Extremely high surface temperatures of the sea (24-25 ° C) were observed between 17 and 22 May in the Southeastern Mediterranean which is directly related to the heat conditions in the region.
The difference in the surface temperature of the sea reached locally + 6 σχέση C compared to the normal levels of the last 12 years and about + 5 ° C in relation to the normal values for the season according to the climatic values 1982-2012.
What do we call “sea heat” and how is it created?
According to the meteo, the large amounts of heat absorbed by the ocean as a result of its constant interaction with the atmosphere can, under certain conditions, create an abnormal and prolonged increase in the temperature of the surface (but also the deeper) layers of the sea.
This phenomenon is called “marine heatwave” – in line with the atmospheric heat – and is observed with increasing frequency (compared to the period 1925-2016), especially in the last 20 years in various areas. of the world’s oceans. There are two main factors that create the heat of the sea:
-The very high temperatures and the apnea in the atmosphere that does not favor the mixing of surface waters with the deeper and colder waters
-Ocean currents that carry hot masses of water from other basins
What is the frequency of the phenomenon?
In the Mediterranean region, previous heatwaves have been observed on a large scale, e.g. in 2003 (duration> 1 month), in 2006 and 2015 with average surface temperature anomalies ranging from ~ + 2-3 ºC, locally reaching up to + 5ºC (relative to the average surface temperature between 1982-2012).
Recent studies with model simulations have shown that between 1982 and 2017, about 27 fuel phenomena developed in the Mediterranean Sea with an average duration of 2 weeks, an average of about 40% in the Mediterranean and an average temperature anomaly of 0.5ºC greater than average. term of the most extreme temperatures in the last 30 years (study period 1982-2012). Their frequency increased from 0.5 kasons per year in the period 1983-2000 to 0.9 per year in the period 2001-2017.
Some of the effects of sea heat:
Unlike the heat waves in the atmosphere, the effects of the fuels on the sea are not immediately visible to the human eye.
The main ones are found in marine organisms that die (eg Northwest Mediterranean 2003) while many marine species migrate unable to cope with high sea temperatures (eg Australia 2011), with their location sometimes being they get new species, causing a sharp and huge reorganization of marine ecosystems. As a result, there is a huge food and economic blow to fishing-based societies.
Also, the economic impact on industrial fishing could even create tensions between countries.
The scientific community’s interest has been strongly focused on the further understanding and prediction of these phenomena, as the frequency of fuel in the sea is expected to increase in the context of the overall rise in average ocean temperature in the 21st century.