CDF number_pixels_y number_pixels_x Z time Conventions CF-1.5 projection lat lon Measurement_time 2017.12.31 time long_name Date of observation units Minutes since 2010-1-1 0:0:0 UTC p lat standard_name latitude long_name latitude units degrees_north coordinates number_pixels_y number_pixels_x { x lon standard_name longitude long_name longitude units degrees_east { ( so2_column_density standard_name so2_column_density long_name SO2 Column Density units DU coordinates lat lon { AP ?