Appendix B. Glossary of Terms and Abbreviations Used* ______________________________________________________________________________ Term Meaning and description 5c grid 5x5° (latitude x longitude) boxes between latitudes 50N and 50S, 5x10 for latitudes 50-70, 5x20 for latitudes 70-80, 5x40 for latitudes 80-85, and 5x360 for 85-90. actual amount Fraction of the sky covered by a cloud, visible or not. all reports All reports regardless of whether they are light or dark. awp Amount-when-present. The average fraction of the sky covered by a cloud type when it is present, whether it is visible or not. dark reports Reports for which illuminance criterion is not met (IB=0). ECR Edited Cloud Report. Synoptic cloud reports screened and edited for cloud code consistencies and written as the 56-character report described in Table 9. ECRA Archive made up of edited cloud reports. extended code The synoptic code extended beyond the usually allowed values of 0-9 to allow CL=10 to represent Cb, CL=11 to represent fog and CM=10,11,12 to represent Ns cloud. f Frequency of occurrence. For a cloud type it is the fraction of weather observations in which the cloud type is present, whether it can be seen or not. light reports Reports for which illuminance criterion is met (IB=1). NOL Non-overlapped; refers to method for determining upper level cloud amounts. ROL Random overlap; refers to method for determining upper level cloud amounts. total reports Reports suitable for total cloud analyses (and clear sky, fog, and precipitation); either all reports (the entire ECR data set) or light reports only. type reports Reports in which cloud type information is given (Nh>/=0 and CL>/=0. These may be light, dark, or all reports. ______________________________________________________________________________ * Terms not shown here may be defined in Table 1, 2, 4 or 9.