ACE-1 R/V DISCOVERER STATUS FORM

DATE/TIME: (95120619)

PREPARED BY: Tim Bates

• LOCATION PRESENT: LATITUDE: 45 00.35S LONGITUDE: 139 07.5E
• LOCATION -6 HOURS: LATITUDE: 44 03.4S LONGITUDE: 137 49.1E
• LOCATION -12 HOURS: LATITUDE: 42 32.5S LONGITUDE: 137 43.7E
• LOCATION -18 HOURS: LATITUDE: 41 24.3S LONGITUDE: 138 25.1E

PRESENT WEATHER:

Winds 295 degrees at 7 m/s, pressure 1009.3 and steady, clear skies, dry bulb 10.5C, wet bulb 8.2C, SST 11.1

SEA STATE:

Southwesterly 2-3 M swell, wind waves from 295 at <1 M

INSTRUMENTS/SYSTEMS STATUS

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• Sea Surface Measurements:

  1. DMS: Current concentration 1-2nM
  2. DMSP/DMSO: Dissolved DMSPconcentrations are about 5 nM, particulate DMSP about 15 nM. Incubation from 12/03 showed 15 hour turnover time for DMSP.
  3. NH4+NH3/pH:
  4. CO: Surface seawater concentrations have a diurnal cycle with a late night minimum of 1 and and an afternoon maximum of 2 nM.
  5. NMHC: Low ppb levels of butane. sub ppb levels of pentane in equilibrated air samples.
  6. CO2:
  7. Nitrate/Chlorophyll: Nitrate concentrations are approximately 6 uM. Seawater fluorescence is being recorded continuously. Surface seawater samples are being collected every 4 hours for discrete chlorophyll analysis.

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• Atmospheric Measurements:

  1. DMS: Atmospheric DMS concentrations ranged from 40-200 ppt in high pressure region sampled yesterday.
  2. SO2: Current concentrations are 10-20 ppt.
  3. NH3: Using oxalic acid coated filters. Concentrations measured with oxalic acid coated filters range from 3 to 10 pptv.
  4. CO: Concentrations near 60ppb.
  5. NMHC: ppt levels of a few hydrocarbons. very clean air.
  6. O3: Surface concentrations range from 16 to 20 ppb.
  7. Nitrogen oxides and PAN: NO, NO2, NOy had maxima of ~500, ~20, and ~12 ppt resp between 2100-2200. PAN not functional.
  8. Radon:
  9. CO2:
  10. Solar Radiation:
  11. Aerosol physics: At 9:00GMT - prefrontal zone , Ntot=120pp/cc, 2 modes - 40 and 160nm. At 1800 (45S 139E) - postfrontal aerosol, 3 modes - 20 nm, 35nm, 130 nm. Ntot = 500 pp/cc.
  12. 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.
  13. Aerosol optical properties: Absorption coefficient very low.
  14. TDMA-RH:
  15. TDMA-Thermal:

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• ISS Status and Schedule:

  ISS status report for ACE-1 for today is here

  System operational with 8 sondes/day through 1100 GMT. Now returning to 4 sondes/day until Lagrangian start.

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• Routine Weather Observations: Going well.
• Satellite Observations: None
• CTD Cast Schedule: None.

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• SPECIAL PLANNED OBSERVATIONS (NEXT 24-HOURS):

  Currently in post-frontal clear air running downwind after front. At present course and speed we will reach 45S, 145E at 1000 GMT. Underway sampling will continue.

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• PAST 24-HR OPERATIONS SUMMARY: Discoverer headed southsouthwest yesterday keeping the air 60 degrees from the bow for air sampling.
• OTHER COMMENTS: 1. We did not receive the operations summary yesterday. 2. We are concerned about starting the Lagrangian further north than 45 S because: a. Seawater DMS concentrations will be more variable in the coastal region b. There is a stronger possibility of continental contamination. c. There is a stronger possibility of contamination from fishing boats. 3. Our current plan will be to sample the airmass at the start of the Lagrangian for as long as we are able to get clean marine air. After that we will turn downwind to survey the seawater DMS and NH3 concentrations along the balloon track.