scholarly journals Carbon monoxide in the upper troposphere over the western Pacific between 1993 and 1996

1998 ◽  
Vol 103 (D15) ◽  
pp. 19093-19110 ◽  
Author(s):  
Hidekazu Matsueda ◽  
Hisayuki Y. Inoue ◽  
Yosuke Sawa ◽  
Yukitomo Tsutsumi ◽  
Masao Ishii
Keyword(s):  
Carbon Monoxide ◽  
Western Pacific ◽  
Upper Troposphere ◽  
The Western Pacific

scholarly journals Deriving an atmospheric budget of total organic bromine using airborne in situ measurements from the western Pacific area during SHIVA

2014 ◽  
Vol 14 (13) ◽  
pp. 6903-6923 ◽  
Author(s):  
S. Sala ◽  
H. Bönisch ◽  
T. Keber ◽  
D. E. Oram ◽  
G. Mills ◽  
...  
Keyword(s):  
Stratospheric Ozone ◽  
Radiative Heating ◽  
Western Pacific ◽  
Data Set ◽  
Tropical Regions ◽  
Upper Troposphere ◽  
Tropical Tropopause ◽  
Vertical Range ◽  
The Western Pacific

Abstract. During the recent SHIVA (Stratospheric Ozone: Halogen Impacts in a Varying Atmosphere) project an extensive data set of all halogen species relevant for the atmospheric budget of total organic bromine was collected in the western Pacific region using the Falcon aircraft operated by the German Aerospace agency DLR (Deutsches Zentrum für Luft- und Raumfahrt) covering a vertical range from the planetary boundary layer up to the ceiling altitude of the aircraft of 13 km. In total, more than 700 measurements were performed with the newly developed fully automated in situ instrument GHOST-MS (Gas chromatograph for the Observation of Tracers – coupled with a Mass Spectrometer) by the Goethe University of Frankfurt (GUF) and with the onboard whole-air sampler WASP with subsequent ground-based state-of-the-art GC / MS analysis by the University of East Anglia (UEA). Both instruments yield good agreement for all major (CHBr3 and CH2Br2) and minor (CH2BrCl, CHBrCl2 and CHBr2Cl) VSLS (very short-lived substances), at least at the level of their 2σ measurement uncertainties. In contrast to the suggestion that the western Pacific could be a region of strongly increased atmospheric VSLS abundance (Pyle et al., 2011), we found only in the upper troposphere a slightly enhanced amount of total organic bromine from VSLS relative to the levels reported in Montzka and Reimann et al. (2011) for other tropical regions. From the SHIVA observations in the upper troposphere, a budget for total organic bromine, including four halons (H-1301, H-1211, H-1202, H-2402), CH3Br and the VSLS, is derived for the level of zero radiative heating (LZRH), the input region for the tropical tropopause layer (TTL) and thus also for the stratosphere. With the exception of the two minor VSLS CHBrCl2 and CHBr2Cl, excellent agreement with the values reported in Montzka and Reimann et al. (2011) is found, while being slightly higher than previous studies from our group based on balloon-borne measurements.

scholarly journals Carbon and hydrogen isotopic ratios of atmospheric methane in the upper troposphere over the Western Pacific

2012 ◽  
Vol 12 (4) ◽  
pp. 9035-9077 ◽  
Author(s):  
T. Umezawa ◽  
T. Machida ◽  
K. Ishijima ◽  
H. Matsueda ◽  
Y. Sawa ◽  
...  
Keyword(s):  
Atmospheric Chemistry ◽  
Isotopic Ratio ◽  
Lower Troposphere ◽  
Western Pacific ◽  
Boreal Summer ◽  
Additional Contribution ◽  
Mixing Ratio ◽  
Upper Troposphere ◽  
The Tropics ◽  
The Western Pacific

Abstract. We present the mixing ratio, δ13C and δD of atmospheric CH4 using commercial aircraft in the upper troposphere (UT) over the Western Pacific for the period December 2005–September 2010. The observed results were compared with those obtained using commercial container ships in the lower troposphere (LT) over the same region. In the Northern Hemisphere (NH), the UT CH4 mixing ratio shows high values in the boreal summer–autumn, when the LT CH4 mixing ratio reaches a seasonal minimum. From tagged tracer experiments made using an atmospheric chemistry transport model, we found that such high CH4 values are due to rapid transport of air masses influenced by CH4 sources in South Asia and East Asia. The observed isotopic ratio data suggest that CH4 sources in these areas have relatively low δ13C and δD signatures, implying biogenic sources. Latitudinal distributions of the annual average UT and LT CH4 mixing ratio intersect each other in the tropics; the mixing ratio value is lower in the UT than in the LT in the NH and the situation is reversed in the Southern Hemisphere (SH), due mainly to the NH air intrusion into the SH through the UT. Such intersection of the latitudinal distributions is observable in δD but not in δ13C, implying additional contribution of a reaction of CH4 with active chlorine in the marine boundary layer. δ13C and δD show low values in the NH and high values in the SH both in the UT and in the LT. We also observed an increase in the CH4 mixing ratio and decreases in δ13C and δD during 2007–2008 in the UT and LT over the Western Pacific, possibly due to enhanced biogenic emissions in the tropics and NH.

