QUALITY ASSESSMENT OF SEA LEVEL DATA                
                                           by the                               
                   UH SEA LEVEL CENTER/NATIONAL OCEANOGRAPHIC DATA CENTER     
                                 JOINT ARCHIVE FOR SEA LEVEL                    
                                       updated: 20 Apr 2017
              Station  : Charleston,SC-A           Latitude:  32 46.9N
              Country  : USA                      Longitude: 079 55.5W
              JASL #   : 261A                 Time Meridian: 075W (GMT - 5 hr)  
              GLOSS #  : none Originator #:8665530   NODC #: 73072901           
              Contributor  : National Ocean Service (NOS)                       
                             National Ocean. and Atmos. Administration (NOAA)   
                             N/OES22
                             SSMC4, STATION 7109
                             1305 East West Highway
                             Silver Spring, MD. 20910-3233
              Originator   : US Coastal Geodetic Survey
              Original Data: analog 
              Instrmnt Type: standard mechanical, float/wire  
              Digitzd Intvl: hourly
              Present Data : Hourly, daily, and monthly values obtained by:     
                    Hourly : The original digitizing interval was hourly        
                    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 : 01 Jan 1901 - 31 Dec 1903
              Gaps > 1 mon : none
              Time Refernce: GMT (hours 00-23)   Space-filler Flag   :-9999     
              Units        : millimeters         Missing Data Flag   : 9999     
              Existing     : Yes                 Operational         : Yes      
              Sat. Trans.  : Yes                 Distribution        : 1901-1903
              Refernce Levl: All heights have been referred to the station tide 
                             staff zero which is linked to fixed bench marks.
                             While standard mechanical or ADR instrument was the
                             primary gauge, leveling calibration factors were
                             applied monthly based on tide staff comparisons.

                             The difference of daily data between Charleston 
                             and Fernandina Beach, FL 1901-2016 shows the
                             1901-1903 offset ~10 cm relative to the rest. 
                             Until this suspect reference level shift is
                             resolved, the Charleston series is broken into
                             261A and 261B.                          

              Comment      : The residual series are very noisy which are       
                             probably due to shallow water tides that are not   
                             resolved by the harmonic analysis; thus, only      
                             questionable fluctuations greater than 40 cm are   
                             noted below that may represent timing inaccuracies.
                             Also the daily plot shows noise due to a great     
                             amount of energy with periods from 3 to 15 days.   
                             The monthly plot reveals a consistent annual and   
                             semi-annual signal.  
      
                    CI MISSING              REPLACED GAPS     QUESTIONABLE      
              YEAR (%) DATA                 OR BAD DATA       FLUCTUATIONS      
              ---- --- -------------------- --------------- --------------------
              1901  98 1,78-85              none            none
              1902 100 none                 none            none
              1903 100 none                 none            none