A new type research on hydrographic state using satellite-derived sea surface temperature, sea surface height, and solar insulation

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Using satellite-derived Sea Surface Temperature (SST), Sea Surface Height (SSH), and Solar Insulation, hydrographic state around Japan is investigated.Main results of the research is ;1.Derivation systems of the SST from AVHRR data and the SSH from the Topex altimeter data have been established.2.The sea surface cooling event caused by the passage of typhoons is found in the Tohoku area. The reason of the event is examined using the satellite SST,hydrographic observation data, and the numerical model, and is proved to be related to the vertical mixing of the strong wind and the stratification condition in the Tohoku Area.3.The SSHs derived from the Topex altimeter data are compared with the hydrographic observation data in the Tohoku Area. The satellite SSH has an rms error of about 13cm. The comparison with the SST images is also made, and good agreement is proved.4.A derivation method of the daily solar insulation over the ocean is developed, and one year estimation of the insulation is made. The validation of the estimated insulation using ship-observed insulation data shows an rms error of about 20W/m^2.5.The hydrographic state in the Pacific ocean off the Hokkaido is investigated using the Topex SST and the hydrographic observation data. The geostrophic velocities estimated from the SSH agrees well with those measured by moored current meter. The correlation coefficient is 0.55 and the rms error is 7.6cm/s. The combination of the satellite SSH,SST,and the hydrographic data is proved to contribute to detailed analyzes of the hydrographic state in this area.6.Using the satellite SST and SSH,wavy patterns propagating toward west at around the Subtropical front is found. The pattern has a wavelength of 800-1000km, and the phase speed of 7-8cm/s, and a characteristic period of 3-6months.