTRACT FROM AUTHOR]- Published
- 2020
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60. Global modelling studies of composition and decadal trends of the Asian Tropopause Aerosol Layer.
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Bossolasco, Adriana, Jegou, Fabrice, Sellitto, Pasquale, Berthet, Gwenaël, Kloss, Corinna, and Legras, Bernard
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The Asian Summer Monsoon (ASM) traps convectively-lifted boundary layer pollutants inside its upper-tropospheric lower-stratospheric Asian monsoon anticyclone (AMA). It is associated with a seasonal and spatially-confined enhanced aerosol layer, called the Asian Tropopause Aerosol Layer (ATAL). The knowledge of the ATAL properties in terms of aerosol budget, chemical composition, as well as its variability and temporal trend is still largely uncertain, due to the dynamical variability of the AMA, the dearth of in situ observations in this region, the complex transport pathways of pollutants and its atmospheric chemical processes. In this work, we use the Community Earth System Model (CESM 1.2 version) based on the coupling of the Community Atmosphere Model (CAM5) and the MAM7 (Modal Aerosol Model) aerosol module to simulate the composition of the ATAL and its decadal trends. Our simulations cover a long-term period of 16 years from 2000 to 2015. We identify a double-peak aerosols vertical profile for the ATAL. We attribute the upper peak (around 100 hPa, predominant during early ATAL in June) to dry aerosols, possibly from nucleation processes and the lower peak (around 250 hPa, predominant for a well-developed and late ATAL, in July and August) to cloud-borne aerosols associated with convective clouds. We find that mineral dust is the dominant aerosol by mass in the ATAL showing a large interannual variability, but no long-term trend, due to its natural variation. The results between 120-80 hPa (dry aerosol peak) suggest that for aerosols other than dust the ATAL is composed of around 40 % of sulfate, 30% of secondary and 15 % of primary organic aerosols, 14 % of ammonium aerosols and less than 3 % of black carbon. The analysis of the anthropogenic and biomass burning aerosols shows a positive trend for all aerosols simulated by CESM-MAM7. [ABSTRACT FROM AUTHOR]
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- 2020
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61. Stratospheric aerosol layer perturbation caused by the 2019 Raikoke and Ulawun eruptions and climate impact.
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Kloss, Corinna, Berthet, Gwenaël, Sellitto, Pasquale, Ploeger, Felix, Taha, Ghassan, Tidiga, Mariam, Eremenko, Maxim, Bossolasco, Adriana, Jégou, Fabrice, Renard, Jean-Baptiste, and Legras, Bernard
- Abstract
In June 2019 a stratospheric moderate eruption occurred at Raikoke (48° N, 153° E). Satellite observations show the injection of ash and SO
2 into the lower stratosphere and an early entrainment of the plume into a cyclone. Following the Raikoke eruption stratospheric Aerosol Optical Depth (sAOD) values increased in the whole northern hemisphere and tropics and remained enhanced for more than one year, with peak values at 0.040 (shorter-wavelength visible, higher northern latitudes) to 0.025 (shorter-wavelength visible, average northern hemisphere). Discrepancies between observations and models indicate that ash has played a role on evolution and sAOD values. Top of the atmosphere radiative forcings are estimated at values between -0.3 and -0.4 W/m² (clear-sky), and of -0.1 to -0.2 W/m² (all-sky), comparable to what was estimated for the Sarychev eruption in 2009. Almost simultaneously two significantly smaller stratospheric eruptions occurred at Ulawun (5° S, 151° E) in June and August. Aerosol enhancements from the Ulawun eruptions had mainly an impact on the tropics and southern hemisphere. The Ulawun plume circled the Earth within one month in the tropics. Peak shorter- wavelength sAOD values at 0.01 are found in the tropics following the Ulawun eruptions, and a radiative forcing not exceeding -0.15 (clear-sky) and -0.05 (all-sky). Compared to the Canadian Fires (2017), Ambae eruption (2018), Ulawun (2019) and the Australian fires (2019/2020) highest sAOD values and RF are found for the Raikoke eruption. [ABSTRACT FROM AUTHOR]- Published
- 2020
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62. Convective uplift of pollution from the Sichuan basin into the Asian monsoon anticyclone during the StratoClim aircraft campaign.
