Long-term variation of surface phytoplankton chlorophyll a in the Southern Ocean during 1965-2002
The variation in the phytoplankton biomass over a decadal time scale, and its relationship with the Antarctic Circumpolar Wave (ACW) and climate change, has been poorly interpreted because of the limited satellite chlorophylla (chl a) data compared with the physical parameters from satellite. We analysed a long-term chl a dataset along the Japanese Antarctic Research Expedition (JARE) cruise ... tracks since 1965 to investigate inter-annual variation of phytoplankton biomass. In the Southern Ocean, increasing trends of chl a and the spreading of higher chl a area to the north with 3-7 year cycles were found. Although relationships between the decadal change in chl a and climate change such as variation of sea ice extent and the El Nino are still obscure, large variation of primary production in proportion to the chl a is implied.
The chl a concentration of sea surface water has been measured routinely on board the icebreakers Fuji and Shirase during almost every cruise of the JARE.
The download file contains chlorophyll a data collected from ship tracks on JARE voyages between 1965 and 2002.
The field in this dataset are:
Date (local time)
Corrected Chlorophyll a
See the attached paper for more details.
Download point for the data - Excel spreadsheet
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In the dataset over the 38-year period of 1965-2002, we used the value of water between 25 degrees N to 55 degrees S along the cruise track between Tokyo and Antarctica, during the period between 15 November and 28 December of each year.
Although the sea surface water was sampled with a plastic bucket or pump (8 m), no significant difference in the chl a between sampling procedures was found. The chl a was determined colourimetrically until 1980 (except in 1967 and 1972) and fluorometrically since 1981. The data collected colourimetrically was corrected to a concentration corresponding to the fluorometric measurements. Difference in the chl a between the solvents was not significant.
These data are publicly available from the provided URL.
Data Set Progress
hirawake at salmon.fish.hokudai.ac.jp
Faculty of Fisheries, Hokkaido University
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+61 3 6232 3244
+61 3 6232 3351
dave.connell at aad.gov.au
Australian Antarctic Division
203 Channel Highway
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The publications on the data collected during the 1965-1976 and 1988-1993 cruises are listed in Fukuchi  and Suzuki and Fukuchi , respectively. For data on the 1977-1985 and 1994-1997 cruises, see [Kanda and Fukuchi, 1979; Fukuchi and Tamura, 1982; Tanimura, 1981; Watanabe and Nakajima, 1983; Ino and Fukuchi, 1984; Sasaki, 1984; Hamada et al., 1985; Fukuda et al., 1986; Hattori and ... Fukuchi, 1988; Midorikawa et al., 2000]. Data post 1998-2002 cruises is in Hirawake and Fukuchi . Data from the 1986-1987 will be published in the JARE data report of digital media, including all cruise data.
Auxiliary Material for paper 2004GL021394 Long-term variation of surface phytoplankton chlorophyll a in the Southern Ocean during 1965-2002. Toru Hirawake, Tsuneo Odate and Mitsuo Fukuchi (National Institute of Polar Research, Tokyo) Geophys. Res. Lett., Vol (Num), doi:10.1029/2004GL021394
All of the chl a data have been reported in the publications of the National Institute of Polar Research (NIPR).
Fukuchi, M. (1980), Phytoplankton chlorophyll stocks in the Antarctic Ocean, J. Oceanogr. Soc. Jpn., 36, 73-84.
Fukuchi, M., and S. Tamura (1982), Chlorophyll a distribution in the Indian sector of the Antarctic Ocean in 1978-1979, Antarct. Rec., 74, 143-162.
Fukuda, Y., M. Ohno, K. Iwanami, and H. Touju (1986), Chlorophyll a content in the surface and subsurface waters along the course of the Shirase to Antarctica in 1984-1985, Antarct. Rec., 30, 103-112.
Hamada, E., A. Taniguchi, M. Okazaki, and Y. Naito (1985), Report on the phytoplankton pigments measured during the JARE-25 Cruise to Syowa Station, Antarctica, November 1983 to April 1984, JARE Data Rep. 103, 89 pp., Natl. Inst. Polar Res., Tokyo.
Hattori, H., and M. Fukuchi (1988), Report on the phytoplankton pigments concentrations, zooplankton and benthos sampling during the JARE-27 cruise, November 1985 - April 1986, JARE Data Rep. 135, 28 pp., Natl. Inst. Polar Res., Tokyo.
Hirawake, T., and M. Fukuchi (2004), Chlorophyll a concentration of phytoplankton during the cruises of 40-44th Japanese Antarctic Research Expedition in 1998-2003, JARE Data Rep. 279, 31 pp., Natl. Inst. Polar Res., Tokyo.
Ino, Y., and M. Fukuchi (1984), Report on chlorophyll a distribution along the course of the Fuji in 1981-1982, Antarct. Rec., 81, 38-44.
Kanda, H., and M. Fukuchi (1979), Surface chlorophyll a concentration along the course of the Fuji to and from Antarctica in 1977-1978, Antarct. Rec., 66, 37-49.
Midorikawa, T., K. Nomura, Y. Miyamoto, T. Odate, A. Ishikawa, N. Washiyama, T. Hirawake, M. Namiki (2000), Report on phytoplankton pigments measured during the JARE-36~-39 cruises to Syowa Station, Antarctica in 1994-1998, JARE Data Rep. 249, 36 pp., Natl. Inst. Polar Res., Tokyo.
Sasaki, H. (1984), Distribution of nano- and microplankton in the Indian sector of the Southern Ocean, Mem. Natl. Inst. Polar Res. Spec. Issue, 32, 38-50.
Suzuki, T., and M. Fukuchi (1997), Chlorophyll a concentration measured with a continuous water monitoring system during the cruise to Syowa Station, Antarctica, JARE-27 (1985/86) to JARE-35 (1993/94), 60 pp., Natl. Inst. Polar Res., Tokyo.
Tanimura, A. (1981), Distribution of the surface chlorophyll a along the course of the Fuji to and from Antarctica in 1979-1980, Antarct. Rec., 72, 35-48.
Watanabe, K., and Y. Nakajima (1983), Surface distribution of chlorophyll a along the course of the Fuji (1980/81) in the Southern Ocean, Antarct. Rec., 77, 33-43.
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