ACE-1 R/V DISCOVERER STATUS FORM

DATE/TIME: (95120519)

PREPARED BY: Tim Bates

• LOCATION PRESENT: LATITUDE: 41 21.8S LONGITUDE: 138 6.7E
• LOCATION -6 HOURS: LATITUDE: 41 23.6S LONGITUDE: 138 9.8E
• LOCATION -12 HOURS: LATITUDE: 41 25.5S LONGITUDE: 138 3.5E
• LOCATION -18 HOURS: LATITUDE: 41 17.8S LONGITUDE: 139 8.4E

PRESENT WEATHER:

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

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• Sea Surface Measurements:

  1. DMS: Current concentration 1-2nM
  2. DMSP/DMSO:
  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 approx 3 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:
  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 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.
  7. Nitrogen oxides and PAN: NO rose to ~20ppt local noon. NO2 at 15-18ppt throughout day. NOy ~400 ppt. PAN not functional.
  8. Radon:
  9. CO2:
  10. Solar Radiation:
  11. Aerosol physics: At 0740GMT (C130 overpass) the size distribution showed 3 modes at 22-25, 40 and 130nm. UFCN = 600-700 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.

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• Routine Weather Observations: Going well.
• Satellite Observations: None
• CTD Cast Schedule: One cast scheduled for 2330.

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• SPECIAL PLANNED OBSERVATIONS (NEXT 24-HOURS):

  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.

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• 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.
• OTHER COMMENTS: