1. Summary of Data Buoy Observations
 

    The JMA has been operating drifting ocean data buoys. 
The buoys have cylindrical shape hull with a diameter of 64 centimeters. Sensors 
for position, air pressure, sea surface temperature and wave height/period 
are equipped within the hull, at levels close to the sea surface. 
    The observation is usually carried out every three hours. When wave height 
exceeds the threshold set beforehand (e.g.3.0m), each buoy changes the function 
automatically to one-hourly observation. The threshold value can be changed anytime
via two-way satellite telecommunication system.
    Observation data of each buoy are stored on the CD-ROM in a file named 
"yy-nn.txt", while the chart is is  stored in a file named "yy-nn.gif". 
Where yy shows year and nn is a consecutive number assigned in order of 
deployment in the year. 


2.Explanation of File Format

Element         	Start 	Field   	Description of Field
			     Position   Type

Buoy number         	1	I5	        WMO station index number.
Year	                7	I4
Month                	12	I2
Day	                    15	I2
Hour    	            18	I2	        Universal Time.
Latitude    	        
 N or S                 21  A1          N:North,S:South.
 Degrees                23  I5          Latitude in degrees to thousandths.
Longitude	            
 E or W                 29  A1          E:East,W:West.
 Degrees                30  I5          Longitude in degrees to thousandths.
Air pressure	        37	I5      	Air pressure in hPa to tenths.
Sea surface temp.       43	I3	        Sea surface temperature in degrees 
                                        centigrade to tenths.
Wave height	            47	I3	        Significant wave height in meter to tenths.
Wave period	            51	I2	        Significant wave period in seconds.



3. Caption

Track chart:Paths of the buoys. -- yy-nn ( yy shows a deployed year and nn is a 
consecutive number assigned in order of deployment in the year.)


			
