VISITORS: Effective 21 July 2014, Visitor Center Security will no longer accept IDs from some US states for site access. Please see security procedures for details.
 

R/V Ronald H. Brown Daily Summaries

Daily Summary July 15, 2002, DOY = 196

Just after midnight, the ship began her approach to New York Harbor from the southeast. At about 3:00 am ET the wind shifted from the southeast to the west. The change in wind direction was accompanied by an abrupt increase in pollutant levels with nitrogen oxide concentrations approaching 20 ppb, particle number increasing to 40,000 per cc, and ozone levels decreasing due to nighttime titration. The first measurements of NO3in maritime air were made in the pre dawn hours. The concentrations of all anthropogenic tracers and radon increased dramatically. By 5:30 AM ET the ship was on station approximately 2 nm off Rockaway Beach. A few hours later the ship was moved closer to the main shipping corridor into New York to sample ship plumes. The plumes from several large cargo vessels were sampled in the morning. During these periods significant excursions in most gaseous and aerosol measures were observed including the conservative tracer, CO2. Concentrations of MVK and MACR exceeded those for isoprene indicating a chemically aged biogenic mix.

During the late morning and early afternoon the sea breeze filled in with flow turning to the south. Under this flow the measurements on board reflected aged pollution from sources along the East Coast, with ozone slowly increasing to approximately 80 ppb. Intercomparisons of VOC measurements under clean and polluted conditions indicated excellent agreement.

For all plots, time is indicated in GMT. Eastern time is -5 hours.

graph
Location
graph
Temperature, Pressure
graph
Sea Surface Temperature, Relative Humidity
graph
True Wind Speed, Direction
graph
Ship Speed, Direction
graph
Relative Wind Speed, Direction

Textual information and data plots are for quicklook and overview purposes only.