A study of transport and deposition of black carbon using the Oslo CTM2 chemical transport model : a comparison of two aerosol parameterizations
The chemical transport model Oslo CTM2 has been used to test two different parameterizations of the black carbon (BC) aerosol. Key uncertainties associated with the representation aerosols in modeling are size distribution, mixing state and removal processes. An important parameter for black carbon...
Main Author: | |
---|---|
Format: | Master Thesis |
Language: | English |
Published: |
2008
|
Subjects: | |
Online Access: | http://hdl.handle.net/10852/12484 http://urn.nb.no/URN:NBN:no-19770 |
id |
ftoslouniv:oai:www.duo.uio.no:10852/12484 |
---|---|
record_format |
openpolar |
spelling |
ftoslouniv:oai:www.duo.uio.no:10852/12484 2023-05-15T15:08:02+02:00 A study of transport and deposition of black carbon using the Oslo CTM2 chemical transport model : a comparison of two aerosol parameterizations Lund, Marianne Tronstad 2008 http://hdl.handle.net/10852/12484 http://urn.nb.no/URN:NBN:no-19770 eng eng http://urn.nb.no/URN:NBN:no-19770 Lund, Marianne Tronstad. A study of transport and deposition of black carbon using the Oslo CTM2 chemical transport model . Masteroppgave, University of Oslo, 2008 http://hdl.handle.net/10852/12484 info:ofi/fmt:kev:mtx:ctx&ctx_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft.au=Lund, Marianne Tronstad&rft.title=A study of transport and deposition of black carbon using the Oslo CTM2 chemical transport model &rft.inst=University of Oslo&rft.date=2008&rft.degree=Masteroppgave URN:NBN:no-19770 80531 09204834x Fulltext https://www.duo.uio.no/bitstream/handle/10852/12484/1/masterthesis.pdf snø is regionale bidrag aging M7 VDP::450 Master thesis Masteroppgave 2008 ftoslouniv 2020-06-21T08:42:08Z The chemical transport model Oslo CTM2 has been used to test two different parameterizations of the black carbon (BC) aerosol. Key uncertainties associated with the representation aerosols in modeling are size distribution, mixing state and removal processes. An important parameter for black carbon is the aging time. In the original aerosol parameterization, aging was represented by a constant transfer of 24% per day from hydrophobic to hydrophilic mode. A new aerosol parameterization called M7, which gives a more physical representation of BC aging by including particle interaction, was recently included in the CTM2 model. This module describes size distribution, mixing state and particle interaction for sulphur, dust, black and organic carbon and sea salt. In this thesis, several simulations have been done to test the effect of using M7 on the modeled BC distribution, lifetime, deposition and regional contributions. Applying the M7 module results in regional and seasonal differences in BC aging. In high-latitudes, the aging is slower than with the original version, leading to an increased burden of mainly insoluble BC particles. Between 30 ◦N and 30 ◦S the burden is reduced, indicating a shorter lifetime caused by faster aging. Global mean BC lifetime and burden is only slightly changed; from 7.63 days and 0.17 Tg with the original parameterization to 7.3 days and 0.14 Tg. Modeled BC content in Arctic snow and ice show high concentrations on the continents, andmaximumnear industrialized areas. Concentrations in the snow and ice in the Arctic Ocean are mostly less than 10 ng g−1 with both aerosol representations. Regional experimentswith emissions in China and Europe separately, show that European emissions contributemost to total BC burden north of 60 ◦N in the lower atmosphere, while emissions from China are important above 6 km. European emissions also provide the largest contribution to accumulated BC in snow and ice north of 60 ◦N. These results are consistent with several other studies. The choice of aerosol parameterization strongly influences the regional impact. BC aging time in China is reduced from 4.16 days in the original version to 3.16 days with M7, while aging time in Europe is increased to 5.16 days. As a consenquence, the contribution from China to atmospheric BC burden and to accumulated BC in snow and ice is reduced, while the European contributions are strenghtened. There is potential for improvement in the M7 module. However, the regional and seasonal variation in BC aging is captured, and there does not appear to be any large errors in the model results compared to previous calculations and observations. M7 allow for a closer study of regional impact and interaction between co-emitted pollutants, and may improve the calculation of radiative forcing. Master Thesis Arctic Arctic Ocean black carbon Universitet i Oslo: Digitale utgivelser ved UiO (DUO) Arctic Arctic Ocean |
institution |
Open Polar |
collection |
Universitet i Oslo: Digitale utgivelser ved UiO (DUO) |
op_collection_id |
ftoslouniv |
language |
English |
topic |
snø is regionale bidrag aging M7 VDP::450 |
spellingShingle |
