Last update 14 July 2014 ACCLAIM COASTAL SITES - PHASE 1 =============================== This directory contains records of sub-surface pressure (SSP) obtained by coastal sub-surface pressure transducers during Phase 1 of the ACCLAIM programme. The parameter SSP should not be interpreted as 'sea level' for two reasons. First, SSP includes the pressure loading from both the height of water above the sensor, and from the air pressure above that. Second, many of these sensors have a long term drift (some of the older sensors drift enormously) which invalidates their use for long term sea level trend studies. For more information on ACCLAIM Phase 1 see Spencer, R., Foden, P.R., McGarry, C., Harrison, A.J., Vassie, J.M., Baker, T.F., Smithson, M.J., Harangozo, S.A. and Woodworth, P.L. 1993. The ACCLAIM programme in the South Atlantic and Southern Oceans. International Hydrographic Review, 70, 7-21. For file formats, see www.ntslf.org/files/acclaimdata/readme.formats Site Name Start Date End Date File Name Ascension 22-Apr-1983 21-May-1985 asc_263.8385 (GLOSS 263) 24-May-1985 29-Oct-1985 asc_263.8585 30-Oct-1985 14-Jul-1986 asc_263.8586 15-Jul-1986 23-May-1987 asc_263.8687 24-May-1987 21-May-1988 asc_263.8788 21-May-1988 27-Jan-1989 asc_263.8889 28-Jan-1989 16-Jan-1990 asc_263.8990 17-Jan-1990 07-Sep-1991 asc_263.9091 Oct-1991 Mar-1993 asc_263.9193 May 1993 Nov 1993 data missing (see ../phase2 for data from new sensor in English Bay. IMPORTANT NOTE: Be aware that the datums of the two systems are different) Nov-1993 Dec-1995 asc_263.9395 St. Helena 01-Aug-1986 05-Nov-1987 sth_264.8687 (GLOSS 264) 06-Nov-1987 23-Feb-1988 sth_264.8788 27-May-1988 03-Feb-1989 sth_264.8889 03-Feb-1989 27-Jan-1990 sth_264.8990 02-Feb-1990 27-Sep-1990 sth_264.9090 28-Sep-1990 19-Feb-1992 sth_264.9092 20-Feb-1992 9-Oct-1992 sth_264.9292 Port Stanley 24-Nov-1988 21-Nov-1989 pst_305.8889 (GLOSS 305) 01-Jan-1990 04-Feb-1990 pst_305.9090a 01-Mar-1990 10 Dec-1990 pst_305.9090b 06-Jan-1991 18-Dec-1991 pst_305.9191 27-Dec-1991 25-Oct-1992 pst_305.9192 Signy Island 19-Dec-1988 16-Sep-1989 sig_306.8889 (GLOSS 306) 17-Nov-1989 11-Oct-1990 sig_306.8990 26-Nov-1990 06-Mar-1991 sig_306.9091 01-Feb-1991 20-Feb-1992 sig_306.9192 05-Jan-1992 24-Nov-1992 sig_306.9292 24-Nov-1992 01-Mar-1994 sig_306.9294 02-Mar-1994 29-Aug-1994 sig_306.9494a 29-Aug-1994 04-Nov-1994 sig_306.9494b 04-Nov-1994 03-Jan-1995 sig_306.9495 11-Jan-1995 31-Dec-1995 sig_306.9595 31-Dec-1995 06-Apr-1996 sig_306.9696a 16-Jun-1996 31-Dec-1996 sig_306.9696b 01-Jan-1997 31-Mar-1997 sig_306.9797 19-Nov-1999 30-Mar-2000 sig_306.9900 21-Feb-2002 23-Mar-2002 sig_2002.acc.Z 23-Nov-2003 22-Dec-2003 sig_2003.acc.Z 21-Nov-2004 14-Feb-2005 sig_2004-5.acc.Z 06-Mar-2006 22-Nov-2006 sig_2006.acc.Z 327/2006 340/2007 sig0607.tsk 59/2009 311/2009 sig09.tsk 69/2011 209/2011 sig_2011.tsk 353/2011 72/2012 sig_2011-12.tsk THE SIGNY PRESSURE SENSOR IS NOW BROKEN (POST-2012) AND WE HAVE NO PLANS TO REPLACE IT GIVEN THAT THERE IS A GAUGE AT KING EDWARD POINT, SOUTH GEORGIA. South Georgia 26-Jan-2008 31-Dec-2008 kep.task.2008 - King Edward 1-Jan-2009 31-Dec-2009 kep.task.2009 Point 1-Jan-2010 31-Dec-2010 kep.task.2010 (GLOSS 187) 1-Jan-2011 31-Dec-2011 kep.task.2011 1-Jan-2012 31-Dec-2012 kep.task.2012 1-Jan-2013 31-Dec-2013 kep.task.2013 1-Jan-2014 31-Dec-2014 kep.task.2014 1-Jan-2014 26-Nov-2017 kep.task.2014-17 Tristan da 31-Oct-1984 19-Nov-1985 tdc_266.8485 Cunha 19-Nov-1985 13-May-1986 tdc_266.8586 (GLOSS 266) 29-Jun-1986 11-Oct-1986 tdc_266.8686 16-Oct-1986 8-Oct-1987 tdc_266.8687 8-Oct-1987 19-Oct-1988 tdc_266.8788 19-Oct-1988 8-Feb-1989 tdc_266.8889 8-Feb-1989 7-Feb-1990 tdc_266.8990 7-Feb-1990 19-Oct-1990 tdc_266.9090 19-Oct-1990 11-Jan-1992 tdc_266.9092 12-Jan-1992 10-Dec-1992 tdc_266.9292 28-Jan-1993 3-Feb-1994 tdc_266.9394 3-Feb-1994 23-Feb-1995 tdc_266.9495 23-Feb-1995 24-Jan-1996 tdc_266.9596 24-Jan-1996 30-Dec-1997 tdc_266.9697 9-Jan-1998 28-Dec-1998 tdc_266.9898 Rothera 19-Nov-1992 5-Mar-1993 rothera.92119303 8-Dec-1993 9-Dec-1994 rothera.93129412 4-Jan-1995 31-Dec-1995 rothera.95019512 1-Jan-1996 25-Nov-1996 rothera.96019611 1-Jan-1997 31-Dec-1997 rothera.97019712 23-Nov-1997 30-Nov-1998 rothera.97129811 5-Dec-1998 2-Oct-1999 rothera.98129910 Vernadsky 28-Dec-1997 16-Mar-1999 ver_188.9799 (GLOSS 188) 07-Dec-2007 30-Nov-2009 ver_2007-09.acc 28-Nov-2009 03-Sep-2010 ver_2009-10.acc 246/2010 27/2012 ver_sep10-jan12.tsk SHORT DOCUMENTATION FOR EACH SITE ================================= Station: Ascension (GLOSS No. 263) ================================== Instrument was an offshore Aanderaa tide gauge in Clarence Bay, Ascension for which the data tapes and general refurbishments were made by diver. The gauge is not to be confused with the Phase 2 gauge in English Bay. For further information, see Spencer et al. 1993 (see above) and Woodworth, P.L., Windle, S.A. and Vassie, J.M. 1995. Departures from the local inverse barometer model at periods of 5 days in the central South Atlantic. Journal of Geophysical Research, 100(C9), 