Temperature and salinity distribution characteristics in seas around Japan, and statistical parameters used in a visual quality-control
software
Yutaka Nagata1, Toru Suzuki1, Sachiko Oguma1, Shizuo Iwata1, Hidetoshi Watanabe2 and Tomoichi Yoshimura3
1 Marine Information Research Center, Japan Hydrographic Association, Mishima Bldg. 5F, 7-15-4 Ginza, Chuo-ku, Tokyo 103-0061, Japan
2 Sanyo Techno Marine, Inc., 1-3-17 Nihonbashi-Horidome-cho, Chuo-ku. Tokyo 103-0012, Japan
3 PASSCO Environmental Science Institute, 2-32-1 Yoga, Setagayaku, Tokyo 158-0097, Japan
1. Introduction
Range checks on temperature, salinity and their vertical gradients, and density inversion check are very effective in quality-control procedure of oceanic data, and are used by almost all data management organization in the world. For example, (US) NODC made a quality-control on their database by used this technique prior to compile World Ocean Dataset 1998 (W0D98). However the reasonable or permissive ranges of values are usually by NODC are very wide, and its purpose appears to detect errors caused by clear mistypes. NODC set the ranges for 9 sub-domains of the worldwide ocean (Fig.1), and whole North Pacific Ocean except its equatorial region is considered one sub-domain. If we confine our attention to the limited area, we would be able to set more precise ranges for higher level quality-control software.
We selected two unique areas in vicinity of Japan as test areas: the Mixed Water Region to the east of Honshu and the Kuroshio Region to the south of Honshu. The Mixed Water Region between Oyashio and Kuroshio Fronts are very complicated, and the distribution patterns of temperature and salinity would be very skewed because three kinds water masses, Oyashio Water Tsugaru Current Water and Kuroshio Water, intrude into this region. On the other hand, the Kuroshio has two stable flow patterns, Straight Path and Meandering Path, to the south of Honshu. The bi-modal structure of the Kuroshio would influence the distribution patterns inevitably. In this paper we introduce our results of analysis mainly for these regions, and propose the range parameters to be used in a quality-control software of higher level.
