Unprecedented Maritime Heatwave Grips Mediterranean

Heatwave in Italy: Mediterranean Sea at Record-Breaking Highs.

An unprecedented maritime heatwave has gripped the Mediterranean Sea, as it witnesses a substantial upswing in water temperatures, especially surrounding Italy, climbing as high as 30 degrees Celsius – an unusual five-degree surge from the normal readings.

The Mediterranean, presently at its boiling point, recently posted a record value of +28.4°C, thereby outdoing the long-standing record from the summer of 2003, where an average value of +28.25°C was noted. This escalation of sea temperatures, experts attribute to the dominance of a potent subtropical anticyclone bringing exceptionally high temperatures in its wake.

The general dearth or weakness of winds has further curtailed the intermixing of colder deep waters with warmer surface waters, thereby fostering an additional rise in average temperatures within the topmost water layers.

What’s notable about this record heat is that it occurred earlier than usual. Back in 2003, the highest temperature peak was recorded in August. This year, however, the intense heat wave arrived as early as the third week of July.

The temperature data for the ocean surface that wa utilized was supplied by the Copernicus service, specifically from the SST_MED_SST_L4_NRT_OBSERVATIONS_010_004 product. The climatological value, which represents the long-term average, is calculated for each point on a 0.125×0.125 degree grid (roughly 14 x 11 km) and for each day of the year, based on the histograms of the data gathered from 1982 to 2019. Marine Heat Waves (MHW) are identified by comparing the value of each grid cell to its climatological value. This information illustrates that the trend of the Sea Surface Temperature for the period of 1982-2019 is significant and cannot be overlooked. This supports the theory that the Mediterranean Sea is a critical area for observing climate change. Indeed, the warming trend can be seen in the accompanying figure, with rates reaching as high as 0.68 degrees Celsius per decade.

The relentless heatwave has been particularly oppressive for Italy and has significantly contributed to the Mediterranean’s historic high sea temperature. The aquatic heatwave, translating into alarming surface sea temperature anomalies, is causing figures to hover around five degrees above normal in expansive areas – a magnitude of heat hitherto unseen, even for this time of year.

In several areas, the surface temperature lingers around 30 degrees Celsius, particularly in the Southern Tyrrhenian Sea, off the coasts of Campania, Calabria, and Sicily. Even the rest of Italy’s sea territory is feeling the heat, touching 28-29 degrees Celsius.

When the entire surface area of the Mediterranean is taken into account, we are confronted with record anomalies, boasting of temperatures never encountered in the past 43 years. This heat wave has propelled the average temperature well beyond the norm, hitting record values nearing 28 degrees.

Usually, the Mediterranean reaches its peak average temperature for the year during mid-August. However, this year, the average temperature in this latter half of July has even surpassed the highest average temperatures recorded over the past 43 years, typically observed in August. These figures are indeed a first, setting a record in the 43-year observational history.

Topics: Historic High Sea Temperatures in Mediterranean, Unprecedented Maritime Heatwave, Mediterranean Sea Record Temperatures, Climate Change Effects in Mediterranean, Rising Sea Temperatures, Extreme Weather Conditions Mediterranean, Global Warming Impact on Mediterranean Sea

Data: cosmo.icm.csic.es