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Keun-Ok Lee, Barret, Brice, Flochmoën, Eric L., Tulet, Pierre, Bucci, Silvia, von Hobe, Marc, Kloss, Corinna, Legras, Bernard, Leriche, Maud, Sauvage, Bastien, Ravegnani, Fabrizio, and Ulanovsky, Alexey
- Abstract
The StratoClim airborne campaign took place in Nepal from 27 July to 10 August 2017 to document the physical and chemical properties of the South Asian Upper Troposphere Lower Stratosphere (UTLS) during the Asian Summer Monsoon (ASM). In the present paper, simulations with the Meso-NH cloud-chemistry model at a horizontal resolution of 15 km are performed over the Asian region to characterize the impact of monsoon deep convection on the composition of Asian Monsoon Anticyclone (AMA) and on the formation of the Asian Tropopause Aerosol Layer (ATAL) during the StratoClim campaign. StratoClim took place during a break phase of the monsoon with an intense convective activity over south China and Sichuan. Comparisons between Brightness Temperature (BT) at 10.8 microns observed by satellite sensors and simulated by Meso-NH highlight the ability of the model to correctly reproduce the life cycle of deep convective clouds. Comparison between CO and O3 concentrations from Meso-NH and airborne observations (StratoClim and IAGOS) demonstrates that the model captures most of the observed variabilities. Nevertheless, for both gases, the model tends to overestimate the concentrations and misses some thin CO plumes related to local convective events probably because of a too coarse resolution, but the convective uplift of pollution is very well captured by the model. We have therefore focused on the impact of Sichuan convection on the AMA composition. A dedicated sensitivity simulation showed that the 7 August convective event brought large amounts of CO deep into the AMA and even across the 380 K isentropic level located at 17.8 km. This Sichuan contribution enhanced the CO concentration by ~15 % to reach more than 180 ppbv over a large area around 15 km height. Noteworthy, Meso-NH captures the impact of the diluted Sichuan plume on the CO concentration during a StratoClim flight south of Kathmandu highlighting its ability to reproduce the transport pathway of Sichuan pollution. According to the model, primary organic aerosol and black carbon particles originating from Sichuan are transported following the same pathway as CO. The large particles are heavily scavenged within the precipitating part of the convective clouds but remain the most important contributor to the particle mass in the AMA. Over the whole AMA region, the 7 August convective event resulted in a 0.5% increase of CO over the 10-20 km range that lasted about 2 days. The impact of pollution uplift from three regions (India, China and Sichuan) averaged over the first 10 days of August has also been evaluated with sensitivity simulations. Even during this monsoon break phase, the results confirm the predominant role of India relative to China with respective contributions of 11 and 7 % to CO in the 10[sup -1]5 km layer. Moreover, during this period a large part (35 %) of the Chinese contribution comes from the Sichuan basin alone. [ABSTRACT FROM AUTHOR]
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- 2020
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63. On sampling bias adjustment for sparsely observing satellite instruments for the example of carbonyl sulfide (OCS)
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Kloss, Corinna, primary, von Hobe, Marc, additional, Höpfner, Michael, additional, Walker, Kaley A., additional, Riese, Martin, additional, Ungermann, Jörn, additional, Hassler, Birgit, additional, Kremser, Stefanie, additional, and Bodeker, Greg E., additional
- Published
- 2018
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64. Transport of the 2017 Canadian wildfire plume to the tropics and global stratosphere via the Asian monsoon circulation.
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Kloss, Corinna, Berthet, Gwenaël, Sellitto, Pasquale, Ploeger, Felix, Bucci, Silvia, Khaykin, Sergey, Jégou, Fabrice, Taha, Ghassan, Thomason, Larry W., Barret, Brice, Le Flochmoen, Eric, von Hobe, Marc, Bossolasco, Adriana, Bègue, Nelson, and Legras, Bernard
- Abstract
We show that a fire plume originating at high northern latitudes during the Canadian wildfire event in July/August 2017 reached the tropics, and subsequently the tropical stratosphere via the ascending branch of the Brewer-Dobson Circulation (BDC). The transport from high to low latitudes in the upper troposphere and lowermost stratosphere was mediated by the anticyclonic flow of the Asian monsoon circulation. The fire plume reached the Asian monsoon area in late August/early September, when the Asian Monsoon Anticyclone (AMA) was still in place. While there is no evidence of mixing into the center of the AMA, we show that a substantial part of the fire plume is entrained into the anticyclonic flow at the AMA edge, and is transported into the tropical Upper-Troposphere–Lower-Stratosphere (UTLS), and possibly the Southern Hemisphere particularly following the north-south flow on the eastern side. In the tropics the fire plume is lifted by ~1.5 km per month. Inside the AMA we find evidence of the Asian Tropopause Aerosol Layer (ATAL) in August, doubling background aerosol conditions with a calculated top of the atmosphere shortwave radiative forcing (RF) of −0.05 W/m
2 . The regional climate impact of the fire signal in the wider Asian monsoon area in September exceeds the impact of the ATAL by a factor of 2–4 and compares to that of a plume coming from an advected moderate volcanic eruption. The stratospheric, trans-continental transport of this plume to the tropics and the related regional climate impact point at the importance of long-range dynamical interconnections of pollution sources. [ABSTRACT FROM AUTHOR]- Published
