Organic and inorganic bromine measurements around the extratropical tropopause and lowermost stratosphere: insights into the transport pathways and total bromine
We report on measurements of total bromine ( Br tot ) in the upper troposphere and lower stratosphere taken during 15 flights with the German High Altitude and LOng range research aircraft (HALO). The research campaign WISE (Wave-driven ISentropic Exchange) included regions over the North Atlantic,...
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2021
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Online Access: | https://doi.org/10.5194/acp-21-15375-2021 https://acp.copernicus.org/articles/21/15375/2021/ |
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Copernicus Publications: E-Journals |
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We report on measurements of total bromine ( Br tot ) in the upper troposphere and lower stratosphere taken during 15 flights with the German High Altitude and LOng range research aircraft (HALO). The research campaign WISE (Wave-driven ISentropic Exchange) included regions over the North Atlantic, Norwegian Sea, and northwestern Europe in fall 2017. Br tot is calculated from measured total organic bromine ( Br org ) added to inorganic bromine ( <math xmlns="http://www.w3.org/1998/Math/MathML" id="M4" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><msubsup><mi mathvariant="normal">Br</mi><mi>y</mi><mi mathvariant="normal">inorg</mi></msubsup></mrow></math> <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="31pt" height="18pt" class="svg-formula" dspmath="mathimg" md5hash="e88d8aeec27451686ce7641dc343d6a9"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-21-15375-2021-ie00001.svg" width="31pt" height="18pt" src="acp-21-15375-2021-ie00001.png"/></svg:svg> ), evaluated from measured BrO and photochemical modeling. Combining these data, the weighted mean [ Br tot ] is 19.2±1.2 ppt in the northern hemispheric lower stratosphere (LS), in agreement with expectations for Br tot in the middle stratosphere ( Engel and Rigby et al. , 2018 ). The data reflect the expected variability in Br tot in the LS due to variable influx of shorter lived brominated source and product gases from different regions of entry. A closer look into Br org and <math xmlns="http://www.w3.org/1998/Math/MathML" id="M11" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><msubsup><mi mathvariant="normal">Br</mi><mi>y</mi><mi mathvariant="normal">inorg</mi></msubsup></mrow></math> <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="31pt" height="18pt" class="svg-formula" dspmath="mathimg" md5hash="aa35d9da0bf4baf3b5d28a7da605f5ca"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-21-15375-2021-ie00002.svg" width="31pt" height="18pt" src="acp-21-15375-2021-ie00002.png"/></svg:svg> , as well as simultaneously measured transport tracers ( CO and N 2 O ) and an air mass lag time tracer ( SF 6 ), suggests that bromine-rich air masses persistently protruded into the lowermost stratosphere (LMS) in boreal summer, creating a high bromine region (HBrR). A subsection, HBrR ∗ , has a weighted average of [Br tot ] = 20.9±0.8 ppt. The most probable source region is air recently transported from the tropical upper troposphere and tropopause layer (UT/TTL) with a weighted mean of [Br tot ] = 21.6±0.7 ppt. CLaMS Lagrangian transport modeling shows that the HBrR air mass consists of 51.2 % from the tropical troposphere, 27.1 % from the stratospheric background, and 6.4 % from the midlatitude troposphere (as well as contributions from other domains). The majority of the surface air reaching the HBrR is from the Asian monsoon and its adjacent tropical regions, which greatly influences trace gas transport into the LMS in boreal summer and fall. Tropical cyclones from Central America in addition to air associated with the Asian monsoon region contribute to the elevated Br tot observed in the UT/TTL. TOMCAT global 3-D model simulations of a concurrent increase of Br tot show an associated O 3 change of <math xmlns="http://www.w3.org/1998/Math/MathML" id="M28" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><mo>-</mo><mn mathvariant="normal">2.6</mn><mo>±</mo><mn mathvariant="normal">0.7</mn></mrow></math> <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="52pt" height="10pt" class="svg-formula" dspmath="mathimg" md5hash="2ca2fb1a44b733a81112243441cb4142"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-21-15375-2021-ie00003.svg" width="52pt" height="10pt" src="acp-21-15375-2021-ie00003.png"/></svg:svg> % in