18281-18290. Datum information is not available. Datum can drift within and between each file. All data have been tidally analysed and constants and residuals checked. All are essentially ok with the exception of May 85 - Oct 85, see below. All records have been visually inspected for spikes. file asc_263.8385: This period contains data from several deployments of the Aanderaa gauge, with each pressure record reduced to zero mean and joined together. There are two short gaps at 1984 days 99-101 with values of 99.90 and days 319-322 with values of 100.30 which are not flagged. These mark the separate deployments. The file is in ACCLAIM format with SSP in channel 7 (mbar). Sea temperature is also in channel 6 (deg C). However, it is messy. It should be rejected for 1984 (days 99-101 and 319-322) which were the two gaps mentioned above but more generally for 1983 (up to and including day 117), 1984 (days 314 onwards) and 1985 (all of it). Generally, the temperatures are a bit suspect - see strange blocks of 12 with the same temperature in the first half of the file. file asc_263.8585: This period contains data recovered with uncertain timings at start and end and, from tidal analysis, what appears to be a data gap as the tidal residuals contain large tide-like signals. THIS FILE MUST NOT BE USED BY ANYONE FOR TIDAL CONSTANTS STUDIES. This file contains hourly values obtained from filtering of original half- hourly data. The file is in ACCLAIM format with SSP in channel 7 (mbar) and sea temperature in channel 6 (deg C). Ignore other data channels. file asc_263.8586: This file contains hourly values obtained from filtering of original half- hourly data. The file is in ACCLAIM format with SSP in channel 7 (mbar) and sea temperature in channel 6 (deg C). Ignore other data channels. files asc_263.8687, asc_263.8788, asc_263.8889, asc_263.8990 and asc_263.9091: these files are in ACCLAIM format with 3 data channels: sea temperature (deg C), total pressure (mbar) and non-tidal residual pressure (mbar). The third parameter may be disregarded. file asc_263.9193: this file is in ACCLAIM format with channel 7 sea temperature (deg C), channel 8 SSP (mbar). Records with a '1' in the channel 2 flag at start and end should be ignored. The file stops in early March 1993 which was when the data logger tape came to its end; the sensor was actually recovered in May. file asc_263.9395: this file is in ACCLAIM format with channel 6 sea temperature (deg C), channel 7 SSP (mbar), channel 8 tidal residuals. Channel 8 may be ignored. This file, the last from the Clarence Bay gauge, overlaps with the new Phase 2 gauge in English Bay installed May 1993. SSP values from the two are in very good agreement, an internal report on the comparison is available. This ends the Phase 1 Clarence Bay Ascension recording. ============================================================================ Station: St.Helena (GLOSS No. 264) ================================== The Phase 1 instrument at Jamestown Harbour Steps St.Helena consisted of a Digiquartz pressure sensor on the end of a data cable to a data logger in a nearby building. The logger also recorded air pressure. In principle, the SSP and air pressure can be combined to give a sea level time series, even though the sensors have instrumental drift, as there is extensive tide pole information available. This exercise has not been completed. All data have been tidally analysed and constants and residuals checked. All are essentially ok and records have been visually inspected for spikes. file sth_264.8687: this file is in ACCLAIM format with two data channels: atmospheric pressure (mbar), SSP (mbar). Atmospheric pressure values are in units of whole mbar which is somewhat crude. file sth_264.8788: this file is in ACCLAIM format with one data channel: SSP (decibar) file sth_264.8889: this file is in ACCLAIM format. Channel 7 is SSP (mbar) file sth_264.8990: this file is in ACCLAIM format with SSP in channel 8 (mbar). Other data channels have been deleted, as they are incorrect. (e.g. air pressure values incorrect). file sth_264.9090: ditto (air pressure values incorrect) file sth_264.9092: ditto, except air pressure in channel 6 measured to 1/10 mbar except for some records for which air pressure shown zero. There were data gaps 2 Feb 1991 at 11.00 to 5 Feb 1991 at 13.00 1 Apr 1991 at 11.00 to 2 Apr 1991 at 01.00 10 Dec 1991 at 11.00 to 11 Dec 1991 at 01.00. file sth_264.9292: ditto, except air pressure in channel 6 measured to 1/10 mbar. (This file renamed from sth_264.jan92jan93 as, while the data were recovered Jan93 the gauge failed in Oct 92) For the files in ACCLAIM format, there are several short gaps which have been filled with predictions and flagged by a 1 in channel 2. Note that, as can be seen above, the barometer data for each of these files should not be used without caution (i.e. without consulting POL) as at times it appeared to work but had eccentric behaviour. Also note that no sea temperature data were available from