R/V Ronald H. Brown Daily Summaries

Cruise Day 20040729

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RHB encountered light rain overnight. The ship moved away from Cape Ann early to reach our spot for the MISER local mode overpass at 42deg 40' N, 69deg 45'. The ship arrived on station about 9:00 AM greeted by solid overcast (stratus?). Miraculously, about an hour before the scheduled overpass the skies started to clear. At about 11:15 the J31 was on station and pointed RHB to clearer skies just to the west of our position. RHB moved and we had a successful overpass with the J31 making several low-level passes near RHB.

After consulting with Lisa Darby and Mike Hardesty, we decided to return to the area of Cape Ann. Traveling west we passed through an aged plume with processed NOy and SOx. We found what appeared to be the Boston plume next to the NH coast with CO levels above 300 ppb and O3 above 80 ppb. RHB will continue to do East/West tracks north of Cape Ann through the night. Plans call for RHB to work downwind in the urban plume through the day on Friday.