OSC07_Jianjun_Wang by yan198555

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									                                                           Possible Origin of High Concentrations of
                                                              Methane Sulfonic Acid (MSA) near
                                                              Coastal Antarctica: Penguin Feces
                                                                           Jianjun Wang1,2, Liqi Chen1﹡, Liguang Sun2﹡, Xulin Yang1, and Qi Lin1
          1. Key Laboratory of Global Change and Marine-Atmospheric Chemistry,Third Institute of Oceanography, SOA, Xiamen, Fujian, China (361005)
                      2. School of Earth and Space Sciences, University of Science and Technology of China, Hefei, Anhui, China (230026)
                                                                                 * E-mail: lqchen@soa.gov.cn,slg@ustc.edu.cn, jjun@ustc.edu

              Abstract: Four-year samples of bulk, high-volume aerosol were collected during the cruises of Chinese National
              Antarctic Research Expedition from Shanghai, China, to the Southern Ocean to Zhongshan Station in the East
              Antarctica. The results were compared to those from the cruises from China to the Arctic. nss-SO42- peaked near
              cities (e.g. Shanghai), however, the concentrations of MSA peaked near maritime Antarctica. We suggested the
              possible sources for MSA, besides phytoplankton, were sea animals (penguins or seals) feces.
                                 30.0                                                                                                                                                 30.0
                                             1999 Antarctica cruise                                                                                                                                   1999 Antarctica cruise
                                             2001 Antarctica cruise                                                                                                                                   2001 Antarctica cruise
                                 25.0                                                                                                                                                 25.0
                                             2002 Antarctica cruise                                                                                                                                   2002 Antarctica cruise




                                                                                                                                                                       nssSO42- (μg/m3)
                                             2004 Antarctica cruise                                                                                                                                   2004 Antarctica cruise
                                 20.0                                                                                                                                                 20.0
                                             1999 Arctica cruise                                                                                                                                      1999 Arctica cruise
                  Cl- (μg/m3)




                                 15.0                                                                                                                                                 15.0

                                 10.0                                                                                                                                                 10.0

                                  5.0                                                                                                                                                     5.0

                                  0.0                                                                                                                                                     0.0
                                        90       75   60    45        30    15   0   -15   -30   -45       -60   -75   -90                                                                      90     75     60     45        30   15      0   -15   -30   -45   -60   -75   -90

                                             N                        Latitude                         S                                                                                                                             Latitude
                                                                                                                                                                                                             N                                                          S


              Concentration of Cl- showed no clear                                                                                                                                                    Concentration of nssSO42- peaked near
              trends along latitude.                                                                                                                                                                                   cities (e.g. Shanghai).




                                0.30                                                                                                                                               0.36
                                             1999 Antarctica cruise                                                                                                                                  1999 Antarctica cruise
                                             2001 Antarctica cruise                                                                                                                                  2001 Antarctica cruise
                                0.25                                                                                                                                               0.30
                                             2002 Antarctica cruise                                                     Cruise of Chinese Antarctica Exploration                                     2002 Antarctica cruise
                                                                                                                                                                                                     2004 Antarctica cruise
                                                                                                                                                                   MSA/nssSO42-




                                0.20         2004 Antarctica cruise                                                                                                                0.24
                  MSA (μg/m3)




                                             1999 Arctica cruise                                                                                                                                     1999 Arctica cruise

                                0.15                                                                                                                                               0.18

                                0.10                                                                                                                                               0.12

                                0.05                                                                                                                                               0.06

                                0.00                                                                                                                                               0.00
                                        90       75   60    45        30    15   0   -15   -30   -45       -60   -75    -90                                                                     90    75     60     45        30    15      0   -15   -30   -45   -60   -75   -90

                                             N                        Latitude                         S                                                                                                      N                          Latitude                       S


              Concentration of MSA slowly increased with                                                                                                                       MSA/nssSO42- slowly increased with latitude
              latitude and peaked near coastal Antarctica.                                                                                                                           and peaked near coastal Antarctica.

                                                                                                            Aerosols of Antarctica had been found to contain relatively high levels of sulfur. The
             A: Fresh penguin droppings                                                                predominant and continuous source of atmospheric sulfur in this region is understood to be
           DMTS                 DMTTS                                                                  biogenic DMS emissions from the surface waters of the Southern Ocean. Less significant
                                             DMPS
                                                                                                       source is dusts from distant continents and aerosols from the stratospheric reservoir, which
                                                                                                       is occasionally enhanced by explosive volcanic eruptions. But this cannot explain that why
                                                                                                       concentrations of MSA increase near coastal Antarctica but not Arctic.
                                                                                                            We have raised one possible explanation for the abnormal high concentrations of MSA:
                                                                                                       penguin and seal feces. There were two evidences:
             B: Aged penguin droppings                                                                      We analyzed the volatile compounds in the fresh penguin feces and aged penguin
             sediment core Y2-20cm                                                                     dropping (sediments from penguin colony). Results showed that dimethyl trisulfide (DMTS),
                                                                                                       dimethyl tetrasulfide (DMTTS), and dimethyl pentasulfide (DMPS) composed more than 12% in
                                                                                                       the volatile components of fresh penguin feces, but no organosulfur compounds were found
                                                                                                       in the aged penguin dropping sediments. This indicated that organosulfur compounds had
                                                                                                       been emitted to the air (Xie et al. 2001).
             C: Aged penguin droppings                                                                     Near Dumont D’Urville on Ile des Petrels, with 12,000 penguin living there, the
             sediment core Y2-35cm
                                                                                                       concentration of nss-SO42- was 3.77 nmol/m3 for downwind location and 3.11 nmol/m3 for
                                                                                                       upwind (Legrand et al., 1998).
                                                                                                           There are now 120 million penguins living densely around the Antarctica, and they might
                                                                                                       contributed a considerable percentage to the atmospheric sulfur.

             D: Aged penguin droppings                                                                  Reference:
             sediment core Y2-45cm                                                                      Legrand M, Ducroz F, Wagenbach F et al., 1998., Ammonium in coastal Antarctic aerosol and snow:
                                                                                                       Role of polar ocean and penguin emissions, J. Geophys. Res., 103, 11,043– 11,056
                                                                                                        Xie ZQ, Sun LG, Wang JJ, et al. 2002. A potential source of atmospheric sulfur from penguin
                                                                                                       colony emissions. J. Geophys. Res., 107: art. no. 4617.


Gas chromatograms of gases extracted from penguin excrement                                      Acknowledgements: We thank Prof. Rahn KA and Prof. Xie ZQ for their help in
samples. (A): Fresh penguin droppings; (B–D): Aged penguin                                       data analysis and valuable suggestion in the poster, and Chinese Arctic and
droppings collected in different depth (20cm, 35cm, and 45cm) of
lake sediment core Y2 on Ardley Island, Antarctica.
                                                                                                 Antarctic Administration for their support in field exploration. We also thank the
                                                                                                 CAPaBLE program of the Asia-Pacific Network for Global Change Research for
                                                                                                 their financial support for attending the conference.

								
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