20 Jan 2022
20 Jan 2022
Status: a revised version of this preprint is currently under review for the journal ESSD.

A New Operational Mediterranean Diurnal Optimally Interpolated SST Product within the Copernicus Marine Environment Monitoring Service

Andrea Pisano1, Daniele Ciani1, Salvatore Marullo1,2, Rosalia Santoleri1, and Bruno Buongiorno Nardelli3 Andrea Pisano et al.
  • 1CNR-ISMAR, Via del Fosso del Cavaliere 100, Rome, 00133, Rome, Italy
  • 2ENEA, Via Enrico Fermi, 45, 00044 Frascati, Italy
  • 3CNR-ISMAR, Calata Porta di Massa, Napoli, 80133 , Italy

Abstract. Within the Copernicus Marine Environment Monitoring Service (CMEMS), a new operational MEDiterranean Diurnal Optimally Interpolated SST (MED DOISST) product has been developed. This product provides hourly mean maps (Level-4) of sub-skin SST at 1/16° horizontal resolution over the Mediterranean Sea from January 2019 to present. The product is built by combining hourly SST data from the Spinning Enhanced Visible and InfraRed Imager (SEVIRI) on board Meteosat Second Generation and model analyses through optimal interpolation. SEVIRI and model data are respectively used as the observation source and first-guess. The differences between satellite and model SST are free, or nearly free, of any diurnal cycle, thus allowing them to be interpolated in space and time using satellite data acquired at different times of the day. The accuracy of the MED DOISST product is assessed here by comparison against surface drifting buoy measurements, covering the years 2019 and 2020. The diurnal cycle reconstructed from DOISST is in good agreement with the one observed by independent drifter data, with a mean bias of 0.041 ± 0.001 K and root-mean-square difference (RMSD) of 0.412 ± 0.001 K. The new SST product is more accurate than the input model during the central warming hours, when the model, on average, underestimates drifter SST by one tenth of degree. The MED DOISST product is also able to reproduce accurately the extreme diurnal warming events frequently observed in the Mediterranean Sea, which may reach amplitudes larger than 5 K during the warm season. This product can contribute to improve the prediction capability of numerical weather forecast systems (e.g., through improved forcings/assimilation), as well as the monitoring of surface heat budget estimates and temperature extremes which can have significant impacts on the marine ecosystem.

The full MED DOISST product (released on 04 May 2021) is available upon free registration at (Pisano et al., 2021). The reduced subset used here for validation and review purposes is openly available at (Pisano, 2021).

Andrea Pisano et al.

Status: final response (author comments only)

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
  • RC1: 'Comment on essd-2021-462', Anonymous Referee #1, 21 Feb 2022
    • AC1: 'Reply on RC1', Andrea Pisano, 13 May 2022
  • RC2: 'Comment on essd-2021-462', Anonymous Referee #2, 22 Feb 2022
    • AC2: 'Reply on RC2', Andrea Pisano, 13 May 2022
  • RC3: 'Comment on essd-2021-462', Anonymous Referee #3, 16 Mar 2022
    • AC3: 'Reply on RC3', Andrea Pisano, 13 May 2022

Andrea Pisano et al.

Data sets

CNR Mediterranean Sea High Resolution Diurnal Subskin Sea Surface Temperature Analysis: Validation subset Pisano, Andrea

Andrea Pisano et al.


Total article views: 559 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
415 123 21 559 6 9
  • HTML: 415
  • PDF: 123
  • XML: 21
  • Total: 559
  • BibTeX: 6
  • EndNote: 9
Views and downloads (calculated since 20 Jan 2022)
Cumulative views and downloads (calculated since 20 Jan 2022)

Viewed (geographical distribution)

Total article views: 485 (including HTML, PDF, and XML) Thereof 485 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
Latest update: 24 May 2022
Short summary
A new operational diurnal sea surface temperature (SST) product has been developed within the Copernicus Marine Service, providing gap-free hourly mean SST fields from January 2019 to present. This product is able to accurately reproduce the diurnal cycle, the typical day-night SST oscillation mainly driven by solar heating, including extreme diurnal warming events. This product can thus represent a valuable dataset to improve the study of those processes that require sub-daily frequency.