Winds 260 degrees at 8 m/s, pressure 1014.2 and falling, 7/8 stratus,
dry bulb 12.2C, wet bulb 8.4C, SST 1286
SEA STATE:
Southwesterly 1-2 M swell, wind waves from 260 at <1 M
INSTRUMENTS/SYSTEMS STATUS
Sea Surface Measurements:
DMS: Current concentration 1-2nM
DMSP/DMSO:
NH4+NH3/pH:
CO:
Surface seawater concentrations have a diurnal cycle with a late night
minimum of 1 and and an afternoon maximum of 2 nM.
NMHC:
Low ppb levels of butane. sub ppb levels of pentane in equilibrated air
samples.
CO2:
Nitrate/Chlorophyll:
Nitrate concentrations are approx 3 uM.
Seawater fluorescence is being recorded continuously.
Surface seawater samples are being collected every 4 hours
for discrete chlorophyll analysis.
Atmospheric Measurements:
DMS:
SO2:
Current concentrations are 10-20 ppt.
NH3:
Using oxalic acid coated filters. Concentrations measured with oxalic
acid coated filters range from 3 to 10 pptv.
CO:
Concentrations near 60ppb.
NMHC:
ppt levels of a few hydrocarbons. very clean air.
O3:
Surface concentrations were lower today (Tuesday), 16 to 20 ppb.
An ozonesonde was launched at 0430 during the aircraft
intercompariston. Between the surface and 1.3 km concentrations
ranged from 18 to 19 ppb, between 1.5 and 5 km concentrations
were between 25 to 50 ppb. The profile extended to 33 km.
Nitrogen oxides and PAN:
NO rose to ~20ppt local noon.
NO2 at 15-18ppt throughout day. NOy ~400 ppt.
PAN not functional.
Radon:
CO2:
Solar Radiation:
Aerosol physics:
At 0740GMT (C130 overpass) the size distribution showed 3 modes
at 22-25, 40 and 130nm. UFCN = 600-700 pp/cc.
Aerosol chemistry:
2-stage and 7-stage impactors currently sampling for time periods
ranging from 24 to 72 hours for IC, total organic carbon, speciated
organics, and gravimetric analysis.
Aerosol optical properties: Absorption
coefficient very low.
Continue observations of diurnal cycles in area of high pressure system and
survey of seawater DMS concentrations in region. Later today we will
begin heading south or southwest toward the start of the next Lagrangian.
PAST 24-HR OPERATIONS SUMMARY:
Discover remained on the edge of the temperature/nutrient/DMS front
yesterday devoting the day to air sampling with the particular goal of
observing diurnal cycles in atmospheric DMS and SO2. The C-130 worked
in the vicinity with similar goals. The clear sky was ideal for sun
photometer measurements. Half-hourly measurements were increased to
4/hour during the 2 hour period around the satellite overpass (0500). An
ozonesonde was released at 0430.