The devastating bushfires that swept through parts of Victoria in February have produced unprecedented effects on the atmosphere of the Southern Hemisphere. Satellite measurements show smoke from the fires penetrated into the stratosphere and dispersed over a wide geographical area. This phenomenon was captured by NASA’s CALIPSO (Cloud-Aerosol LIDAR and Infrared Pathfinder Satellite Observation). Since late February, the Australian Antarctic Division’s atmospheric LIDAR instrument at Davis has detected the smoke at altitudes of 14—20 km (see image at right). The smoke layer has also been detected by LIDAR instruments in Brazil and at Dumont d'Urville in Antarctica.
Together with collaborators at the US Naval Research Laboratory and other LIDAR sites, the Antarctic Division is gathering data on the smoke layer to understand its dispersal and climate effects. The smoke particles act as nucleation sites, promoting the growth of sulphuric acid droplets. These droplets are likely to have a small effect on the climate at high altitudes, either by warming or cooling the atmosphere (which depends on the size of the droplets), and by producing chemical reactions that will ultimately result in loss of stratospheric ozone
This image was produced from LIDAR measurements collected in April and shows thin layers in the lower stratosphere that were illuminated by the LIDAR’s green laser beam.
Ice, Ocean, Atmosphere and Climate program, AAD