MADRID – The warming of the surface temperature of the oceans has a major impact on the Mediterranean Sea. The temperature there in 2022 was 1.4ºC above normal values. Furthermore, these high water temperatures even lasted until last December and January.
That is of course nice for those who like swimming even in the winter. Worryingly, however, was that most of the Mediterranean spent 95% of the days of the year with temperatures above the historical average.
Sea water temperature record
Sea water temperatures in the western Mediterranean reached levels of up to 4 degrees above normal last summer, with particularly significant heat waves in the Balearic Islands. A new seawater temperature record of 31 ºC was set there. Heatwaves are currently being registered in various areas along the Spanish coast.
In April 2023, there are areas that will experience a heatwave at sea. Data from the State Meteorological Agency (Aemet) on Twitter shows that the Cantabrian Sea and the Northwest Atlantic Ocean were between 15 and 17ºC. The south exceeded 19ºC. The Mediterranean Sea went beyond 20ºC. The overall anomaly compared to the average for the period 2010-2020 was 0.7ºC more. But in the Mediterranean, it was up to 1.4ºC above its average.
Unprecedented marine heatwaves in 2022
“All sub-regions of the Western Mediterranean have experienced unprecedented marine heatwaves in 2022,” summarised Mélanie Juza for elDiario.es. Juza is a researcher of the Balearic Islands Coastal Observation System (SOCIB). “On August 13, 2022, a record average sea surface temperature of 31ºC was recorded in the Balearic Islands, which was 3.3 degrees above the historical average,” said Juza.
Thermometers in the south and east of Spain continued to rise and did not fall. “In the Balearic Islands and along the Spanish east coast, the seawater was warmer than normal on 95% of the days of the year 2022,” the measurements illustrate.
More affected by the greenhouse effect
The seas collect most of the heat that global warming traps. It is about 80%. The process described by scientists is that many human activities involving the use of fossil fuels, such as factory farming or massive forest fires, release greenhouse gases into the atmosphere. There they capture radiation from the sun that has bounced off the planet’s surface instead of escaping into space. And the oceans are relatively affected by this.
2022 was the warmest summer ever
The summer of 2022 was the warmest in Spain since records have been kept (1961). The average temperature on the peninsula was 24.7 degrees. Two degrees more than the historical average. Therefore, the water had to process a lot of extra heat.
With higher-than-normal temperatures, ecosystems are damaged. In addition, it increases the temperature of the coastal cities, Aemet concludes. In fact, that same summer of 2022 it led to tropical nights – above 20ºC – and equatorial nights (above 24ºC). “The number of tropical nights in Valencia has quadrupled in recent decades,” says Aemet.
Also historical data on Costa Brava
The record of seawater temperatures off the coast of L’Estartit (Torroella de Montgrí, Baix Empordà) indicates the deviation of 2022 from the average of the last decades. It also points to the relatively high temperature since the beginning of 2023. On almost all days of this year, the seawater temperatures at this point on the Costa Brava are higher than normal.
No relief is expected in 2023
The Mediterranean Sea is a semi-closed basin. This means that the water is more sensitive to warming than other areas. The loss of marine biodiversity is one of the first results of the increase in sea surface temperature. As a result, the oxygen content in the water drops and it becomes uninhabitable for many species. The effects of warming waters on fisheries are also evident, with catches reduced in some areas. The Atlantic is also experiencing record warming, while the El Niño event in the Pacific could increase the risk of extreme weather events and further challenge global heat records.
Related post: Concerns about unusual heat and high sea temperatures