README FILE FOR BERING STRAIT MOORING DATA 10th Aug 2008 ================================================================================ 12345678901234567890123456789012345678901234567890123456789012345678901234567890 RUSALCA (i.e. Russian Channel) Bering Strait Moorings 2004 to 2006 This is an archive of data from moorings deployed in the russian (western) channel of the Bering Strait from summer 2004 to summer 2006, as part of the NOAA RUSALCA (Russian US Long-term Census of the Arctic) program (PI: Weingartner, University of Alaska, Fairbanks (UAF)) in collaboration with Russian colleagues from the Arctic and Antarctic Research Institute (AARI). It includes data from 2 years of mooring deployments. From summer 2004 to summer 2005, one mooring (A1-04, also called A1-U) was deployed in the centre of the russian channel from the russian vessel Khromov, and recovered by the russian vessel Sever. From summer 2005 to summer 2006, three moorings were deployed from the russian vessel Sever - A1-05 (also called A1-1-05) in the centre of the strait; A1W-05 (also called A1-2-05) west of A1; and A1E-05 (also called A1-3-05) east of A1. These three moorings were recovered in summer 2006 also by the Sever. Mooring site A1 was established in the 1990s, but has only been occupied for a few years between 1990 and 2004. In 2004, a further russian mooring was deployed A1-R. For the same time period, moorings have been maintained in the US (eastern) channel of the strait. These data are archived separately, but can be found at NODC and http://psc.apl.washington.edu/BeringStrait.html. This website also contains an overview of previous and on-going Bering Strait mooring (and accompanying) CTD work. 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. 12345678901234567890123456789012345678901234567890123456789012345678901234567890 ID Deployed Latitude Longitude Instrument S/N Time Inst. Water in Year (N) (W) Int. Depth Depth A1-04 2004 65 53.96 169 26.03 SBE16woptic 4693 60min 32m 50m (A1-U) RCM9Turb 1173 60min 34m 50m A1-05 2005 65 54.03 169 25.73 300kHz-ADCP 5027 20min 42m 50m (A1-1-05) SBE37 Microcat 0450 15min 44m 50m A1W-05 2005 65 55.91 169 36.81 ISUS* 074 - 33m 48m (A1-2-05) SBE16woptic 4113 30min 35m 48m RCM9Turb 1173 60min 39m 48m A1E-05 2005 65 51.89 169 16.72 AARI-CM&CTD* 8/25/1503 - 33m 48m (A1-3-05) RCM7 9658 flooded 36m 48m SBE37 Microcat 1131 15min 37m 48m Mooring depths are based on instrument pressure records, mooring design and ship soundings. Instruments included here: 300KHz ADCP - 300kHz RDI/Teledyne Workhorse Acoustic Doppler Current Profiler SBE37 Microcat - Seabird SBE 37 Temperature Salinity Pressure recorder SBE16woptic - Seabird SBE16plus with optical turbidity sensor and fluorometer RCM9Turb - Aanderaa RCM9 acoustic current meter with turbidity sensor RCM7 - Aanderaa RCM7 mechanical current meter Instruments 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 Each data file contains the data from one instrument-year. The listed year is the year in which the mooring was deployed. Turbidity and fluorometer data from the RCM and SBE instruments are included in this archive, although only minimal quality control of the data has been performed 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. The SBE-16 hexidecimal files are also included, indicated by extension .hex. 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) BeringStrait_yyyy__ID_#####mbin01.rdat = ASCII water data from re-averaged Bin 1 BeringStrait_yyyy__ID_#####mbin02.rdat = ASCII water 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: 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 ------------------------------------------------------------------------------ Meta data ========= 1) Platform: Subsurface oceanographic moorings 2) Project title: Bering Strait 3) Data collection dates: summer 2004 to summer 2006 4) PI: Tom Weingartner (weingart@ims.uaf.edu) processed by: 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: Where information is available, 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), by ESI, or at APL/UW. - 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. - pre and post calibrations linearly time-weighted through the deployment. ADCPS: Tested by APL/UAF/manufacturer pre deployment. - 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-9 recording hourly. Sea-Bird SBE16 recorders with optics sensors sampling at 30min or 60min interval. Sea-Bird SBE37 recorder sampling at 15min RDI 300 kHz Workhorse ADCP recording every - on A1-05 (#5027) - 20min and 0.5m bins (reaveraged here to 2m bins) 8) Quality control procedures: Quality control variously provided by Rebecca Woodgate. In general, records are very clean and very little despiking has been performed. (All despiking is recorded in the header.) 