St.Helena in Phase 1. This brings to end the Phase 1 gauge at St.Helena. A Phase 2 gauge was installed in May 1993. ========================================================================= Station: Port Stanley, Falkland Is. (GLOSS No. 305) =================================================== The Phase 1 instrument at Port Stanley consisted of a Digiquartz pressure sensor on the end of a data cable to a data logger in the nearby floating warehouse. The logger also recorded air pressure. The same pressure sensor has been used throughout, but no datum information is available for conversion to sea level. All data have been tidally analysed and constants and residuals checked. All are essentially ok and records have been visually inspected for spikes. All temperature channels seem to be a little on the high side. file pst_305.8889: this file is in 11 column ACCLAIM format and contains 4 data channels: sea temperature, deg C atmospheric pressure, mbar total (subsurface) pressure, mbar sea pressure ( = total pressure - atmospheric pressure), mbar file pst_305.9090a: this file is in 11 column ACCLAIM format and contains 4 data channels: sea temperature, deg C atmospheric pressure, mbar total (subsurface) pressure, mbar There is what looks like a 1 hour timing error in the first 72 hours (12.4 hour signal in residuals, phase estimate off by 30 deg). Correcting this upsets the phases of the rest of the record, SO THIS FILE CONTAINS THE ORIGINAL (UNSHIFTED) DATA. Record checked by Philip Axe. 1 Feb 2000 file pst_305.9090b: this file is in 11 column ACCLAIM format and contains 5 data channels: sea temperature, deg C atmospheric pressure, mbar NOT FUNCTIONING total (subsurface) pressure, mbar non-tidal residual, mbar Looking at the frequency spectrum of the non-tidal residuals, there appear to be signals at 2.7, 4.2, 4.8, 6.3. 8.0 and, worryingly 12.43 hours. The last one implies some timing error, although this is not apparent in the time series of the residuals, SO THIS FILE CONTAINS THE ORIGINAL DATA. Record checked by Philip Axe. 1 Feb 2000 file pst_305.9191: this file is in 11 column ACCLAIM format and contains 4 data channels: sea temperature, deg C atmospheric pressure, mbar total (subsurface) pressure, mbar Gap from 1991/01/07 at 12.00 to 1991/01/10 at 01.00. file pst_305.9192: this file is in 11 column ACCLAIM format and contains 4 data channels: sea temperature, deg C atmospheric pressure, mbar total (subsurface) pressure, mbar Gap from 1992/02/20 at 23.00 to 1992/02/23 at 01.00 =========================================================================== Station: Signy, South Orkney Is. (GLOSS No. 306) ================================================ The Phase 1 instrument at Signy consists of a Digiquartz pressure sensor on the end of a data cable to a data logger in the nearby British Antarctic Survey building. The logger also records air pressure. The same pressure sensor has been used throughout, but no datum information is available for conversion to sea level. All data have been tidally analysed and constants and residuals checked. All are essentially ok and records have been visually inspected for spikes. Spikes and data gaps have been deleted, interpolated through (when < 8.1 hours in length), or flagged with a '1' in column 2 of data file. All data are in 11 column ACCLAIM format (col.1 count, col.2 flag, cols 3-5 time, cols 6-11, data). There was a large data gap between October 1990 and January 1992 when the data logger power was turned off by mistake by BAS personnel. This period has been inflled with data telexed from the instrument. This has breaks in transmission, and is also datum shifted approximately 15 mb relative to the data logger signal. There is a big shift of about 20 mbar in SSP around August 93. After detailed checks by Bob Spencer etc., it was concluded that this datum change was probably caused by ice. Indeed, from maps of Antarctic sea ice coverage, August is the maximum northern sea ice extent and reaches just north of Signy. Of course, there could also be local sea ice around Signy, additional to that generally surrounding Antarctica. See Woodworth, P.L., Vassie, J.M., Hughes, C.W. and Meredith, M.P. 1996. A test of the ability of TOPEX/POSEIDON to monitor flows through the Drake Passage. Journal of Geophysical Research, 101(C5), 11935-11947. file sig_306.8889: ------------------ This file contains 5 data channels: sea temperature (deg C) - channel 6; SSP (decibar)- Channel 7; air pressure (mbar) - channel 8 SSP and sea temperature data are missing for days 60-97 1989. Air pressure data are present. SSP values have been inferred from a tidal analysis. file sig_306.8990: ------------------ This file contains 4 data channels: sea temperature (deg C) - channel 6;, total sub surface pressure (mbar) - channel 7; air pressure (mbar) - channel 8; and SSP (mbar) less air pressure - channel 9. Last six points are spikes and should be disregarded. file sig_306.9091: ------------------ This file contains 4 data channels: sea