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TAO Data information

The standard TAO data set is divided into 4 subdirectories; surface, temps, currents, and hourly. Below you will find the contents of the four readme files for these directories.

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Directory taodata/surface

This directory contains ascii files of daily averaged surface meteorological data from the TAO array of ATLAS and Current Meter moorings maintained by NOAA's Pacific Marine Environmental Laboratory. Time series of mooring latitude, longitude, zonal wind (WND-U: west < 0, east > 0), meridional wind (WND-V: south < 0, north > 0), air temperature (AIRT), sea surface temperature (SST), and relative humidity (RH) are included from the TAO array. Several mooring sites were first occupied in 1979; however data from the majority of the sites begin during the past five years. Relative humidity measurements were not available at any site until 1989. All data are daily averages centered at 1200z on the day listed in each line.

This directory also contains data from island wind stations (courtesy of Mr H. Paul Freitag, NOAA/PMEL). Please note that island winds may be influenced by local orographic features. Contact P. Freitag (paul.freitag at noaa.gov) for specific details. The islands and the file names are listed below:

Kapingamarangi 1n155e_isl.met
Nauru 1s167e_isl.met
Baker Island 0n176w_isl.met
Christmas Island 2n157w_isl.met

Winds from the moored buoys are measured at a nominal height of 4m above the ocean surface, AIRT and RH at 3m above the surface, and SST at 1m depth. Island winds are measured from 10m or 30m height (see headers for each site), and the island AIRT is measured at 8m height.

Also included at the right end of each line of data are are integer values which indicate the quality of the data at left. The column header for these quality values reads PWDHAS which means

P quality of lat and lon mooring position
W quality of wind speed
D quality of wind direction
H quality of relative humidity
A quality of air temperature
S quality of sea surface temperature

The quality values may be interpreted using the following key:

0 = datum missing
1 = highest quality; pre/post-deployment calibrations agree
2 = standard quality; pre-deployment calibrations applied
3 = lower quality; pre/post calibrations differ
4 = questionable; doesn't agree with adjacent buoys, climatology, or other data sources
5 = sensor or tube failed
8 = position: buoy drifted or drifting with speed less than 0.1 knots
9 = position: buoy drifting and speed greater than 0.1 knots

The quality values at this time are all set to either 2, 0, or 5. As calibration comparisons progress, quality value indices will be updated as appropriate.

The most recent data in this directory (past 12 months) should be considered preliminary until post-deployment calibrations are performed for sensors presently deployed. Preliminary data are subject to revision.

The files in this directory are organized by site. For example, 0n110w.met contains all the data from the site at the Equator and longitude 110W. At the top of each file you will find a two line header which gives the nominal location, the time range covered by the file, the total number of days, the number of data blocks, the measured variables and their units, and the missing value. Gaps in time longer than 7 days have been removed, and a three line header is inserted at the location of each gap. Blocks of data are separated by these headers which give for their block the time range, the time index range relative to the start of the file, and sensor heights or depths. (The time index range is used by programs that read the files; see below). For sensors above the ocean surface, depth values are negative. The file tao_met.index details the number of daily mean values at each site for Winds, RH, AIRT and SST.

Moorings have on occasion broken free from their anchors and drifted from their deployed location while still returning data. These events can be found by inspection of the mooring location time series. Wind data from these drifting buoys have been corrected using drift velocities computed from location changes.

Any of the data files in this directory can be read using the example fortran program met_read.f. You may copy this program, and adapt it to your needs. It uses the time index range mentioned above to create real arrays in program memory of winds, RH, AIRT, and SST as well as integer arrays of data quality. All of these arrays are evenly spaced in time with gaps filled by missing data values.

The nearest to realtime data from the TAO array is available in NetCDF (i.e. binary) format in the directory [anonymous.tao], which includes documentation and tar files for the TAO DISPLAY SOFTWARE package for use on UNIX workstations. See the readme files in that directory for details.

DISK STORAGE REQUIREMENTS: As of Jan 1994, the files in this directory require about 5 Megabytes of disk space.

If you GET any of these data, please notify "atlasrt@pmel.noaa.gov" so that we can inform you of any modifications to the data sets. Also, please provide a 1-2 line description of your intended use of the data, so that we can advise you of other TAO analysis projects underway on related topics. If you use TAO data in publications, please acknowledge the TAO Project Office, Dr. Michael J. McPhaden, Director. Also, we would appreciate receiving a preprint and/or reprint of those publications utilizing TAO data for inclusion in the TAO bibliography. These publications should be sent to:

The TAO Project Office
NOAA/Pacific Marine Environmental Laboratory
7600 Sand Point Way NE
Seattle, WA 98115

Please send comments, questions, or problems to "atlasrt@pmel.noaa.gov".

