Cloud, precipitation and radiation responses to large perturbations in global dimethyl sulfide
<p>Natural aerosol emission represents one of the largest uncertainties in our understanding of the radiation budget. Sulfur emitted by marine organisms, as dimethyl sulfide (DMS), constitutes one-fifth of the global sulfur budget and yet the distribution, fluxes and fate of DMS remain poo...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2018-07-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://www.atmos-chem-phys.net/18/10177/2018/acp-18-10177-2018.pdf |
| _version_ | 1818510855232290816 |
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| author | S. L. Fiddes S. L. Fiddes S. L. Fiddes M. T. Woodhouse Z. Nicholls T. P. Lane R. Schofield |
| author_facet | S. L. Fiddes S. L. Fiddes S. L. Fiddes M. T. Woodhouse Z. Nicholls T. P. Lane R. Schofield |
| author_sort | S. L. Fiddes |
| collection | DOAJ |
| description | <p>Natural aerosol emission represents one of the largest
uncertainties in our understanding of the radiation budget. Sulfur emitted by
marine organisms, as dimethyl sulfide (DMS), constitutes one-fifth of the
global sulfur budget and yet the distribution, fluxes and fate of DMS remain
poorly constrained. This study evaluates the Australian Community Climate and
Earth System Simulator (ACCESS) United Kingdom Chemistry and Aerosol (UKCA)
model in terms of cloud fraction, radiation and precipitation, and then
quantifies the role of DMS in the chemistry–climate system. We find that
ACCESS-UKCA has similar cloud and radiation biases to other global climate
models. By removing all DMS, or alternatively significantly enhancing marine DMS,
we find a top of the atmosphere radiative effect of 1.7 and −1.4 W m<sup>−2</sup>
respectively. The largest responses to these DMS perturbations
(removal/enhancement) are in stratiform cloud decks in the Southern
Hemisphere's eastern ocean basins. These regions show significant differences
in low cloud (−9∕ + 6 %), surface incoming shortwave radiation (+7∕ − 5 W m<sup>−2</sup>) and large-scale rainfall (+15∕ − 10 %). We demonstrate a precipitation
suppression effect of DMS-derived aerosol in stratiform cloud deck regions
due to DMS, coupled with an increase in low cloud fraction. The difference in
low cloud fraction is an example of the aerosol lifetime effect. Globally, we
find a sensitivity of temperature to annual DMS flux of 0.027 and
0.019 K per Tg yr<sup>−1</sup> of sulfur, respectively. Other areas
of low cloud formation, such as the Southern Ocean and stratiform cloud decks
in the Northern Hemisphere, have a relatively weak response to DMS
perturbations. We highlight the need for greater understanding of the
DMS–climate cycle within the context of uncertainties and biases of climate
models as well as those of DMS–climate observations.</p> |
| first_indexed | 2024-12-10T23:25:49Z |
| format | Article |
| id | doaj.art-0bd10fa625794dd8a596bb256fa28c3f |
| institution | Directory Open Access Journal |
| issn | 1680-7316 1680-7324 |
| language | English |
| last_indexed | 2024-12-10T23:25:49Z |
| publishDate | 2018-07-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Atmospheric Chemistry and Physics |
| spelling | doaj.art-0bd10fa625794dd8a596bb256fa28c3f2022-12-22T01:29:35ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242018-07-0118101771019810.5194/acp-18-10177-2018Cloud, precipitation and radiation responses to large perturbations in global dimethyl sulfideS. L. Fiddes0S. L. Fiddes1S. L. Fiddes2M. T. Woodhouse3Z. Nicholls4T. P. Lane5R. Schofield6Australian–German Climate and Energy College, University of Melbourne, Parkville, 3010, AustraliaARC Centre of Excellence for Climate System Science, School of Earth Sciences, University of Melbourne, Parkville, 3010, AustraliaClimate Science Centre, Oceans and Atmosphere, Commonwealth Scientific and Industrial Research Organisation, Aspendale, 3195, AustraliaClimate Science Centre, Oceans and Atmosphere, Commonwealth Scientific and Industrial Research Organisation, Aspendale, 3195, AustraliaAustralian–German Climate and Energy College, University of Melbourne, Parkville, 3010, AustraliaARC Centre of Excellence for Climate Extremes, School of Earth Sciences, University of Melbourne, Parkville, 3010, AustraliaARC Centre of Excellence for Climate System Science, School of Earth Sciences, University of Melbourne, Parkville, 3010, Australia<p>Natural aerosol emission represents one of the largest uncertainties in our understanding of the radiation budget. Sulfur emitted by marine organisms, as dimethyl sulfide (DMS), constitutes one-fifth of the global sulfur budget and yet the distribution, fluxes and fate of DMS remain poorly constrained. This study evaluates the Australian Community Climate and Earth System Simulator (ACCESS) United Kingdom Chemistry and Aerosol (UKCA) model in terms of cloud fraction, radiation and precipitation, and then quantifies the role of DMS in the chemistry–climate system. We find that ACCESS-UKCA has similar cloud and radiation biases to other global climate models. By removing all DMS, or alternatively significantly enhancing marine DMS, we find a top of the atmosphere radiative effect of 1.7 and −1.4 W m<sup>−2</sup> respectively. The largest responses to these DMS perturbations (removal/enhancement) are in stratiform cloud decks in the Southern Hemisphere's eastern ocean basins. These regions show significant differences in low cloud (−9∕ + 6 %), surface incoming shortwave radiation (+7∕ − 5 W m<sup>−2</sup>) and large-scale rainfall (+15∕ − 10 %). We demonstrate a precipitation suppression effect of DMS-derived aerosol in stratiform cloud deck regions due to DMS, coupled with an increase in low cloud fraction. The difference in low cloud fraction is an example of the aerosol lifetime effect. Globally, we find a sensitivity of temperature to annual DMS flux of 0.027 and 0.019 K per Tg yr<sup>−1</sup> of sulfur, respectively. Other areas of low cloud formation, such as the Southern Ocean and stratiform cloud decks in the Northern Hemisphere, have a relatively weak response to DMS perturbations. We highlight the need for greater understanding of the DMS–climate cycle within the context of uncertainties and biases of climate models as well as those of DMS–climate observations.</p>https://www.atmos-chem-phys.net/18/10177/2018/acp-18-10177-2018.pdf |
| spellingShingle | S. L. Fiddes S. L. Fiddes S. L. Fiddes M. T. Woodhouse Z. Nicholls T. P. Lane R. Schofield Cloud, precipitation and radiation responses to large perturbations in global dimethyl sulfide Atmospheric Chemistry and Physics |
| title | Cloud, precipitation and radiation responses to large perturbations in global dimethyl sulfide |
| title_full | Cloud, precipitation and radiation responses to large perturbations in global dimethyl sulfide |
| title_fullStr | Cloud, precipitation and radiation responses to large perturbations in global dimethyl sulfide |
| title_full_unstemmed | Cloud, precipitation and radiation responses to large perturbations in global dimethyl sulfide |
| title_short | Cloud, precipitation and radiation responses to large perturbations in global dimethyl sulfide |
| title_sort | cloud precipitation and radiation responses to large perturbations in global dimethyl sulfide |
| url | https://www.atmos-chem-phys.net/18/10177/2018/acp-18-10177-2018.pdf |
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