General ------- This folder contains current meter data gathered during the World Ocean Circulation Experiment (WOCE). We have included time series and statistics from 44 experiments that were part of WOCE. The experiments were conducted by scientists from universities and institutes in the North America, Europe, Australia, and Asia. This is Edition 3 of the data set. It was completed in August 2001. Navigating the disk ------------------- The disk is meant to be accessed by a web browser, such as Opera, Netscape Navigator or Internet Explorer. We have tested the portion of the disk that contains current meter data with these three browsers and find that all three display the HTML documents correctly. We cannot guarantee that other browsers will do so. The documents were designed on a computer monitor with a resolution of 800 x 600 pixels and also display well at 1240 x 768 pixels. If you do not have a web browser you can still download the current records. You will find instructions in a subsequent section of this readme. Assuming for the moment that you are going to use a web browser, you start by opening "welcome.htm" which is in the same directory as this readme. welcome.htm is the disk's top document for the WOCE current meter experiments. On it you will find links to the data. (This directory also contains a file named "index.htm", which is an exact copy of welcome.htm. We include it because some conventions expect the top document of a website to have that name.) There are two primary links in welcome.htm that take you to data. The first, "Browse the WOCE current meter records", will bring up a list of all the WOCE experiments in which current meters were employed. Each item in the list is a link that takes you to a particular experiment. If you follow the link you will have an opportunity to see a map of the mooring area, look at metadata and statistics, and download the current meter records. A second data link in welcome.htm, "CMDAC's WOCE flow statistics", also takes you to a list of experiments. Again, each item in the list points to information from one experiment - in this case a table that contains flow statistics from the experiment. Included are means and variances of the measured quantities as well as momentum fluxes and heat fluxes. Other links lead to a description of the format of the current meter records, and to tables that list the hydrographic sections associated with the current meter arrays. Data Formats ------------ Each of the WOCE current meter records is available here in two distinct formats: netCDF and the Stranger format of the OSU Buoy Group. netCDF is a compact binary format that is in wide use for geophysical data. The Stranger format is an easy-to-read ASCII format. All of the records, in both formats, have been compressed using the zip algorithm. Once you have downloaded a compressed file you can expand it with any of a large number of readily available software tools. A recent survey of the Tucows site http://www.tucows.com/ turned up 18 Windows shareware or freeware applications capable of expanding zipped files. Free or inexpensive zip utilities also are available for other operating systems - Linux, Unix, VMS, OS/2, MS-DOS, AmigaDOS, Macintosh, etc. Directory structure of this disk -------------------------------- The top directory of the current meter folder (the directory that contains this readme) is named cmdac. It contains two main subdirectories named netcdf and stranger. The first contains current meter records in netCDF format and the second contains the same records in the ASCII Stranger format. The organization of these two directories is the same: each contains 44 subdirectories that correspond to the 44 WOCE current meter arrays. Schematically, this portion if the disk looks like this: cmdac | __________________|___________________ netcdf stranger | | _____________|_____________ _____________|_____________ acm1a acm1b acm1c . . . acm1a acm1b acm1c . . . . . . . . . . . . . . . . . . . . . . . . . . . Contents of these directories: acm1a - metadata, description, and time series from the STACS-10 component of ACM1 acm1b - metadata, description, and time series from the WATTS component of ACM1 acm1c - metadata, description, and time series from the ACCP-1 component of ACM1 and so forth. In addition, cmdac contains a third subdirectory named stats that contains flow statistics from the WOCE arrays: means, variances, heat fluxes and momentum fluxes. We have also included in a fourth subdirectory named dickson some more general tables of flow statistics compiled by Robert Dickson and Ken Medler. To reach them go to cmdac/dickson/stats, which contains eight text files suitable for printing. Those labeled "pre" contain statistics from the pre-WOCE period (the period prior to January 1989). The tables labeled "post" are from the period after January 1989. If you don't have a web browser ... ----------------------------------- You really do need a web browser to get at most of the information here. But failing that, you will be able at least to download the current meter records. The current records are the only items here that are not expressed in HTML, which requires a browser for interpretation. We show how to find current meter records with an example. Suppose you are interested in data from ACM4, and want to download the netCDF versions of the current records. 1. Go to the directory that contains this readme (cmdac) and change to cmdac/acm4. 2. In cmdac/acm4 you will find four subdirectories: acm4_1, acm4_2, acm4_3, and acm4_4. The subdirectories correspond to the four moorings of ACM4. Each subdirectory contains data from one mooring. Change to acm4_1. 3. You are now in cmdac/acm4/acm4_1. This directory contains four files: mta00992.htm mta00993.htm rcm00992.zip rcm00993.zip The files whose names begin with "mta" contain metadata, statistics, and possibly a comment on data quality. They are ascii files written in HTML. Even in the absence of a browser you might want to copy them from the CD and look at them, since some of the information about data quality is crucial. The other two files, whose names begin with "rcm", are zip-compressed current meter records. You can copy them to your hard drive and then expand them into netCDF files with any standard zip utility. 4. If you are interested in data from ACM4's other moorings you can change to any of the other three directories (acm4_2, acm4_3, and acm4_4) and copy the files there. Note the names of the zipped current meter records: rcm00992.zip, rcm00993.zip, etc. The general format is rcmXXXXX.zip, where XXXXX is an the accession, or catalog, number by which CMDAC identifies these records. The "rcm" prefix means that these records are from the OSU Buoy Group's current meter record archive. (This archive contains data from other types of moored instrument, such as temperature recorders and Seacat CTDs - as does this disk - but most are designated with the "rcm" prefix.) In general, the data from ACM1a are in subdirectories of cmdac/acm1a; those of PCM15 are in subdirectories of cmdac/pcm15; and so on. In some cases each subdirectory contains records from a single mooring. In other cases a given subdirectory will contain records from many moorings, all of which were occupied during a single phase of the experiment. The disk's organization is fluid in this regard.