README FILE FOR BERING STRAIT MOORING DATA                 28th November 2012
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Bering Strait Moorings 2010-2011

This is an archive of data from US moorings deployed in the Bering Strait 
from summer 2010 to summer 2011.  Moorings were also deployed for this 
period in Russian waters.  This archive will be updated once these Russian
data are available.

Mooring deployments were funded by the NSF Arctic Observing Network (AON)
award ARC-0855748 (PIs: Woodgate, Weingartner, Whitledge and Lindsay) 
with shiptime support from the NOAA RUSALCA (Russian-US Long Term Census 
of the Arctic) program.  

The mooring work required 2 dedicated cruises:
- in 2010 (31st July - 11th August), a ~ 10 day cruise on the Russian vessel 
Khromov deployed the moorings.  Some CTD sections were run on this cruise, 
and these data are archived separately.
- in 2011 (12th - 23rd July), a ~ 10 day cruise on the Russian vessel 
Khromov recovered the moorings. Some CTD sections were run on this cruise, 
and these data are archived separately.  (Note that this cruise also 
redeployed the moorings, under NSF-AON funding.)
Cruise reports are included in this archive.

For 2010 to 2011, a total of eight moorings were deployed:
- three moorings (A1W, A1, A1E, also called A12,A11 and A13)
in the Russian channel of the Strait
- four moorings (A2W, A2, A4W, A4) in the US channel of the strait
- one mooring (A3) at a site just north of the strait in US waters. 
In what follows, mooring names include a two digit suffix to represent
year of deployment.  

Sites A1, A2, and A3 were established in 1990. A2 and A3 have been occupied 
almost continuously (all years except 96-97) since then. A1 was occupied for 
a few years from 1990,(90-91, 92-94) and then again since 2004.  Site A4 
was established in 2001. Sites A1E and A1W were established in 2005, and 
also carry Russian instrumentation not included in this archive (although 
documented in the cruise reports and here).
Sites A2W and A4W were established in 2007.     

Mooring location A1 (also called A1-1) is in the middle of the western 
(Russian side) channel.  Mooring location A1W (also called A1-2) is
between A1 and the Russian coast.  Mooring location A1E (also called
A1-3) is between A1 and the Diomede Islands, which divide the strait.  
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
Russian-US EEZ (Exclusive Economic Zone) 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.

For an overview of previous and on-going Bering Strait mooring work,
please see http://psc.apl.washington.edu/BeringStrait.html.

Moorings carry a variety of instruments, listed in the table below.
All records are year-round, sampling hourly or more frequently (Time
Int. in table below).
Data from instruments marked with * are not included in this archive.
For access to these data, please contact the named PI in list below table.  

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--------------------------------------------------------------------------
ID  Deployed Latitude  Longitude  Instrument      S/N  Time   Inst.  Water  
     in Year   (N)        (W)                          Int.   Depth  Depth  
--------------------------------------------------------------------------
A3-10  2010  66 19.61  168 57.93  ISCAT          5430   5min   17m    58m  
                                  ISCAT-Logger     26  60min   ...    58m
                                  600kHz-ADCP    2144  30min   44m    58m
                                  SBE37 Microcat 4510  15min   44m    58m 

A2W-10 2010  65 48.07  168 47.90  ISCAT          5472   5min   19m    53m  
                                  ISCAT-Logger     23  30min   ...    53m
                                  300kHz-ADCP    2269  30min   44m    53m
                                  SBE16          1400  60min   48m    53m 
                                  FLTUSBWetlabs*  932          48m    53m
                                  WhaleRecorder*  129          48m    53m

A2-10  2010  65 46.87  168 34.05  ISCAT          5470   NR     19m    56m  
                                  ISCAT-Logger      7  30min   ...    56m
                                  300kHz-ADCP    1495  30min   45m    56m
                                  SBE16woptic    4973  60min   48m    56m
                                  ISUS*           087    -     48m    56m        