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Directory taodata/temps

This directory contains ascii files of daily averaged temperature data from the TAO array of ATLAS and Current Meter moorings maintained by NOAA's Pacific Marine Environmental Laboratory. Time series of Ocean Temperature at a range of instrument depths from 1 meter to 500 meters are included. At the right end of each line of data are integer values in the same order in depth as the data which indicate the quality of the data at left. These may be interpreted using the following key:

0 = datum missing
1 = highest quality; no pre/post-cruise deviation in calibrations
2 = standard quality
3 = does not agree with climatology, but considered valid
4 = does not agree with ship and climatology, considered questionable
5 = sensor or tube failed

The quality values at this time are all set to either 2, 0, or 5. As calibration comparisons progress, quality value indices will be updated as appropriate.

The most recent data in this directory (past 12 months) should be considered preliminary until post-deployment calibrations are performed for sensors presently deployed. Preliminary data are subject to revision.

The nearest to realtime data from the TAO array are available in NetCDF (i.e. binary) format in the directory [anonymous.tao], which includes documentation and tar files for the TAO DISPLAY SOFTWARE package for use on UNIX workstations. See the readme files in that directory for details.

The files in this directory are organized by site. For example, 0n110w.tmp contains all the data from the site at the Equator and longitude 110W. At the top of each file you will find a two line header which gives the nominal location, the time range covered by the file, the total number of days, the total number of instrument depths, the number of data blocks, the units for the data, and the missing value. The data have been divided into blocks, each of which has a four line header, whenever major changes in instrument depths occur, or data is unavailable at all depths for periods longer than 7 days. These headers give, for their data block, the time range, the time index range relative to the start of the file, the number of days, the number of instrument depths, the depth indices, and the depths in meters. (The time index range and the depth indices are used by programs which read the data; see below). The file tao_tmp.index details the number of daily average data from each instrument depth at each mooring.

Daily mooring locations can be found in the corresponding met data files. For example, to find the locations for the mooring at 0n110w, refer to the file 0n110w.met in the directory taodata/surface. Moorings have on occasion broken free from their anchors and drifted from their deployed locations. These events can be found by inspection of the mooring location time series in the met files. Care should be used in the interpretation of the subsurface temperatures during these events since the sensor depths are not accurately known.

Any of the data files in this directory can be read using the example fortran program tmp_read.f. You may copy this program, and adapt it to your needs. It uses the time index range and the depth indices mentioned above to create real arrays in program memory of Ocean Temperature as well as integer arrays of data quality. All of these arrays are evenly spaced in time with gaps filled by missing data values. The subroutine tmp_sub can readily be linked to various other programs.

DISK STORAGE REQUIREMENTS: As of Jan 1994, the files in this directory require about 8 Megabytes of disk space.

If you GET any of these data, please notify "atlasrt@pmel.noaa.gov" so that we can inform you of any modifications to the data sets. Also, please provide a 1-2 line description of your intended use of the data, so that we can advise you of other TAO analysis projects underway on related topics. If you use TAO data in publications, please acknowledge the TAO Project Office, Dr. Michael J. McPhaden, Director. Also, we would appreciate receiving a preprint and/or reprint of those publications utilizing TAO data for inclusion in the TAO bibliography. These publications should be sent to:

The TAO Project Office
NOAA/Pacific Marine Environmental Laboratory
7600 Sand Point Way NE
Seattle, WA 98115

Please send comments, questions, or problems to "atlasrt@pmel.noaa.gov".

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Directory taodata/currents

This directory contains files of daily averaged wind, current, temperature and humidity data from current meter moorings maintained by NOAA's Pacific Marine Environmental Laboratory. This directory also contains data from island wind stations. Acoustic Doppler Current Profiler (ADCP) data from TAO moorings may be found in the subdirectory taodata/currents/adcp.

The data are organized by location and measured parameter. File names are of the form "site.parameter", e.g. "140w.temperature". Unless specified otherwise, all mooring sites are on the equator. The "parameter" field in mooring filenames can be "temperature", "humidity", or "velocity".

Daily means are computed between 0000 and 2359 GMT.

"Velocity" files contain both wind and current, and are sectioned by depth and each depth section begins with 4 header records which explain content and format. "Velocity" files have 4 daily means per data line, i.e. zonal and meridional velocity for 4 consecutive days starting from day "n" would be listed in the order U(n),V(n),U(n+1),V(n+1),U(n+2),V(n+2),U(n+3),V(n+3).

