README FILE FOR BERING STRAIT MOORING DATA 6th Aug 2008 ================================================================================ 12345678901234567890123456789012345678901234567890123456789012345678901234567890 Bering Strait Moorings 2006 to 2007 This is an archive of data from moorings deployed in Bering Strait from summer 2006 to summer 2007. It includes 2 mooring programs: - the three moorings A2, A3, A4 deployed in the eastern (US) channel of the strait and at the climate site to the north of the strait, with the deployment funded by the AOOS (Alaskan Ocean Observing System)program (PI: Woodgate, University of Washington(UW)) and the mooorings deployed from the Canadian Coastguard Vessel CCGS Sir Wilfrid Laurier in July 2006. - the three moorings A1, A1W (also called A1-2), A1E (also called A1-3) deployed in the western (Russian) channel of the strait, with the deployment funded by 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) and the moorings deployed from the Russian Research Vessel Sever in August 2006. Both sets of moorings were recovered August 2007 from the Russian Research Vessel Sever, with funding from NOAA RUSALCA, on a joint US-Russian cruise, also part of the Bering Strait project funded by NSF's Office of Polar Programs (ARC-0714078, Lead PI: Woodgate) as part of the Arctic Observing Network (AON) and the International Polar Year (IPY). For an overview of previous and on-going Bering Strait mooring work, please see http://psc.apl.washington.edu/BeringStrait.html. 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. All three sites are established mooring sites in the region -A2 and A3 since 1990, A4 since 2001. 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. Site A1 was established in 1990. A1W and A1E were also occupied in 2005 - 2006. 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 Water in Year (N) (W) Int. Depth Depth Depth (S) (I+M) A1-06 2006 65 54.00 169 25.78 300kHz-ADCP 7967 20min 44m 51m 50m SBE37 Microcat 4942 15min 45m 51m 50m A1W-06 2006 65 55.98 169 36.86 AARI-CM&CTD* 5/1336 - 30m 51m 48m (A1-2) ISUS* 098 - 33m 51m 48m SBE16woptic 4973 30min 35m 51m 48m RCM9Turb 1173 60min 38m 51m 48m A1E-06 2006 65 51.76 169 16.96 AARI-CM&CTD* 2/1556 - 32m 51m 47m (A1-3) RCM7 9513 60min 34m 51m 47m SBE37 Microcat 4943 15min 36m 51m 47m A2-06 2006 65 46.78 168 34.47 APL-ULS* 2302 - 41m 56m 53m RCM9LW 107 60min 44m 56m 53m SBE16woptic 4956 60min 45m 56m 53m ISUS* 089 - 47m 56m 53m A3-06 2006 66 19.54 168 58.01 APL-ULS* 2301 - 45m 58m 56m RCM9LW 108 60min 48m 58m 56m SBE37 Microcat 4510 10min 49m 58m 56m A4-06 2006 65 44.73 168 15.67 300kHz-ADCP 7695 20min 39m 49m 48m SBE37 Microcat 4600 - 41m (flooded) Depth in Bering Strait is approximately 50-55 m. Although all moorings are stated here as in 51m of water corresponding to ship's echo sounder readings (S) this does not always tally with an estimate of water depth given by instrument pressure readings and mooring lengths (I+M). The latter values are likely the more accurate and are used in the data headers. 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 RCM9LW - Aanderaa Lightweight RCM9 acoustic current meter 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 APL-ULS - Upward Looking Sonar, measuring ice thickness, PI: Dick Moritz, UW Moorings were deployed from summer 2006 to summer 2007. 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 (note there are two files for the ADCP on A4 - see notes below) 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 2006 to summer 2007 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 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: 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. - A4 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 -9 recording hourly. Sea-Bird SBE16 recorders (some with optics sensors) sampling at 30min or 60min interval. Sea-Bird SBE37 recorder sampling at 10min or 15min RDI 300 kHz Workhorse ADCP recording every - on A1-06 (#7967) - 20min and 0.5m bins (reaveraged here to 2m bins) - on A4-06 (#7695) - 30min and 2m bins 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. ADCP data rely on ADCP internal temperature for speed of sound corrections. ADCP on A1-06 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 A1-06 - avbin 16, ~ 20m avbin 10, ~ 14m A4-06 - bin 10, ~ 17m bin 13, ~ 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: SBE37-4600 on A4-06 flooded and no data was recoverable. SBE37-4510 on A3-06 shows ~ 0.05 psu change in calibration between pre and post calibrations. SBE16-4973 on A1W06 (A1-2-06)- Fluorometer and Turbidity data bad for last ~ 22 days of deployment, possibly due to biowiper jamming. Also - batteries were exhausted ~ 8 days before recovery SBE16-4956 on A2-06 lost 2 records prior to deployment due to interrogating instrument. Thus, start time is faked to 1000, so that all timestamps during the deployment are correct. ADCP-7695 on A4-06 inexpected split the record into 2 files. The first file is from start to 2006 Nov 28th 0600. The second file starts 2006 Nov 28th 0657, i.e. 3min before the full hour. This 3 min change is included in the clock drift correction (otherwise 7min) to give a constant time increment to the data. 