A4W-10 2010  65 45.42  168 21.97  ISCAT          7622   5min   20m    55m  
                                  ISCAT-Logger     21  30min   ...    55m
                                  300kHz-ADCP    2230  30min   43m    55m
                                  SBE16          2341  60min   45m    55m 

A4-10  2010  65 44.76  168 15.76  ISCAT          5471   5min   19m    49m  
                                  ISCAT-Logger     22  30min   ...    49m
                                  300kHz-ADCP    2234  30min   39m    49m
                                  SBE16             8  60min   41m    49m 
                                  FLTUSBWetlabs*  935          41m    49m
                                  SBE26p-BPG     1175  30min   47m    49m 
--------------------------------------------------------------------------
Depths are estimated from mooring design and pressure sensors where available,
and are good to 1-2m. 
  NR=instrument not recovered     ND=No data
Instruments with data included here:
 300KHz-ADCP - 300kHz RDI/Teledyne Workhorse Acoustic Doppler Current Profiler
 600KHz-ADCP - 600kHz RDI/Teledyne Workhorse Acoustic Doppler Current Profiler
 SBE37 Microcat - Seabird SBE 37 Temperature Salinity Pressure recorder
 SBE16woptic - Seabird SBE16plus with optical data (including some or all of
               fluorescence, turbidity, transmissivity and PAR) - see headers
 SBE26p-BPG - Seabird SBE26plus Bottom Pressure Gauge
 RCM9Turb - Aanderaa RCM9 acoustic current meter with turbidity sensor
 RCM9LW   - Aanderaa Lightweight RCM9 acoustic current meter
Instruments with data not included here:
 AARI-CM&CTD - Current meter and CTD from AARI (Arctic and Antarctic Research
               Institute, Russia), PI: Igor Lavrenov, AARI
 ISUS - ISUS Nitrate sensor, PI: Terry Whitledge, UAF
 WhaleRecorder - Passive Acoustic Whale recorder, PI: Kate Stafford, UW
 FLTUSBWetlabs - Wetlabs self-contained Fluoresence/Turbidity instrument,
               PI:  Rebecca Woodgate, UW

Each data file contains the data from one instrument-year - the listed year 
in the mooring name is the year in which the mooring was deployed. 
   Turbidity, fluorometer and PAR data from the RCM and SBE instruments are 
included in this archive, although only minimal quality control of the 
data has been performed.  In this form of the data, these channels are
recorded only as external voltage, as calibration data was unavailable.
For calibration data, please contact Tom Weingartner, UAF. 
   The SBE16plus BPG also recorded wave burst data - this may be extracted
from the .hex files included in this archive, but has not been processed here.

For RCMs and SBEs, calibrated data are recorded in one file per instrument 
per year, with naming convention:
   BeringStrait_yyyy_ID_III_#####.ttt
yyyy=Deployment year; ID=mooring ID; III=instrument type; #####=serial number;
ttt=indicates calibration, with .pre=pre-deployment calibration used,
.ppp=pre and post deployment calibrations merged. 
The SBE-16 and 26 hexidecimal files (unaltered from the download) are also 
included, indicated by extension .hex.

For the ADCPs, there are multiple files per instrument.
   BeringStrait_yyyy__ID_#####ADCPraw.000 = Binary download from the ADCP
     (note there are sometimes two files for the ADCP - see notes below)
   BeringStrait_yyyy__ID_#####_ADCPrecovery.txt = post deployment tests
The remainder are ASCII conversions of the data, 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 in Bin 1
   BeringStrait_yyyy__ID_#####.bin02.rdat = ASCII water velocity data in Bin 2
    etc.  (Bin depths are given in the data files)
   BeringStrait_yyyy__ID_#####mbin01.rdat = ASCII data from re-averaged Bin 1
   BeringStrait_yyyy__ID_#####mbin02.rdat = ASCII data from re-averaged Bin 2
    etc.  (Bin depths are given in the data files)

Header information is included in each data file.

