Marine Climatology from Research VesselsMarine Climatology from Research Vessels

Shawn R. Smith1, Scott D. Woodruff2, and Steve Worley3

1Center for Ocean-Atmospheric Prediction Studies, FSU, Tallahassee, FL USA2NOAA/OAR/Earth System Research Laboratory, Boulder, CO, USA

3National Center for Atmospheric Research, Boulder, CO, USA

MARCDAT-II, Exeter, UK

Funding provided by NOAA Office of Climate Observation and the NOAA Environmental Services Data and Information Management program.

OverviewOverview 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

Sources of data from RVsSources 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)

Courtesy NOAA OCO

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

Advantages of RV climate dataAdvantages 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

RV data reaching ICOADSRV data reaching ICOADS Extracting RV reports from ICOADS for 1997 reveals

– Wide coverage of ocean– Low observational density

Courtesy NOAA OCO

– ~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.

Problem of locating RVsProblem 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

Providing FSU data to ICOADSProviding 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

Courtesy NOAA OCO

All FSU data have undergone scientific data quality evaluation

Providing FSU data to ICOADSProviding 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

Courtesy NOAA OCO

– 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

Comparing FSU to ICOADSComparing FSU to ICOADS Number of marine reports for 22 WOCE

cruises of the RV Meteor (1990 - 1997)

Courtesy NOAA OCO

Reports counted over length of cruise known to FSU

12229 science data reports from FSU

6958 reports available in ICOADS

Comparing FSU to ICOADSComparing FSU to ICOADS Number of marine reports for 26 WOCE

cruises of the RV Knorr (1990 - 1997)

Courtesy NOAA OCO

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

Comparing FSU to ICOADSComparing 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

Comparing FSU to ICOADSComparing 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

Comparing FSU to ICOADSComparing 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

Questions to considerQuestions 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

Final ThoughtsFinal 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