A day in the tropical sky
It is the middle of the night on the coast of West Africa. A team of sleepy aircraft technicians and atmospheric researchers exit the hotel lobby. The humidity hits them like a brick wall – it is already 25 degrees Celsius outside. Their departure for Gnassingbé Eyadéma Airport is scheduled at four AM sharp. The first motorcycles of the day thunder past the walls of the hotel complex. Today’s take-off is set for 09:30. But the chauffeurs are late – again.
At 04:30, two cars drive up along the beach promenade through the still quiet streets of Lomé, the capital city of Togo.
Twenty minutes later, the group reaches their destination – a small hangar next to the international airport. Waiting for them, ready for use, is the Falcon 20E , a very reliable member of DLR’s fleet of research aircraft.##markend##
Upon arrival, the technicians immediately switch on the aircraft’s power supply. The scientific instruments on board need to be charged so they do not run out of juice during the flight.
Then, at 07:30, the pilots, mechanics, the Flight Operations Manager for the DLR Flight Experiments and scientists from the DLR Institute of Atmospheric Physics enter the hangar.
As the pilots and mechanics begin their pre-flight checks, the scientists prepare the instruments for the flight. The Falcon can accommodate more than one ton of scientific equipment. More instruments are attached to the exterior of the aircraft, under the wings.
The pilot and scientists go over the flight plan for the day once again.
The temperature is now over 30 degrees Celsius. The humidity sticks to the body like a second skin. The pilots climb into the flight deck. The auxiliary power units are fired up – they supply power to the scientific equipment and, very importantly, the air conditioning.
Today, the lack of personal space is caused by the racks of instruments upon entering the research aircraft rather than the pushing and shoving in the queue prior to the security check. It is time to go. The scientists not joining the flight leave the cabin and stroll back to the hangar. The door closes, and the Falcon rolls out to the runway.
The Falcon tears down the runway and elegantly lifts its nose into the tropical skies above Togo. It is less and less obvious during the flight that the Falcon was originally constructed as a corporate jet. Space for comfort is sacrificed as much as possible to have more capacity for scientific instruments. This is great for collecting excellent measurement data, but those on board often have to do without the luxury of former days.
The temperatures in the cabin soon become tropical too. The thermometer registers over 40 degrees Celsius after just half an hour. This means sweating, drinking and checking that the scientific instruments are in order.
On today’s flight plan: the emissions from shipping traffic off the coast of West Africa.
Climate change in the region is affecting the clouds and climatic properties. Emissions from burning rubbish, shipping traffic, out-dated engines and other substances are mixed with the monsoon wind and Saharan dust. Combined with deforestation, urbanisation and population growth, these factors form a thin layer of cloud whose impact on the region and the atmosphere is still not understood.
The air in the region is a mixture of a wide range of trace gases, liquids and particulates. In the measurement campaign, the pilots and scientists fly over the various emission sources in the region to collect data on their components. The campaign is part of the EU project DACCIWA (Dynamics-Aerosol-Chemistry-Cloud Interactions in West Africa).
Three-and-a-half hours later the Falcon lands back at Gnassingbé Eyadéma Airport.
After refuelling and completing the work, the Falcon is rolled back into the hangar.
There, the mechanic carries out a critical post-flight check. Then he hands the aircraft over to the measurement and sensor technology technicians, who immediately start powering the equipment up again. The scientists in the hangar are ready to transfer the measurement data and recalibrate the equipment.
After another four hours the power is disconnected for the day. A long but typical day in the DACCIWA flight campaign in Togo comes to an end. Everyone climbs into taxis, exhausted but satisfied. Tomorrow they will do it all over again – an early start, hoping that the chauffeurs will be on time.