scholarly journals Impact of typhoons on the composition of the upper troposphere within the Asian summer monsoon anticyclone: the SWOP campaign in Lhasa 2013

2016 ◽  
Author(s):  
Dan Li ◽  
Bärbel Vogel ◽  
Jianchun Bian ◽  
Rolf Müller ◽  
Laura L. Pan ◽  
...  
Keyword(s):  
Water Vapour ◽  
Tropical Cyclones ◽  
Summer Monsoon ◽  
Asian Summer Monsoon ◽  
Vertical Transport ◽  
Western Pacific ◽  
Lagrangian Model ◽  
Upper Troposphere ◽  
Asian Summer ◽  
The Western Pacific

Abstract. In the frame of the SWOP (sounding water vapour, ozone, and particle) campaign during the Asian summer monsoon (ASM), ozone and water vapour profiles were measured by balloon-borne sensors launched from Lhasa (29.66° N, 91.14° E, elevation 3650 m), China, in August 2013. In total, 24 soundings were launched, nearly half of which show some strong variations in the relationship between ozone and water vapour in the tracer-tracer correlation in the upper troposphere and lower stratosphere (UTLS). 20-day backward trajectories of each sounding were calculated using the trajectory module of the Chemical Lagrangian Model of the Stratosphere (CLaMS) to analyse these variations. The trajectory calculations demonstrate that three tropical cyclones (tropical storm Jebi, typhoons Utor and Trami), which occurred over the Western Pacific Ocean during August 2013, had a considerable impact on the vertical distribution of ozone and water vapour by uplifting marine air masses to altitudes of the ASM anticyclone. Air parcels subsequently arrived at the observation site via two primary pathways: firstly via direct horizontal transport from the location of the typhoon to the station within approximately three days, and secondly via rotational subsidence, during which air parcels descend slowly along a circle following the anticyclone flow within a timescale of one week. Furthermore, the interplay between the spatial position of the ASM anticyclone and tropical cyclones plays a key role in controlling the transport pathways of air parcels from the boundary layer of the Western Pacific to Lhasa in horizontal as well as vertical transport. Moreover, the statistical analysis shows that the strongest impact by typhoons is found at altitudes between 14.5 km and 17 km (365–375 K). Low ozone values (50–80 ppbv) were observed between 370 K and 380 K due to the strong vertical transport within tropical cyclones.

scholarly journals Impact of typhoons on the composition of the upper troposphere within the Asian summer monsoon anticyclone: the SWOP campaign in Lhasa 2013

2017 ◽  
Vol 17 (7) ◽  
pp. 4657-4672 ◽  
Author(s):  
Dan Li ◽  
Bärbel Vogel ◽  
Jianchun Bian ◽  
Rolf Müller ◽  
Laura L. Pan ◽  
...  
Keyword(s):  
Water Vapour ◽  
Tropical Cyclones ◽  
Summer Monsoon ◽  
Asian Summer Monsoon ◽  
Vertical Transport ◽  
Western Pacific ◽  
Lagrangian Model ◽  
Upper Troposphere ◽  
Asian Summer ◽  
The Western Pacific

Abstract. In the frame of the SWOP (sounding water vapour, ozone, and particle) campaign during the Asian summer monsoon (ASM), ozone and water vapour profiles were measured by balloon-borne sensors launched from Lhasa (29.66° N, 91.14° E, elevation 3650 m), China, in August 2013. In total, 24 soundings were launched, nearly half of which show strong variations in the relationship between ozone and water vapour in the tracer–tracer correlation in the upper troposphere and lower stratosphere (UTLS). For each sounding, 20-day backward trajectories were calculated using the trajectory module of the Chemical Lagrangian Model of the Stratosphere (CLaMS) to analyse these variations. The trajectory calculations demonstrate that three tropical cyclones (tropical storm Jebi, typhoons Utor and Trami), which occurred over the western Pacific Ocean during August 2013, had a considerable impact on the vertical distribution of ozone and water vapour by uplifting marine air masses to altitudes of the ASM anticyclone. Air parcels subsequently arrived at the observation site via two primary pathways: firstly via direct horizontal transport from the location of the typhoon to the station within approximately 3 days, and secondly via transport following the clockwise wind flow of the ASM within a timescale of 1 week. Furthermore, the interplay between the spatial position of the ASM anticyclone and tropical cyclones plays a key role in controlling the transport pathways of air parcels from the boundary layer of the western Pacific to Lhasa in horizontal and vertical transport. Moreover, the statistical analysis shows that the strongest impact by typhoons is found at altitudes between 14.5 and 17 km (365–375 K). Low ozone values (50–80 ppbv) were observed between 370 and 380 K due to the strong vertical transport within tropical cyclones.

scholarly journals Inverting for emissions of carbon monoxide from Asia using aircraft observations over the western Pacific

