MORSETS (MIO Ocean Radar data Site for Eastern Tsugaru Strait) exhibits quasi-real-time surface current maps of the Eastern Tsugaru Strait. This site also provides archived data since April 2014.

Mutsu Institute for Oceanography (MIO), Japan Agency for Marine Earth Science and Technology (JAMSTEC) has been observing these surface currents by HF radar from three radar stations surrounding the Eastern Tsugaru Strait (ESAN Station: Hakodate Hokkaido, OHATA Station: Mutsu Aomori, IWAYA Station: Higashidori Aomori).

This site aims to contribute to the fisheries industry, shipping industry, disaster prevention, marine accident response, and research for marine environment change.

Contents of MORSETS

You can see the current maps from quasi-real-time and the past 48hr observations on your browser. The numerical data will be available for download if you submit an application. Please contact us for the required terms and conditions and the procedures of the application.

This site also displays the sea surface temperatures (SSTs) measured at the several coastal stations. The latest SSTs are shown in the current map and the SST graphs over the past two weeks are on "About Water temperature". Attribution of each SST data is described in "About Water temperature". The SST data can not be downloaded from this site. Please contact the belonging organization of each data if you would like to use the data.

Note) Uncorrected data is contained in our data set. Whether corrected or not, the archived data may be updated by the calibration of the HF radar system, modifying the correction methods, and so on without notice.

Help us to improve the quality of MORSETS

If you notice something odd about the data set (Discrepancy with the actual current, etc.) or have any requests for this site, please send your questions or comments to our address (see bottom of this page). Your comments may lead to improvements of MORSETS (as reference for planning on site observation to verify data quality, examining methods of the data corrections and/or quality controls, and improving the site page structures.

About HF radar system (High frequency ocean radar system)

The HF radar stations irradiate the ocean surface with radio waves, and receive the backscatter. The radial current vectors are obtained from the backscattering spectrum (Doppler shift measurement). The radar system installed at the Eastern Tsugaru Strait is SeaSonde R manufactured by CODAR Ocean Sensors, LTD. using a 13.9 MHz band HF radio wave. The observational range of the radial vectors is 3 to 60km from each radar station and spatial resolution is ~3km. The 2-D ocean current vectors are computed by syntheses of the radial vectors at overlapping areas of two or more observational ranges of the radar stations. Please refer to the Fujii (2004), if you need more information about the principle of how to measure ocean current by the HF radar.

Reference : Fujii (2004) Introduction of High-Frequency Ocean Radar: Technology and History., Bulletin Coastal Oceanogr., 41, 73-82 (in Japanese with English abstract)