During the early spring of this year, over 130 participants were welcomed to the 12th session of the Ship Observations Team (SOT-12) in Melbourne, Australia and virtually – co-sponsored by the World Meteorological Organization and the Bureau of Meteorology, Australia.
Helen Beggs (BoM) and Werenfrid Wimmer (SOTON) represented GHRSST at the meeting, shedding light on GHRSST and its use of Ship SST. The session sparked a great deal of genuine interest among the attendees for the work of GHRSST and Ships4SST and led to insightful feedback about the various in-situ SST data streams. Let us take you through these feedback and achievements that emerged from this event.
GHRSST’s recommendation put forward in our dedicated session found success with its acceptance for integration into the SOT-12 meeting list of actions/recommendations. We left our mark embodied in the following statement “It is requested that meteorological and oceanographic agencies focus on improving the total standard uncertainty in measured ship SSTdepth supplied to the GTS to be less than 0.2 K, to improve the quality of SST analyses and climate data records.”
GHRSST Anchors the Ship Observations Team
TRUSTED buoys comply with the requirement of calibration total standard uncertainty < 0.05 K, and most global drifting buoys (coordinated by the DBCP and GDP) are also now of HRSST-2 standard. The previous standard (not HRSST-1 or HRSST-2) drifting buoys reported SST observations to 0.1 K and 0.01-degree latitude and longitude resolution. The HRSST-1 and HRSST-2 specification improved position and accuracy reporting to 0.01 degrees (HRSST-1) and SST uncertainty to 0.05K with reporting to 0.01K measuring hourly, with reporting time within +/-5minutes (HRSST-2).
VOS Ship SST
Dr. Elizabeth Kent noted, “SSTs from engine intakes have improved in recent years and now approach the accuracy of hull-temperature sensors”. In a broader conversation, the discourse revolved around the challenges of enhancing the accuracy of SST observations from Voluntary Observing Ships (VOS), since Meteorological Agencies are faced with limitations in equipping most VOS with their own instruments. Interestingly, this is where the participation of racing yachts and even recreational yachts became a valuable asset with their eagerness to be instrumented and ability to yield good public data. The discussion was vibrant around this point, punctuated by examples from the attendees.
SOT Instruments and Standards Task Team, under the lead of Jean-Baptise Cohuet from Meteo-France, is actively exploring more economic alternatives for hull-temperature sensors, aiming for options costing less than 100 Euros. However, this pursuit is not without its hurdles, as they encounter obstacles related to insulation from the surrounding atmospheric conditions.
In the conversation, Tamaryn Morris shared, “I believe the Saildrone community is advocating to become an emerging ocean observing network under the OCG (Ocean Carbon and Biogeochemistry)”, signifying a potential expansion of ocean exploration efforts. Elizabeth Kent introduced Argo’s contribution by highlighting their archive of observations, extending to the ocean’s surface. For those interested, the repository of near-surface profiles can be accessed at: https://argo.ucsd.edu/data/auxiliary-directory/.
In-situ Data SST density
John/Hua-Min Zhang brought the following article into discussion on the topic of in-situ data SST density, “A systematic study on in-situ data density on correcting satellite SST biases” which can be found here: https://journals.ametsoc.org/view/journals/atot/23/1/jtech1828_1.xml
A noteworthy contribution came from virtual attendee, Shawn Smith (Florida State University and SAMOS Project Lead). Shawn brought forth the point that there be an intercomparison of less expensive shipborne radiometric sensors (such as Heitronics) with other radiometric sensors. Shawn’s perspective highlighted the need for accessible solutions in the area of “skin” sea temperature measurements. He acknowledged the cost of currently available research-grade radiometric SST sensor and questioned if there were more affordable commercial off-the-shelf IR radiometric SST sensors like Apogee and Heitronics could yield impactful results when deployed more widely.
Collaborative efforts with the Ships4SST team and participation in the upcoming GHRSST24 International SST Users’ Symposium and GHRSST Science Team Meeting were suggested as avenues for further exploration and collaboration.
Ocean Racing Yachts as SOOPs
Amidst the final discussions, Ocean Racing Yachts were pinpointed as a key contribution for the Ship of Opportunity Program. These yachts equipped with water inlet temperature sensors present an invaluable source for observations. The observations collected by these vessels will also be available soon on the Global Telecommunication System (GTS).