README FILE FOR BERING STRAIT MOORING DATA 18 Sept 2006 ================================================================================ 12345678901234567890123456789012345678901234567890123456789012345678901234567890 Bering Strait Moorings 2002-2004 This is an archive of data from moorings deployed in Bering Strait from summer 2002 to summer 2005, with annual replacement of moorings. The mooring program was part of the NSF-ONR SBI (Shelf Basin Interaction) project. Mooring sponsorship came from ONR (N00014-99-1-0345, Aagaard & Woodgate) with shiptime from NSF (OPP-0125082, Grebmeier). 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 2004, 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 typically 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 38 m and a Sea-Bird Temperature-Conductivity recorder 3 m deeper. Moorings were replaced annually in late summer. Each data file thus contains the data from one instrument-year. The listed year is the year in which the mooring was deployed. Some moorings were equipped with an upward-looking sonar (PI: Moritz, UW), but these data are not included in this archive. The Sea-Bird instruments at Mooring A3 (indicated as wOptical in the following list) were equipped with optical sensors for fluorescence, turbidity and, for 2002 and 2004 only, 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. The A3 Moorings in 2002 and 2003 were also equipped with NAS-2E nitrate analyzers (PI: Whitledge, UAF), but these data are not included in this archive. ID Year - Latitude Longitude - Instrument S/N - Inst. Water Depth Depth A2-02 2002 - 65 46.774 N 168 34.526 W - RCM-7 6547 - 47m 56m A2-02 2002 - 65 46.774 N 168 34.526 W - SBE-16 1399 - 48m 56m A3-02 2002 - 66 19.563 N 168 58.034 W - RCM-11 99 - 48m 57m A3-02 2002 - 66 19.563 N 168 58.034 W - SBE-16wOptics 1559 - 49m 57m A4-02 2002 - 65 44.705 N 168 15.777 W - ADCP 2269 - 39m 49m A4-02 2002 - 65 44.705 N 168 15.777 W - SBE-16 1401 - 42m 49m A2-03 2003 - 65 46.758 N 168 34.508 W - RCM-7 6926 - 46m 55m A2-03 2003 - 65 46.758 N 168 34.508 W - SBE-16 1935 - 47m 55m A3-03 2003 - 66 19.567 N 168 58.032 W - RCM-9 523 - 48m 57m A3-03 2003 - 66 19.567 N 168 58.032 W - SBE-16wOptics 4112 - 49m 57m A4-03 2003 - 65 44.704 N 168 15.780 W - ADCP 1495 - 39m 48m A4-03 2003 - 65 44.704 N 168 15.780 W - SBE-16 2263 - 42m 48m A2-04 2004 - 65 46.780 N 168 34.480 W - RCM-7 11135 - 46m 55m A2-04 2004 - 65 46.780 N 168 34.480 W - SBE-16 1400 - 47m 55m A3-04 2004 - 66 19.540 N 168 58.030 W - RCM-11 119 - 48m 57m A3-04 2004 - 66 19.540 N 168 58.030 W - SBE-16wOptics 1559 - 49m 57m A4-04 2004 - 65 44.720 N 168 15.710 W - ADCP 2270 - 37m 47m A4-04 2004 - 65 44.720 N 168 15.710 W - SBE-16 5 - 41m 47m 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. ------------------------------------------------------------------------------- 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., in press 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., in press. For an overview, please see: http://psc.apl.washington.edu/BeringStrait.html For queries, please contact one of the following: Knut Aagaard aagaard@apl.washington.edu (206) 543-8942 Rebecca Woodgate woodgate@apl.washington.edu (206) 221-3268 Roger Andersen roger@apl.washington.edu (206) 543-1258 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: SBI Bering Strait 3) Data collection dates: summer 2002 to summer 2005 4) PIs: Knut Aagaard (aagaard@apl.washington.edu) 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 - 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 SBEs: Pre and post calibrated by the manufacturer. - pre and post calibrations linearly time-weighted through the deployment. 