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 A1W-06 (A1-2-06) and A2-06 consisted of Wetlabs FLNTU Chlorophyll and Neophelometric Turbidity Sensor protected from fouling by a biowiper and copper. Other than on A1W-06 (SBE16-4973) where the biowiper may have been jamming for the last ~ 22 days of the record, these measures appear to have been successful. 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. 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 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 or 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: 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) - AOOS (Alaskan Ocean Observing System) http://www.aoos.org/ (PI: Woodgate) 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: 66 Size (b) Name ------- ---- = Metadata file (1) 22927 Bering_Strait_Moorings_RUSALCAAOOS0607_ReadMe.txt = cruise reports (3) 1964631 UWmooringreportSEVER2007Aug.pdf 1789726 UWmooringreportSWL2006July.pdf 780712 UAFRUSALCACruiseReportSever2006.pdf = sbe37 records (3) 5069865 BeringStrait_2006_A3_sbe37_4510.txt 3027466 BeringStrait_2006_A1_sbe37_4942.txt 3027634 BeringStrait_2006_A1E_sbe37_4943.txt = sbe16 uncalibrated hex files (2) 394000 BeringStrait_2006_A2_sbe16_raw4956.hex 682000 BeringStrait_2006_A1W_sbe16_raw4973.hex = sbe16 records (2) 1738964 BeringStrait_2006_A1W_sbe16_4973.txt 1004362 BeringStrait_2006_A2_sbe16_4956.txt = rcm records (4) 773812 BeringStrait_2006_A1E_rcm7_09513.txt 863837 BeringStrait_2006_A1W_rcm9_01173.txt 814858 BeringStrait_2006_A2_rcm9_00107.txt 814858 BeringStrait_2006_A3_rcm9_00108.txt = ADCP records - binary files (3) 54992704 BeringStrait_2006_A106_ADCP07967.000 4690047 BeringStrait_2006_A406_ADCP07695.000 9116547 BeringStrait_2006_A406_ADCP07695.001 - ascii files (48) 6338155 BeringStrait_2006_A1_07967.btm 3266173 BeringStrait_2006_A1_07967.ins 4775223 BeringStrait_2006_A1_07967mbin01.rdat 4775223 BeringStrait_2006_A1_07967mbin02.rdat 4775223 BeringStrait_2006_A1_07967mbin03.rdat 4775223 BeringStrait_2006_A1_07967mbin04.rdat 4775223 BeringStrait_2006_A1_07967mbin05.rdat 4775223 BeringStrait_2006_A1_07967mbin06.rdat 4775223 BeringStrait_2006_A1_07967mbin07.rdat 4775223 BeringStrait_2006_A1_07967mbin08.rdat 4775223 BeringStrait_2006_A1_07967mbin09.rdat 4775223 BeringStrait_2006_A1_07967mbin10.rdat 4775223 BeringStrait_2006_A1_07967mbin11.rdat 4775223 BeringStrait_2006_A1_07967mbin12.rdat 4775223 BeringStrait_2006_A1_07967mbin13.rdat 4775223 BeringStrait_2006_A1_07967mbin14.rdat 4775223 BeringStrait_2006_A1_07967mbin15.rdat 4775223 BeringStrait_2006_A1_07967mbin16.rdat 4775223 BeringStrait_2006_A1_07967mbin17.rdat 4775223 BeringStrait_2006_A1_07967mbin18.rdat 4775223 BeringStrait_2006_A1_07967mbin19.rdat 4775223 BeringStrait_2006_A1_07967mbin20.rdat 4775223 BeringStrait_2006_A1_07967mbin21.rdat 4775223 BeringStrait_2006_A1_07967mbin22.rdat 4771171 BeringStrait_2006_A4_07695.btm 2459569 BeringStrait_2006_A4_07695.ins 3595099 BeringStrait_2006_A4_07695_bin01.rdat 3595099 BeringStrait_2006_A4_07695_bin02.rdat 3595099 BeringStrait_2006_A4_07695_bin03.rdat 3595099 BeringStrait_2006_A4_07695_bin04.rdat 3595099 BeringStrait_2006_A4_07695_bin05.rdat 3595099 BeringStrait_2006_A4_07695_bin06.rdat 3595099 BeringStrait_2006_A4_07695_bin07.rdat 3595099 BeringStrait_2006_A4_07695_bin08.rdat 3595099 BeringStrait_2006_A4_07695_bin09.rdat 3595099 BeringStrait_2006_A4_07695_bin10.rdat 3595099 BeringStrait_2006_A4_07695_bin11.rdat 3595099 BeringStrait_2006_A4_07695_bin12.rdat 3595099 BeringStrait_2006_A4_07695_bin13.rdat 3595099 BeringStrait_2006_A4_07695_bin14.rdat 3595099 BeringStrait_2006_A4_07695_bin15.rdat 3595099 BeringStrait_2006_A4_07695_bin16.rdat 3595099 BeringStrait_2006_A4_07695_bin17.rdat 3595099 BeringStrait_2006_A4_07695_bin18.rdat 3595099 BeringStrait_2006_A4_07695_bin19.rdat 3595099 BeringStrait_2006_A4_07695_bin20.rdat 3595099 BeringStrait_2006_A4_07695_bin21.rdat 3595099 BeringStrait_2006_A4_07695_bin22.rdat