the LS and <math xmlns="http://www.w3.org/1998/Math/MathML" id="M29" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><mo>-</mo><mn mathvariant="normal">3.1</mn><mo>±</mo><mn mathvariant="normal">0.7</mn></mrow></math> <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="52pt" height="10pt" class="svg-formula" dspmath="mathimg" md5hash="f2bbdeb4ea116c4f3047dc9f32a7a998"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-21-15375-2021-ie00004.svg" width="52pt" height="10pt" src="acp-21-15375-2021-ie00004.png"/></svg:svg> % near the tropopause. Our study of varying Br tot in the LS also emphasizes the need for more extensive monitoring of stratospheric Br tot globally and seasonally to fully understand its impact on LMS O 3 and its radiative forcing of climate, as well as in aged air in the middle stratosphere to elucidate the stratospheric trend in bromine. |
format |
Text |
author |
Rotermund, Meike K. Bense, Vera Chipperfield, Martyn P. Engel, Andreas Grooß, Jens-Uwe Hoor, Peter Hüneke, Tilman Keber, Timo Kluge, Flora Schreiner, Benjamin Schuck, Tanja Vogel, Bärbel Zahn, Andreas Pfeilsticker, Klaus |
spellingShingle |
Rotermund, Meike K. Bense, Vera Chipperfield, Martyn P. Engel, Andreas Grooß, Jens-Uwe Hoor, Peter Hüneke, Tilman Keber, Timo Kluge, Flora Schreiner, Benjamin Schuck, Tanja Vogel, Bärbel Zahn, Andreas Pfeilsticker, Klaus Organic and inorganic bromine measurements around the extratropical tropopause and lowermost stratosphere: insights into the transport pathways and total bromine |
author_facet |
Rotermund, Meike K. Bense, Vera Chipperfield, Martyn P. Engel, Andreas Grooß, Jens-Uwe Hoor, Peter Hüneke, Tilman Keber, Timo Kluge, Flora Schreiner, Benjamin Schuck, Tanja Vogel, Bärbel Zahn, Andreas Pfeilsticker, Klaus |
author_sort |
Rotermund, Meike K. |
title |
Organic and inorganic bromine measurements around the extratropical tropopause and lowermost stratosphere: insights into the transport pathways and total bromine |
title_short |
Organic and inorganic bromine measurements around the extratropical tropopause and lowermost stratosphere: insights into the transport pathways and total bromine |
title_full |
Organic and inorganic bromine measurements around the extratropical tropopause and lowermost stratosphere: insights into the transport pathways and total bromine |
title_fullStr |
Organic and inorganic bromine measurements around the extratropical tropopause and lowermost stratosphere: insights into the transport pathways and total bromine |
title_full_unstemmed |
Organic and inorganic bromine measurements around the extratropical tropopause and lowermost stratosphere: insights into the transport pathways and total bromine |
title_sort |
organic and inorganic bromine measurements around the extratropical tropopause and lowermost stratosphere: insights into the transport pathways and total bromine |
publishDate |
2021 |
url |
https://doi.org/10.5194/acp-21-15375-2021 https://acp.copernicus.org/articles/21/15375/2021/ |
long_lat |
ENVELOPE(-154.583,-154.583,-85.550,-85.550) |
geographic |
Norwegian Sea Rigby |
geographic_facet |
Norwegian Sea Rigby |
genre |
North Atlantic Norwegian Sea |
genre_facet |
North Atlantic Norwegian Sea |
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op_doi |
https://doi.org/10.5194/acp-21-15375-2021 |
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Atmospheric Chemistry and Physics |
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20 |
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ftcopernicus:oai:publications.copernicus.org:acp93364 2023-05-15T17:37:32+02:00 Organic and inorganic bromine measurements around the extratropical tropopause and lowermost stratosphere: insights into the transport pathways and total bromine Rotermund, Meike K. Bense, Vera Chipperfield, Martyn P. Engel, Andreas Grooß, Jens-Uwe Hoor, Peter Hüneke, Tilman Keber, Timo Kluge, Flora Schreiner, Benjamin Schuck, Tanja Vogel, Bärbel Zahn, Andreas Pfeilsticker, Klaus 2021-10-15 application/pdf https://doi.org/10.5194/acp-21-15375-2021 https://acp.copernicus.org/articles/21/15375/2021/ eng eng doi:10.5194/acp-21-15375-2021 https://acp.copernicus.org/articles/21/15375/2021/ eISSN: 1680-7324 Text 2021 ftcopernicus https://doi.org/10.5194/acp-21-15375-2021 2021-10-18T16:22:31Z We report on measurements of total bromine ( Br tot ) in the upper troposphere and lower stratosphere taken during 15 flights with the German High Altitude and LOng range research aircraft (HALO). The research campaign WISE (Wave-driven ISentropic