EUMETSAT & CLS, committed to better understanding weather systems

The strength and frequency of extreme weather events has grown due to climate change: floods, cyclones, storms, typhoons, but also droughts are more and more devastating.

So, it comes as no surprise that the theme chosen by the World Meteorological Organization (WMO) for this year’s World Meteorological day is Early Warning and Early Action.

To better understand our planet, obtaining reliable, high quality and highly accurate data is of vital importance.

CLS, a key partner to the international meteorological community, was chosen by EUMETSAT, the European operational satellite agency for monitoring weather, climate and the environment from space, to lead the Copernicus funded TRUSTED project which has developed high resolution sea surface temperature buoys that provide unprecedented observations for climate studies.

Through the TRUSTED project, science, technology, engineers from CLS and its partners and EUMETSAT project teams are all focused on serving of humankind and our planet. Together they are advancing science for the good of the humankind and the environment.

Today, Anne O’Carroll, Ocean Remote Sensing Scientist, at EUMETSAT and Marc Lucas, Senior Oceanographer & Project Manager at CLS talk to us about the project in more detail.

Marc: I’m a senior oceanographer and project manager at CLS. After 3 post Docs in France and Germany mostly focused on numerical modelling, I joined the CLS team dedicated to providing metocean services for Offshore Energy. This involved working on the use and interpretation of combined Satellite In Situ and numerical model data.

I then joined the environmental downstream application unit focusing on issues such as sargassum invasion and marine plastic.

I currently supervise innovative projects focusing on Earth Observation data and the acquisition of high quality in situ data for satellite applications.

Anne: I’m a Remote Sensing Scientist for Surface Temperature Radiometry, based at EUMETSAT in Darmstadt, Germany.

We generate and validate Sea Surface Temperature products from the Sea and Land Surface Temperature Radiometer (SLSTR) on board the EU Copernicus Sentinel-3 satellite.

I previously worked at the Met Office in the U.K. on satellite Sea Surface Temperature from ENVISAT-AATSR. I also chair the international science team of the Group for High Resolution Sea-Surface Temperature.

The aim is to provide so called ‘Fiducial Reference Measurements, FRM’ which are extremely high-quality calibrated measurements, with known and validated uncertainties, traceable to international SI measurement and calibration standards.

The first EU Copernicus Sentinel-3 satellite was launched in 2016, with the Sea and Land Surface Temperature Radiometer (SLSTR) on-board for collecting operational and climate quality Sea Surface Temperature observations. The design of the satellite instrument, including two views to the surface through the atmosphere, means it is the most accurate satellite instrument in-orbit for Sea-Surface Temperature.

It is used as reference measurements by the operational oceanography and weather forecasting community. Therefore, it is really important that we also use high quality in-situ surface temperatures to check and ensure the satellite data quality. This means we can better implement product improvements to the satellite data. This is important not only for day-to-day observations, but also long-term stability and understanding the uncertainties on the measurements, so they can be correctly used by forecasting and climate applications.

These satellite data are critical for climate monitoring and understanding. They are also important for operational near-real time weather forecasting and ocean modelling.

For example, this enables improved knowledge of storm strength, tracks and flooding. The buoy data also provides data in near real time, transmitted every hour, and also contributes to these climate and operational monitoring and modelling applications.

Marc: Drifting buoys are at the heart of all our weather predictions systems as they provide critical data, namely Sea Level pressure and Sea Surface temperature data that is assimilated into the numerical weather forecast models that our run every day. Furthermore, the in-situ data collected is also used to calibrate and validate the Satellite observation data ensuring that it is of the highest quality and hence that it enables scientist to investigate the variability in the climate system and the impact of human activities.

Anne: They provide important measurements in data sparse regions for weather and ocean forecasting. For example, these are the only observations of surface air pressure in the global ocean and so critical for the forecasting of storm tracks and intensity.

The satellite Sea-Surface Temperature scientists, belonging to an international science team, the Group for High Resolution Sea-Surface Temperature (GHRSST) started coordinating together with the drifting buoy community which is coordinated by the World Meteorological Office (WMO) Data Buoy Cooperation Panel (DBCP).

This coordination led to a new specification for drifting buoys (called HRSST-2) to be defined and requested by GHRSST, and today, most global drifting buoys, including those in the NOAA Global Drifter Programme, are of this quality. This is excellent for both the satellite data scientists using the buoy data for validation, but also for operational weather forecasting and oceanography. Here the drifting buoys were defined with total standard uncertainties better than 0.05K.

The TRUSTED project builds further on these developments to provide high quality measurements, with important steps towards SI traceability, providing Fiducial Reference Measurements (FRM). This means that sensors are calibrated or characterised in a laboratory and have known uncertainties. The conditions in the laboratory are also characterised, and therefore this means the uncertainties are consistent with other laboratory checks around Europe and the world through National Metrology Institute standards.

More coordination work is also being done on Quality Control procedures, and the archiving of metadata, and standardising them within the community. So important advances have been made due to the way that these global satellite and buoy scientists, engineers and communities work well together.

TRUSTED has also led to the development of a new drifting buoy by NKE instrumentation, the SVP-BRST which is unique in that it carries 2 types of temperature sensors, one standard and one high resolution.

Anne: We have just started the next phase of the project. We will be focusing on high-latitudes and other data sparse regions, particularly those that are more difficult in the satellite retrievals and need more validation and checks. We will also progress with the next steps for Fiducial Reference Measurements, focusing on the measurement uncertainties and defining uncertainty budgets; improving metadata and Quality Control in routine and offline data-streams; and coordinating with National Metrology Institutes for the approval of Fiducial Reference Measurement standards and post-deployment calibration and analysis if we are able to recover some buoys.

Marc: We are also starting to design a new sea-ice drifter which is crucial for the development of satellite products and algorithms of sea-ice surface temperature, to check that we are producing the highest quality data that we can.

The Arctic is at a critical stage of climate change, and it is of paramount importance that we extend and build on monitoring the temperature of this vulnerable region.

Thank you both for taking the time to talk about this amazing project. We look forward to speaking again soon for more details on phase 2!