The Western Mediterranean Sea reached record temperatures in 2022

  • In 2022, the western Mediterranean Sea and the Balearic islands region suffered the warmest ocean temperatures ever registered since 1982 and unprecedented marine heat waves in duration and intensity.
  • The Balearic Islands Coastal Observing and Forecasting System (SOCIB) has implemented applications that provide valuable information on ocean temperature variations and marine heat waves, among other ocean indicators, in the Mediterranean Sea over the last four decades.

Mélanie Juza. In recent years, the number of periods with records in positive air temperature anomaly and heat wave events have increased worldwide (IPCC, 2021). Recently, 2022 was a “year of extremes, with many temperature records broken,” as stated by the Copernicus Climate Change Service (2022 Global Climate Highlights). Indeed, 2022 was the world’s fifth warmest year on record while it was the second warmest year with the hottest summer ever registered in Europe.

Global warming affects both atmospheric and oceanic temperatures. In particular, the Mediterranean Sea is one of the most vulnerable regions to climate change (Lionello and Scarascia, 2018) and responds rapidly to global warming. The surface Mediterranean warming rate is approximately three or four times higher than the global ocean (Juza and Tintoré, 2021, von Schuckmann et al., 2020) and marine heat waves have substantially increased in intensity, duration, and frequency in the last years (Juza et al., 2022, Dayan et al., 2022).

Warmest ocean temperatures

In 2022, the Mediterranean Sea experienced the warmest Sea Surface Temperatures (SST) on record since 1982 with a basin-averaged value of 20.7 ºC (Figures 1 and 2). While 2022 was the fifth warmest year on SST record in the eastern basin (21.4 ºC), it was the warmest year in the western basin (20.4 ºC) with the warmest spring, summer. and autumn (19.0, 26.1, and 20.2 ºC, respectively). SST continues to increase with significant positive linear trends. In particular, as recently updated, SST has increased by 1.49+/-0.002 and 1.55+/-0.003 ºC over the period 1982-2022 in the western Mediterranean and the Balearic Sea, respectively.

Sea surface temperature in Mediterranean Sea in 2022

Sea surface temperature in the Mediterranean Sea. Summer 2022

Figure 1. Maps of annual (top) and summer (bottom) means of SST in the Mediterranean Sea in 2022.
 

Annual mean sea surface temperature from 1982 to 2022 (ºC)

Figure 2. Timeseries of annual mean SST spatially averaged in the Mediterranean Sea, eastern and western sub-basins from 1982 to 2022.

The rapid increase of SST is associated with an increasing number of extreme events. In particular, in 2022, the western Mediterranean Sea suffered extreme temperatures and several Marine Heat Waves (MHW). MHWs were exceptional for their early occurrence (as in May and June), duration, spatial extent, and intensity. All the sub-regions of the western Mediterranean Sea experienced unprecedented extreme temperature events (Figures 3 and 4). In the Balearic Sea, five successive MHWs were observed from May to December 2022 (Figure 3). In this region, the warmest spatially-averaged SST ever registered was observed on the 13th of August 2022 with a value of 29.2 ºC, corresponding to an anomaly of 3.3 ºC (w.r.t. historical data over the period 1982-2015), exceeding the previous regional record in summer 2003. In the Balearic Islands region, 2022 was the year with the highest annual total days of marine heat waves (230 days) over the period 1982-2022 in the region (Figure 4).

Daily sea surface temperature in the Balearic Sea (ºC)

Figure 3. Timeseries of daily SST averaged in the Balearic Sea in 2022. MHWs are indicated.

Marine heat wave total days - 2022

Figure 4. Map of MHW total days in the Mediterranean Sea in 2022. 


It is worth mentioning that these values are spatially averaged and warmer SSTs have been found locally since the spatial variations in ocean temperature are strong. In the summer of 2022, ocean temperatures reaching more than 32ºC were observed in the Ibiza Channel and along the Balearic Island coast, while SST anomalies (w.r.t. historical observations) exceeded 6ºC in French waters.

Web-based visualization applications

The systematic and long-term ocean monitoring, enabled by satellite observations for SST and other essential ocean variables, allows for estimating the ocean surface variations over the last decades. As an Observatory of the Mediterranean Sea, SOCIB has implemented free and open-access web-based applications for the Mediterranean Sea to continuously monitor and visualize timely information on the ocean state and variability in the different sub-regions at various temporal scales. These visualization tools have been enabled by the Copernicus Marine Service which provides full, free, and open access to quality-controlled historical and near real-time data. These user-friendly portals have been designed to be consulted by diverse stakeholders, including the scientific community, educators in marine science, environmental agencies, and policy decision-makers.

Reference articles

  • Juza, M. and Tintoré, J. (2021). Multivariate sub-regional ocean indicators in the Mediterranean Sea: from event detection to climate change estimations, Frontiers in Marine Science, 8:610589, https://doi.org/10.3389/fmars.2021.610589.
  • Juza, M., Fernández-Mora, A., and Tintoré, J. (2022). Sub-regional marine heat waves in the Mediterranean Sea from observations: long-term surface changes, sub-surface and coastal responses, Frontiers in Marine Science, 785771, https://doi.org/10.3389/fmars.2022.785771.