Project SHIVA reveals presence of ozone-depleting halogen compounds
The coastal regions of Malaysia are major source areas of biogenic halogen compounds capable of damaging the ozone layer. This was the verdict reached by scientists from the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) together with partners from the SHIVA project (Stratospheric ozone: Halogen Impacts in a Varying Atmosphere). Measurement flights with the DLR Falcon research aircraft also showed that huge tropical storms lift these halogen compounds into the upper troposphere – from where they can reach the region of the ozone layer. The measurements were conducted in November and December 2011.
Research at 80 percent humidity
DLR project leader Hans Schlager from the DLR Institute of Atmospheric Physics and his team carried out 16 of these flights – at 35 degrees Celsius and 80 percent humidity. "The Falcon was stationed at Miri, Borneo, and set out on its research flights from there. The measurements ran very successfully – our flights into the storm clouds were able to verify that halogen compounds are transported into higher layers of the atmosphere by these tropical storms," explains Schlager. In this process, the scientists were investigating biogenic compounds that contain halogens such as chlorine, bromine and iodine, all of which have a detrimental impact on ozone. Aquatic plants like seaweed and macro algae release these halogens into the air. The data collected by SHIVA will form the basis for simulations of the future development of the ozone layer incorporating these natural sources of halogens. "We want to find out a number of things, including what damage these halogen compounds could do to the ozone layer in a changing climate, and what interactions might exist with other emissions, such as those from aviation," says Schlager. The Falcon flew into the air masses flowing out of storms at altitudes of up to 12 kilometres, where it was able to verify the presence of halogen compounds. Through a series of near-ground measurements along the coastline of Malaysia, important source areas for natural halogen compounds were found along the entire northern coast of Borneo and in the Strait of Malacca, to the south of the Malaysian peninsula.
Measurements were conducted at water level, from the air and from space. The Falcon was joined on location by the German research vessel 'Sonne', which performed measurements of surface water and air. Route management on board the ‘Sonne’ was in the hands of the GEOMAR Helmholtz Center for Ocean Research, based in Kiel. In addition, small boats operated by Malaysian partners were involved along the coasts of Langkawi, Johor and in the Strait of Malacca, as well as off the coast of Borneo in the vicinity of Kuching, Kota Kinabalu and Semporna. The SHIVA scientists employed satellite data to record the large-scale meteorological processes, the biological activity in the waters being studied and the distribution of ozone.
Financing and partners
SHIVA is financed by the European Union and various national funding organisations from Europe and Malaysia. DLR is a partner in a European-Malaysian consortium comprising 130 scientists and 17 institutions. Project coordination is in the hands of the University of Heidelberg's Institute of Environmental Physics. Other German partners include the GEOMAR Helmholtz Center for Ocean Research, the Alfred Wegener Institute for Polar and Marine Research, the University of Bremen and the University of Frankfurt. The most significant cooperation partners in Malaysia are the universities of Malaya, Kuala Lumpur, Sarawak, Kuching, Sabah and Kota Kinabalu, the National Oceanic Department (NOD) and the Malaysian Meteorological Department (MMD).