Satellite Sea Surface Temperature – current and future observations at ESA C Donlon ESA/ESTEC, Noordwijk, the Netherlands Observations and analysis of SST and SI for NWP and Climate ECMWF, Reading UK, 22-25 January 2018 ESA UNCLASSIFIED - For Official Use Overview • Satellite SST measurements • SST Requirements • ESA Thermal infrared satellite activities • ESA Microwave radiometry activities • Fiducial Reference Measurements • Future outlook (O. Embury) ESA UNCLASSIFIED - For Official Use C Donlon | 23/01/2018 | Slide 2 ESA UNCLASSIFIED - For Official Use C Donlon | 23/01/2018 | Slide 3 Early SST measurements Franklin – Folker Chart of the Gulf Stream (1768) compiled AVHRR satellite composite from ships logs over many years image of a similar area ESA UNCLASSIFIED - For Official Use C Donlon | 23/01/2018 | Slide 4 Satellite instruments generally measure 2D surface expressions of 4D structures ESA UNCLASSIFIED - For Official Use C Donlon | 23/01/2018 | Slide 5 Interpretation framework for SST Donlon et al, BMS, 2007, http://dx.doi.org/10.1175/BAMS-88-8-1197 SSTskin – SST10m (K) SSTskin – SST10m (K) -0.3 -0.2 -0.1 0.0 0 0.5 1.0 1.5 2.0 2.5 3.0 10m 10m 1 mm 1 mm Tskin Tdiurnal ~0 - 0.5K ~0 – 4.0K 1 m 1 m SSTint SSTskin Depth Depth SSTsubskin Model SSTdepth 10 m 10 m SSTfnd (a) Night time situation, light wind (b) Day time situation, strong solar radiation and light winds ESA UNCLASSIFIED - For Official Use C Donlon | 23/01/2018 | Slide 6 Can’t Measurement of SST measure (T <1s) SSTskin – SST10m (K) 0 0.5 1.0 1.5 2.0 2.5 3.0 10m Infrared sensors (T ~10s) 1 mm Microwave Sensors (T ~10+ s) 1 m Contact thermometers Ships/Buoys (T ~minutes) SSTint SSTskin Depth SSTsubskin SSTdepth 10 m Contact thermometers Ships/Buoys (T ~hours) SSTfnd Day time situation, strong solar radiation and light winds ESA UNCLASSIFIED - For Official Use C Donlon | 23/01/2018 | Slide 7 Validating the SST framework (Peter Minnett, RSMAS) ESA UNCLASSIFIED - For Official Use C Donlon | 23/01/2018 | Slide 8 Diurnal SST stratification (variability) Arabian Sea WHOI Mooring Data (From the work of A. Stuart-Menteth) - Spring 1995 (1mm data estimated using Fairall et al. (1996)) C) o SSTfnd Temperature ( Temperature Temperatures at all depths collapse to the same value before local sunrise Year Day ESA UNCLASSIFIED - For Official Use C Donlon | 23/01/2018 | Slide 9 Time evolution of near-surface thermal gradients at the same location SkinDeEP profiles on 12 October 1999. Off Baja California, R/V Melville., From Ward, B. and P. J. Minnett, 2001 ESA UNCLASSIFIED - For Official Use C Donlon | 23/01/2018 | Slide 10 Diurnal SST signatures: Atlantic (MSG SEVIRI) (ESA Medspiration) Basin wide deviation of 0.08 K each day ESA UNCLASSIFIED - For Official Use C Donlon | 23/01/2018 | Slide 11 Arctic DV: Northern Novaya Zemlya ESA UNCLASSIFIED - For Official Use C Donlon | 23/01/2018 | Slide 12 Regional SST every 10 minutes Himawari-8 SST 2015-04-26 Hourly composite data Yukio Kurihara (JAXA) ESA UNCLASSIFIED - For Official Use C Donlon | 23/01/2018 | Slide 13 DV “Structure” masking: 15 to 25 August 2012 °C • SMOS reveals SSS structure of the Gulf Stream with an unprecedented Space and time resolution • Cold/fresh Core rings are better captured by SSS observations than by SST during summer. • Implications for assimilation