Aircraft-satellite combo to improve heat wave forecasts in Athens

Paris, August 28 (ANI): Scientists, using aircraft and satellites, have been collecting data amid the ancient ruins in the Greek capital of Athens, in order to improve 'urban heat island' forecasts to make life in the city easier during heat waves.

Heat waves strike with relative frequency in the summer months across southern Europe but the Greek capital of Athens is notorious for its sweltering conditions.

The city is particularly prone to high temperatures because of its dense layout, narrow streets, limited green space and long-standing air pollution problem.

While the average daytime temperature for July is 33.5 degrees Celsius, statistics show that the number of days that exceed 38 degrees C appears to be increasing dramatically. eriods of hot weather are always felt more acutely in cities, especially at night.

This is down to a phenomenon called an urban heat island, where the temperature in the city can be up to 10 degrees C higher than the surrounding countryside.

The built-up urban environment tends to act like a giant storage heater, soaking up the heat during the day and releasing it at night.

Air pollution, traffic, lack of open space and low evaporation also contribute to the heat of the city.

Increased daytime temperatures and reduced night-time cooling have a huge impact on human health and comfort.

Urban heat islands are associated with above-average rates of mortality, especially amongst the elderly.

This is illustrated by the 10-day heat wave that engulfed Athens in 1987 and responsible for claiming 926 lives.

During this extreme event, the mercury climbed to 48 degrees C - the all-time highest temperature recorded for metropolitan Athens.

In order to improve the understanding of the complexities of how urban heat islands arise, so that more efficient alert systems can be developed and effective mitigation strategies adopted, ESA (European Space Agency) organized an airborne campaign that was recently carried out over Athens.

In a series of coordinated activities, a group of thermal remote-sensing and urban-climate experts from Greece and Spain carried out ground-based measurements at various sites in and around the Greek capital, whilst aircraft equipped with sensitive instrumentation passed overhead and satellites orbiting Earth acquired data simultaneously from space.

According to Dr Maria Varinou, from the General Secretariat for Civil Protection, "Detailed mapping of urban temperatures and the associated heat stress for the citizens can help us position ambulances during heat waves; thus considerably shortening transport times to the hospitals for those suffering from the heat." (ANI)