The works for this project have been started since March and the finished items include the establishment of QA/QC processes for parallel comparison, the routine and random auditing, the three times field intercomparison measurements, the data evaluation for January to October measurement results, and the analyses for episodic events. From the routine and random auditing, the operation of the PM supersite has been improved all the times. However, there are some items needed to be improved and they can be classified into two different categories: 1. field operation staff: incomplete book keeping; the absence of operation record, which was taken away from the cabin; improvement of the technological capability of operation staff; better management of the field operation; 2. instruments evaluation of accuracy of calibration solutions for RP8400N and RP8400S; the error codes for RP8400N and RP8400S; the missing data in Grimm SMPS+C, especially at nighttime; the differences of NO concentrations between NOy and NH3 monitors; the zero or negative values of Sunset EC/OC monitor; the low H2O2 concentration; the NH3 monitors at all three satellite sites. Among all the instruments, the performances for RP1400 for both PM10 and PM2.5 measurements are the best with an average of greater than 88% during January to October measurements. But those for RP8400N and Sunset EC/OC monitors are the worst with average less than 80%. The worst instruments are the Grimm SMPS+C and H2O2 due to the long time malfunction. The low H2O2 concentrations have been found to be due to the interferences from the long sampling tube, as discussed from the intercomparison measurements. The PM2.5 concentrations measured by RP1400 were consistent with those measured by RP2300 and annular denuder. Although both RP8400N and RP8400S concentrations are highly correlated with those by reference method, they are either greater or less, respectively. The differences may be due to the different sampling and analytical methods or the conversion factors. During PM episodic events, the contributions from secondary aerosol are from 50 to 70%, that is, the dominant source for PM episodes is secondary aerosol. By using CO as tracer for dispersion effect, the major excess secondary speices are estimated to be SOA and sulfate at Chatou and Chizou, respectively and it accounts for another 6 to 12% of PM concentrations.

field intercomparison measurements,supersite,routine auditing