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, -9 and -11 -sampling hourly. Sea-Bird SBE16 recorders (some with optics sensors) sampling at 30 or 60 min intervals as stated in headers. RDI 300 kHz Workhorse ADCPs, recording every 30min (data averaged over the time interval) 8) Quality control procedures: Quality control variously provided by Knut Aagaard, Roger Andersen, Kay Runciman, and Rebecca Woodgate. SBE data have been despiked manually (cf., headers). In general, this was done conservatively, so some outliers likely remain. RCM and SBE data checked against each other where possible. For SBI data, at times of rapid temperature change, the converted salinity record is very spikey - this is possibly a sampling artifact. 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 A4-02 - bin 13, ~ 11m bin 14, ~ 9m A4-03 - bin 12, ~ 13m bin 13, ~ 11m A4-04 - bin 13, ~ 9m bin 14, ~ 7m 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: 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, although occasional data drop outs in speed likely indicate temporary rotor jamming possibly by jelly-fish. 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 (except for 2003-04) one LI-COR PAR/irradiance sensor. 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. A daily cycle is apparent in PAR/irradiance early in both records, and can be seen near the end of 2004-05, although not near the end of 2002-03. The transmissometers did not have shutters or wipers to clean the lenses, and generally suffered most from biofouling. In two instances, instruments or sensors failed before the end of the 1-year deployment. - On mooring A2-03, the SBE failed after ~ 157 days due to a battery issue - On mooring A3-03, the fluorometer on the SBE appears to have failed after ~ 331 days. This information is also given in the header files of these instruments. 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 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. 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) Optical Sensor Data (fluorescence, beam transmission, beam attenuation, and PAR): These unmodified records are included, although only minimal 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 ONR (N00014-99-1-0345, Aagaard & Woodgate) with shiptime from NSF (OPP-0125082, Grebmeier). 15) Sample repository locations: Earth Observing Lab (JOSS/EOL) at UCAR (http://www.eol.ucar.edu/) (data also to be transfered to ADCC or NODC) University of Washington (http://psc.apl.washington.edu/HLD) ============================================================================== FILE LISTING ============= This archive contains 95 data files, i.e., = 1 readme file (this file) Bering_Strait_Moorings_2002-2004_ReadMe.txt = 4 cruise reports e.g. HX260cruisereport02.pdf = 6 RCM files e.g., BeringStrait_2002_A2_rcm06547.txt = 9 SBE files e.g., BeringStrait_2002_A2_sbe01399.txt The remaining 75 files relate to the 3 ADCPs. Specifically, there are: = 3 ADCP binary data files (1 per ADCP instrument) e.g., BeringStrait_2002_A4_ADCP02269.000 = 3 ADCP ascii files of bottom track data (1 per ADCP instrument) e.g., BeringStrait_2002_A4_02269.btm = 3 ADCP ascii files of instrument data (1 per ADCP instrument) e.g., BeringStrait_2002_A4_02269.ins = 66 ADCP ascii files of water data (22 per ADCP instrument) e.g., BeringStrait_2002_A4_02269_bin01.rdat The full file listing is: Name Size/bytes ========================== ========== Bering_Strait_Moorings_2002-2004_ReadMe.txt 23436 BeringStrait_2002_A2_rcm06547.txt 779972 BeringStrait_2002_A2_sbe1399.txt 1345481 BeringStrait_2002_A3_rcm00099.txt 734293 BeringStrait_2002_A3_sbe1559.txt 1132572 BeringStrait_2002_A4_02269.btm 4276417 BeringStrait_2002_A4_02269.ins 2168325 BeringStrait_2002_A4_02269_bin01.rdat 3222377 BeringStrait_2002_A4_02269_bin02.rdat 3222377 BeringStrait_2002_A4_02269_bin03.rdat 3222377 BeringStrait_2002_A4_02269_bin04.rdat 