Summertime nitrate aerosol in the upper troposphere and lower stratosphere over the Tibetan Plateau and the South Asian summer monsoon region
We use the global three-dimensional Goddard Earth Observing System chemical transport model (GEOS-Chem) to examine the contribution of nitrate aerosol to aerosol concentrations in the upper troposphere and lower stratosphere (UTLS) over the Tibetan Plateau and the South Asian summer monsoon (TP/S...
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2016-06-01
|
| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://www.atmos-chem-phys.net/16/6641/2016/acp-16-6641-2016.pdf |
| _version_ | 1818482889794256896 |
|---|---|
| author | Y. Gu Y. Gu H. Liao J. Bian |
| author_facet | Y. Gu Y. Gu H. Liao J. Bian |
| author_sort | Y. Gu |
| collection | DOAJ |
| description | We use the global three-dimensional Goddard Earth Observing System chemical
transport model (GEOS-Chem) to examine the contribution of nitrate aerosol
to aerosol concentrations in the upper troposphere and lower stratosphere (UTLS)
over the Tibetan Plateau and the South Asian summer monsoon (TP/SASM)
region during summertime of year 2005. Simulated surface-layer aerosol
concentrations are compared with ground-based observations, and simulated
aerosols in the UTLS are evaluated by using the Stratospheric Aerosol and
Gas Experiment II satellite data. Simulations show elevated aerosol
concentrations of sulfate, nitrate, ammonium, black carbon, organic carbon,
and PM<sub>2.5</sub> (particles with diameter equal to or less than 2.5 µm,
defined as the sum of sulfate, nitrate, ammonium, black carbon,
and organic carbon aerosols in this study) in the UTLS over the TP/SASM
region throughout the summer. Nitrate aerosol is simulated to be of
secondary importance near the surface but the most dominant aerosol species
in the UTLS over the studied region. Averaged over summertime and over the
TP/SASM region, <i>C</i><sub>NIT</sub> (the ratio of nitrate concentration to PM<sub>2.5</sub> concentration) values are 5–35 % at the surface, 25–50 % at 200 hPa, and could exceed 60 % at 100 hPa. The mechanisms for the accumulation of
nitrate in the UTLS over the TP/SASM region include vertical transport and
the gas-to-aerosol conversion of HNO<sub>3</sub> to form nitrate. The high
relative humidity and low temperature associated with the deep convection
over the TP/SASM region are favorable for the gas-to-aerosol conversion of HNO<sub>3</sub>. |
| first_indexed | 2024-12-10T11:52:41Z |
| format | Article |
| id | doaj.art-a9effed4989a4561a92aa974b6f3d6f8 |
| institution | Directory Open Access Journal |
| issn | 1680-7316 1680-7324 |
| language | English |
| last_indexed | 2024-12-10T11:52:41Z |
| publishDate | 2016-06-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Atmospheric Chemistry and Physics |
| spelling | doaj.art-a9effed4989a4561a92aa974b6f3d6f82022-12-22T01:49:53ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242016-06-01166641666310.5194/acp-16-6641-2016Summertime nitrate aerosol in the upper troposphere and lower stratosphere over the Tibetan Plateau and the South Asian summer monsoon regionY. Gu0Y. Gu1H. Liao2J. Bian3State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry (LAPC), Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, ChinaUniversity of Chinese Academy of Sciences, Beijing, ChinaSchool of Environmental Science and Engineering, Nanjing University of Information Science & Technology, Nanjing, ChinaKey Laboratory of Middle Atmosphere and Global Environment Observation (LAGEO), Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, ChinaWe use the global three-dimensional Goddard Earth Observing System chemical transport model (GEOS-Chem) to examine the contribution of nitrate aerosol to aerosol concentrations in the upper troposphere and lower stratosphere (UTLS) over the Tibetan Plateau and the South Asian summer monsoon (TP/SASM) region during summertime of year 2005. Simulated surface-layer aerosol concentrations are compared with ground-based observations, and simulated aerosols in the UTLS are evaluated by using the Stratospheric Aerosol and Gas Experiment II satellite data. Simulations show elevated aerosol concentrations of sulfate, nitrate, ammonium, black carbon, organic carbon, and PM<sub>2.5</sub> (particles with diameter equal to or less than 2.5 µm, defined as the sum of sulfate, nitrate, ammonium, black carbon, and organic carbon aerosols in this study) in the UTLS over the TP/SASM region throughout the summer. Nitrate aerosol is simulated to be of secondary importance near the surface but the most dominant aerosol species in the UTLS over the studied region. Averaged over summertime and over the TP/SASM region, <i>C</i><sub>NIT</sub> (the ratio of nitrate concentration to PM<sub>2.5</sub> concentration) values are 5–35 % at the surface, 25–50 % at 200 hPa, and could exceed 60 % at 100 hPa. The mechanisms for the accumulation of nitrate in the UTLS over the TP/SASM region include vertical transport and the gas-to-aerosol conversion of HNO<sub>3</sub> to form nitrate. The high relative humidity and low temperature associated with the deep convection over the TP/SASM region are favorable for the gas-to-aerosol conversion of HNO<sub>3</sub>.https://www.atmos-chem-phys.net/16/6641/2016/acp-16-6641-2016.pdf |
| spellingShingle | Y. Gu Y. Gu H. Liao J. Bian Summertime nitrate aerosol in the upper troposphere and lower stratosphere over the Tibetan Plateau and the South Asian summer monsoon region Atmospheric Chemistry and Physics |
| title | Summertime nitrate aerosol in the upper troposphere and lower stratosphere over the Tibetan Plateau and the South Asian summer monsoon region |
| title_full | Summertime nitrate aerosol in the upper troposphere and lower stratosphere over the Tibetan Plateau and the South Asian summer monsoon region |
| title_fullStr | Summertime nitrate aerosol in the upper troposphere and lower stratosphere over the Tibetan Plateau and the South Asian summer monsoon region |
| title_full_unstemmed | Summertime nitrate aerosol in the upper troposphere and lower stratosphere over the Tibetan Plateau and the South Asian summer monsoon region |
| title_short | Summertime nitrate aerosol in the upper troposphere and lower stratosphere over the Tibetan Plateau and the South Asian summer monsoon region |
| title_sort | summertime nitrate aerosol in the upper troposphere and lower stratosphere over the tibetan plateau and the south asian summer monsoon region |
| url | https://www.atmos-chem-phys.net/16/6641/2016/acp-16-6641-2016.pdf |
| work_keys_str_mv | AT ygu summertimenitrateaerosolintheuppertroposphereandlowerstratosphereoverthetibetanplateauandthesouthasiansummermonsoonregion AT ygu summertimenitrateaerosolintheuppertroposphereandlowerstratosphereoverthetibetanplateauandthesouthasiansummermonsoonregion AT hliao summertimenitrateaerosolintheuppertroposphereandlowerstratosphereoverthetibetanplateauandthesouthasiansummermonsoonregion AT jbian summertimenitrateaerosolintheuppertroposphereandlowerstratosphereoverthetibetanplateauandthesouthasiansummermonsoonregion |