Simulations of the trend and annual cycle in stratospheric CO 2
The distribution and evolution of stratospheric CO2 in response to the observed annual cycle, interannual variations, and long-term trends in tropospheric CO2 is simulated with the GISS 23 layer stratospheric general circulation model. Carbon dioxide is a tracer of stratospheric transport which has...
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ftcdlib:qt5x24j8n3 2023-05-15T14:01:41+02:00 Simulations of the trend and annual cycle in stratospheric CO 2 Hall, Timothy M Prather, Michael J 10573 1993-01-01 application/pdf http://www.escholarship.org/uc/item/5x24j8n3 english eng eScholarship, University of California qt5x24j8n3 http://www.escholarship.org/uc/item/5x24j8n3 Attribution (CC BY): http://creativecommons.org/licenses/by/3.0/ CC-BY Hall, Timothy M; & Prather, Michael J. (1993). Simulations of the trend and annual cycle in stratospheric CO 2. Journal of Geophysical Research, 98(D6), 10573. doi:10.1029/93JD00325. UC Irvine: Department of Earth System Science, UCI. Retrieved from: http://www.escholarship.org/uc/item/5x24j8n3 Physical Sciences and Mathematics atmospheric carbon-dioxide Antarctic ozone arctic vortex transport model troposphere exchange impact air article 1993 ftcdlib https://doi.org/10.1029/93JD00325 2016-04-02T18:21:20Z The distribution and evolution of stratospheric CO2 in response to the observed annual cycle, interannual variations, and long-term trends in tropospheric CO2 is simulated with the GISS 23 layer stratospheric general circulation model. Carbon dioxide is a tracer of stratospheric transport which has essentially no local sources or sinks but still displays gradients due to the forcing at the surface. Consequently, observations of stratospheric CO2, until recently limited to a few flask samples, but now included as high frequency in situ sampling in aircraft campaigns, provide a test of tracer transport in stratospheric simulations independent of model chemistry. In our model, CO2 enters the stratosphere primarily through the tropical tropopause, where air parcels are effectively labeled in time by their CO2values (although not uniquely because of the cycles in tropospheric concentration). Parcels of differing ages are subsequently mixed in the stratosphere. Only when the growth is purely linear can the CO2 offset in a parcel relative to the troposphere be interpreted as the average time since stratospheric air was last in contact with the troposphere, i.e., the “age” of the stratosphere. Our model is in qualitative agreement with multiyear averages of balloon soundings at northern mid- and high latitudes; the stratosphere at 30 km at mid-latitudes is about 4 years (6 ppm of CO2) behind the troposphere. We predict significant propagation of the CO2 annual cycle into the lower stratosphere, an effect which must be accounted for when interpreting observations. While the annual cycle is negligible above the lower stratosphere, interannual oscillations, such as those associated with El Ninos, can propagate well into the middle stratosphere as positive offsets from the linear trend lasting significantly longer than their duration in the troposphere. Article in Journal/Newspaper Antarc* Antarctic Arctic University of California: eScholarship Antarctic Arctic Journal of Geophysical Research 98 D6 10573 |
institution |
Open Polar |
collection |
University of California: eScholarship |
op_collection_id |
ftcdlib |
language |
English |
topic |
Physical Sciences and Mathematics atmospheric carbon-dioxide Antarctic ozone arctic vortex transport model troposphere exchange impact air |
spellingShingle |
Physical Sciences and Mathematics atmospheric carbon-dioxide Antarctic ozone arctic vortex transport model troposphere exchange impact air Hall, Timothy M Prather, Michael J Simulations of the trend and annual cycle in stratospheric CO 2 |
topic_facet |
Physical Sciences and Mathematics atmospheric carbon-dioxide Antarctic ozone arctic vortex transport model troposphere exchange impact air |
description |
The distribution and evolution of stratospheric CO2 in response to the observed annual cycle, interannual variations, and long-term trends in tropospheric CO2 is simulated with the GISS 23 layer stratospheric general circulation model. Carbon dioxide is a tracer of stratospheric transport which has essentially no local sources or sinks but still displays gradients due to the forcing at the surface. Consequently, observations of stratospheric CO2, until recently limited to a few flask samples, but now included as high frequency in situ sampling in aircraft campaigns, provide a test of tracer transport in stratospheric simulations independent of model chemistry. In our model, CO2 enters the stratosphere primarily through the tropical tropopause, where air parcels are effectively labeled in time by their CO2values (although not uniquely because of the cycles in tropospheric concentration). Parcels of differing ages are subsequently mixed in the stratosphere. Only when the growth is purely linear can the CO2 offset in a parcel relative to the troposphere be interpreted as the average time since stratospheric air was last in contact with the troposphere, i.e., the “age” of the stratosphere. Our model is in qualitative agreement with multiyear averages of balloon soundings at northern mid- and high latitudes; the stratosphere at 30 km at mid-latitudes is about 4 years (6 ppm of CO2) behind the troposphere. We predict significant propagation of the CO2 annual cycle into the lower stratosphere, an effect which must be accounted for when interpreting observations. While the annual cycle is negligible above the lower stratosphere, interannual oscillations, such as those associated with El Ninos, can propagate well into the middle stratosphere as positive offsets from the linear trend lasting significantly longer than their duration in the troposphere. |
format |
Article in Journal/Newspaper |
author |
Hall, Timothy M Prather, Michael J |
author_facet |
Hall, Timothy M Prather, Michael J |
author_sort |
Hall, Timothy M |
title |
Simulations of the trend and annual cycle in stratospheric CO 2 |
title_short |
Simulations of the trend and annual cycle in stratospheric CO 2 |
title_full |
Simulations of the trend and annual cycle in stratospheric CO 2 |
title_fullStr |
Simulations of the trend and annual cycle in stratospheric CO 2 |
title_full_unstemmed |
Simulations of the trend and annual cycle in stratospheric CO 2 |
title_sort |
simulations of the trend and annual cycle in stratospheric co 2 |
publisher |
eScholarship, University of California |
publishDate |
1993 |
url |
http://www.escholarship.org/uc/item/5x24j8n3 |
op_coverage |
10573 |
geographic |
Antarctic Arctic |
geographic_facet |
Antarctic Arctic |
genre |
Antarc* Antarctic Arctic |
genre_facet |
Antarc* Antarctic Arctic |
op_source |
Hall, Timothy M; & Prather, Michael J. (1993). Simulations of the trend and annual cycle in stratospheric CO 2. Journal of Geophysical Research, 98(D6), 10573. doi:10.1029/93JD00325. UC Irvine: Department of Earth System Science, UCI. Retrieved from: http://www.escholarship.org/uc/item/5x24j8n3 |
op_relation |
qt5x24j8n3 http://www.escholarship.org/uc/item/5x24j8n3 |
op_rights |
Attribution (CC BY): http://creativecommons.org/licenses/by/3.0/ |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1029/93JD00325 |
container_title |
Journal of Geophysical Research |
container_volume |
98 |
container_issue |
D6 |
container_start_page |
10573 |
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1766271714325430272 |