and interpretation ESA UNCLASSIFIED - For Official Use C Donlon | 23/01/2018 | Slide 14 ESA UNCLASSIFIED - For Official Use C Donlon | 23/01/2018 | Slide 15 Use of SST to constrain Altimeter derived ocean surface currents (M-H Rio, L. Gautier) Propagation of the « good » altimeter velocities along the SST streamlines assuming geostrophy Altimeter geostorphic velocities Corrected velocities Streamlines from AVISO (left), current corrected by ODL (right) and plotted over regional ODYSSEA SST and Sentinel 1 SAR image on 2015/04/23. International Context ESA NASA NOAA EUMETSAT JAXA CMA NSOAS … SST aspects Coordinated by CEOS SST- VC and GHRSST ESA UNCLASSIFIED - For Official Use C Donlon | 23/01/2018 | Slide 17 Transitioned from ESA R&D to GHRSST CEOSto operations SST-VC at EUMETSAT Interaction CEOS SST GHRSST Virtual GHRSST Project CEOS-SIT Constellati Advisory on Office (SST-VC) Council International GHRSST Science Team Analysis and User, Data and Estimation and Climate Data Intercompariso Services Validation Records n Technical Technical Technical Technical Advisory Advisory Advisory Advisory Group Group Group Group (UDS-TAG) (EV-TAG) (CDR-TAG) (AI-TAG) User requirements for high resolution sea surface temperature data products and services from operational, scientific and climate communities ESA UNCLASSIFIED - For Official Use C Donlon | 23/01/2018 | Slide 18 GHSST International Science Team G-VI, Exeter, 2005 G-XII, Edinburgh, 2011 - Locations of GHRSST annual G-XVII, Washington DC, 2016 meetings - Next meeting in Cape Town G-1, Ispra, 2000 G-X, Santa Rosa, 2009 G-II, Tokyo, 2002 G-IV, Pasadena, 2003 G-XIII, Tokyo, 2012 G-VII, Boulder, 2006 G-XVIII, Qingdao, 5-9 June 2017 G-XIV, Woods Hole, 2013 G-III, Frascati, 2002 G-IX, Perros Guirrec, 2008 G-V, Townsville, 2004 G-XI, Lima, 2010 G-VIII, Melbourne, 2007 G-XV, Cape Town, 2014 G-XVI, Noordwijk, 2015 G-IXX EUMETSAT, 4-8 June 2018 Science Team Meetings are open to all ESA UNCLASSIFIED - For Official Use C Donlon | 23/01/2018 | Slide 19 Many satellite data sets…in a common format Ancillary information in L2P products: dynamic flags ESA UNCLASSIFIED - For Official Use C Donlon | 23/01/2018 | Slide 20 Multi-Product L4 SST Ensemble: Medspiration Operations http://ghrsst- pp.metoffice.com/pages/latest_analysis/sst_monitor/weekly/ gbl/index.html ESA UNCLASSIFIED - For Official Use C Donlon | 23/01/2018 | Slide 21 SST Requirements (GHRSST) • GHRSST conducted a wide international survey of operational, climate and scientific SST User needs. • These have been translated into general SST User Requirements set out into the table below. • Additional service requirements are found in the GHRSST User Requirements Document. ESA UNCLASSIFIED - For Official Use C Donlon | 23/01/2018 | Slide 22 European SST measurement capability today • International coordination and exchange • GHRSST and CEOS SST-VC • Thermal Infrared Radiometry • Polar orbiting Copernicus Sentinel-3/MetOP • Geostationary MSG/MTG • Microwave Radiometry • Polar Orbiting Potential Copernicus Mission • In situ and Fiducial Reference Measurements (FRM) • FRM4STS, AMT4Sentinel, TIR Radiometers • Each have complementary aspects that deliver excellent synergy -- In fact, all of these are required for an effective SST measurement system ESA UNCLASSIFIED - For Official