Dr. David M. Legler, Co-PI
DAC Data Holdings, Data Collection, and Data Products
We reviewed surface meteorology data records at the WOCE Data Information Unit (DIU) and discovered the cruise plans files were inadequate to document the details of how/what surface meteorology data were recorded or planned during WOCE cruises. Therefore, we composed an initial contact survey and mailed it to over 130 chief scientists worldwide representing over 400 WOCE cruise segments for the period 1987-1995. Recipients were requested to provide 1) a data contact and 2) a brief profile of the surface meteorology data recorded for each WOCE cruise. The returned information (nearly half of the survey recipients returned their survey to date) overwhelmingly indicated that there are much more surface meteorology data available than previously thought. With this new information in hand, we have composed a master table of WOCE surface meteorology data to collect and process. This table appears on our web page.
Our data collection efforts to date are reflected in Table 1. We have had good success obtaining data when we determine the data holder or data contact. Significant amounts of high resolution (continuous means each 1-5 minutes) data (e.g. IMET) from the Knorr, Oceanus, and Thompson, as well as from British, Australian, German, and South African ships have already been acquired as well.
We are still working with some institutions with regards to data transfer. Data from the German oceanographic data center (e.g. Meteor) have been difficult to transfer due to incompatible tape formats and lack of network access at the center. Archived IMET data from the Melville (Scripps) have now been promised to us, but talks continue on providing regular updates. We are also continuing our discussions with R/V home institutions and funding agencies to insure the value of these data are known and the instruments are deployed regularly.
Table 1. Data collection status at FSU DAC for surface meteorology (January, 1996).
|Year(s) of WOCE Cruises||Number of WOCE cruise segments recording surface meteorology data||Data source is known (Number of segments)||Data at FSU DAC (Number of segments)||Known high resolution (15 minute means or better) data sets (Number of segments)|
The WOCE DAC Handbook of Quality Control Procedures and Methods reference document for our quality control procedures is in final form with publication set for early spring 1996. Copies will be distributed widely.
Some data have been processed or in the process of undergoing final checks. The first data sets released were from the Chilean R/V Vidal Gormaz. Data are available in a variety of formats. Our newly available web pages allow the browser to view the cruise track of any cruise for which we have data, download various data sets, and view reports. Additionally, the SAC portion of the web page allows one to view monthly mean surface wind maps. The primary product of the DAC is a set of data files containing the quality-controlled data as well as the most important metadata (e.g. instrument height/depth). Quality-control reports for each data set accompany the file.
We have worked with ship technicians from Woods Hole in suggesting improvements to the IMET recording system to facilitate better and more accurate IMET data. Additionally we have developed a series of processing algorithms for determining rain rates from the IMET precip gauges. We noticed there were obvious problems with Knorr IMET winds and wind-calculations, obtained further information and data files and have attained reasonable estimates of the surface winds for limited periods. Some of these data were used in a pilot study to validate ERS-1 surface winds.
We have contacted NCAR regarding the inclusion of IMET-type and other research vessel data into the COADS project. They are receptive to the idea and will work with us on this. Thus the impact of WOCE-era surface meteorology data will be more permanent and globally beneficial.
Review of SAC Activities
Production of monthly mean fields of pseudo-stress for the Indian ocean and tropical Pacific continues and are regularly used in ENSO prediction schemes. The Indian ocean wind fields in particular have been used in support of WOCE activities in the Indian ocean. An initial product of monthly mean values of most surface met variables (e.g. winds, temperatures, humidity) and turbulent fluxes (wind stress, sensible and latent heat) for the Indian ocean for the period 1960-1989 were released two years ago. In 1995, an update of this data product for the period 1990-1992 was produced and is now available. This is the type of product which we aim to release in order to fulfill part of our objectives.We are planning to produce similar data sets for other ocean basins in the coming years. Additionally, we are continually improving our analysis techniques. A new improvement to our objective analysis scheme is in the testing phases. It involves the objective tuning of the constraint weights.
Priorities for 1996
We anticipate significant effort will be directed towards collecting the remaining surface meteorology data from WOCE R/V's, and processing the data. We expect to have substantial quantities of quality-controlled data ready for distribution in the fall of 1996. The FSU WOCE DAC Handbook of Quality Control Procedures and Methods will be distributed in early Spring 1996. Additionally, we anticipate producing papers on our data set processing, the Pacific wind analyses, the new Indian ocean flux fields, and variational scheme improvements. Towards the end of the year, we will be preparing to focus on the Pacific for additional flux field products and analysis. Our initial three-year funding ends Feb 97. We are hopeful a two-year extension can be obtained to focus (primarily) on SAC-related analyses.