QUALITY ASSESSMENT OF SEA LEVEL DATA                
                                           by the                               
                   UH SEA LEVEL CENTER/NATIONAL OCEANOGRAPHIC DATA CENTER     
                                 JOINT ARCHIVE FOR SEA LEVEL                    
                                       updated: 08 Mar 2023
              Station  : Ammassalik, Greenland     Latitude:  65 36.9N
              Country  : Denmark                  Longitude: 037 37.5W
              JASL #   : 297A                 Time Meridian: 045W (GMT-3hrs)
              GLOSS #  : 228      TOGA #: none       NODC #: 76035701
              Contributor  : Royal Danish Administration of Navigation
                             & Hydrography
                             Overgaden o.Vandet 62B
                             Postboks 1919,DK-1023
                             Copenhagen-K
                             DENMARK
              Originator   : same 
              Original Data: unconfirmed
              Instrmnt Type: pressure gauge
              Digitzd Intvl: 15 minutes
              Present Data : Hourly, daily, and monthly values obtained by:     
                    Hourly : 1990-1995 unconfirmed; 1996- three-point Hanning
                             centered on the sample time closest to the hour
                    Daily  : 119-point convolution filter (Bloomfield, 1976)    
                             centered on noon applied to the hourly data        
                             with respective periods of the 95, 50, and 5%      
                             amplitude points at 124.0, 60.2, and 40.2 hours    
                    Monthly: Simple average of all daily values; calculated if  
                             7 or fewer days are missing                        
              Span of data : 13 Nov 1990 - 31 Dec 1998
              Gaps > 1 mon : 14 Aug 1991 - 12 Nov 1991;09 Apr 1993 - 09 May 1993
                             01 Jan 1996 - 01 Jul 1996;26 Feb 1998 - 16 May 1998
              Time Refernce: GMT (00-23 hours)   Space-filler Flag   :-9999     
              Units        : millimeters         Missing Data Flag   : 9999     
              Existing     : Yes                 Operational         : Yes
              Sat. Trans.  : No                  Distribution        : 1990-1998
              Refernce Levl: All data are referred to LAT, which is Chart Datum
                             for Greenland
                 Tide gauge benchmark (TGBM) description:
                     TGBM 5298.6cm below 'bronze' mark near Ammassalik 
                     town-cairn. Also benchmark 4321.1cm below 'bronze' 
                     mark about 10m from church entrance.
              Comment      : 
              All  data  are  corrected for  atmospheric  pressure. Salinity not
              measured, sea level elevation calculated from pressure using a sea
              water  density based  on  measured  temperature  and a salinity of
              31.5ppt.  The hourly residuals reveal good timing for 1990-1995.
              The timing is off on the order of minutes for select periods
              starting in 1996.  An obvious reference level shift was removed 
              from the data for 03-13 Aug 1997.
         
                    CI MISSING              REPLACED GAPS     QUESTIONABLE      
              YEAR (%) DATA                 OR BAD DATA       FLUCTUATIONS      
              ---- --- -------------------- --------------- --------------------
              1990  12 353-357,364-365      none            none
              1991  56 1-9,17-40,180-182,   none            none
                       217-221,226-316,317-
                       321,326-336,343-351,
                       354-365 
              1992  79 1-12,113-122,148-    (11)034-(22)034 see comment above
                       157,163-188,198-201, (13)096-(20)096
                       221-223,231-243,251-
                       254,261-262,354-357
              1993  69 16-21,73-80,99-145,  (04)007-(18)007 none
                       149-154,167-174,185-
                       191,200-206,217-218,
                       220-249
              1994  99 228-229              none            none
              1995 100 none                 none            none
              1996  50 1-183                none            none
              1997  94 48-50,136-145,215-   (10)029-(19)029 29-32,145-215
                       225                  (01)033-(12)033
                                            (15)070-(00)071
              1998  78 57-136               none            24-57,233-365