Sea temperature soars beyond 30 oC around the Maltese islands
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The intense solar radiation associated with the high air temperatures in recent days has naturally also affected the sea temperature, meaning that swimmers taking a dip in the sea will not find it as refreshing.
In a statement, the Physical Oceanography Research Group Department of Geosciences University of Malta, said that sea surface temperature (SST) has been on the high all around the Maltese Islands, reaching values well beyond 29oC and peaking up to 30.1oC in the coastal stretch of sea opposite Marsascala on Saturday 5th August, in the early evening hours.
SST is regularly monitored by orbiting satellites which keep an eye on its variability in time and in space.
The Physical Oceanography Research Group at the Dept. of Geosciences of the University of Malta elaborates such data which provide snapshots of SST centred around midnight each day. Numerical models further produce maps of SST around the Maltese Islands as it changes during the day.
It said that these maps show how the sea temperatures change from place to place as well as in time, rising to highest values in late afternoon when the sea has accumulated the sun’s radiation during the day, and cooling down by around 2oC during the night when the sea surface re-radiates part of its acquired heat energy back to the atmosphere.
The satellite SST for the night between Thursday 4th and Friday 5th August reached peaks of 28.6oC, the Department said.
It added that data shows the sea continued to absorb heat energy during the day as solar radiation fluxes, measured by the heat station at the University of Malta, poured on land and at sea at persisting rates of up to 875 Watts per square meter.
The sea temperature measured at 3m depth in a yacht marina on the eastern coast reached close to 31oC. The warm waters near Malta are in contrast to the relatively cooler patch of sea west of the islands.
The University pointed out that the exceptional warming of the sea are in sharp contrast with the much cooler daily average temperatures registered in Delimara in the period 1977 – 2006 by the Malta Meteorological Office. The highest sea temperatures are typically reached in early August each year, but are 2 oC cooler than the recent values.
“The mean sea surface temperature in the coastal waters of the Maltese Islands has been steadily increasing at a hefty average rate of close to 0.05 oC per year since the late 70s.”
Top photo shows the modelled SST map of the sea on Saturday in the early evening hours when sea water temperatures reached their highest. Sea temperatures in shallower areas, ports, embayments and beaches were even higher and below Climatology of sea surface temperature on the basis of long term measurements at Delimara (1977 – 2006).