The top image represents sea surface temperature around the island for 31 August 2003, while the second image shows it for 30 August 2002. The brighter the colour the higher the temperature: there is a five-degree difference between the two recorded in waters north of Crete, and a two-to-three degree difference south of Crete. The maximum (bright red) temperature shown in the two images is 25 degrees, the minimum (dark blue) is 16 degrees. Areas in black are either land or covered by cloud.
The data come from Envisat's Advanced Along Track Radiometer (AATSR), which functions like a space-based thermometer. The instrument records infrared wavelengths of light to calculate sea surface temperature to an accuracy of 0.3 degrees and a spatial resolution of 1 sq km. The images were prepared for ESA by the Rutherford Appleton Laboratory.
"The difference between the two years is a striking demonstration of how variable the climate can be," said Professor David Llewellyn-Jones of University of Leicester, the Principal Investigator for AATSR. "Sea surface temperature is an especially important factor in climate studies because it takes a long time and the transfer of a lot of heat to change it.
"The oceans actually represent an enormous reservoir of heat. It's not generally realised but they absorb directly the majority of energy radiated from the Sun due to their surface area covering about 71 per cent of the Earth's surface. The oceans then transfer heat directly to the atmosphere."
The oceans are a good indicator of possible climate change because they actually store a huge amount of solar heat, and their temperatures are an indication of how much heat they hold. They take much longer to warm up or cool down by comparison to the land or the air, so sea surface temperature records can be used to help identify longer-term climatic trends.
"By themselves, these particular AATSR images just show us is that the climate varies and thatPage: 1 2 Related biology news :1
Contact: Henri Laur
European Space Agency
. The Mediterranean connection: ecological effects of El Nio in the Northern hemisphere2
. Mediterranean fishery recovers, thanks to manmade pollutants3
. A major scientific survey finds more species than in the entire Mediterranean at Lifou, Loyalty Islands4
. ¡Ciao! down: Mediterranean diet after a heart attack adds years to life5
. Destructive Algae Overtaking Mediterranean Waters6
. Will Global Change Increase Fire Activity In The Mediterranean Basin?7
. Wrapping a memory with an experience, capacity for recollection detected in non-human species8
. Smallpox in 50-year-old tissues detected by integrated diagnostics approach9
. Missing link detected in insulin mechanism10
. Ovarian cancer detected in blood samples11
. HIV-like virus detected in wild chimpanzee