README FILE FOR BERING STRAIT MOORING DATA                      12 February 2007
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Bering Strait Moorings 2005

This is an archive of data from moorings deployed in Bering Strait from
summer 2005 to summer 2006.  The mooring program was a one-year deployment
sponsored by NSF's Office of Polar Programs (ARC-0611967, Woodgate).
This data set is a continuation of a time series started in 1990.
For further details, see http://psc.apl.washington.edu/BeringStrait.html

Bering Strait is bisected by the Russia-U.S. Exclusive Economic Zone (EEZ)
boundary, requiring specific permission to work in the western channel of the
strait.  Although prior measurements exist from the western channel,
this present data set is only from US waters.  Note that in 2005, moorings
were also placed in the Russian channel under NOAA sponsorship
(PIs: Weingartner and Whitledge, UAF).

Mooring location A2 is in the middle of the eastern (Alaskan side) channel.
Mooring location A3 is just north of the strait, immediately east of the
EEZ line.  Experience has shown that site A3 samples both eastern and western
channel water.  Mooring location A4 is close to the Alaskan coast and allows
measurement of the Alaska Coastal Current.

Depth in Bering Strait is approximately 50-55 m.  Moorings A2 and A3
carried an Aanderaa RCM current meter at about 47 m and a Sea-Bird
Temperature-Conductivity recorder 1 m deeper.  Mooring A4 carried an
upward-looking ADCP at about 39 m and a Sea-Bird Temperature-Conductivity
recorder 2 m deeper.

Moorings were deployed from summer 2005 to summer 2006.  Each data file contains
the data from one instrument-year.  The listed year is the year in which the
mooring was deployed.  Moorings A2 and A3 were equipped with an upward-looking sonar
(PI: Moritz, UW), but these data are not included in this archive.  The Sea-Bird
instrument at Mooring A2 (indicated as wOptical in the following list) was
equipped with optical sensors for fluorescence, turbidity and PAR
(Photosynthetically Active Radiation) (PI: Whitledge, UAF).
These data are included in this archive, although only minimal quality control
of the data has been performed, as noted in the header files.  This leaves
to the user final judgments about which portions of the optical records are
usable.  Very basic tests suggest the PAR data is likely unusable.
The A2 Mooring was also equipped with NAS-2E nitrate analyzer
(PI: Whitledge, UAF), but these data are not included in this archive.

ID     Year  - Latitude      Longitude     - Instrument      S/N  - Inst.  Water
                                                                    Depth  Depth
A2-05  2005  - 65 46.78 N   168 34.50 W  - RCM-7          11454  -  46m    55m
A2-05  2005  - 65 46.78 N   168 34.50 W  - SBE-16wOptics   1717  -  47m    55m
A3-05  2005  - 66 19.54 N   168 58.02 W  - RCM-11          0099  -  49m    57m
A3-05  2005  - 66 19.54 N   168 58.02 W  - SBE-16          1225  -  50m    57m
A4-05  2005  - 65 44.73 N   168 15.68 W  - ADCP            1495  -  39m    48m
A4-05  2005  - 65 44.73 N   168 15.68 W  - SBE-16          0008  -  41m    48m

For RCMs and SBEs, data are recorded in one file per instrument per year.
with naming convention:
   BeringStrait_yyyy_ID_III#####.txt
yyyy=Deployment year; ID=mooring ID; III=instrument type; #####=serial number.

For the ADCPs, there are multiple files per instrument.
   BeringStrait_yyyy__ID_ADCP#####.000 = Binary data downloaded from the ADCP
The remainder are ASCII conversions of this file, corrected for clock drift
and magnetic declination.
   BeringStrait_yyyy__ID_#####.btm = ASCII bottom track data
        (including ice range and velocity)
   BeringStrait_yyyy__ID_#####.ins = ASCII instrument data
        (e.g. heading, pitch, roll, temperature)
   BeringStrait_yyyy__ID_#####_bin01.rdat = ASCII water velocity data from Bin 1
   BeringStrait_yyyy__ID_#####.bin02.rdat = ASCII water velocity data from Bin 2
    etc.  (Bin depths are given in the data files)

Header information is included in each data file.

