Open AccessMethane in the western part of the Sea of Okhotsk in 1998–2000
Author(s) -
Yoshida Osamu,
Inoue Hisayuki Y.,
Watanabe Shuichi,
Noriki Shinichiro,
Wakatsuchi Masaaki
Publication year - 2004
Publication title -
journal of geophysical research: oceans
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2003jc001910
Subject(s) - methane , oceanography , geology , seawater , stratification (seeds) , bottom water , flux (metallurgy) , water mass , climatology , atmospheric sciences , chemistry , seed dormancy , germination , dormancy , biology , botany , organic chemistry
We measured oceanic methane in the western part of the Sea of Okhotsk in 1998, 1999, and 2000. An anomalously high methane concentration was found in near‐bottom water above the shelfbreak (∼200 m) off northeast Sakhalin every year: up to 488 nmol kg −1 in 1998, 981 nmol kg −1 in 1999, and 556 nmol kg −1 in 2000. This anomalously high concentration can be used to trace the water with density range 26.6 to 26.8 σ θ in the upper Dense Shelf Water. In the shelf off east Sakhalin, a strong stratification caused by freshwater from Amur River controlled the upward transport of methane through the suppression of vertical convection. The calculated methane flux was largest in the northeastern shelf region of Sakhalin (88 mol CH 4 km −2 d −1 ). In the western part of the Sea of Okhotsk (0.73 × 10 6 km 2 , 51% of total Sea of Okhotsk area), the emission rate of methane was 11 Gg CH 4 yr −1 .