Marine Ecosystems Research Department - jamstec japan agency ...

More documents

Recommendations

Info

JAMSTEC 2002 Annual Report Mutsu Research Group BGC mooring K2-MEX PO mooring ~ 30m ~ 30m ~ 40m Incubation chamber (SID) Phytoplankton sampler (PPS) Water sampler (RAS) ~ 50m ~ 50m Zooplankton sampler (ZPS) ~ 150m ~ 250m ~ 400m CTD/ACM profiler (MMP) ~ 1000m Sediment trap ~ 500m ~ 600m ~ 800m ~ 2000m ~ 1000m ~ 5000m ~ 2000m ~ 4950m ~ 5000m ~ 4550m 5100 ~ 5200m Fig. 2 Mooring systems for biogeochemistry (BGC mooring) and physical oceanography (PO mooring) 30 10/25 Si(OH)4(35) 50 25 10/9 NOx(35) 11/26 11/18 40 10/17 NOx(35) (µmol / kg) 20 11/10 30 n-Si(OH)4(35) (µmol / kg) 15 10/1 11/2 20 Oct.-Dec. Jan.-Mar. Apr.-Jun. Jul.-Sep. 10 0 50 100 150 julian day 200 250 300 350 Oct.1 2001 Nov.19 2001 Jan.8 2002 Feb.27 2002 Apr.18 2002 Jun.7 2002 Jul.27 2002 Sep.15 2002 10 Fig. 3 Seasonal variability in concentrations of nutrients (silicate and opal) at 50m observed using RAS pler (RAS). In October just after BGC mooring was deployed, concentrations changed significantly and suddenly. Based on seasonal variability in water temperature and salinity around m observed by using CTD profiler (MMP) (Fig. ), high temperature and low salinity were observed when concentrations of nutrients decreased. It indicates that sudden and unstable vertical mixing took place in October, and surface mixed layer thickened temporally, resulting in the increase in productivity. It was certified that the time-series mooring system enables us to observe such a short-term event and oceanographic change. Meanwhile, our group and our partner in cooperative research, the Joint North Pacific Research Center of Woods Hole Oceanographic Institution (J-PAC), launched the HiLATS web site for science and education (http://jpac.whoi.edu/hilats/index.html). 186
Japan Marine Science and Technology Center Mutsu Research Group 10 33.2 10/6/01 33.15 8 10/26/01 11/5/01 33.1 Temp. (deg-C) 6 4 9/16/01 11/25/01 sal 33.05 33 Salinity (PSU) 2 9/26/01 10/16/01 11/15/01 12/05/01 12/25/01 1/14/02 3/2/02 32.95 temp 32.9 9/6/01 0 0 40 80 julian day 120 160 32.85 Fig. 4 Seasonal variability in water temperature and salinity at 50m observed by using MMP 2. Study on the past marine environmental changes Since FY, a paleoceanography project, "Study on the past marine environmental changes" has been carried out as one of the Research Projects in Mutsu Institute for Oceanography (MIO). We focus on reconstructing the natural variability of global and regional climate recorded in the deep-sea sediment during the late Quaternary. We are seeking to clarify the following themes: a) Changes in sea surface temperature and surface current systems b) Changes in biogeochemical cycles in the ocean (Carbon Cycle) c) Changes in global thermohaline circulation We also seek to find new paleo-proxies and to develop the paleo-proxies as follows: - Proxies of chronology (Compound-specific radiocarbon analysis and amino acid chronology) - Proxies of nutrients and temperature (analysis of trace elements such as Cd, Mg, Ca contained in foraminiferal tests with culture experiments of foraminifers) We introduce the following two results as the main results of this research project in FY. () The past change in intermediate/deep water in the North Pacific since the Last Glacial Maximum is not well understood because of sparse data in