R/V FRANKLIN - HIGH RESOLUTION SURFACE METEOROLOGICAL AND FLUX DATA

F. Bradley (CSIRO, Australia)

Announced availability: 1 November 1995

Data Access

R/V Franklin high-resolution surface met data are available from the Florida State University Center for Ocean-Atmospheric Prediction Studies (COAPS) (http://www.coaps.fsu.edu/coare/). Data are also archived and distributed by the Pennsylvania State University Department of Meteorology Field Project Data Archive (http://wwwarc.essc.psu.edu).

After June 1996, data will also be available upon request from NOAA's National Climatic Data Center (NCDC) in Asheville, NC (http://www.ncdc.noaa.gov) and from the National Center for Atmospheric Research (NCAR) in Boulder, CO (http://dss.ucar.edu/pub/toga_coare/).

Background

Surface meteorological data were obtained during the two Franklin COARE cruises out of Townsville; Fr 9/92, 18 November 1992 - 17 December 1992 and Fr 1/93, 7 January 1993 - 9 February 1993. Each cruise was interrupted by a port call in Rabaul (30 November - 1 December 1992 and 21 - 22 January 1993, respectively).

The meteorological sensors were high-resolution instruments installed specially for COARE on the foremast at 11.3 meters above sea level. The Middleton net radiometer was mounted on a boom 12 meters forward of the bow at 6.5 meters above sea level. Eppley PSP and PIR radiometers were mounted high on the ship's main mast. An infrared radiometer for SST was installed above the wheelhouse pointed at 45 degrees to the sea surface. Bulk sea temperature and salinity were measured by the ship's thermosalinograph taking water from 2.4 meters below the surface.

Data File Information

Number of data files: 5 (lkbdat1e.fsu, lkbdat2e.fsu, lkbdat3e.fsu, lkbdat4e.fsu, lkbdat5e.fsu). These files correspond to the separate deployments of the Franklin's Lagrangian drifting buoy, but contain data preceding and following the deployments as long as the ship was within the IFA.
Data format: ASCII
Data volume: 675 KB

File Header

Each data file contains header information which is mostly self-explanatory.

Time (UTC)
Latitude
Longitude
air temperature T air (deg C)
specific humidity Q air (g/kg)
thermosalinograph T sea (deg C)
thermosalinograph Q sea (g/kg)
Salinity (psu)
Ship speed (m/s)
Ship heading (deg)
Wind speed (m/s)
Wind direction (deg)
Radiation, shortwave (W/m2)
Radiation, longwave (W/m2)
Radiation, net (W/m2)
SST (deg C)
Rainfall (mm)
Skin Temp (deg C)
H (W/m2)
E (W/m2)
Webb (W/m2)
tau (N/m2)

Some notes follow:

  1. Date, Time are UTC and mark the beginning of the 15-minute averaging period.
  2. Lat, Long are also position at the beginning of the 15 minutes. NOTE: At the beginning of cruise 9/92, the GMS receiver was unstable, and produced serious (up to 30 km) jumps. Position data in file 1 is not reliable.
  3. Air temperature and specific humidity are from a Bradley-design aspirated psychrometer.
  4. Ts and Qs are ship's thermosalinograph data from the CSIRO Division of Oceanography archive.
  5. True wind speed is corrected for flow distortion over the ship (-3%) and increased by a fixed 0.2 m/s following intercomparisons with Moana Wave.
  6. Rshort includes the increase of 0.2% implied by the Canberra intercomparison of pyranometers using the Wecoma instrument as reference.
  7. Rlong (downwelling) - the PIR has been corrected for dome heating using the method of Alados-Arboledas et al. (1988), verified against Moana Wave and the Cessna.
  8. The net radiometer has not been corrected for possible effects of radiation from the ship. Estimates based on solid angles viewed by the two hemispheres suggest that these are insignificant.
  9. SST is from the IR radiometer, adjusted for emissivity and sky reflection with a fixed correction of 0.4C.
  10. Rainfall is from an optical rain gauge (ORG) mounted on the foremast.
  11. The last 5 columns are output from COARE bulk algorithm version 2.5a, see Fairall et al. (1995) and Bradley and Weller (1995). The modeled skin temperature is represented by sst_out; Webb is the correction to latent heat flux for density fluctuations.
Data Example 
Franklin COARE  Time                       T air    Q air    T sea  Q sea
SalinityShip spd.Ship HeadWind spd.  Wind    R short  R long    R net     SST
Rainfall Skin T      H        E      Webb      tau
Cruise1 Drift1   UTC       Lat.    Long.    øC      g/kg      øC      g/Kg
psu      m/s     Deg.      m/s      Direct  W/m2     W/m2     W/m2      øC
mm       øC      W/m2     W/m2     W/m2     N/m2
================================================================================
================================================================================
====================================================
    22-Nov-92    16:00  -3.7808 154.9482    28.19    19.38    29.22    24.90
    34.15     4.98     30.2     1.50    347.3      0.0    418.3    -51.9    29.28
    0.00    28.92     1.64    34.54     1.34   0.0037
    22-Nov-92    16:15  -3.7487 154.9692    28.15    19.50    29.23    24.91
    34.16     4.16     31.0     1.11      3.1      0.0    413.0    -57.3    29.25
    0.00    28.92     1.47    28.49     1.13   0.0023
    22-Nov-92    16:30  -3.7212 154.9863    28.14    19.54    29.16    24.82
    34.18     4.02     81.8     1.67    348.2      0.0    414.5    -55.6    29.38
    0.00    28.86     1.72    35.06     1.38   0.0044
For more information, please contact:

Frank Bradley
CSIRO Centre for Environmental Mechanics
PO Box 821
Canberra, ACT 2601
Australia

e-mail: bradley@enmech.csiro.au
Phone: (61) 62-46-5575
FAX: (61) 62-46-5560

General reports are available from:

ORV Operations Manager
CSIRO, Division of Oceanography
GPO Box 1538
Hobart, Tasmania 7001
Australia

References

Alados-Arboledas, L., J. Vida and J.I. Jiminez, 1988: Effects of solar radiation on the performance of pyrgeometers with silicon domes. J. Atmos. Ocean. Tech., 5, 666-670.

Bradley, E.F., and R.A. Weller, 1995: Report of the Third Workshop of the TOGA COARE Air-Sea Interaction (Flux) Working Group, Honolulu. TCIPO/UCAR. Available from UCAR Communications, PO Box 3000, Boulder, CO 80307 USA.

Fairall, C. W., E. F. Bradley, D. P. Rogers, J. B. Edson and G. S. Young, 1995: Bulk parameterization of air-sea fluxes for COARE. JGR (in press).

Webb, E. K., G. I. Pearman and R. Leuning, 1980: Correction of flux measurements for density effects due to heat and water vapour transport. Q. J. R. Met. Soc., 106, 85-100.

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