Marine Climatology from Research Vessels

1. Marine Climatology from Research Vessels 1Center for Ocean-Atmospheric Prediction Studies, FSU, Tallahassee, FL USA 2NOAA/OAR/Earth System Research Laboratory, Boulder, CO, USA 3National Center for Atmospheric Research, Boulder, CO, USA Shawn R. Smith1, Scott D. Woodruff2, and Steve Worley3 MARCDAT-II, Exeter, UK Funding provided by NOAA Office of Climate Observation and the NOAA Environmental Services Data and Information Management program.

2. Overview • For decades, research vessels (RVs) have been collecting a wide array of atmospheric and ocean measurements over the global oceans. • E.g., Russian RV data (1936-2000) provided as auxiliary data in ICOADS • Recent technological advances have allowed for transmission of high volumes of marine climate observations from RVs. • Presently, RV marine reports make up only a small fraction of records in ICOADS • Bridge reports not transmitted routinely • Stewardship of science data is fragmented • Typically held by chief scientists, operating institutions, or national archives • No clear path exist to provide data to ICOADS Courtesy NOAA OCO

3. Sources of data from RVs • All vessels equipped with meteorological sensors to aid navigation • These sensors typically used for reports by bridge crew • Scientific instrument systems (e.g., IMET, NOAA SCS, Multimet) • Typically the bridge and scientific instrument systems are independent. • Insufficient metadata to determine whether marine reports in ICOADS are from bridge or science observing systems Courtesy NOAA OCO

4. Advantages of RV climate data • Operate in all parts of the ocean, including regions of extreme conditions (e.g., polar latitudes, high wind regimes). • Science systems provide • High sampling rates • Research data quality (on par with delayed mooring data) • Instruments monitored by onboard technicians • Additional measurements not provided in bridge reports (radiation, direct fluxes, etc.) • RVs provide ideal platform to develop new sensors (CO2, infrared SST) Courtesy NOAA OCO

5. RV data reaching ICOADS • Extracting RV reports from ICOADS for 1997 reveals • Wide coverage of ocean • Low observational density • ~80000 individual marine reports from 154 vessels • Highest densities around Japan and Europe • 60% of reports provided by only 12 vessels • 49% of reports from 21 vessels participating in WOCE • Polarstern alone provides ~10% of obs. Courtesy NOAA OCO

6. Problem of locating RVs • Creating plots of research vessel coverage problematic • Most common method is to search for vessel call sign • Locating call signs difficult, typically from Pub 47 or vessel operators • Change frequently • Recent addition of “kind of vessel” metadata to ICOADS helps • Only as complete as Pub 47 it is based upon • Result omits many well known vessels (e.g., Meteor) • Research vessel tracking system needed • Surprisingly hard just to find out when and where RVs are making measurements • Web resources (e.g., www.researchvessels.org) are incomplete and under-funded • J. Gould and others have proposed that JCOMM-OPS take on responsibility Courtesy NOAA OCO

7. Providing FSU data to ICOADS • FSU RV data center is working to make historical and near-real time RV data available to ICOADS. • Historical data: • Current FSU holdings contain science data from WOCE and other select cruises (1988-Present) • Additional science and bridge data from operating institutions and national archives could be acquired with additional funding • Near-real time data: • obtained through the Shipboard Automated Meteorological and Oceanographic System (SAMOS) initiative • Science data provided to FSU on daily basis • Pilot project underway with Knorr and Atlantis • Additional information in poster presentation • All FSU data have undergone scientific data quality evaluation Courtesy NOAA OCO

8. Providing FSU data to ICOADS • Most FSU marine reports must be temporally sub-sampled for ICOADS • Similar methods are currently employed by ICOADS for moored buoys • Bulk of RV records are at one- minute intervals • Desire to retain diurnal cycle • FSU producing 10-min. averages leading up to top of hour • Developing hourly sub-samples in IMMA format for ICOADS • Include average and measure of uncertainty for each value • Additional parameters beyond core ICOADS records • Format may be useful for archiving future RV and mooring reports Courtesy NOAA OCO

9. Comparing FSU to ICOADS • Number of marine reports for 22 WOCE cruises of the RV Meteor (1990 - 1997) • Reports counted over length of cruise known to FSU • 12229 science data reports from FSU • 6958 reports available in ICOADS Courtesy NOAA OCO

10. Comparing FSU to ICOADS • Number of marine reports for 26 WOCE cruises of the RV Knorr (1990 - 1997) • 18071 science data reports from FSU • 324 reports available in ICOADS • A substantial increase in records can be achieved by adding science observations to ICOADS Courtesy NOAA OCO

11. Comparing FSU to ICOADS • For the WOCE cruises of the Meteor and the Knorr, how well do reports found in ICOADS compare to sub-sampled data from FSU archive? • Note: comparisons do not take into account differing sensor depths (some metadata lacking) • ICOADS for Knorr are colder than FSU reports. Courtesy NOAA OCO

12. Comparing FSU to ICOADS • Air temperatures show similar cold bias in ICOADS reports for the Knorr (or warm bias for the FSU data). • Lower number of matches may skew results for Knorr • Meteor comparison very good without adjusting for differing thermometer heights (ICOADS: 11 m, FSU 28 m) Courtesy NOAA OCO

13. Comparing FSU to ICOADS • Biases are low for wind speed on both vessels. • Meteor shows more scatter at higher wind speeds (both measurements taken at 40 m height) • Anemometer height for Knorr not available for ICOADS reports Courtesy NOAA OCO

14. Questions to consider • Should data averaged from high-sampling rate science systems (SAMOS, moorings) be retained as independent in ICOADS (not replace existing GTS/DM reports)? • Can an effort be launched to request participation by RVs in routine VOS reporting? • Many operators seem unaware of VOS reporting • Can RV operators provide metadata regarding: • Whether and how they provide routine marine weather reports? • Whether these reports are derived from science instrument system? • Note: some effort to improve metadata can be taken up by the SAMOS initiative • What is the volume of RV science and bridge observations held by operating institutions and national archives? Courtesy NOAA OCO

15. Final Thoughts • Research vessels are presently an underutilized resource for marine climate observations • Efforts should be made to mine historical RV observations from operating institution and national archives • This effort could support ongoing plans for atmospheric and oceanic reanalyses • An expansion of near-real time transmission of science data from RVs should be encouraged • Resources and the need to improve ship-to-shore communications are primary limitations • SAMOS initiative seeks to recruit additional vessels in 2006 • 1st Joint GOSUD/SAMOS Workshop scheduled for May 2006 (interested parties should contact smith@coaps.fsu.edu) Courtesy NOAA OCO