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. ADCP data rely on ADCP internal temperature for speed of sound corrections. ADCP on A1-05 recorded in 0.5m 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. The following are the shallowest good bins: last bin < 8 errors last bin < 100 errors A1-05 - avbin 13, ~ 15m avbin 15, ~ 11m 9) Data format: RCM and SBE data - ASCII, format given in individual headers (uncalibrated "hex" data also included for SBE16s) ADCP data - 2 formats: a) BINARY download file from ADCP and b) ASCII conversion of these files (in 2m bins) 10) Data collection problems: Estimates of clock drift are generally not available for these data. 2004 deployments: RCM9-1173 on A1-04 (A1U) - battery failed 11 days before recovery - one spike in Conductivity has been removed 2005 deployments: ADCP 5027 on A1-05 (A1-1-05) - pressure data shows an unexplained jump in pressure from 45 to 40m. Such a jump is not evident in other data. Since instrument deployment depth was 42m in 50m of water, we assume the 45m readings are erroneous. - Data collected in 0.5m bins (see binary file), but reaveraged onto 2m for the ascii archive. SBE37-0450 on A1-05 (A1-1-05) has a 0.03 psu drift in salinity between pre and post calibrations. RCM9-1173 on A1W-05 (A1-2-05) - direction distribution has two modes at 50 and 210 deg, rather than the typical bimodal distribution usually separated by ~ 180 deg - one record has been despiked SBE16-4113 on A1W-05 (A1-2-05) - optics data uses only post calibrations and is not quality controlled. Turbidity record is especially dubious. SBE37-1131 on A1E-05 (A1-3-05) has a 0.03 psu drift in salinity between pre and post calibrations. Instrument fouling is an concern in Bering Strait deployments, and precautions have been taken to mitigate problems. Standard anti-fouling techniques are used for the SBE instruments, and this has been generally successful for the temperature and salinity records. The user is cautioned to consider biofouling when using the optics records. Information on biofouling is given in the header files. 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. A set of moorings were also deployed in the eastern (US) channel at the same time as these data. 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 ADCP data: Standard RDI limitations apply - estimated accuracy < 0.5 cm/s in speed for water velocities (~100 pings per ensemble) Estimated errors (given in the data files) vary with bin and time < 1 cm/s in speed for ice velocities (2 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: 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 - NOAA Arctic Research RUSALCA (Russian-US Longterm Census of the Arctic: http://www.arctic.noaa.gov/aro/russian-american/ (PI: Weingartner) 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: 37 Size (b) Name ------- ---- = Metadata file (1) 18970 Bering_Strait_Moorings_RUSALCA0406_ReadMe.txt = cruise reports (3) 39367 UAF_2004RUSALCA_Khromovmooringreport.pdf 14777 UAF_2005RUSALCA_SeverMooringNarrative.pdf 780712 UAF_2006RUSALCA_SeverCruiseReport.pdf = sbe37 records (2) 2987834 BeringStrait_2005_A1_sbe37_0450.txt 2988109 BeringStrait_2005_A1E_sbe37_1131.txt = sbe16 uncalibrated hex files (2) 356408 BeringStrait_2004_A1_sbe16_raw4639.hex 534624 BeringStrait_2005_A1W_sbe16_raw4113.hex = sbe16 records (2) 888060 BeringStrait_2004_A1_sbe16_4639.txt 1775739 BeringStrait_2005_A1W_sbe16_4113.txt = rcm records (2) 836964 BeringStrait_2004_A1_rcm9_01173.txt 862668 BeringStrait_2005_A1W_rcm9_01173.txt = ADCP records - binary files (1) 54070081 BeringStrait_2005_A1_05027.000 - ascii files (24) 4452 BeringStrait_2005_A1_05027.btm 3218572 BeringStrait_2005_A1_05027.ins 4706454 BeringStrait_2005_A1_05027mbin01.rdat 4706454 BeringStrait_2005_A1_05027mbin02.rdat 4706454 BeringStrait_2005_A1_05027mbin03.rdat 4706454 BeringStrait_2005_A1_05027mbin04.rdat 4706454 BeringStrait_2005_A1_05027mbin05.rdat 4706454 BeringStrait_2005_A1_05027mbin06.rdat 4706454 BeringStrait_2005_A1_05027mbin07.rdat 4706454 BeringStrait_2005_A1_05027mbin08.rdat 4706454 BeringStrait_2005_A1_05027mbin09.rdat 4706454 BeringStrait_2005_A1_05027mbin10.rdat 4706454 BeringStrait_2005_A1_05027mbin11.rdat 4706454 BeringStrait_2005_A1_05027mbin12.rdat 4706454 BeringStrait_2005_A1_05027mbin13.rdat 4706454 BeringStrait_2005_A1_05027mbin14.rdat 4706454 BeringStrait_2005_A1_05027mbin15.rdat 4706454 BeringStrait_2005_A1_05027mbin16.rdat 4706454 BeringStrait_2005_A1_05027mbin17.rdat 4706454 BeringStrait_2005_A1_05027mbin18.rdat 4706454 BeringStrait_2005_A1_05027mbin19.rdat 4706454 BeringStrait_2005_A1_05027mbin20.rdat 4706454 BeringStrait_2005_A1_05027mbin21.rdat 4706454 BeringStrait_2005_A1_05027mbin22.rdat