-----------------------------------------------------------------------------
For details of the measurements and their interpretation, please see:
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.
Woodgate, R. A., T. Weingartner, and R. Lindsay (2010), The 2007 Bering 
   Strait oceanic heat flux and anomalous Arctic sea-ice retreat,
   Geophys. Res. Lett., 37, L01602, doi:10.1029/2009GL041621.
Woodgate, R. A., T. Weingartner, and R. Lindsay (2012), Observed increases 
   in Bering Strait oceanic fluxes from the Pacific to the Arctic from 
   2001 to 2011 and their impacts on the Arctic Ocean water column
   Geophys. Res. Lett., in press.


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) 543-6785

------------------------------------------------------------------------------

Meta data
=========

1) Platform: Subsurface oceanographic moorings

2) Project title: Bering Strait

3) Data collection dates: summer 2010 to summer 2011

4) PI:   Rebecca Woodgate (woodgate@apl.washington.edu)
         Tom Weingartner (weingart@ims.uaf.edu)

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

6) Data calibration method:
     Unless noted otherwise in the header on each data file, 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:   
     - Predeployment calibrated by the manufacturer (AA),
     - pre-calibration used for data reduction.
     - where 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
     - RCM9 data has been corrected for the temperature/pressure variability
       of the speed of sound using temperature data from the RCM

  SBEs:  
     - Generally pre and post calibrated by the manufacturer (indicated
       by suffix .ppp)
     - pre and post calibrations linearly time-weighted through the
       deployment.
     - .pre suffix indicates only pre-cruise calibration used
     
  ADCPS:  Tested by APL/UAF/manufacturer pre deployment.
     - A2W, A2, A4W, A4 compasses calibrated as per manufacturer's
       specifications in Seattle prior to deployment.  Estimated 
       compass error is included in the header file
     - A1 and A3 ADCPs may have batteries exchanged at sea and thus
       compass calibration may be poor - see headers
     - where available, at sea compass check also included in 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:  (see table for sampling frequencies)
     Aanderaa current meters RCM-9 (one with optics sensor)
     Sea-Bird SBE26plus recorders
     Sea-Bird SBE16 recorders
     Sea-Bird SBE16plus recorders with optics sensors
     Sea-Bird SBE37 recorders
     ISCAT loggers (SBE37 Microcat logging data to an APL-Logger)
     RDI 300 and 600 kHz Workhorse ADCP - bin size either 2m or 1m.
       (if the latter, .000 data is at original bin size, and
        extracted data averaged onto 2m bins).

8) Quality control procedures:
     Quality control provided by Rebecca Woodgate.
     RCM and SBE data checked against each other where possible.
     RCM-9 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 temperature and mooring information of instrument depth to
       obtain a more accurate speed of sound at the RCM during
       deployment, and thus recompute the water velocity (Cor Speed).
     SBE optical data is not quality controlled and should be treated
       with caution.
     ADCP data rely on ADCP internal temperature for speed of sound
       corrections.
     ADCP on A1 and A3 recorded in 1m bins. This archive contains the
       original binary file of this data (without correction for magnetic
       declination).  For the ascii files in this archive (which are
       corrected for magnetic declination), these data are averaged onto  
       2m bins to match other deployments. 
     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.  

9) Data format:
     RCM and SBE data - ASCII, format given in individual headers
        (uncalibrated "hex" data also included for SBE16s and SBE26p)
     ADCP data - 2 formats: a) BINARY download file from ADCP and 
                            b) ASCII conversion of these files (in 2m bins)

10) Data collection problems:
    By Mooring:
      - the 2010-2011 moorings were biofouled on recovery (photographs
      included in archive)
      Optics data is likely contaminated by this biofouling and should
      be treated with caution.
      - Mooring A3-10 did not released properly and required dragging.
      This is noted in the headers, and the release time is the time
      the mooring was sighted on the surface
    
    By Instrument:

     === SBE26p (Bottom Pressure Gauge and Wave Recorder)
       A410_1175
         - .hex files contain unprocessed wave burst data
         - converted pressure data show no obvious problems