Use C Donlon | 23/01/2018 | Slide 23 Geostationary Imagers ESA UNCLASSIFIED - For Official Use C Donlon | 23/01/2018 | Slide 24 Polar Orbiting Thermal infrared Radiometers ESA UNCLASSIFIED - For Official Use C Donlon | 23/01/2018 | Slide 25 Changing Meteo Copernicus Science ESA UNCLASSIFIED - For Official Use C Donlon | 23/01/2018 | Slide 26 Microburst, Long Island, in The Bahamas. © Dene Georgelin. ESA UNCLASSIFIED - For Official Use C Donlon | 23/01/2018 | Slide 27 Sentinel-3 ESA UNCLASSIFIED - For Official Use C Donlon | 11/09/2017 | Slide 28 Sentinel-3 Mission Heritage Poseidon-1 Poseidon-2 Poseidon-3 2012:AltiKa 1992: TOPEX / 2001: JASON-1 2008: JASON-2 Poseidon-1 SIRAL SIRAL SARAL 2005: CryoSat-1 RA 2010: CryoSat-2 ATSR RA-2 SRAL, MWR, 1992: ERS-1 POD 1995: ERS-2 AATSR SLSTR MERIS OLCI 2002: ENVISAT 2013: Sentinel-3 ESA UNCLASSIFIED - For OfficialVegetation Use C Donlon | 11/09/2017 | Slide 29 1998: SPOT-4 S3: Sea and Land Surface Temperature Radiometer (SLSTR) Comparison AATSR • number of spectral bands from 7 to 9 (new 1.3 and 2.2um) for better Ci Cloud detection • increased resolution for VIS and SWIR channels (0.5 km @ nadir, TIR 1 km @nadir) • maintain along track scanning with increased swath of oblique view to 740 km • Multi-spectral TIR • increased nadir swath coverage to capability 1400 km • Along track scanning • 100% overlap with OLCI • Cryo-cooled • improved coverage Ocean < 4 days detectors (practically ~ 2 days) • 2-point on-board • dedicated Active Fire channels black-body • Timeliness: 3 hours NRT Level 2 calibration product ESA UNCLASSIFIED - For Official Use C Donlon | 23/01/2018 | Slide 30 Sentinel-3 Collocated measurements SRAL (>2 km) and MWR (20 km) nadir track 1400 km SLSTR (nadir) 740 km SLSTR (oblique) 1270 km OLCI ESA UNCLASSIFIED - For Official Use C Donlon | 11/09/2017 | Slide 32 S3 SLSTR: Basic Geometry • To enable a wider swath SLSTR uses two scan systems (nadir and oblique) and optical paths • A flip mirror (new) is used to select which optical path is directed to the detectors • The nadir swath has a westerly offset to completely overlap the OLCI swath and mitigate sun-glint • The oblique view 55°inclination maintains a longer atmospheric path length compared to nadir • better atmospheric correction • Both scan chains view the ESA sameUNCLASSIFIED -blackbodyFor Official Use and VISCAL C Donlon | 11/09/2017 | Slide 33 targets S3 SLSTR: Instrument Radiators FPA FMA with FMD BBC (+Y and –Y) OB Earth View Baffle Cryo cooler Parabolic Mirrors SUE NA Earth View Baffle Alignment Cubes CDE BBEU/TAEO Scanner (OB and NA) VISCAL SLSTR is composed of two main units: SLOSU (Optical Scanning Unit) and CPE (Control and Processing Electronics). mounted inside the satellite on a dedicated panel SLOSU is composed of an Opto-mechanical Enclosure (OME) and a Detection Assembly (DA) ESA UNCLASSIFIED - For Official Use CPEC Donlon | 11/09/2017 | Slide 34 S3 SLSTR: Calibration SLSTR is a self-calibrating IR instrument. SLSTR uses an on-board calibration system: - TIR channels use two specially designed and highly stable blackbody cavities observed every scan - Fire Channels rely on pre-launch calibration and use of hot BB (dynamic range >600 K) as best effort Vicarious VIS/SWIR calibration - Solar diffuser illuminated once per orbit at at the the S.