Exchange) included regions over the North Atlantic, Norwegian Sea, and northwestern Europe in fall 2017. Br tot is calculated from measured total organic bromine ( Br org ) added to inorganic bromine ( <math xmlns="http://www.w3.org/1998/Math/MathML" id="M4" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><msubsup><mi mathvariant="normal">Br</mi><mi>y</mi><mi mathvariant="normal">inorg</mi></msubsup></mrow></math> <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="31pt" height="18pt" class="svg-formula" dspmath="mathimg" md5hash="e88d8aeec27451686ce7641dc343d6a9"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-21-15375-2021-ie00001.svg" width="31pt" height="18pt" src="acp-21-15375-2021-ie00001.png"/></svg:svg> ), evaluated from measured BrO and photochemical modeling. Combining these data, the weighted mean [ Br tot ] is 19.2±1.2 ppt in the northern hemispheric lower stratosphere (LS), in agreement with expectations for Br tot in the middle stratosphere ( Engel and Rigby et al. , 2018 ). The data reflect the expected variability in Br tot in the LS due to variable influx of shorter lived brominated source and product gases from different regions of entry. A closer look into Br org and <math xmlns="http://www.w3.org/1998/Math/MathML" id="M11" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><msubsup><mi mathvariant="normal">Br</mi><mi>y</mi><mi mathvariant="normal">inorg</mi></msubsup></mrow></math> <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="31pt" height="18pt" class="svg-formula" dspmath="mathimg" md5hash="aa35d9da0bf4baf3b5d28a7da605f5ca"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-21-15375-2021-ie00002.svg" width="31pt" height="18pt" src="acp-21-15375-2021-ie00002.png"/></svg:svg> , as well as simultaneously measured transport tracers ( CO and N 2 O ) and an air mass lag time tracer ( SF 6 ), suggests that bromine-rich air masses persistently protruded into the lowermost stratosphere (LMS) in boreal summer, creating a high bromine region (HBrR). A subsection, HBrR ∗ , has a weighted average of [Br tot ] = 20.9±0.8 ppt. The most probable source region is air recently transported from the tropical upper troposphere and tropopause layer (UT/TTL) with a weighted mean of [Br tot ] = 21.6±0.7 ppt. CLaMS Lagrangian transport modeling shows that the HBrR air mass consists of 51.2 % from the tropical troposphere, 27.1 % from the stratospheric background, and 6.4 % from the midlatitude troposphere (as well as contributions from other domains). The majority of the surface air reaching the HBrR is from the Asian monsoon and its adjacent tropical regions, which greatly influences trace gas transport into the LMS in boreal summer and fall. Tropical cyclones from Central America in addition to air associated with the Asian monsoon region contribute to the elevated Br tot observed in the UT/TTL. TOMCAT global 3-D model simulations of a concurrent increase of Br tot show an associated O 3 change of <math xmlns="http://www.w3.org/1998/Math/MathML" id="M28" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><mo>-</mo><mn mathvariant="normal">2.6</mn><mo>±</mo><mn mathvariant="normal">0.7</mn></mrow></math> <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="52pt" height="10pt" class="svg-formula" dspmath="mathimg" md5hash="2ca2fb1a44b733a81112243441cb4142"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-21-15375-2021-ie00003.svg" width="52pt" height="10pt" src="acp-21-15375-2021-ie00003.png"/></svg:svg> % in the LS and <math xmlns="http://www.w3.org/1998/Math/MathML" id="M29" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><mo>-</mo><mn mathvariant="normal">3.1</mn><mo>±</mo><mn mathvariant="normal">0.7</mn></mrow></math> <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="52pt" height="10pt" class="svg-formula" dspmath="mathimg" md5hash="f2bbdeb4ea116c4f3047dc9f32a7a998"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-21-15375-2021-ie00004.svg" width="52pt" height="10pt" src="acp-21-15375-2021-ie00004.png"/></svg:svg> % near the tropopause. Our study of varying Br tot in the LS also emphasizes the need for more extensive monitoring of stratospheric Br tot globally and seasonally to fully understand its impact on LMS O 3 and its radiative forcing of climate, as well as in aged air in the middle stratosphere to elucidate the stratospheric trend in bromine. Text North Atlantic Norwegian Sea Copernicus Publications: E-Journals Norwegian Sea Rigby ENVELOPE(-154.583,-154.583,-85.550,-85.550) Atmospheric Chemistry and Physics 21 20 15375 15407 |