Impacts of East Asian summer and winter monsoons on interannual variations of mass concentrations and direct radiative forcing of black carbon over eastern China
We applied a global three-dimensional chemical transport model (GEOS-Chem) to examine the impacts of the East Asian monsoon on the interannual variations of mass concentrations and direct radiative forcing (DRF) of black carbon (BC) over eastern China (110–125° E, 20–45° N). With emissions fixed at...
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2017-04-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | http://www.atmos-chem-phys.net/17/4799/2017/acp-17-4799-2017.pdf |
| _version_ | 1818288938311221248 |
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| author | Y.-H. Mao H. Liao H.-S. Chen |
| author_facet | Y.-H. Mao H. Liao H.-S. Chen |
| author_sort | Y.-H. Mao |
| collection | DOAJ |
| description | We applied a global three-dimensional chemical transport model
(GEOS-Chem) to examine the impacts of the East Asian monsoon on the
interannual variations of mass concentrations and direct radiative forcing
(DRF) of black carbon (BC) over eastern China (110–125° E,
20–45° N). With emissions fixed at the year 2010 levels, model
simulations were driven by the Goddard Earth Observing System (GEOS-4)
meteorological fields for 1986–2006 and the Modern Era
Retrospective-analysis for Research and Applications (MERRA) meteorological
fields for 1980–2010. During the period of 1986–2006, simulated June–July–August (JJA) and December–January–February
(DJF)
surface BC concentrations were higher in MERRA than in GEOS-4 by
0.30 µg m<sup>−3</sup> (44 %) and 0.77 µg m<sup>−3</sup>
(54 %), respectively, because of the generally weaker precipitation in
MERRA. We found that the strength of the East Asian summer monsoon (EASM;
East Asian winter monsoon, EAWM) negatively correlated with simulated JJA
(DJF) surface BC concentrations (<i>r</i> = −0. 7 (−0.7) in GEOS-4 and −0.4
(−0.7) in MERRA), mainly by the changes in atmospheric circulation.
Relative to the 5 strongest EASM years, simulated JJA surface BC
concentrations in the 5 weakest monsoon years were higher over northern
China (110–125° E, 28–45° N) by
0.04–0.09 µg m<sup>−3</sup> (3–11 %), but lower over southern
China (110–125° E, 20–27° N) by
0.03–0.04 µg m<sup>−3</sup> (10–11 %). Compared to the 5
strongest EAWM years, simulated DJF surface BC concentrations in the 5
weakest monsoon years were higher by 0.13–0.15 µg m<sup>−3</sup>
(5–8 %) in northern China and by 0.04–0.10 µg m<sup>−3</sup>
(3–12 %) in southern China. The resulting JJA (DJF) mean all-sky DRF of
BC at the top of the atmosphere was 0.04 W m<sup>−2</sup> (3 %;
0.03 W m<sup>−2</sup>, 2 %) higher in northern China but 0.06 W m<sup>−2</sup>
(14 %; 0.03 W m<sup>−2</sup>, 3 %) lower in southern China. In the
weakest monsoon years, the weaker vertical convection at the elevated
altitudes led to the lower BC concentrations above 1–2 km in southern
China, and therefore the lower BC DRF in the region. The differences in
vertical profiles of BC between the weakest and strongest EASM years
(1998–1997) and EAWM years (1990–1996) reached up to
−0.09 µg m<sup>−3</sup> (−46 %) and
−0.08 µg m<sup>−3</sup> (−11 %) at 1–2 km in eastern China. |
| first_indexed | 2024-12-13T02:04:20Z |
| format | Article |
| id | doaj.art-62ef549be0384813b1db1e3b63da3d7b |
| institution | Directory Open Access Journal |
| issn | 1680-7316 1680-7324 |
| language | English |
| last_indexed | 2024-12-13T02:04:20Z |
| publishDate | 2017-04-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Atmospheric Chemistry and Physics |