    === SBE16 (no optics)
       A2W10_1400
         - light biofouling, cell clear on recovery
         - 0.05 psu salinity difference pre-post calibrations
       A4W10_2341 
         - light biofouling, cell clear on recovery
         - 0.07 psu salinity difference pre-post calibrations  
         - 7 temperature spikes removed    
       A410_0008        
         - heavy biofouling, but cell mostly clear on recovery
         - 0.09 psu salinity difference pre-post calibrations

    === SBE16Plus (with optics)
       Note - none of optics data is quality controlled.
       Uncalibrated (.hex) files included in archive
       A210_4973 - with biowiper
         - moderate biofouling, but cell clear
         - instrument deployed horizontally (perhaps trapping
         sediment in cell, but comparison to other SBEs in
         array suggests no ill effects)
         - optics calibrations unavailable, external voltages
         included here. 
      
      === SBE37s (non-ISCAT)
       A310_4510
         - only precal available
         - one suspected low salinity spike
 
    === ISCATS (Loggers and SBE37s)
       A310  - SBE37 5430 - recovered with full record
                - pre-post drift ~ 0.03 psu
             - Logger - stopped in Oct 2010

       A2W10 - SBE37 5472 - recovered with full record 
                 - pre-post drift ~ 0.03 psu
             - Logger - 6 spikes removed 

       A210  - SBE37 - lost ~ 18hrs before recovery
             - Logger - data ok

       A4W10 - SBE37 7622 - recovered with full record
                 - pre-post drift ~ 0.06 psu
             - Logger - stopped in Dec 2010
  
       A410  - SBE37 5471 - recoverd with full record
                 - pre-post drift ~ 0.05 psu
                 - ~ 10min clock discrepancy with in water times
            - Logger - data ok

   === ADCPs
      Note that ADCP range measurements are not corrected
      for pitch and roll.  For full discussion and correction,
      see: Woodgate and Holroyd, 2011, included in archive.
      A310_adcp2144 (600kHz)
         - bin 1 has high velocity errors
         - wrote 2 files, missing 1 record indicated with 9999
         - erroneous temperature sensor for start of record
         introduces 2-13% error in early velocities (see header).
         - originally 1m data, reaveraged to 2m bins
         - compass calibration error may be up to 10deg
      A2W10_adcp2269
         - bins 1 and 2 have high velocity errors
         - bins 8 and 9 have high velocity errors likely from iscat
      A210_adcp1495
         - bin 1 has high velocity errors
      A4W10_adcp2230
         - bin 1 has high velocity errors
         - bin 9 has high velocity errors likely from iscat
         - instrument leaked just before or at recovery
      A410_adcp2234
         - bin 1 has high velocity errors
         - bin 7 has high velocity errors likely from iscat

      Photographic documentation of biofouling on recovery is available 
      via cruise reports, included here and on the Bering Strait website:  
       http://psc.apl.washington.edu/BeringStrait.html.

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 have
       already been archived via the SBI project, managed by JOSS/EOS, 
       and at NODC.
       For details see
        http://psc.apl.washington.edu/BeringStrait.html
        http://www.eol.ucar.edu/projects/sbi/
        http://sbi.utk.edu/
        http://www.nodc.noaa.gov
       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
       SBE26plus data: Standard Sea-Bird limitation apply
            - estimated accuracy 0.01 deg C, 0.01% of full scale 
            (for these deployments, range 60db, thus accuracy 0.006db)
       ADCP data: Standard RDI limitations apply
            - estimated accuracy
              ~ 0.5 cm/s for water velocities (~100 pings per ensemble)
              Estimated errors (given in the files) vary with bin and time
              ~ 1 cm/s for ice velocities (2 or 5 pings per ensemble)
              Estimated errors (given in the files) vary with time
              ~ 1 deg in direction (see header files)
              Range to ice - accurate to 1% of range to surface (i.e. ~ 0.4 m)
              ~ 0.4 deg C in temperature
       Optical Sensor Data:
              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 Polar Programs Arctic Observing Network 
        ARC-0855748 (PIs: Woodgate, Weingartner, Whitledge and Lindsay) 
      with shiptime support from
      - NOAA Arctic Research RUSALCA - Russian-US Longterm Census
          of the Arctic: http://www.arctic.noaa.gov/aro/russian-american/