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For details of the measurements and their interpretation, please see:
Roach, A.T., K. Aagaard, C. H. Pease, S.A. Salo, T. Weingartner, V. Pavlov,
   and M. Kulakov (1995) Direct measurements of transport and water properties
   through Bering Strait, J. Geophys. Res., 100, 18,443-18,457.
Woodgate, R.A., and K. Aagaard (2005) Revising the Bering Strait freshwater
    flux into the Arctic Ocean, Geophys. Res. Lett., 32, L02602,
    doi:10.1029/2004GL021747.
Woodgate, R.A., K. Aagaard, and T. Weingartner (2005) Monthly temperature,
    salinity, and transport variability of the Bering Strait throughflow,
    Geophys. Res. Lett., 32, No. 4, L04601, doi:10.1029/2004GL021880.
Woodgate, R. A., K. Aagaard, and T. J. Weingartner (2005) A year in the
    physical oceanography of the Chukchi Sea: Moored measurements from autumn
    1990-1991,Deep-Sea Res., Part II, 52, 3116-3149,
    doi: 10.1016/j.dsr2.2005.10.016.
Woodgate, R. A., K. Aagaard, and T. J. Weingartner (2006) Interannual changes
    in the Bering Strait fluxes of volume, heat and freshwater between 1991
    and 2004, Geophys. Res. Lett., 33, L15609, doi:10.1029/2006GL026931.
Aagaard, K., T.J.Weingartner, S.L. Danielson, R.A. Woodgate, G.C.Johnson,
    T.E.Whitledge (2006), Some controls on flow and salinity in Bering Strait,
    Geophys. Res. Lett., 33, L19602, doi:10.1029/2006GL026612.
Serreze, M.C., A.P. Barrett, A.G.Slater, R.A.Woodgate K.Aagaard, R.Lammers,
    M.Steele, R.Moritz, M.Meredith, and C.Lee (2006) The Large-scale Freshwater
    Cycle of the Arctic, J. Geophys. Res., 111, C11010, doi:10.1029/2005JC003424.

For an overview, please see:
   http://psc.apl.washington.edu/BeringStrait.html

For queries, please contact:
   Rebecca Woodgate   woodgate@apl.washington.edu   (206) 221-3268

  Polar Science Center, Applied Physics Lab, University of Washington
  1013 NE 40th, Seattle, WA  98105-6698   USA      FAX (206) 616-3142

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Meta data
=========

1) Platform: Subsurface oceanographic moorings

2) Project title: Bering Strait

3) Data collection dates: summer 2005 to summer 2006

4) PI:   Rebecca Woodgate (woodgate@apl.washington.edu)

5) Data collection method:
     Year-round moorings carrying
     - Aanderaa recording current meters (RCM)
     - Sea-Bird temperature/conductivity recorders (SBE)
     - RDI 300kHz Workhorse Acoustic Doppler Current Profilers (ADCP)

6) Data calibration method:
     Timestamps have been corrected for observed instrument clock drift.
     All times are given in GMT.
     For RCMs and SBEs, calibration coefficients are given in header file.
     RCMs:   Pre and post calibrated by the manufacturer (AA), by ESI,
     or at APL/UW.
     - pre-calibration used for data reduction, except for direction which
       uses post-calibration
     - as indicated in the headers, direction has been corrected by lookup
       table rather than fitted polynomial
     - direction corrected to true north, magnetic declination used is
       cited in the header
     - RCM11 data has been corrected for the temperature/pressure variability
       of the speed of sound using temperature data from the RCM
     SBEs:   Generallly pre and post calibrated by the manufacturer.
     - pre and post calibrations linearly time-weighted through the deployment.
     - pre calibration only available for 1717 sensor with optics
     ADCPS:  Tested by APL/manufacturer pre and post deployment.
     - compass calibrated as per manufacturer's specifications in Seattle prior
       to deployment.  Estimated compass error is included in the header file.
     - direction corrected to true north, magnetic declination used is cited
       in the header.
     - data requiring speed of sound in water is corrected by the ADCP using
       the water temperature measured by the ADCP.
     - intensity of returned signals is not specially calibrated.