3222377 BeringStrait_2002_A4_02269_bin05.rdat 3222377 BeringStrait_2002_A4_02269_bin06.rdat 3222377 BeringStrait_2002_A4_02269_bin07.rdat 3222377 BeringStrait_2002_A4_02269_bin08.rdat 3222377 BeringStrait_2002_A4_02269_bin09.rdat 3222377 BeringStrait_2002_A4_02269_bin10.rdat 3222377 BeringStrait_2002_A4_02269_bin11.rdat 3222377 BeringStrait_2002_A4_02269_bin12.rdat 3222377 BeringStrait_2002_A4_02269_bin13.rdat 3222377 BeringStrait_2002_A4_02269_bin14.rdat 3222377 BeringStrait_2002_A4_02269_bin15.rdat 3222377 BeringStrait_2002_A4_02269_bin16.rdat 3222377 BeringStrait_2002_A4_02269_bin17.rdat 3222377 BeringStrait_2002_A4_02269_bin18.rdat 3222377 BeringStrait_2002_A4_02269_bin19.rdat 3222377 BeringStrait_2002_A4_02269_bin20.rdat 3222377 BeringStrait_2002_A4_02269_bin21.rdat 3222377 BeringStrait_2002_A4_02269_bin22.rdat 3222377 BeringStrait_2002_A4_ADCP02269.000 12273021 BeringStrait_2002_A4_sbe1401.txt 1345728 BeringStrait_2003_A2_rcm06926.txt 888261 BeringStrait_2003_A2_sbe1935.txt 599040 BeringStrait_2003_A3_rcm00523.txt 834733 BeringStrait_2003_A3_sbe4112.txt 2322985 BeringStrait_2003_A4_01495.btm 4844728 BeringStrait_2003_A4_01495.ins 2456148 BeringStrait_2003_A4_01495_bin01.rdat 3650444 BeringStrait_2003_A4_01495_bin02.rdat 3650444 BeringStrait_2003_A4_01495_bin03.rdat 3650444 BeringStrait_2003_A4_01495_bin04.rdat 3650444 BeringStrait_2003_A4_01495_bin05.rdat 3650444 BeringStrait_2003_A4_01495_bin06.rdat 3650444 BeringStrait_2003_A4_01495_bin07.rdat 3650444 BeringStrait_2003_A4_01495_bin08.rdat 3650444 BeringStrait_2003_A4_01495_bin09.rdat 3650444 BeringStrait_2003_A4_01495_bin10.rdat 3650444 BeringStrait_2003_A4_01495_bin11.rdat 3650444 BeringStrait_2003_A4_01495_bin12.rdat 3650444 BeringStrait_2003_A4_01495_bin13.rdat 3650444 BeringStrait_2003_A4_01495_bin14.rdat 3650444 BeringStrait_2003_A4_01495_bin15.rdat 3650444 BeringStrait_2003_A4_01495_bin16.rdat 3650444 BeringStrait_2003_A4_01495_bin17.rdat 3650444 BeringStrait_2003_A4_01495_bin18.rdat 3650444 BeringStrait_2003_A4_01495_bin19.rdat 3650444 BeringStrait_2003_A4_01495_bin20.rdat 3650444 BeringStrait_2003_A4_01495_bin21.rdat 3650444 BeringStrait_2003_A4_01495_bin22.rdat 3650444 BeringStrait_2003_A4_ADCP01495.000 13905171 BeringStrait_2003_A4_sbe2263.txt 1627817 BeringStrait_2004_A2_rcm11135.txt 665951 BeringStrait_2004_A2_sbe1400.txt 1222863 BeringStrait_2004_A3_rcm00119.txt 628912 BeringStrait_2004_A3_sbe1559.txt 961046 BeringStrait_2004_A4_02270.btm 3649518 BeringStrait_2004_A4_02270.ins 1850914 BeringStrait_2004_A4_02270_bin01.rdat 2750222 BeringStrait_2004_A4_02270_bin02.rdat 2750222 BeringStrait_2004_A4_02270_bin03.rdat 2750222 BeringStrait_2004_A4_02270_bin04.rdat 2750222 BeringStrait_2004_A4_02270_bin05.rdat 2750222 BeringStrait_2004_A4_02270_bin06.rdat 2750222 BeringStrait_2004_A4_02270_bin07.rdat 2750222 BeringStrait_2004_A4_02270_bin08.rdat 2750222 BeringStrait_2004_A4_02270_bin09.rdat 2750222 BeringStrait_2004_A4_02270_bin10.rdat 2750222 BeringStrait_2004_A4_02270_bin11.rdat 2750222 BeringStrait_2004_A4_02270_bin12.rdat 2750222 BeringStrait_2004_A4_02270_bin13.rdat 2750222 BeringStrait_2004_A4_02270_bin14.rdat 2750222 BeringStrait_2004_A4_02270_bin15.rdat 2750222 BeringStrait_2004_A4_02270_bin16.rdat 2750222 BeringStrait_2004_A4_02270_bin17.rdat 2750222 BeringStrait_2004_A4_02270_bin18.rdat 2750222 BeringStrait_2004_A4_02270_bin19.rdat 2750222 BeringStrait_2004_A4_02270_bin20.rdat 2750222 BeringStrait_2004_A4_02270_bin21.rdat 2750222 BeringStrait_2004_A4_02270_bin22.rdat 2750222 BeringStrait_2004_A4_ADCP02270.000 10472121 BeringStrait_2004_A4_sbe0005.txt 612983 HX260cruisereport02.pdf 92833 HX274cruisereport03.pdf 161394 HX290cruisereport04.pdf 207678 UWmooringreportSWL2005July.pdf 1648339 ==============================================================================