caa a22 4500 605455384 CHVBK 20210128100212.0 cr unu---uuuuu 210128e20150601xx s 000 0 eng 10.1007/s10872-015-0279-3 doi (NATIONALLICENCE)springer-10.1007/s10872-015-0279-3 Long-term variations of North Pacific Tropical Water along the 137°E repeat hydrographic section [Elektronische Daten] [Toshiya Nakano, Tomoyuki Kitamura, Shusaku Sugimoto, Toshio Suga, Masafumi Kamachi] The spatiotemporal variability of North Pacific Tropical Water (NPTW), characterized as a subsurface salinity maximum, is investigated using a half-century-long repeat hydrographic dataset of the Japan Meteorological Agency (JMA) along the 137°E meridian, historical objective analysis of monthly global temperature and salinity dataset, sea surface dynamic height dataset, and atmospheric dataset. The cross-sectional area of NPTW (S>34.9) at 137°E shows decreasing trend with freshening after the mid-1970s. Significant decadal-scale variation is also revealed; this resulted from meridional excursion of its northern boundary, fluctuating between 15°N and 25°N. It was found that the northern boundary excursions at 137°E were induced by westward expansion of the NPTW formation region related to excess evaporation and increased Ekman pumping in the formation region. It is also inferred that the larger eddy activity around the northern boundary of the NPTW also possibly influences the northward movement of the NPTW northern boundary at 137°E through enhanced eddy mass transport. The Oceanographic Society of Japan and Springer Japan, 2015 North Pacific Tropical Water nationallicence JMA 137°E meridian nationallicence Decadal variability nationallicence Flesh water flux nationallicence Eddy activity nationallicence Nakano Toshiya Global Environment and Marine Department, Japan Meteorological Agency, 1-3-4 Otemachi Chiyoda-ku, 100-8122, Tokyo, Japan aut Kitamura Tomoyuki Global Environment and Marine Department, Japan Meteorological Agency, 1-3-4 Otemachi Chiyoda-ku, 100-8122, Tokyo, Japan aut Sugimoto Shusaku Department of Geophysics, Graduate School of Science, Tohoku University, Sendai, Japan aut Suga Toshio Department of Geophysics, Graduate School of Science, Tohoku University, Sendai, Japan aut Kamachi Masafumi Oceanography and Geochemistry Research Department, Meteorological Research Institute, Tsukuba, Japan aut Journal of Oceanography Springer Japan 71/3(2015-06-01), 229-238 0916-8370 71:3<229 2015 71 10872 https://doi.org/10.1007/s10872-015-0279-3 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s10872-015-0279-3 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Nakano Toshiya Global Environment and Marine Department, Japan Meteorological Agency, 1-3-4 Otemachi Chiyoda-ku, 100-8122, Tokyo, Japan aut NATIONALLICENCE 700 1- Kitamura Tomoyuki Global Environment and Marine Department, Japan Meteorological Agency, 1-3-4 Otemachi Chiyoda-ku, 100-8122, Tokyo, Japan aut NATIONALLICENCE 700 1- Sugimoto Shusaku Department of Geophysics, Graduate School of Science, Tohoku University, Sendai, Japan aut NATIONALLICENCE 700 1- Suga Toshio Department of Geophysics, Graduate School of Science, Tohoku University, Sendai, Japan aut NATIONALLICENCE 700 1- Kamachi Masafumi Oceanography and Geochemistry Research Department, Meteorological Research Institute, Tsukuba, Japan aut NATIONALLICENCE 773 0- Journal of Oceanography Springer Japan 71/3(2015-06-01), 229-238 0916-8370 71:3<229 2015 71 10872