7) Instrumentation used:
     Aanderaa current meters RCM-7 and -11 -sampling hourly.
     Sea-Bird SBE16 recorders (some with optics sensors)
         sampling at 60 min interval.
     RDI 300 kHz Workhorse ADCP,
         recording every 30min (data averaged over the time interval)

8) Quality control procedures:
     Quality control variously provided by Rebecca Woodgate.
       In general, records are very clean and no despiking has
       been performed.
     RCM and SBE data checked against each other where possible.
     RCM-11 measurements of water velocity depend on the speed of
       sound in water.  The manufacturer's default is to assume
       a sound speed of 1500 m/s.  In data processing, we use
       RCM-11 temperature and mooring information of instrument depth to
       obtain a more accurate speed of sound at the RCM-11 during
       deployment, and thus recompute the water velocity (Cor Speed).
     SBE optical data is not quality controlled and should be treated
       with caution, especially the PAR data.
     ADCP data rely on ADCP internal temperature for speed of sound corrections.
     ADCP Data files are included for all bins up to the surface although
       bins near the surface contain much larger errors (likely due to
       surface effects) and should be treated with caution.  The following
       are the shallowest good bins:
                last bin < 8 errors          last bin < 100 errors
      A4-05 -     bin 10, ~ 17m               bin 12, ~  13m

9) Data format:
     RCM and SBE data - ASCII, format given in individual headers
     ADCP data - BINARY download file from ADCP and ASCII conversion
                 of these files

10) Data collection problems:
      SBE1225 on mooring A3-05 shows significant (~0.1 psu) change in
         calibration between pre and post calibrations.
      RCM11454 shows a 2-3 deg offset in compass calibration between
         2004 and 2006.
      Instrument fouling is an concern in Bering Strait deployments, and
      precautions have been taken to mitigate problems.
         Fouling of mechanical rotors (RCM-7) has been a regular problem
      in the past.  The present data show little obvious evidence of this
      problem.
         Standard anti-fouling techniques are used for the SBE instruments,
      and this has been generally successful for the temperature and salinity
      records.
         The optical sensor suite mounted on the Sea-Bird instruments at
      Mooring A3 consisted of one Chelsea/Seatech/Wetlabs Transmissometer,
      one WETLabs WETStar Fluorometer, and one LI-COR PAR/irradiance sensor,
      although the PAR data in this archive is likely unusable.
      It appears that records from these instruments are increasingly degraded
      by biofouling through the deployment year.
      However, records in this archive are unmodified, and the user is
      cautioned to use these data with care. Photographic documentation of
      biofouling on recovery is available via cruise reports and the Bering
      Strait website:  http://psc.apl.washington.edu/BeringStrait.html.
      Generally, fluorescence seems to have survived the biofouling rather
      better than the other measurements. The transmissometer
      did not have shutters or wipers to clean the lenses, and generally
      suffered most from biofouling. The entire PAR record is highly
      suspect, showing no discernible difference between day and night,
      or season.

11) Other related data sets:
       This data set is a continuation of mooring measurements made in the
       Bering Strait almost continuously since 1990.  Mooring data from
       1990 to 2002, and 2002 to 2004 have already been archived via
       the SBI project, managed by JOSS/EOS.  For details see
        http://psc.apl.washington.edu/BeringStrait.html
        http://www.eol.ucar.edu/projects/sbi/
        http://sbi.utk.edu/
       Since 2000, CTD sections have been run in the Bering Strait on
       the mooring cruises.  This data is also accessible via the http
       links above.

12) Conditions for use or citation:
       Data freely available
       Please, as a courtesy, contact the PIs before using these data

13) Data qualifications or warnings:
       See also Data collection problems.
       The temperature (T) and conductivity (C) recorded by a RCM are
       significantly less accurate than those recorded by a SBE.  In most
       instances, a SBE was located very close to a RCM, so that the former
       would provide the record of choice for T and C even when the RCM
       measured both parameters. For data issues relevant to a specific
       deployment, see the individual headers.  In general:
       RCM data: Standard Aanderaa limitations apply
            - estimated accuracy 2 cm/s in speed, 5 deg in direction,
              0.05 deg C in temperature, >= 0.01 S/m in conductivity
              (corresponds to >= 0.2 psu in salinity).
       SBE data: Standard Sea-Bird limitations apply
            - estimated accuracy 0.02 deg C, 0.0012 S/m
              (corresponding to 0.02 psu), and < 1 db.
            - see header files for difference between pre and post calibration
       ADCP data: Standard RDI limitations apply
            - estimated accuracy
              < 0.5 cm/s in speed for water velocities (115 pings per ensemble)
              Estimated errors (given in the data files) vary with bin and time
              < 1 cm/s in speed for ice velocities (5 pings per ensemble)
              Estimated errors (given in the data files) vary with time
              < 1 deg in direction (see header files)
             range to ice only accurate to 1% of range to surface (i.e. ~ 0.4 m)
              < 0.4 deg C in temperature
       Optical Sensor Data (fluorescence, beam transmission, beam attenuation,
              and PAR):
              These unmodified records are included, although no
              quality control of the data has been performed, as noted in the
              header files.  This leaves final judgments about record quality
              to the user.

