气候变化领域集成服务门户

The dissolved organic carbon in precipitation (water-soluble organic carbon, WSOC) can provide a carbon subsidy to receiving ecosystems. The concentrations, isotopic signatures (C-13/Delta C-14), and molecular signatures (transform ion cyclotron mass spectrometry) of WSOC being delivered to Nam Co-a remote site on the inland Tibetan Plateau (TP)were compared to those of WSOC in the snowpack, and in wet deposition from urban cities fringing the TP. The average WSOC concentration at Nam Co (1.0 +/- 0.9mg C L-1) was lower than for the large cities (1.6 to 2.3mgCL(-1)) but higher than in the snowpack samples (0.26 +/- 0.09mgCL(-1)). Based upon radiocarbon data, it is estimated that 156% of Nam Co WSOC was fossil derived, increasing to 208% for snowpack WSOC, 29 +/- 4% for Lhasa WSOC, and 34 +/- 8% for the three cities. Transform ion cyclotron mass spectrometry results revealed that the abundance of dissolved black carbon and sulfur-containing molecules of WSOC increased in the order Nam Co