2013 Taiwanese GEOTRACES test cruise in the Western Philippine Sea successfully completed

During the 2013 Taiwanese GEOTRACES test cruise carried out by our newly launched 3,000-ton research vessel Ocean Research 5 (OR/5), we successfully sampled 6 full depth stations down to 6,000 m in the Western Philippine Sea on the transect from E 122 to 128 degree on N 23.5 degree. In addition to the samples of dissolved and particulate trace metals, we used large volume filtration apparatus to collect size-fractionated particles with the following fractions, 0.2-2, 2-10, 10-60, 60-150, and >150 um. We also successfully deployed floating trap at St 7 for 24 hr to collect sinking particles at 3 depths in upper 200 m. Interestingly, the planned sampling stations were exactly located on the pathway of a powerful category-4 typhoon, Soulik, which just passed through the stations about one week ago. We observed significant amount of sinking particles in the floating traps and the maximum Chl a was elevated up to 1.2 ug per liter in the euphotic zone of the oligotrophic water, which is about 10 fold of its normal concentrations. The twelve laboratories involved in this cruise also studied aerosols and the biogeochemiscal roles of bacteria, phytoplankton, and zooplankton on material cycling. Through this unique sampling occasion, we expect to reveal the mechanism how super typhoon changes the ecosystem and material cycling and transport both for biologically active major and minor elements.

Chief Scientist: Tung-Yuan Ho (Academia Sinica, China-Taipei)