- 2019
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65. Supplementary material to "Oceanic emissions unlikely to account for the missing source of atmospheric carbonyl sulfide"
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Lennartz, Sinikka T., primary, Marandino, Christa A., additional, von Hobe, Marc, additional, Cortes, Pau, additional, Quack, Birgit, additional, Simo, Rafel, additional, Booge, Dennis, additional, Pozzer, Andrea, additional, Steinhoff, Tobias, additional, Arevalo-Martinez, Damian L., additional, Kloss, Corinna, additional, Bracher, Astrid, additional, Röttgers, Rüdiger, additional, Atlas, Elliott, additional, and Krüger, Kirstin, additional
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- 2016
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66. Oceanic emissions unlikely to account for the missing source of atmospheric carbonyl sulfide
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Lennartz, Sinikka T., primary, Marandino, Christa A., additional, von Hobe, Marc, additional, Cortes, Pau, additional, Quack, Birgit, additional, Simo, Rafel, additional, Booge, Dennis, additional, Pozzer, Andrea, additional, Steinhoff, Tobias, additional, Arevalo-Martinez, Damian L., additional, Kloss, Corinna, additional, Bracher, Astrid, additional, Röttgers, Rüdiger, additional, Atlas, Elliott, additional, and Krüger, Kirstin, additional
- Published
- 2016
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67. On sampling bias adjustment for sparsely observing satellite instruments for the example of carbonyl sulfide (OCS).
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Kloss, Corinna, von Hobe, Marc, Höpfner, Michael, Walker, Kaley A., Riese, Martin, Ungermann, Jörn, Hassler, Birgit, Kremser, Stefanie, and Bodeker, Greg E.
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SULFIDES , *ATMOSPHERIC chemistry - Abstract
When computing climatological averages of atmospheric trace gas mixing ratios obtained from satellite-based measurements, sampling biases arise if data coverage is not uniform in space and time. Complete homogeneous spatio-temporal coverage is essentially impossible to achieve. Solar occultation measurements, by virtue of satellite orbits and the requirement of direct observation of the sun through the atmosphere, result in particularly sparse spatial coverage. In this study, a method is presented to adjust for such sampling biases when calculating climatological means. The method is demonstrated using carbonyl sulfide (OCS) measurements at 16km altitude from the ACE-FTS (Atmospheric Chemistry Experiment Fourier Transform 15 Spectrometer). At this altitude, OCS mixing ratios show a steep gradient between the poles and equator. ACE-FTS measurements, which are provided as vertically resolved profiles, and integrated stratospheric OCS columns are used in this study. The bias adjustment procedure requires no additional observations other than the satellite data product itself and is expected to be generally applicable when constructing climatologies of long-lived tracers from sparsely and heterogeneously sampled satellite data. In a first step of the adjustment procedure, a regression model is used to fit a 2-D surface to all available ACE-FTS OCS measurements as a function of day-of-year and latitude. The regression model fit is used to calculate an adjustment factor, 20 which is then used to adjust each measurement individually. The mean of the adjusted measurement points of a chosen spatio-temporal frame is then used as the bias-free climatological value. When applying the adjustment factor to seasonal averages in 30° zones, the maximum spatio-temporal sampling bias adjustment was 11% for OCS mixing ratios at 16km and 5% for the stratospheric OCS column. The adjustments were validated against the much denser and more homogeneous OCS data product from the limb-sounding MIPAS (Michelson Interferometer for Passive Atmospheric Sounding) instrument, and both the direction and sign of the adjustments were in agreement with the adjustment of the ACE-FTS data. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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68. Oceanic emissions unlikely to account for the missing source of atmospheric carbonyl sulfide.
- Author
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Lennartz, Sinikka T., Marandino, Christa A., von Hobe, Marc, Cortes, Pau, Quack, Birgit, Simo, Rafel, Booge, Dennis, Pozzer, Andrea, Steinhoff, Tobias, Arevalo-Martinez, Damian L., Kloss, Corinna, Bracher, Astrid, Röttgers, Rüdiger, Atlas, Elliott, and Krüger, Kirstin
- Abstract
The climate active trace-gas carbonyl sulfide (OCS) is the most abundant sulfur gas in the atmosphere. A missing source in its atmospheric budget is currently suggested, resulting from an upward revision of the vegetation sink in top-down approaches. Oceanic emissions have been proposed to close the resulting gap in the atmospheric budget. We present a bottom-up approach including new observations of OCS in surface waters of the tropical Atlantic, Pacific and Indian oceans to show that direct OCS emissions are insufficient to account for the missing source. Extrapolation of our observations using a biogeochemical box model suggests oceanic net uptake instead of emission for the entire tropical ocean area and, further, a global ocean source strength well below that suggested by top-down estimates. This bottom-up estimate of oceanic emissions has implications for using OCS as a proxy for terrestrial CO
2 uptake, which is currently hampered by the inadequate quantification of atmospheric OCS sources and sinks. [ABSTRACT FROM AUTHOR]- Published
- 2016
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69. Investigating chemical and dynamical processes in the Asian Monsoon UTLS using in-situ and satellite observations of carbon monoxide (CO) and carbonyl sulfide (OCS).