2003 ◽  
Vol 108 (D21) ◽  
Author(s):  
Paul I. Palmer ◽  
Daniel J. Jacob ◽  
Dylan B. A. Jones ◽  
Colette L. Heald ◽  
Robert M. Yantosca ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Western Pacific ◽  
Aircraft Observations ◽  
The Western Pacific

scholarly journals Carbon and hydrogen isotopic ratios of atmospheric methane in the upper troposphere over the Western Pacific

2012 ◽  
Vol 12 (17) ◽  
pp. 8095-8113 ◽  
Author(s):  
T. Umezawa ◽  
T. Machida ◽  
K. Ishijima ◽  
H. Matsueda ◽  
Y. Sawa ◽  
...  
Keyword(s):  
Atmospheric Chemistry ◽  
Transport Model ◽  
Isotopic Ratio ◽  
Lower Troposphere ◽  
Western Pacific ◽  
Boreal Summer ◽  
Additional Contribution ◽  
Mixing Ratio ◽  
Upper Troposphere ◽  
The Western Pacific

Abstract. We present the mixing ratio, δ13C and δD of atmospheric CH4 using commercial aircraft in the upper troposphere (UT) over the Western Pacific for the period December 2005–September 2010. The observed results were compared with those obtained using commercial container ships in the lower troposphere (LT) over the same region. In the Northern Hemisphere (NH), the UT CH4 mixing ratio shows high values in the boreal summer–autumn, when the LT CH4 mixing ratio reaches a seasonal minimum. From tagged tracer experiments made using an atmospheric chemistry transport model, we found that such high CH4 values are due to rapid transport of air masses influenced by CH4 sources in South Asia and East Asia. The observed isotopic ratio data imply that these areas have CH4 sources with relatively low δ13C and δD signatures such as biogenic sources. Latitudinal distributions of the annual average UT and LT CH4 mixing ratio intersect each other in the tropics; the mixing ratio value is lower in the UT than in the LT in the NH and the situation is reversed in the Southern Hemisphere (SH), due mainly to the NH air intrusion into the SH through the UT. Such intersection of the latitudinal distributions is observable in δD but not in δ13C, implying an additional contribution from reaction of CH4 with active chlorine in the marine boundary layer. δ13C and δD show low values in the NH and high values in the SH both in the UT and in the LT. We also observed an increase in the CH4 mixing ratio and decreases in δ13C and δ

scholarly journals Transport of trace gases via eddy shedding from the Asian summer monsoon anticyclone and associated impacts on ozone heating rates

2018 ◽  
Vol 18 (15) ◽  
pp. 11493-11506 ◽  
Author(s):  
Suvarna Fadnavis ◽  
Chaitri Roy ◽  
Rajib Chattopadhyay ◽  
Christopher E. Sioris ◽  
Alexandru Rap ◽  
...  
Keyword(s):  
Lower Stratosphere ◽  
Asian Summer Monsoon ◽  
Trace Gases ◽  
Western Pacific ◽  
Heating Rates ◽  
Upper Troposphere ◽  
Western Africa ◽  
Asian Summer ◽  
The Western Pacific ◽  
Eddy Shedding

Abstract. The highly vibrant Asian summer monsoon (ASM) anticyclone plays an important role in efficient transport of Asian tropospheric air masses to the extratropical upper troposphere and lower stratosphere (UTLS). In this paper, we demonstrate long-range transport of Asian trace gases via eddy-shedding events using MIPAS (Michelson Interferometer for Passive Atmospheric Sounding) satellite observations, ERA-Interim reanalysis data and the ECHAM5–HAMMOZ global chemistry-climate model. Model simulations and observations consistently show that Asian boundary layer trace gases are lifted to UTLS altitudes in the monsoon anticyclone and are further transported horizontally eastward and westward by eddies detached from the anticyclone. We present an event of eddy shedding during 1–8 July 2003 and discuss a 1995–2016 climatology of eddy-shedding events. Our analysis indicates that eddies detached from the anticyclone contribute to the transport of Asian trace gases away from the Asian region to the western Pacific (20–30∘ N, 120–150∘ E) and western Africa (20–30∘ N, 0–30∘ E). Over the last two decades, the estimated frequency of occurrence of eddy-shedding events is ∼68 % towards western Africa and ∼25 % towards the western Pacific. Model sensitivity experiments considering a 10 % reduction in Asian emissions of non-methane volatile organic compounds (NMVOCs) and nitrogen oxides (NOx) were performed with ECHAM5–HAMMOZ to understand the impact of Asian emissions on the UTLS. The model simulations show that transport of Asian emissions due to eddy shedding significantly affects the chemical composition of the upper troposphere (∼100–400 hPa) and lower stratosphere (∼100–80 hPa) over western Africa and the western Pacific. The 10 % reduction of NMVOCs and NOx Asian emissions leads to decreases in peroxyacetyl nitrate (PAN) (2 %–10 % near 200–80 hPa), ozone (1 %–4.5 % near ∼150 hPa) and ozone heating rates (0.001–0.004 K day−1 near 300–150 hPa) in the upper troposphere over western Africa and the western Pacific.

Sign in / Sign up

Export Citation Format

Share Document