PCM1 (Kuroshio Current East of Taiwan)

This experiment produced

• 20 current meter records (Aanderaa and VACM)
• 102 current records from 3 ADCPs
• 12 records from Seacat temperature-pressure recorders
• 8 records from temperature recorders

You can view metadata and/or download the records by clicking on links in the table below. A brief description of the experiment also is available. Each record is identified in the table by its depth and the name of the mooring. You may want to look at a map of the array first to see where the moorings were. If you download any of the current meter records you should review the note on file format. From here you can also move up one level to the list of WOCE experiments.

All of the PCM1 data in this archive are filtered and have a time increment of 12 hours. The diurnal tides and all higher frequencies have been removed. The original unfiltered files may be available from the PI.

• ADCP data from Mooring T3A (18 Sep 94 - 22 May 95)
• ADCP data from Mooring T3B (09 Oct 95 - 12 May 96)
• ADCP data from Mooring T4A (19 Sep 94 - 05 May 95)

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The volume and heat transport of the Kuroshio were observed with a moored array of current meters and other instruments during a period extending from September 1994 through May 1996. The array spanned the width and depth of the Kuroshio across the channel between Taiwan and the Ryukyu Islands (see map), and was a joint US - Taiwan collaborative effort. Some moorings were in place for the entire period. In other cases, moorings were replaced part-way through the experiment. (Moorings whose names end with "A" in the table above were in place during the first portion of PCM1, from September 1994 until mid or late 1995. Moorings whose names end with "B" were installed during October 1995 and retrieved in May 1996.)

Previous to this experiment, neither the Kuroshio's mean flow nor its temporal and spatial variability in the East China Sea were well described or understood. PCM1's initial results show energetic, coherent fluctuations of currents and temperature on time scales of several months and several weeks, that appear to be related to transport changes and meandering of the current axis. Volume transports derived from direct current measurements and dynamic height calculations were found to be in good agreement. Mean volume transports were estimated to be 23.3 Sv with a standard error of 2.0 Sv and a range of 5 to 40 Sv. The observed annual cycle has an amplitude of 5 SV with a maximum in July-August and a minimum in October. Transport fluctuations with periods on the order of several months appear to be related to eddy features that propagate westward into the Phillipine Basin from the ocean interior.

Related publications

Johns, W.E., T.N. Lee, C.T. Liu and D. Zhang (1995): PCM-1 array monitors Kuroshio transport. WOCE Notes, 7(3), 10-13.

Liu, C.T., S.P. Cheng, W.S. Chuang, Y. Yang, T.N. Lee, W.E. Johns and H.W. Li (1998): Mean structure and transport of Taiwan Current (Kuroshio). Acta Oceanographica Taiwanica, 36(2), 159-176.

Lee, T.N., W. E. Johns, C.T. Liu, D. Zhang, R. Zantopp and Y. Yang (1999): The Kuroshio east of Taiwan: Current structure and transport variability on daily to seasonal time scales. (submitted to J. Phys. Oceanogr.)

Yang, Y., C.T. Liu and M. Koga (1999): Taiwan Current (Kuroshio) and impinging eddies. J. of Oceanog., 55(5), 609-617.

Yang, Y., C.T. Liu, T.N. Lee, W.E. Johns, H.W. Li and M. Koga (1999): Sea surface slope as the estimator of the Kuroshio volume transport east of Taiwan. (submitted to J. Geophys. Res. Let.)

Johns, W.E., T.N. Lee, D. Zhang, R. Zantopp, C.T. Liu and Y. Yang (2001): The Kuroshio east of Taiwan: Moored transport observations from the WOCE PCM-1 array. J. Phys. Oceanogr., 31(4), 1031-1053.

Zhang, D., T.N. Lee, W.E. Johns, C.T. Liu and R. Zantopp (2001): The Kuroshio east of Taiwan: Modes of variability and relationship to interior mesoscale eddies. J. Phys. Oceanogr., 31(4), 1054-1074.

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netCDF is a self-documenting format that can be accessed by a variety of software tools. We have included here a Matlab script that can be used to read netCDF current records in an environment that contains the Matlab/netCDF interface created by CSIRO. You can Click here to learn more about netCDF.

We are aware that users who are unfamiliar with netCDF or who lack software to deal with it, may find the netCDF format more a deterrent than an aid to effective use of the data. We have included in this CDROM set a second disk that is identical to this one, except that the current meter records have OSU's "Stranger" format. The Stranger format, like netCDF, is self-documenting but utilizes the ASCII code. It is easily readable by both humans and computers; you may find it preferable to netCDF.

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