temperature (deg C) - channel 6 (no data); total sub surface pressure (mbar) - channel 7; air pressure (mbar) - channel 8 (no data); and SSP (mbar) less air pressure - channel 9 This is quarter hourly data. Blocks of barometer values of 1000.00 mbar flag air pressure gaps. file sig_306.9192: ------------------ This file contains 5 data channels: sea temperature (deg C) - channel 6; SSP (decibar)- Channel 7; air pressure (mbar) - channel 8; and SSP (mbar) less air pressure - channel 9. Data hourly from telex. Small amounts of missing data - see comments in top of file. file sig_306.9292: ------------------ This file contains 4 data channels: sea temperature (deg C) - channel 6; total sub surface pressure (mbar) - channel 7; Air pressure (mbar) - channel 8; and SSP (mbar) less air pressure - channel 9. This is quarter hourly data from datalogger. Blocks of barometer values of 1000.00 mbar flag air pressure gaps. file sig_306.9294: ------------------ This file contains 4 data channels: channel 6 : sea temperature (deg C) channel 7 : total sub surface pressure (mbar) channel 8 : air pressure (mbar) channel 9 : SSP (mbar) less air pressure Large gap in all channels between scans 10899 and 10946 (day 51-53 1994). MAJOR CONSTITUENTS NSIG= 63 ------------------ NO NAME SPEED H G -- ---- ----- --- --- 1 ZO 0.0000000 1398.5593 0.000 2 SA 0.0410686 5.5832 354.001 3 SSA 0.0821373 4.7247 198.381 9 Q1 13.3986609 4.2210 35.579 11 O1 13.9430356 17.5735 48.595 16 P1 14.9589314 5.0730 61.091 18 K1 15.0410686 15.0419 63.394 29 N2 28.4397295 7.4257 242.305 32 M2 28.9841042 45.2226 264.377 37 S2 30.0000000 24.9719 290.925 39 K2 30.0821373 7.2401 289.067 44 M3 43.4761563 0.1923 19.458 file sig_306.9494a: ------------------- This file originated as si94061.1p. It contains three data channels: channel 6 : sea temperature (deg C) channel 7 : full tide pressure sensor (total sub surface pressure, mbar) channel 8 : barometer (mbar) Data exist between 19.001 hrs, day 61, 1994 ( = 1900:03.6, 02 March) and 12.004 hrs, day 241, 1994( = 1200:14.4, 29 August) There are no data gaps. MAJOR CONSTITUENTS NSIG= 55 ------------------ NO NAME SPEED H G -- ---- ----- --- --- 1 ZO 0.0000000 1391.0033 0.000 2 SSA 0.0821373 1.9419 122.979 8 Q1 13.3986609 4.2651 35.808 10 O1 13.9430356 17.5548 48.410 14 P1 14.9589314 4.9890 62.985 15 K1 15.0410686 15.0703 63.737 25 N2 28.4397295 7.5979 242.515 28 M2 28.9841042 44.9723 264.331 32 S2 30.0000000 25.2247 291.091 33 K2 30.0821373 7.1554 289.018 38 M3 43.4761563 0.2088 20.427 file sig_306.9494b: ------------------- This file is based on DCP (telexed) data (unlike the previous one, which is from the data logger record). It contains three data channels: channel 6 : sea temperature (deg C) channel 7 : full tide pressure sensor (total sub surface pressure, mbar) channel 8 : barometer (mbar) This file created from DCP files stored in : /data/imvscratch1/dunc/matlab/signy/new_data/tidata. Data are sampled hourly from barometer and tide Gaps and data spikes flagged with '1' in Channel 2. Scan 1 : 1.500 (0130:00 hrs), day 73 (14 Mar) 1994 Scan 11347: 0.000 (0000:00 hrs), day 3 ( 3 Jan) 1995 MAJOR CONSTITUENTS NSIG= 27 ------------------ NO NAME SPEED H G -- ---- ----- --- --- 1 Z0 0.0000000 1436.0929 0.000 4 Q1 13.3986609 2.7203 41.714 5 O1 13.9430356 16.1426 51.757 7 K1 15.0410686 15.3029 73.201 11 N2 28.4397295 3.4237 224.572 12 M2 28.9841042 42.1905 266.109 14 S2 30.0000000 24.0563 298.183 17 M3 43.4761563 0.6801 21.138 file sig_306.9495: ------------------ This file contains 6 data channels: channel 6 : Sea temperature (deg C) channel 7 : SSP 1 (mbar) channel 8 : Atmospheric pressure (mbar) channel 9 : SSP 2 (mbar) channel 10: Logger temperature (deg C) channel 11: Air temperature (deg C) This file created from DCP files stored in : /data/imvscratch1/dunc/matlab/signy/new_data/tidata.* Scan 1 : 17.500 (1730:00 hrs), day 308 ( 4 Nov) 1994 First good scan = scan 2506 Scan 2506 : 19.750 (1945:00 hrs), day 334 (30 Nov) 1994 Scan 5691 : 0.000 (0000:00 hrs), day 3 ( 3 Jan) 1995 Barometric pressure works throughout (hence inclusion of first records) file sig_306.9595: ------------------ This file contains 6 data channels: Channel 6 : Sea temperature (deg C) Channel 7 : Total pressure (mbar) Channel 8 : Barometric pressure (mbar) Channel 9 : Total pressure (mbar) - second sensor Channel 10: Logger temperature (deg C - in housing) Channel 11: Air temperature (deg C) This file created from DCP files stored in : /users/gwh/tidegauge/signy.95data P1 values (column 7) replaced with interpolated values for points 30505 to 30509 (day 329). No data from 0000 hrs day 3 (end of previous file) to 1800 hrs day 11. Timings have been shifted by 0.125 hours (have a scan period) as the times in the input file represented the end of the averaging period. Scan 1 : 18.125 (1807:30 hrs), day 11 (11 Jan), 1995 Scan 34007 : 23.625 (2338:30 hrs), day 365 (31 Dec), 1995 Good data, but some problems with sea temperature sensor towards the end of the year. MAJOR CONSTITUENTS