"Temperature" files may have more than one section depending on the number of depth levels at which measurements were made. Each section begins with 4 header records which explain the content and format, followed by data records containing data at several levels on the same day.

"Humidity" files have one section which begins with 4 header records followed by data records, each containing 12 consecutive daily values.

The island stations are combined into one file named "ISLANDS.WIND". which is organized by location. In addition to wind velocity some sites have air temperature and/or barometric pressure at times. Island wind is at either 10 m or 30 m and air temperature and pressure at 8 m above ground.

Moorings are recovered and redeployed at roughly 6-month intervals. After processing and quality checks have been performed data will be appended to existing files 3-6 months after recovery.

Moorings have on occasion broken free from their anchors and drifted from their deployed location while still returning data. Daily mooring locations can be found in the corresponding met data files. For example, to find the locations for the mooring at 0n110w, refer to the file 0n110w.met in the directory taodata/surface. Daily velocity data from these drifting buoys have been corrected using drift velocities computed from location changes. Other variables (temperature and humidity) have not been corrected. Care should be used in the interpretation of the subsurface temperatures during these events since the sensor depths are not accurately known. Information on buoys that have drifted is listed in the file taodata/hourly/drifters.doc.

For a quick look at what is available within this directory (taodata/currents), header information is available in files named "site.xHEAD", where "x" is either "t" (temperature), "v" (velocity) or "h" (humidity).

Files that are currently available and their size (in 512 byte blocks) are listed below:

95W.TEMPERATURE 104 95W.THEAD 1
95W.VELOCITY 256 95W.VHEAD 5
110W.TEMPERATURE 1317 110W.THEAD 2
110W.VELOCITY 1426 110W.VHEAD 8
124W.TEMPERATURE 145 124W.THEAD 2
124W.VELOCITY 214 124W.VHEAD 5
140W.HUMIDITY 15 140W.HHEAD 1
140W.TEMPERATURE 875 140W.THEAD 2
140W.VELOCITY 1107 140W.VHEAD 6
156E.HUMIDITY 6 156E.HHEAD 1
156E.TEMPERATURE 135 156E.THEAD 2
156E.VELOCITY 94 156E.VHEAD 3
165E.HUMIDITY 6 165E.HHEAD 1
165E.TEMPERATURE 624 165E.THEAD 2
165E.VELOCITY 760 165E.VHEAD 5
7N140W.TEMPERATURE| 193 7N140W.THEAD 2
7N140W.VELOCITY 305 7N140W.VHEAD 5
ISLANDS.WIND 397 ISLANDS.HEAD 3

DISK STORAGE REQUIREMENTS: File sizes are variable, with the maximum data file being 1426 blocks or 0.7 Megabytes. As of January 1994, there were 18 data files in this directory requiring a total of 7983 blocks or 4.1 Megabytes. As data accumulates, these figures will increase in proportion.

Please send comments, questions or problems concerning the data to "paul.freitag at noaa.gov".

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Directory taodata/hourly

This directory contains ascii files of hourly surface meteorological data, from the TAO array of ATLAS and Current Meter moorings maintained by NOAA's Pacific Marine Environmental Laboratory (*.met files). Also included are hourly subsurface temperatures from a few sites (*.tmp files).

Time series of zonal wind (WND-U: west < 0, east > 0), meridional wind (WND-V: south < 0, north > 0), air temperature (AIRT), sea surface temperature (SST), and relative humidity (RH) are included. Several mooring sites were first occupied in 1979; however, data from the majority of the sites begin during the past five years. Relative humidity measurements were not available at any site until 1989. Details about the sampling regimes for the different time series are included below.

Winds:

Winds are measured 4m above the sea surface with a propeller-vane sensor. Winds are sampled at 2 Hz for 6 minutes centered on the hour (eg, 0057-0103) then vector averages of these 720 samples are computed which provides an hourly wind estimate. The time word for the hourly wind value is the centered in the middle of the averaging period (eg, 0100). The daily vector average is based upon these 24 hourly values.

AIRT, SST, and RH:

AIRT, SST, and RH are sampled every 10 minutes and then averaged at the end of the hour. Samples are taken at 0010, 0020, 0030, 0040, 0050, and 0100 (for example), averaged after the last sample and given the time word of the last sample (0100). The time word for temperatures and humidity is therefore the end of the averaging period. The daily averages of AIRT, SST, and RH are based on these 24 hourly averages.