snø is regionale bidrag aging M7 VDP::450 Lund, Marianne Tronstad A study of transport and deposition of black carbon using the Oslo CTM2 chemical transport model : a comparison of two aerosol parameterizations |
topic_facet |
snø is regionale bidrag aging M7 VDP::450 |
description |
The chemical transport model Oslo CTM2 has been used to test two different parameterizations of the black carbon (BC) aerosol. Key uncertainties associated with the representation aerosols in modeling are size distribution, mixing state and removal processes. An important parameter for black carbon is the aging time. In the original aerosol parameterization, aging was represented by a constant transfer of 24% per day from hydrophobic to hydrophilic mode. A new aerosol parameterization called M7, which gives a more physical representation of BC aging by including particle interaction, was recently included in the CTM2 model. This module describes size distribution, mixing state and particle interaction for sulphur, dust, black and organic carbon and sea salt. In this thesis, several simulations have been done to test the effect of using M7 on the modeled BC distribution, lifetime, deposition and regional contributions. Applying the M7 module results in regional and seasonal differences in BC aging. In high-latitudes, the aging is slower than with the original version, leading to an increased burden of mainly insoluble BC particles. Between 30 ◦N and 30 ◦S the burden is reduced, indicating a shorter lifetime caused by faster aging. Global mean BC lifetime and burden is only slightly changed; from 7.63 days and 0.17 Tg with the original parameterization to 7.3 days and 0.14 Tg. Modeled BC content in Arctic snow and ice show high concentrations on the continents, andmaximumnear industrialized areas. Concentrations in the snow and ice in the Arctic Ocean are mostly less than 10 ng g−1 with both aerosol representations. Regional experimentswith emissions in China and Europe separately, show that European emissions contributemost to total BC burden north of 60 ◦N in the lower atmosphere, while emissions from China are important above 6 km. European emissions also provide the largest contribution to accumulated BC in snow and ice north of 60 ◦N. These results are consistent with several other studies. The choice of aerosol parameterization strongly influences the regional impact. BC aging time in China is reduced from 4.16 days in the original version to 3.16 days with M7, while aging time in Europe is increased to 5.16 days. As a consenquence, the contribution from China to atmospheric BC burden and to accumulated BC in snow and ice is reduced, while the European contributions are strenghtened. There is potential for improvement in the M7 module. However, the regional and seasonal variation in BC aging is captured, and there does not appear to be any large errors in the model results compared to previous calculations and observations. M7 allow for a closer study of regional impact and interaction between co-emitted pollutants, and may improve the calculation of radiative forcing. |
format |
Master Thesis |
author |
Lund, Marianne Tronstad |
author_facet |
Lund, Marianne Tronstad |
author_sort |
Lund, Marianne Tronstad |
title |
A study of transport and deposition of black carbon using the Oslo CTM2 chemical transport model : a comparison of two aerosol parameterizations |
title_short |
A study of transport and deposition of black carbon using the Oslo CTM2 chemical transport model : a comparison of two aerosol parameterizations |
title_full |
A study of transport and deposition of black carbon using the Oslo CTM2 chemical transport model : a comparison of two aerosol parameterizations |
title_fullStr |
A study of transport and deposition of black carbon using the Oslo CTM2 chemical transport model : a comparison of two aerosol parameterizations |
title_full_unstemmed |
A study of transport and deposition of black carbon using the Oslo CTM2 chemical transport model : a comparison of two aerosol parameterizations |
title_sort |
study of transport and deposition of black carbon using the oslo ctm2 chemical transport model : a comparison of two aerosol parameterizations |
publishDate |
2008 |
url |
http://hdl.handle.net/10852/12484 http://urn.nb.no/URN:NBN:no-19770 |
geographic |
Arctic Arctic Ocean |
geographic_facet |
Arctic Arctic Ocean |
genre |
Arctic Arctic Ocean black carbon |
genre_facet |
Arctic Arctic Ocean black carbon |
op_relation |
http://urn.nb.no/URN:NBN:no-19770 Lund, Marianne Tronstad. A study of transport and deposition of black carbon using the Oslo CTM2 chemical transport model . Masteroppgave, University of Oslo, 2008 http://hdl.handle.net/10852/12484 info:ofi/fmt:kev:mtx:ctx&ctx_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft.au=Lund, Marianne Tronstad&rft.title=A study of transport and deposition of black carbon using the Oslo CTM2 chemical transport model &rft.inst=University of Oslo&rft.date=2008&rft.degree=Masteroppgave URN:NBN:no-19770 80531 09204834x Fulltext https://www.duo.uio.no/bitstream/handle/10852/12484/1/masterthesis.pdf |
_version_ |
1766339461700911104 |