NSIG= 58 ------------------ NO NAME SPEED H G -- ---- ----- --- --- 1 ZO 0.0000000 1398.1591 0.000 4 Q1 13.3986609 4.5129 35.116 6 O1 13.9430356 18.1645 48.424 11 P1 14.9589314 5.2541 61.104 13 K1 15.0410686 15.4285 63.585 24 N2 28.4397295 7.8956 244.021 27 M2 28.9841042 46.5368 264.342 32 S2 30.0000000 25.6944 291.228 34 K2 30.0821373 7.4191 288.629 39 M3 43.4761563 0.2178 22.002 file sig_306.9696a: ------------------- This file contains 6 data channels: Channel 6 : Sea temperature, deg C. No data Channel 7 : Sub surface (total) pressure 1 (mbar) Channel 8 : Barometric pressure (mbar) Channel 9 : Sub surface (total) pressure 2 (mbar) Channel 10 : Logger temperature, deg C, Some spikes + dropouts Channel 11 : Air temperature, deg C. Good data Scan 1 : 2352:30, day 365 (31 December) 1995 Scan 9169 : 1152:30, day 96 (6 April ) 1996 No spikes in pressure data, but some gaps in first half of year. See header and data for more info. Temperature data looks useless for sea temperature and logger temperature. Air temperature data looks good. Data from telex occasionally has missing scans (on the quarter hour for some reason). These have been flagged, but not interpolated through. MAJOR CONSTITUENTS NSIG= 27 ------------------ NO NAME SPEED H G -- ---- ----- --- --- 1 Z0 0.0000000 1400.7411 0.000 4 Q1 13.3986609 4.7839 29.888 5 O1 13.9430356 18.6530 46.694 7 K1 15.0410686 15.9894 63.717 11 N2 28.4397295 7.8796 244.932 12 M2 28.9841042 46.5516 264.407 14 S2 30.0000000 26.0712 291.273 17 M3 43.4761563 0.1574 31.285 file sig_306.9696b: ------------------- This file contains 6 data channels: Channel 6 : Sea temperature, deg C. No data Channel 7 : Sub surface (total) pressure 1 (mbar) Channel 8 : Barometric pressure (mbar) Channel 9 : Sub surface (total) pressure 2 (mbar) Channel 10 : Logger temperature, deg C, Some spikes + dropou Channel 11 : Air temperature, deg C. Good data Scan 1 : 0637:48, day 168 (16 June ) 1996 Scan 19078 : 2345:00, day 366 (31 December) 1996 Interpolated temp values between scans 16170 and 16178 (16.750 & 18.750, day 336) and scans 16846 - 16853 (17.750 & 19.250 day 343) MAJOR CONSTITUENTS NSIG= 55 ------------------ NO NAME SPEED H G -- ---- ----- --- --- 1 ZO 0.0000000 1400.2058 0.000 2 SSA 0.0821373 2.3001 259.131 8 Q1 13.3986609 4.6488 38.113 10 O1 13.9430356 18.4615 48.261 14 P1 14.9589314 5.3993 61.111 15 K1 15.0410686 15.2804 64.607 25 N2 28.4397295 7.8926 245.809 28 M2 28.9841042 46.9259 264.560 32 S2 30.0000000 25.7545 290.627 33 K2 30.0821373 7.8520 285.842 38 M3 43.4761563 0.1925 12.748 file sig_306.9797: ------------------ This file was processed from tidata files. Data channels are as follows: Channel 6 : Sea temperature, deg C. (BAD DATA) Channel 7 : Sub surface (total) pressure (mbar) Channel 8 : Air temperature (deg C) Channel 9 : Total pressure (second sensor) Channel 10 : Logger temperature, deg C Channel 11 : Barometric pressure (mbar) Scan 1 : 0007:30, day 001 (01 January) 1997 Scan 8568 : 0552:30, day 090 (31 March) 1997 Pressure data in column 9 fails after scan 1286. Channel 7 fails at scan 4046. None of the sea temperature data is any good. 56 points in col 7 have been replaced with predicted values. Barometric pressure looks good except for 2 x 6 hour periods at the end of the file, where it is set to zero. Timings look OK throughout. MAJOR CONSTITUENTS NSIG= 27 ------------------ NO NAME SPEED H G -- ---- ----- --- --- 1 Z0 0.0000000 1394.3391 0.000 4 Q1 13.3986609 3.6714 63.584 5 O1 13.9430356 16.5228 46.957 7 K1 15.0410686 16.1505 63.236 11 N2 28.4397295 6.0079 237.131 12 M2 28.9841042 45.1250 263.878 14 S2 30.0000000 23.7595 297.021 17 M3 43.4761563 0.9292 261.895 file sig_306.9900: ------------------ This datafile was provided by Pete Foden and Steve Mack(?). The data were downloaded onto the old Toshiba laptop, and saved as the following files: 50106 Jan 18 2000 TIDATA.18 53772 Jan 29 2000 TIDATA.29 43348 Nov 28 1999 TIDATA.332 139496 Dec 26 1999 TIDATA.360 50106 Feb 8 2000 TIDATA.39 48884 Feb 18 18:54 TIDATA.49 48884 Feb 28 19:18 TIDATA.59 57438 Mar 11 13:16 TIDATA.71 61104 Jan 8 2000 TIDATA.8 47662 Mar 21 10:44 TIDATA.81 48884 Mar 31 10:32 TIDATA.91 These contained output from one pressure sensor, as sea temperature and pressure using the tide gauge's built in calibration, and also a column of raw counts from the sensor that would allow the data to be re-processed in future. The data in sig_306.9900 has come from the pressure data based on the internal calibration, not on any reprocessing of the counts. The data look OK, although there was a timing jump at day 60, 2000, which meant that 1 day had to be added to the date after scan 9840. This was done, and the timings before and after were checked with harmonic analysis. In line with tidata files, 0.125 hours had to be subtracted from the given timings to give a value for time that represented the middle, rather than the end of the scan. Processing the file through tira gave the following constants: MAJOR CONSTITUENTS NSIG= 27 ------------------ NO