Subsurface Temperatures:

The subsurface ocean temperatures were sampled in different ways over the years. Some are continuously sampled, and the value with time 0000 is from 0000 to 0059(:59). Others are spot samples ranging from 7.5 to 30 minutes apart. In these cases the time given is the time of the first sample. We have not attempted to indicate which sampling regime was in effect at any given time. As of August 1996, the only site with hourly subsurface temperatures is 0n110w. More sites will probably follow in the next 12 to 18 months.

A typical line of data from an hourly data file is shown below

940522 1900 -1.1 -2.7 82.80 27.31 27.60 22222

These values are for May 22 1994 at 1900 hours GMT. The first two values are WND-U and WND-V, and the center of their averaging period is at 1900. The next three values are RH, AIRT, and SST, and the center of their averaging period is at 1835, which is just the average time of the samples used: 1810, 1820, 1830, 1840, 1850, and 1900.

Also included at the right end of each line of data are are integer values which indicate the quality of the data at left. The column header for these quality values reads WDHAS which means

W quality of wind speed
D quality of wind direction
H quality of relative humidity
A quality of air temperature
S quality of sea surface temperature

The quality values may be interpreted using the following key:

0 = datum missing
1 = highest quality; pre/post-deployment calibrations agree
2 = standard quality; pre-deployment calibrations applied
3 = lower quality; pre/post calibrations differ
4 = questionable; doesn't agree with adjacent buoys, climatology, or other data sources
5 = sensor or tube failed

The quality values at this time are all set to either 2, 0, or 5. As calibration comparisons progress, quality value indices will be updated as appropriate.

The format of the subsurface temperature files is similar to the description above, but with obvious differences. The quality values are the same as for the *.met files.

All of the data in this directory should be used with caution, since these data have not been part of our standard data sets. Revisions to this data set will be made from time to time. Please refer to the file

taodata/tao_updates.doc

for information about data revisions.

The files in this directory are organized by site. For example, 0n110w_hr.met contains all the data from the site at the Equator and longitude 110W. At the top of each file you will find a two line header which gives the nominal location, the time range covered by the file, the total number of hours, the number of data blocks, the measured variables and their units, and the missing value. Gaps in time longer than 24 hours have been removed, and a three line header is inserted at the location of each gap. Blocks of data are separated by these headers which give, for their corresponding block, the time range, the time index range relative to the start of the file, and sensor heights or depths. (The time index range is used by programs that read the files; see below). For sensors above the ocean surface, depth values are negative. The file tao_highres.index details the number of hourly values at each site for Winds, RH, AIRT and SST. For the number of subsurface values at each site, see file tao_tmp.index.

Moorings have on occasion broken free from their anchors and drifted from their deployed location while still returning data. These events can be found by inspection of the mooring location time series in the daily mean meteorological files in the directory taodata/surface. No corrections for drift velocity have been applied to hourly wind data for periods when a buoy is drifting. However, the daily mean data in taodata/surface have been corrected using drift velocities computed from location changes. Information on buoys that have been drifting during the program is listed in the file drifters.doc in this directory.

Any of the *.met data files in this directory can be read using the example fortran program hr_met_read.f. You may copy this program, and adapt it to your needs. It uses the time index range mentioned above to create real arrays in program memory of winds, RH, AIRT, and SST, as well as integer arrays of data quality. All of these arrays are evenly spaced in time with gaps filled by missing data values. For the subsurface temperature files, use the program tmp_hr_read.f, which is very similar to hr_met_read.f.

All of the hourly TAO data in this directory, as well as near-realtime and historical daily TAO data, are available in NetCDF (i.e. binary) format. These NetCDF files are provided for use with the TAO DISPLAY SOFTWARE package, which displays the data and many analyses in a point and click graphical user interface on color UNIX workstations. The software is available at no cost. For further information contact taogroup@pmel.noaa.gov.

DISK STORAGE REQUIREMENTS: As of September 1994, the files in this directory require about 50 Megabytes of disk space.

If you GET any of these data, please notify "atlasrt@pmel.noaa.gov" so that we can inform you of any modifications to the data sets. Also, please provide a 1-2 line description of your intended use of the data, so that we can advise you of other TAO analysis projects underway on related topics. If you use TAO data in publications, please acknowledge the TAO Project Office, Dr. Michael J. McPhaden, Director. Also, we would appreciate receiving a preprint and/or reprint of those publications utilizing TAO data for inclusion in the TAO bibliography. These publications should be sent to:

The TAO Project Office
NOAA/Pacific Marine Environmental Laboratory
7600 Sand Point Way NE
Seattle, WA 98115

Please send comments, questions, or problems to "atlasrt@pmel.noaa.gov".


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