Clarke: C-130 OPC data These are particle number size distributions of OPC in the unit of number per cubic centimeter (#/cc) at ambient pressure. Indicated sizes are at midpoint of each size bin and there are 135 equally log spaced bins per decade of diameter. These are dry aerosol at about 25% RH, ambient sizes require correction for size due to uptake of water at different relative humidities. The data were cleaned up and processed into one file for each flight and flight numbers are indicated in the filenames. In each file, the first column is time in julian day of the year and the second column gives three instrument sample temperatures 40(C), 150C and 300C. The column 3-235 are particle number concentration (#/cc) at all sizes in micrometer. The particle diameters are listed at the first row of each files.