NAME SPEED H G -- ---- ----- --- --- 1 Z0 0.0000000 1401.1343 0.000 4 Q1 13.3986609 4.6188 35.619 5 O1 13.9430356 18.8683 48.202 7 K1 15.0410686 15.8172 62.758 11 N2 28.4397295 7.4521 245.632 12 M2 28.9841042 46.4554 264.030 14 S2 30.0000000 25.4794 290.227 17 M3 43.4761563 0.1850 12.657 The residuals are generally small (+/- 11 mbar max) but do show some energy at tidal frequencies - although there don't appear to be any timing errors in the file. The is also a great deal of high frequency noise in the residuals. file sig_2002_acc.Z: -------------------- This file contains 4 data channels: sea temperature (deg C) - channel 6 total sub surface pressure (mbar) - channel 7 logger(air) temperature (deg C) - channel 8 air pressure (mbar) - channel 9 This is assumed quarter hourly data as no time drift available file sig_2003_acc.Z: -------------------- This file contains 4 data channels: sea temperature (deg C) - channel 6 total sub surface pressure (mbar) - channel 7 logger(air) temperature (deg C) - channel 8 air pressure (mbar) - channel 9 This is assumed quarter hourly data as no time drift available file sig_2004-5_acc.Z: -------------------- This file contains 4 data channels: sea temperature (deg C) - channel 6 total sub surface pressure (mbar) - channel 7 logger(air) temperature (deg C) - channel 8 air pressure (mbar) - channel 9 This is assumed quarter hourly data as no time drift available file sig_2006_acc.Z: -------------------- This file contains 4 data channels: sea temperature (deg C) - channel 6 total sub surface pressure (mbar) - channel 7 logger(air) temperature (deg C) - channel 8 air pressure (mbar) - channel 9 This is quarter hourly data file sig0607.tsk --------------- Thsi file contains 4 data channels: Channel 6 : Sea temperature, deg C. Channel 7 : Sub surface (total) pressure (mbar) Channel 8 : Logger (air) temperature, deg C Channel 9 : Barometric pressure (mbar) Missing values given as -999.00 No timing information available, therefore a 15 minute sampling interval is assumed file sig09.tsk --------------- Thsi file contains 4 data channels: Channel 6 : Sea temperature, deg C. Channel 7 : Sub surface (total) pressure (mbar) Channel 8 : Logger (air) temperature, deg C Channel 9 : Barometric pressure (mbar) Missing values are given as -999.00 It is assumed to be quarter hour data as no timing information is available. files sig_2011.tsk and sig_2011-12.tsk -------------------------------------- These files were provided by Dave Blackman in October 2012. Headers for both read: Channel 6 : Sea temperature, deg C. Channel 7 : Sub surface (total) pressure (mbar) Channel 8 : Logger (air) temperature, deg C Channel 9 : Barometric pressure (mbar) Time interval assumed as 15 minute as no timing available Missing values given as -999.00 N.B. Sea Temperature assumed to be 0.00 throughout because of sensor fault Note that good data in sig_2011.tsk covers only 2011/69-133, rather dubious thereafter. Note that the timing in the two files must be more or less ok as shown by the existence of the japan tsunami. =========================================================================== Station: South Georgia, King Edward Point. (GLOSS No. 187) ========================================================== A gauge was installed at South Georgia in January 2008 consisting of two KPSI differential pressure sensors that measure water temperature, full tide water level and half tide water level with 1 minute sampling. These differential pressure sensors record sea level (in cm) and do not take account of atmospheric pressure loading. Therefore, they ARE NOT comparable with sub-surface pressure measurements elsewhere in this directory. The half tide sensor was colocated incorrectly from its installation, and although was readjusted a couple of times since was never useful. So its data here are not for general use. files kep.task.2008 to kep.task.2017 (10 files): ----------------------------------------------- These files contains 3 data channels: Channel 6: full tide height,cm Channel 7: half tide height,cm Channel 8: water temperature, deg C These are 15 minute values computed from the original 1 minute data (available on request), with a scaling factor to convert the freshwater-equivalent cm measured by the KPSI sensors into sea water cm using best estimates of local density and gravity. Due to a software glitch, temperatures lower than zero degrees C were not recorded prior to April 2010 and are shown as missing or suspect. A software update corrected this and negative temperatures are recorded from April 2010 onwards. The full tide data appear to be of good quality and compare well to altimetry. More details are archived at the PSMSL (and at NOC see /plw3/acclaim/kep.2008-2014.readme and /plw3.acclaim/kep_2017/readme). Daily values computed from the above 7 15-minute files are contained in 'kep.dailies.total.2008-2014' (units cm) in this directory and 'kep.dailies.2014-2017'. =========================================================================== Station: Tristan da Cunha (GLOSS No. 266) ========================================= The Phase 1 instrument at Tristan consists of a Digiquartz pressure sensor on the end of a data cable to a data logger in the nearby settlement of Edinburgh. The logger also records air pressure. No datum information available. All data have been tidally analysed and constants and residuals checked. Residuals show large positive fluctuations of 1-2 days duration due to wave setup in the small harbour in which the gauge is located. Further documentation comments on each data file are contained in the text file 'tristan.info' in this directory. ============================================================================ Station: Rothera ================ At Rothera, the tide gauge is mounted in a sea water well, approximately 100 metres shorewards of the main jetty. The well is connected to the sea by a boulder filled covered culvert, which has the effect of damping out waves etc. The well is concrete lined, and is used as a sea water take-off point for cooling the base electricity supply. The water level has been observed with water being pumped off for cooling, and with the pumps off, and this pumping has no discernable effect on water levels within the well. Barometric pressure was recorded away from the well, at the data logger installation. In 1992, an Aanderaa WLR PTR475 (SN39913) was operated for a brief time, giving sea temperature and sub-surface pressure information. The gauge was mounted in the sea water well. A new gauge was installed in December 1993. Initially this was a conventional phase 2 gauge (with two co-located sensors and a tube linking one to the half tide point. Freezing caused problems with this system. Initially, a small heating wire was passed down the (insulated) half tide tube, but from the start of 1997 onwards, the half tide sensor has been fixed at the half tide point (the sensors are no longer co-located). This is a phase 2 gauge - in that it has a half tide point. The data from the half tide sensor does not look good however, so we have not converted the pressure values to sea level. This is why the data is held in the phase 1 (sea pressure) directory, and is not in the phase 2 (sea level) directory. Additional quality control information is held in the file 'rothera.info' in this directory. file rothera.92119303 --------------------- Channel 6 : Sea temperature (degC) Channel 7 : Total pressure (mbar) Channel 8 : Blank Channel 9 : Blank Channel 10: Non-tidal residuals (mbar) from Tira analysis 1st data from coolling well Aanderaa gauge placed in well in November 1992 by Pete Marquis and recovered March 1993. Data tape had some corrupted scans Data timeshifted by -2.000 hours, for harmonic constants to agree with those from later records. Timing has been corrected (99.9% sure) Timing has been corrected (99.9% sure) No barometric Pressure file rothera.93129412 --------------------- Channel 6 : Sea temperature (deg C) Channel 7 : Logger temperature (deg C) Channel 8 : Barometric pressure (mbar) Channel 9 : Full tide pressure (mbar) Channel 10: Half tide pressure (mbar) Spikes and dropouts are logged in the file rothera.info. file rothera.95019512 --------------------- Channel 6 : Sea temperature (deg C) Channel 7 : Logger temperature (deg C) Channel 8 : Barometric pressure (mbar) Channel 9 : Full tide total pressure (mbar) Channel 10: Half tide total pressure (mbar) Large gap in record (approx 0.5 years) in the middle of this period. Some variability in predicted datum position from 1/2 tide gauge, particularly over latter half of 1995. From Cruise report 25, Rothera was visited on 1/12/95. Sea temperature data was observed prior to this visit, and was thought to be incorrect. This was confirmed on checking the signal from the sensor. The sensor head was not producing the correct frequency, but due to time constraints, could not be replaced. Sea temperature from the original data logger in the well is used instead. file rothera.96019611 --------------------- Channel 6 : Sea temperature (deg C) Channel 7 : Logger temperature (deg C) Channel 8 : Barometric pressure (mbar) Channel 9 : Full tide total pressure (mbar) Channel 10: Half tide total pressure (mbar) Datum shift in 1/2 tide gauge after day 260, 1996. Some overshoots apparent in half tide record in mid-late 1996. See rothera.info for details. file rothera.97019712 --------------------- Channel 6 : Sea temperature (deg C) Channel 7 : Total pressure (mbar) Channel 8 : Barometric pressure (mbar) Channel 9 : Logger temperature (deg C) Channel 10 : Half tide temperature (deg C) Channel 11 : Half tide pressure (mbar) Datum definition not good - difference between full and half tide pressures vary by ~ 4mb through the record. file rothera.97119812 --------------------- Channel 6 : Sea temperature (deg C) Channel 7 : Total pressure (mbar) Channel 8 : Barometric pressure (mbar) Channel 9 : Logger temperature (deg C) Channel 10 : Half tide temperature (deg C) Channel 11 : Half