this region. Sediment core MR-K PC collected from the continental slope off northern Japan (˚.'N, ˚.'E; m depth) was used for estimating the paleo ventilation by using foraminiferal radiocarbon ( C) technique. The C contents in planktonic and benthic foraminifers were measured by the accelerator mass spectrometry (AMS). Some samples were prepared by using a micro-scale preparation technique (Uchida et al., submitted) because they contained only small amounts of foraminifers. Our preliminary result indicates that there was significant variation in mid-depth ventilation during the last deglaciation in the northwest Pacific, especially in the Bølling–Allerød (ca.– ka) and Younger Dryas (ca..– ka) intervals. The middepth ventilation in the northwest Pacific was significantly reduced in the Bølling–Allerød warming, while the resumption of ventilation was started at the onset of the Younger Dryas cooling (Ahagon and Uchida, submitted). The latter may support the idea that the intermediate water formation in NW Pacific was strengthened in contrast to the interruption of North Atlantic Deep Water formation during the Younger Dryas. () There are few conventional dating methods that can be used to estimate the geological age of siliceous 187
Page 2 and 3:
JAMSTEC 2002 Annual Report J apan M
Page 4 and 5:
Japan Marine Science and Technology
Page 6 and 7:
Page 8 and 9:
Page 10 and 11:
Page 12 and 13:
Page 14 and 15:
Page 16 and 17:
Page 18 and 19:
Page 20 and 21:
Page 22 and 23:
Page 24 and 25:
Page 26 and 27:
JAMSTEC 2002 Annual Report Marine T
Page 28 and 29:
Page 30 and 31:
Page 32 and 33:
Page 34 and 35:
Page 36 and 37:
Page 38 and 39:
Page 40 and 41:
Page 42 and 43:
Page 44 and 45:
Page 46 and 47:
Page 48 and 49:
JAMSTEC 2002 Annual Report Marine E
Page 50 and 51:
Page 52 and 53:
Page 54 and 55:
Page 56 and 57:
Page 58 and 59:
Page 60 and 61:
Page 62 and 63:
Page 64 and 65:
Page 66 and 67:
Page 68 and 69:
Page 70 and 71:
Page 72 and 73:
Page 74 and 75:
Page 76 and 77:
Page 78 and 79:
Page 80 and 81:
Page 82 and 83:
Page 84 and 85:
Page 86 and 87:
Page 88 and 89:
Page 90 and 91:
Page 92 and 93:
Page 94 and 95:
Page 96 and 97:
Page 98 and 99:
Page 100 and 101:
Page 102 and 103:
Page 104 and 105:
Page 106 and 107:
Page 108 and 109:
Page 110 and 111:
Page 112 and 113:
JAMSTEC 2002 Annual Report Frontier
Page 114 and 115:
Page 116 and 117:
Page 118 and 119:
Page 120 and 121:
Page 122 and 123:
Page 124 and 125:
Page 126 and 127:
Page 128 and 129: JAMSTEC 2002 Annual Report Frontier
Page 154 and 155: Japan Marine Science and Technology
Page 158 and 159: 1000 Japan Marine Science and Techn
Page 180 and 181: JAMSTEC 2002 Annual Report Mutsu Re
Page 194 and 195: JAMSTEC 2002 Annual Report Research
Page 228 and 229:
Page 230 and 231:
Page 232 and 233:
Page 234 and 235:
Page 236 and 237:
Page 238 and 239:
Page 240 and 241:
Page 242 and 243:
Page 244 and 245:
Page 246 and 247:
Page 248 and 249:
Page 250 and 251:
Page 252 and 253:
Page 254 and 255:
Page 256 and 257:
Page 258 and 259:
Page 260 and 261:
Page 262 and 263:
Page 264 and 265:
Page 266 and 267:
Page 268 and 269:
Page 270 and 271:
Page 272 and 273:
Page 274 and 275:
Page 276 and 277:
JAMSTEC 2002 Annual Report PATENT .
Page 278:
JAMSTEC Japan Marine Science and Te
show all

Marine Ecosystems Research Department - jamstec japan agency ...

Create successful ePaper yourself

Delete template?

Save as template?