Value of Quality Evaluated, High-temporal Resolution Marine Meteorology Observations

Observations of the near-surface atmosphere over the global oceans have evolved rapidly in the past decade. New satellite sensors provide wind and temperature measurements, while models and reanalyses provide global atmospheric data fields and air-sea flux estimations. Application of these new near-surface datasets requires a knowledge of their accuracy and biases. Marine meteorological observations collected using automated weather systems (AWS) provide a good source of truth to assess the uncertainties in these new products.

The World Ocean Circulation Experiment provided an opportunity to evaluate the quality and usefulness of AWS observations. Since 1994, a surface meteorology data center at the Florida State University has been collecting, evaluating, and archiving AWS observations from select international research vessels. The AWS data typically include wind, temperature, pressure, moisture, and radiation data recorded at one to ten minute intervals. Data quality evaluation has revealed problems with marine AWS, resulting in modifications to some AWS. Overall the quality of AWS marine observations is very good and the data have proven useful in validation studies of satellite sensors and global reanalyses.

Examples from ongoing research show the value of marine AWS data. The research vessel data identify serious overestimations in turbulent fluxes over the global oceans by the NCEP/NCAR reanalysis products. Reanalysis surface sensible and latent heat fluxes are on average 10-30 Wm-2 greater than those calculated from the research vessel AWS data. In addition, AWS observations from research vessels are valuable for the validation of wind observations from the spaceborne NSCAT and SeaWinds scatterometers. Wind directions from research vessels are superior to directions from buoys when evaluating scatterometer winds. The continued collection of AWS observations on research vessels and the future expansion of automated systems to the merchant fleet are essential to assess future satellite sensors and reanalyses.