Data management office notes on supplementary fields - aerosols datalat, lon A nominal ship location is given in lat/lon. The location is the noon position most near the middle of the sampling period, e.g. for a sample which was pumped intermittently from Jan. 3 - 5, the location is given for noon, Jan. 4. Intended as an aid to understanding, not a discrete location. date_begin, date_end We have included the start and stop day for each sample which we believe constrains the sample time about as well as is useful for these data. We also have pump volume and thus a mean concentration of dust per cubic meter of air for that time frame. The actual number of hours sampled during a time block (number of days) is complicated to present. Pumps were turned on and off repetitively depending upon ship maneuvers and relative wind direction (to prevent ship exhaust contamination). Also, the total number of hours the pumps were on is a less useful measure than pump volume, because of the variability in pump efficiency due to changing barometric pressures. An hours worth of pumping does not always yield the same volume of air.