Supporting Material for

Transcription

1 Supporting Material for Seasonal Changes in Gaseous Elemental Mercury in Relation to Monsoon Cycling over the Northern South China Sea C.M. Tseng *, C.S. Liu, and C. Lamborg Institute of Oceanography, National Taiwan University, P.O. Box -, Taipei, Taiwan, Republic of China. Woods Hole Oceanographic Institute, MS, Woods Hole, MA, USA *To whom correspondence should be addressed. This PDF file includes Figure S-S; Table S

2 Figure Supplementary (Fig. S) Ar gas MFC P ST P Transfer lines Cable lines Power supply Gold sand + Charcoal trap Pre-drying tube Gold sand trap Sample gas V MFC Tee injection port Mass flow controller Vent Filter holder MFC V V P AT AFS Vent Pump Sample introduction P ST Two-channel analysis Sample/analytical trap Preconcentration/ desorption Detection/ Data acquisition Fig S Schematic of GEMA with two-channel analysis for GEM determination in natural airs.. sampling introduction device;. six-way injection valves (injection-v, -V, -V);. atomic fluorescence spectrometer (AFS, Tekran );. personal computer for data acquisition (Adopted from Tseng et al., JAAS). Table S Figures of merit of the GEMA Table Figures of merit of the GEMA Characteristic items Potential Hg speciation GEMA Reactive gaseous, particulate and organo-hg Trap efficiency (%) ~ Accuracy (%) ± Absolute detection limit (pg) Method detection limit (ng m - ) Calibration range. ( L of sample) Wide dynamic (pg to ng) R. square (n=).99 Reproducibility (%) Flow rate (L min - ).~ Sample cycle time Memory effect at ng Hg Interference from water vapor Versatile/Practical Feasibility min ~ hours No No Multi-trap applications, multifunctional Hg speciation analysis

3 Figure Supplementary (Fig. S) (a) Back trajectories Cruise-series GEM Daily average Diurnal average OR- (May 9~ ) /9/ // // Mean =.±.; n= (days). ±. (n=) n= n=9 /9 // 9 Time (hr) OR-9 (Aug ~ ) Mean =.±.; n= (days). ±. (n=) n= n= n=9 n= n= // // // // /9/ // / / / / /9 / 9 OR-9 (Oct. ~ ) // // // // // // Mean =.±.; n= (days) n= n=. ±. (n=) n= n=9 n= / / / / // 9

4 Fig. Supplementary (to be continued) (b) Back trajectories Cruise-series GEM Daily average Diurnal average OR- (Dec. ~9 ) OR- (Mar ~ ) OR- (May ~ ) ///////////9/// // // // // // // // // // // // /9/ Mean =.±.; n= n= / / / / / /9 / Mean=.9±.;n= (days) n= n= n= n= n= n=9 n=9 / / / / / / / / / / Mean =.±.; n= (days) n= n=9 n=9 n=.±. (n=) n=9 n=.9±. (n=) n= n= n= n=.±. (n=) n= / / / / / / / 9 9 9

5 Fig. Supplementary (to be continued) (c) Back trajectories Cruise-series GEM Daily average Diurnal average OR- (Aug ~ ) OR- (Nov ~ ) OR- (Jan ~ ) // // // // // // /9/ // // // // /9/ //// // // // // Mean =.9±.; n= (days) n= / / / / / / / Mean =.±.; n= (days) n= n= Mean =.±.; n= (days) n= n= n=.9±. (n=) n= / / / / /9 / // n= n= n= n= n= n=.±. (n=) n=.±. (n=) / / / / 9 Time (hr) 9 9

6 Fig. Supplementary (to be continued) (d) FR- (July ~Aug ) OR- (Nov ~ ) OR- (Dec ~ ) Back trajectories Cruise-series GEM Daily average Diurnal average // // // /9/ // // // // // // /9/ //////////// /////////////9///// Mean =.±.; n= (days) n= n= / / / /9 / / // Mean =.±.; n= (days) n=.±. (n=) n= n= n= n= 9.±. (n=) n= n= n= n= n= n= n= n= / / /9 ///// / 9 Mean =.±.; n= (days).±. (n=) n= n= n= n= n= n= n= n= 9 ///////9// Fig S Summary of temporal GEM variations with related information over the northern SCS obtained during the study period from to. *Blue frame denotes GEM measurements obtained at the SEATS station

7 Fig. Supplementary (S) 9 Time (hr) 9 Spring Summer Autumn Winter OR- (May 9~ ) OR- (Mar ~ ) OR- (May ~ ) OR-9 (Aug ~ ) OR- (Aug ~ ) Time (hr) FR- (July ~Aug ) 9 OR-9 (Oct. ~ ) 9 OR- (Nov ~ ) 9 OR- (Nov ~ ) 9 OR- (Dec. ~9 ) 9 OR- (Jan ~ ) 9 OR- (Dec ~ ) 9 Fig S Summary of seasonally diurnal GEM variations over the northern SCS obtained during the study period from to. Data points are indicated as averages ± standard deviations and red trend lines made by non-linear regression analyses.

8 Fig Supplementary (S) Multiple Comparison Graph 9 9 S 9 9 S Symbol indicates significant difference. Fig S Seasonal differences in the mean values were statistically significant (p<.) estimated by One Way ANOVA-Fisher LSD method for all pairwise multiple comparison procedures.

9 Fig Supplementary (S) Fig. S A map of the mercury source inventory. (top) Spatial distribution of anthropogenic area/point sources and (bottom) biomass burning/volcano sources. The area sources represent emissions per._ grid per year; the biomass emissions are emissions per _ grid per months. (Adopted from Li et al., JGR). Green dot denotes the SEATS station (circle).