14) Grant numbers:
        Mooring sponsorship came from NSF (ARC-0611967, Woodgate)

15) Sample repository locations:
        National Ocean Data Center (http://www.nodc.noaa.gov)
        University of Washington (http://psc.apl.washington.edu/HLD)
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FILE LISTING
=============
This archive contains 33 data files, i.e.,

= 1 readme file (this file)
   Bering_Strait_Moorings_2005_ReadMe.txt

= 2 cruise reports
   e.g. UWmooringreportSWL2005July.pdf

= 2 RCM files
   e.g., BeringStrait_2005_A2_rcm11454.txt
= 3 SBE files
   e.g., BeringStrait_2005_A2_sbe1717.txt

The remaining 25 files relate to the ADCP. Specifically, there
is:
= 1 ADCP binary data file
   i.e., BeringStrait_2005_A4_ADCP01495.000
= 1 ADCP ascii files of bottom track data
   i.e., BeringStrait_2005_A4_01495.btm
= 1 ADCP ascii files of instrument data
   i.e., BeringStrait_2005_A4_01495.ins
= 22 ADCP ascii files of water data
   e.g., BeringStrait_2005_A4_01495_bin01.rdat

The full file listing is:
       Name                                          Size/bytes
       ==========================                    ==========
Bering_Strait_Moorings_2005_ReadMe.txt                   17691
BeringStrait_2005_A2_rcm11454.txt                       765401
BeringStrait_2005_A3_rcm00099.txt                       720280
BeringStrait_2005_A2_sbe1717.txt                       1064602
BeringStrait_2005_A3_sbe1225.txt                        747056
BeringStrait_2005_A4_sbe0008.txt                        747056
BeringStrait_2005_A4_ADCP01495.000                    12046221
BeringStrait_2005_A4_01495.btm                         4197626
BeringStrait_2005_A4_01495.ins                         2128512
BeringStrait_2005_A4_01495_bin01.rdat                  3163074
BeringStrait_2005_A4_01495_bin02.rdat                  3163074
BeringStrait_2005_A4_01495_bin03.rdat                  3163074
BeringStrait_2005_A4_01495_bin04.rdat                  3163074
BeringStrait_2005_A4_01495_bin05.rdat                  3163074
BeringStrait_2005_A4_01495_bin06.rdat                  3163074
BeringStrait_2005_A4_01495_bin07.rdat                  3163074
BeringStrait_2005_A4_01495_bin08.rdat                  3163074
BeringStrait_2005_A4_01495_bin09.rdat                  3163074
BeringStrait_2005_A4_01495_bin10.rdat                  3163074
BeringStrait_2005_A4_01495_bin11.rdat                  3163074
BeringStrait_2005_A4_01495_bin12.rdat                  3163074
BeringStrait_2005_A4_01495_bin13.rdat                  3163074
BeringStrait_2005_A4_01495_bin14.rdat                  3163074
BeringStrait_2005_A4_01495_bin15.rdat                  3163074
BeringStrait_2005_A4_01495_bin16.rdat                  3163074
BeringStrait_2005_A4_01495_bin17.rdat                  3163074
BeringStrait_2005_A4_01495_bin18.rdat                  3163074
BeringStrait_2005_A4_01495_bin19.rdat                  3163074
BeringStrait_2005_A4_01495_bin20.rdat                  3163074
BeringStrait_2005_A4_01495_bin21.rdat                  3163074
BeringStrait_2005_A4_01495_bin22.rdat                  3163074
UWmooringreportSWL2005July.pdf                         1648339
UWmooringreportSWL2006July.pdf                         1789726
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