| spelling | doaj.art-62ef549be0384813b1db1e3b63da3d7b2022-12-22T00:03:10ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242017-04-011774799481610.5194/acp-17-4799-2017Impacts of East Asian summer and winter monsoons on interannual variations of mass concentrations and direct radiative forcing of black carbon over eastern ChinaY.-H. Mao0H. Liao1H.-S. Chen2School of Environmental Science and Engineering, Nanjing University of Information Science and Technology (NUIST), Nanjing 210044, ChinaSchool of Environmental Science and Engineering, Nanjing University of Information Science and Technology (NUIST), Nanjing 210044, ChinaInternational Joint Research Laboratory on Climate and Environment Change (ILCEC), NUIST, Nanjing 210044, ChinaWe applied a global three-dimensional chemical transport model (GEOS-Chem) to examine the impacts of the East Asian monsoon on the interannual variations of mass concentrations and direct radiative forcing (DRF) of black carbon (BC) over eastern China (110–125° E, 20–45° N). With emissions fixed at the year 2010 levels, model simulations were driven by the Goddard Earth Observing System (GEOS-4) meteorological fields for 1986–2006 and the Modern Era Retrospective-analysis for Research and Applications (MERRA) meteorological fields for 1980–2010. During the period of 1986–2006, simulated June–July–August (JJA) and December–January–February (DJF) surface BC concentrations were higher in MERRA than in GEOS-4 by 0.30 µg m<sup>−3</sup> (44 %) and 0.77 µg m<sup>−3</sup> (54 %), respectively, because of the generally weaker precipitation in MERRA. We found that the strength of the East Asian summer monsoon (EASM; East Asian winter monsoon, EAWM) negatively correlated with simulated JJA (DJF) surface BC concentrations (<i>r</i> = −0. 7 (−0.7) in GEOS-4 and −0.4 (−0.7) in MERRA), mainly by the changes in atmospheric circulation. Relative to the 5 strongest EASM years, simulated JJA surface BC concentrations in the 5 weakest monsoon years were higher over northern China (110–125° E, 28–45° N) by 0.04–0.09 µg m<sup>−3</sup> (3–11 %), but lower over southern China (110–125° E, 20–27° N) by 0.03–0.04 µg m<sup>−3</sup> (10–11 %). Compared to the 5 strongest EAWM years, simulated DJF surface BC concentrations in the 5 weakest monsoon years were higher by 0.13–0.15 µg m<sup>−3</sup> (5–8 %) in northern China and by 0.04–0.10 µg m<sup>−3</sup> (3–12 %) in southern China. The resulting JJA (DJF) mean all-sky DRF of BC at the top of the atmosphere was 0.04 W m<sup>−2</sup> (3 %; 0.03 W m<sup>−2</sup>, 2 %) higher in northern China but 0.06 W m<sup>−2</sup> (14 %; 0.03 W m<sup>−2</sup>, 3 %) lower in southern China. In the weakest monsoon years, the weaker vertical convection at the elevated altitudes led to the lower BC concentrations above 1–2 km in southern China, and therefore the lower BC DRF in the region. The differences in vertical profiles of BC between the weakest and strongest EASM years (1998–1997) and EAWM years (1990–1996) reached up to −0.09 µg m<sup>−3</sup> (−46 %) and −0.08 µg m<sup>−3</sup> (−11 %) at 1–2 km in eastern China.http://www.atmos-chem-phys.net/17/4799/2017/acp-17-4799-2017.pdf |
| spellingShingle | Y.-H. Mao H. Liao H.-S. Chen Impacts of East Asian summer and winter monsoons on interannual variations of mass concentrations and direct radiative forcing of black carbon over eastern China Atmospheric Chemistry and Physics |
| title | Impacts of East Asian summer and winter monsoons on interannual variations of mass concentrations and direct radiative forcing of black carbon over eastern China |
| title_full | Impacts of East Asian summer and winter monsoons on interannual variations of mass concentrations and direct radiative forcing of black carbon over eastern China |
| title_fullStr | Impacts of East Asian summer and winter monsoons on interannual variations of mass concentrations and direct radiative forcing of black carbon over eastern China |
| title_full_unstemmed | Impacts of East Asian summer and winter monsoons on interannual variations of mass concentrations and direct radiative forcing of black carbon over eastern China |
| title_short | Impacts of East Asian summer and winter monsoons on interannual variations of mass concentrations and direct radiative forcing of black carbon over eastern China |
| title_sort | impacts of east asian summer and winter monsoons on interannual variations of mass concentrations and direct radiative forcing of black carbon over eastern china |
| url | http://www.atmos-chem-phys.net/17/4799/2017/acp-17-4799-2017.pdf |
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