Table 1. Structure of group files 3-8 (groups 1 and 2 are reserved for "untrimmed" Release 1 products). Each group contains four variables and eight statistics for each variable: the median, the mean, the number of observations, a standard deviation estimate, the mean day-of-month of observations, the fraction of observations in daylight, and the mean longitude and latitude of observations. Derived variables in groups 5-8 are computed as indicated from individual observations of other variables, e.g., the wind-stress parameter "X" is the product of W and U. In addition, QS denotes saturation Q at SST. 

                                      Group
3                      4                5                 6           7     8
===============================================================================
Sea surface temp. (S)  Scalar wind (W)  Total cloud. (C)  D=S - A     I=UA  S
Air temperature (A)    Wind U-comp.     R                 E=(S - A)W  J=VA  A
Specific humidity (Q)  Wind V-comp.     X=WU              F=QS - Q    K=UQ  X
Relative humidity (R)  Pressure (P)     Y=WV              G=FW        L=VQ  Y

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