15) Sample repository locations:
        National Ocean Data Center (http://www.nodc.noaa.gov)
        University of Washington (http://psc.apl.washington.edu/HLD)
==============================================================================
FILE LISTING
=============
Total number of files: 
   Main directory:  29 files and 5 subdirectories

  Size (b) Name
  -------  ----
= Metadata file (1 file)
    Bering_Strait_Moorings_NSFAONRusalca_10to11_ReadMe.txt

= cruise reports (2 files) and technical note (1 file)
  CruiseReportKhromov2010wEL_verNov11.pdf
  Khromov2011CruiseReportwithEL_Oct2011.pdf
  WoodgateandHolroyd2011_BTrangeCorrection.pdf

= photos of biofouling on recovery (5 files)
  BeringStrait_A210_RecoveryPhotos.jpg
  BeringStrait_A2W10_RecoveryPhotos.jpg
  BeringStrait_A410_RecoveryPhotos.jpg
  BeringStrait_A4W10_RecoveryPhotos.jpg
  BeringStrait_A310_RecoveryPhotos.jpg

= SBE26plus - Bottom Pressure and Wave Recorder (2 files)
  - 1 .hex files of raw data   
  - 1 .ppp files of pre-post calibrated Pressure and Temp
  (see below for processing software)
  BeringStrait_2010_A4_sbe26p_1175.hex
  BeringStrait_2010_A4_sbe26p_1175.ppp

= SBE16 (6 files)
  - 3 .hex files of raw data
  - 3 .ppp files of pre-post calibrated data
  BeringStrait_2010_A2W_sbe16_1400.hex
  BeringStrait_2010_A4W_sbe16_2341.hex
  BeringStrait_2010_A4_sbe16_0008.hex
  BeringStrait_2010_A2W_sbe16_1400.ppp
  BeringStrait_2010_A4W_sbe16_2341.ppp
  BeringStrait_2010_A4_sbe16_0008.ppp

= SBE16plus with optics (2 files)
  - 1 .hex files of raw data
  - 1 .pre files of pre calibrated data
  BeringStrait_2010_A2_sbe16opt_4973.hex
  BeringStrait_2010_A2_sbe16opt_4973.pre

= SBE37 Microcat  (1 files)
  BeringStrait_2010_A3_sbe37_4510.pre

= ISCAT data (9 files)
  - 5 ICLog*.pre of pre calibrated logger data
  - 4 ICsbe37*.ppp pre-post calibrated SBE37 data
  BeringStrait_2010_A2W_ICLog23_5472.pre
  BeringStrait_2010_A2_ICLog07_5470.pre
  BeringStrait_2010_A3_ICLog26_5430.pre
  BeringStrait_2010_A4W_ICLog21_7622.pre
  BeringStrait_2010_A4_ICLog22_5471.pre
  BeringStrait_2010_A2W_ICsbe37_5472.ppp
  BeringStrait_2010_A3_ICsbe37_5430.ppp
  BeringStrait_2010_A4W_ICsbe37_7622.ppp
  BeringStrait_2010_A4_ICsbe37_5471.ppp

... and the 5 subdirectories of ADCP data: 

==  BeringStrait_2010_A3_adcp2144
==  BeringStrait_2010_A2W_adcp2269
==  BeringStrait_2010_A2_adcp1495
==  BeringStrait_2010_A4W_adcp2230
==  BeringStrait_2010_A4_adcp2234

Files within each data subdirectories:
==  
- one or more .000 file (original download, sometimes in parts)
- predeployment test file
- recovery test file
- one .btm file - bottom track data
- one .ins file - instrument data
- several  .rdat file - data in each ADCP bin
