1. Particulate scavenging and lateral transport processes in the Kaoping River-Sea System based on 210 Po and 210 Pb distributions and disequilibrium Hung G.W., Wang P., Shen Y.T.

2. Station locations in the KPSC region

3. Potential temperature vs. salinity diagram, showing characteristics of the typical West Philippine Sea (WPS) and South China Sea (SCS) waters and those of stations in the KPSC region.

4. Depth profiles of temperature, salinity and fluorescence for all stations in the study area.

5. Profiles of the suspended particulate matter (SPM). 0.36-19.17 mg/kg for CW1-CW3 0.01-2.13 mg/kg for CW4 and CW5

7. Profiles of the SPM, fluorescence, and 210 Pb and 210 Po in both the particulate and dissolved phases.

8. Particulate 210 Pb and 210 Po concentrations vs. SPM for (a) and (b). Particulate 210 Po activities vs. fluorescence in the surface water. The linear regression was estimated excluding the data from CW1 and CW3 for (c). (a)(b) (c) (d) Plot of log specific activities of 210 Pb and 210 Po vs. log SPM for (d).

9. Plots of 210 Po vs. 210 Pb in the dissolved phase and in the total activities from all stations.

10. Profiles of total 210 Pb, 210 Po and 226 Ra concentrations in the KPSC region. The 226 Ra profile was estimated from data determined by Dr. Chung’s laboratory.

11. CW1CW2CW3CW4CW5 Inventory (dpm/m 2 )(0-75m) (0-50m) I Pb dissolved889510690169251815110826 I Pb particulate113161104511863109756292 I Po dissolved980994966900131117912 I Po particulate1371213515613033654348 Residence time(y) T Pb dissolved0.60.81.21.30.8 T Pb particulate0.8 0.90.83.9 T Po dissolved---2.60.41.2 T Po particulate--- 0.20.10.4 210 Pb and 210 Po inventories and residence times in the surface waters in the KPSC region.

12. StationDepth 210 Pb FluxCoreDepthExcess 210 Pb (m)(dpm/m 2 /d)(m) Inventory (dpm/cm 2 ) Flux (dpm/m 2 /d) CW121436732-323505647 CW230634 CW345631732-355113530 CW455628 CW5103820732-379754539 732-3811563429 Comparison of 210 Pb flux due to particle sinking and calculated from the 210 Pb inventory in the sedimentary column.

13. Summary The dissolved 210 Po and 210 Pb values in the outlet region of the KPSC are generally higher than those observed in the KPSC. The particulate 210 Po and 210 Pb concentrations in the outlet region of the KPSC are generally lower than those in the KPSC, especially in the bottom layer. SPM profiles generally show an increase with depth to a maximum in the bottom layer and display an offshore decrease trend. Positive correlations between both 210 Pb and 210 Po in particulate phase and SPM concentrations as well as negative log specific activities of 210 Pb and 210 Po versus log SPM correlations are observed in the study area.

14. Summary 210 Pb is removed from the surface water with residence times of 0.6-1.3 and 0.8-3.9 years for dissolved and particulate 210 Pb. The residence times of 210 Po in the surface waters are 0.4-2.6 and 0.1-0.4 years for dissolved and particulate 210 Po. Comparing 210 Pb fluxes, calculated from the 210 Pb inventory in the sedimentary column and in the water column, suggest settling 210 Pb flux from the overlying water column is about 51-103% of the excess 210 Pb flux in the bottom sediments.