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Hobe, Marc von, Kloss, Corinna, Bossolasco, Adriana, Höpfner, Michael, Berthet, Gwanael, Jegou, Fabrice, and Sellitto, Pasquale
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CHEMICAL processes , *CARBON monoxide , *TROPOSPHERIC ozone , *TRACE gases , *MONSOONS , *SULFIDES , *BIOLOGICAL transport - Abstract
The UTLS is characterized by significant gradients in trace gas mixing ratios that arise fromi) mixing of different fractions of tropospheric and stratospheric air and ii) photochemicalprocessing as air rises from the troposphere to the stratosphere (particularly in the tropics).We use satellite and in-situ measurements of two different tracers to investigate theseprocesses in the region of the Asian Monsoon Anticyclone (AMA): carbon monoxide (CO)and carbonyl sulfide (OCS). CO is a short-lived tracer with a photochemical lifetime of ∼1 – 4 months. CO mixingratios are sensitive to both photochemical depletion and inmixing of stratospheric air masses.OCS, on the other hand, can be regarded as photochemically inert in the UTLS (significantphotochemical destruction of OCS takes place only in the tropical pipe above ∼ 22 kmaltitude). Therefore, OCS is sensitive only to stratospheric inmixing. Based on observedvertical profiles of the two gases in different positions relative to the core of the AMA, we settwo hypotheses: In and directly above the AMA core, the composition is dominated by photochemical processing Further away from the AMA core, mixing processes become more important.This implies significant active net transport/ascend of upper tropospheric air into thestratosphere close to the AMA core and a more bi-directional transport regime elsewhere. [ABSTRACT FROM AUTHOR]
- Published
- 2019
70. Transport of the 2017 Canadian wild fire plume to the tropics and global stratosphere via the Asian monsoon circulation.
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Kloss, Corinna, Berthet, Gwenaël, Sellitto, Pasquale, Plöger, Felix, Bucci, Silvia, Khaykin, Sergey, Jégou, Fabrice, Barret, Brice, Flochmoen, Eric Le, Hobe, Marc von, Taha, Ghassan, Bossolasco, Adriana, Thomason, Larry, and Legras, Bernard
- Subjects
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WILDFIRES , *STRATOSPHERIC aerosols , *ATMOSPHERIC acoustics , *MONSOONS , *CHEMICAL models , *VOLCANIC eruptions , *STRATOSPHERE - Abstract
We show that a fire plume originating at high northern latitudes during the Canadian wild fireevent in July/August 2017 reached the tropics, and subsequently the stratosphere via theascending branch of the Brewer-Dobson-Circulation (BDC). For this, we use a combinationof aerosol extinction data from the Stratospheric Aerosol and Gas Experiment III (SAGEIII)and the Ozone Mapping Profiler Suite (OMPS), carbon dioxide measurements from theInfrared Atmospheric Sounding Interferometer (IASI), FLEXPART-TRACZILLAback-trajectories and information for the position and strength of the Asian MonsoonAnticyclone (AMA) transport barrier from the Chemical Lagrangian Model of theStratosphere (CLaMS). The transport from high to low latitudes in the upper troposphere andlowermost stratosphere was mediated by the anticyclonic flow of the Asian monsooncirculation. The Canadian fire plume reached the Asian monsoon area in late August/earlySeptember, when the AMA was still in place. While there is no evidence of systematicmixing into the center of the AMA, we show that a substantial part of the Canadian fire plumeis entrained into the circulation at the AMA edge, and is transported into the tropicalUTLS, and possibly the Southern Hemisphere particularly following the North-Southflow on the eastern side. In the tropics the fire plume is lifted by about 1.5 km permonth. Inside the AMA we find evidence of the Asian Tropopause Aerosol Layer (ATAL) inAugust, doubling background aerosol conditions with a top of the atmosphere shortwaveradiative forcing of -0.05 W/m2. This is estimated using the UVSPEC radiative transfermodel and the LibRadtran package. The regional climate impact of the fire signal in the widerAsian monsoon area in September exceeds the impact of the ATAL by a factorof ∼3 (-0.13W/m2). Once in the stratosphere, the climate impact of such kind oftrans-continental transported plumes can be hemispheric and long-lasting, pointing atthe importance of this long-range dynamical interconnection of pollution sources. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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