tide pressure (mbar) There is still an offset of 12.7 mb between the half tide sensor and the barometric pressure sensor. Subtracting the barometric pressure from the half tide pressure shows the (relative) offset of the two units to be unchanging with time. Subtracting the half tide signal from the full tide however shows the full tide signal to be very poor AND SHOULD NOT BE USED. It is thought that the sensor head, or cable, has flooded. This will be checked on the next visit (end of 1998). file rothera.98129910 --------------------- Channel 6 : Sea temperature (deg C) Channel 7 : Total pressure (mbar) Channel 8 : Barometric pressure (mbar) Channel 9 : Logger temperature (deg C) Channel 10 : Half tide temperature (deg C) Channel 11 : Half tide pressure (mbar) The Logger started to fail in October 1999. Bad data points have been set to 0.000, and the flag in column 2 has been set to '1' after the full tide sensor failed. The offset between the half tide pressure, and the atmospheric pressure varies between 8.4 mb at the start of the record, increasing to 10.5 mb towards the end. The offset increases steadily, and may be a simple sensor drift. Comparing the half tide and full tide sensors shows a similar magnitude drift, so it looks like the problem is with the half tide sensor. ======================================================================== Station: Forster ================ We have included in this 'phase 1' directory a file of SSP data from the Georg Forster base in Antarctica provided for ACCLAIM/WOCE studies by Prof.Reinhard Dietrich and Dr.Gunter Liebsch from the Technical University of Dresden in Germany. The SSP data were obtained from a bottom-mounted pressure sensor in shallow water (and hence are 'phase 1' in ACCLAIM terminology) near to the base at coordinates LAT= 70deg 46min 21sec LON= 11deg 51min 56sec. Data file is 'forster.9192' and is in ACCLAIM format with SSP data in channel 7 in mbar. Atmospheric pressure data in channel 8 is in mbar, and is from a nearby meteorological station. Times in these files are GMT+1 hour. A report on the data is in preparation at Dresden. ============================================================================ Station: Vernadsky (formerly Faraday) ===================================== Data from 1997-1999 were acquired from a POL pressure transducer at Vernadsky, adjacent to the stilling well float gauge which provides 'phase 2' data in the 'phase2' directory on this disk. Data are in 11 channel ACCLAIM format with 15 minute sampling: channel 6 sea temperature (deg C) 7 sea pressure (mbar) (with 1000 added as shown above) 8 temperature in the hut (deg C) 9 air pressure (mbar) 10 - 11 - A readme on data processing for these data can be found at POL in /users/plw3/acclaim/vernadsky97-99/readme. Important Note: The sea pressure measured by the above gauge was total pressure, whereas the KPSI gauge described below was based on two differential pressure sensors. Vernadsky KPSI 'B' Gauge ---------------------- This gauge was installed on 7/12/07 and consists of two KPSI differential sensors. These were intended to measure full and half tide water levels, atmospheric pressure and sea temperature, however, the half tide sensor was deployed only 60cm above the full tide sensor and therefore measures the full tide. It requires a further upward adjustment to reach the half tide level. In addition, both sensors were insecurely fastened to the piling and may exhibit slight movement. In view of this, datum control cannot be assured and the data are therefore considered to be Phase 1 in ACCLAIM terms. Both issues are due to be corrected during 2011. files ver_2007-09.acc and ver_2009-10.acc ----------------------------------------- These files contain 4 data channels with 15 minute sampling. Channels are: atmospheric pressure (mb) - channel 6 water temperature (degC)- channel 7 water level sensor 1 (cm) - channel 8 water level sensor 2 (cm) - channel 9 IMPORTANT.Note that the differential sensors do not measure atmospheric pressure, so the water level data are NOT comparable with sub-surface pressures. Data have been inspected for spikes and gaps. Spikes and gaps of one hour or less have been interpolated. Longer gaps and spikes are identified by '-9999.00' in the relevant data channel. The sea level data appear to be of good quality, although slight gradual drift was noted between the two sensors and was attributed to the insecure fastening of the sensors, as described above. Note that because KPSI sensors are calibrated for freshwater, the data have been corrected to give cm of seawater, assuming values for rho and g of 0.001027241 kg cm^-3 and 982.3063 cm s^-2 respectively. file ver_sep10-jan12.tsk ------------------------ was provided by Dave Blackman in October 2012. File contains: Channel 6 Atmospheric Pressure (mbars) Channel 7 Full tide level (cms) Channel 8 Half tide level (cms) Channel 9 Water Temperature (deg C) ============================================================================