Creating daily analyses of surface air temperature globally
T1.1: Data acquisition
T1.2: Homogenisation and quality control of daily in situ data
T1.3: Uncertainty estimation of input data: ensure compatibility between the uncertainty estimates
T1.4: Building understanding of relationships between different observation types: LST/LSAT (land); SST/MAT (ocean); IST/LSAT/MAT (ice); LSWT/LSAT (lake)
EUSTACE utilized a wealth of surface and air temperature measurements from both satellite and in situ measurement platforms including all surfaces i.e. land, lakes, ocean, sea ice, and ice sheets for building the global temperature record over 166 years at the end of the project. The data are from past and on-going projects i.e. ESA CCI, NACLIM, EUMETSAT SAF, Globtemperature, ICOADS, Globolakes etc., supplemented by a data rescue effort within WP3 of the project for the high latitudes. WP 1 integrates all available data and prepares them for the blending and infilling in WP 2. In particular, WP 1 delivered in situ data, test data and a prototype processor including documentation to WP 2. The integration of data included homogenisation of in situ records, assignment of uncertainties to each individual measurement, building of relationships between the many different data sources, measurement techniques and the surface air temperature.
Satellites measure thermal emission from the surface. Ship records may include surface air temperature and in the past different methods have been used for measuring the temperature of the surface water, i.e. wooden and canvas buckets dragged on to the deck for temperature measurement, hull temperature, engine cooling water intake temperature. Sea ice buoys measuring temperature above or within the snow cover. Empirical relations may not suffice and physical models will be developed relating the diverse datasets to the surface air temperature. WP 1 gave input to WP 2, but the work on uncertainties resulted in a unique dataset including uncertainties which can also be valuable for external collaborators working on e.g. ocean or atmospheric reanalysis.
(links to the publicly available reports can be found under EUSTACE final results)