*** Documentation for the CTD data from a series of cruises in the  western                                                         
Irish Sea carried out by University of Wales,  Bangor during 1995 on the RV                                                         
Prince Madog under the direction of Dr A.E. Hill. The work was supported by                                                         
NERC grant GR3/9601, "Seasonal Gyres in Shelf Seas".                                                                                
                                                                                                                                    
                                                                                                                                    
THE  DATA IS ALREADY CALIBRATED.  Coefficients and method are given  below.                                                         
Density  has been derived using the formulation recommended in Unesco Tech.                                                         
reports 36,38,40 (1981).                                                                                                            
                                                                                                                                    
Instrument used                                                                                                                     
================                                                                                                                    
                                                                                                                                    
Neil Brown Instruments System Mark III CTD                                                                                          
                                                                                                                                    
In   all  cases,  observed  parameters  were  pressure,   temperature   and                                                         
conductivity.  The  typical  instrument descent rate was 1 m/s.  Data  were                                                         
logged on an IBM compatible PC.                                                                                                     
                                                                                                                                    
Data  from  the Neil Brown was collected with EG & G CTD  data  acquisition                                                         
module Version 2.02.                                                                                                                
                                                                                                                                    
Data Processing                                                                                                                     
===============                                                                                                                     
                                                                                                                                    
Data from the Neil Brown were processed with EG & G Post Processing  module                                                         
Version 1.22                                                                                                                        
                                                                                                                                    
In all cases, data were checked for rogue values and averaged into 1m depth                                                         
bins.  Calibration coefficients were subsequently applied using an in-house                                                         
program which created the files sent here.                                                                                          
                                                                                                                                    
Calibration                                                                                                                         
===========                                                                                                                         
                                                                                                                                    
Temperature  was calibrated using standard reversing thermometers (0.001  C                                                         
accuracy)  and  salinity  samples  from a rosette.  Salinity  samples  were                                                         
measured with Autosal Model 8400A.  Samples were collected from well  mixed                                                         
regions  of  the water column to ensure good calibration.  The  calibration                                                         
data for each cruise now follows: temperature calibration was calculated as                                                         
a difference.                                                                                                                       
                                                                                                                                    
Temperature = CTD temperature + dT (degrees C)                                                                                      
                                                                                                                                    
Salinity calibration was calculated as a ratio.                                                                                     
                                                                                                                                    
Salinity = CTD salinity / Sr                                                                                                        
                                                                                                                                    
Cruise PM4_95 ==============                                                                                                        
                                                                                                                                    
Number of samples 31                                                                                                                
                                                                                                                                    
Mean dT 0.017                                                                                                                       
                                                                                                                                    
Standard deviation dT 0.003                                                                                                         
                                                                                                                                    
Mean Sr 1.009                                                                                                                       
                                                                                                                                    
Standard deviation Sr 0.0003                                                                                                        
