Storytelling Kit
Figure 1. Stratospheric Aerosol Optical Depth (SAOD) from the Global Satellite-based Stratospheric Aerosol Climatology (GloSSAC)The Stratospheric aerosol layer is a key component of the climate system with global implications on surface temperature and the hydrological cycle. Being highly variable, regular observations are needed to understand its different sources. Since the era of satellite observations in the late 70’s, major and moderate volcanic eruptions affected the total Stratospheric Aerosol Optical Depth by up to a factor of 100 (Fig.1) with subsequent cooling impacts on climate. In addition, recent extreme wildfires in Canada and Australia have impacted the stratosphere at levels never observed before like volcanoes. Finally, the Summer Asian Monsoon exports surface pollution into the stratosphere and represents another significant source.Geoengineering the climate using artificial stratospheric injection of aerosols has been proposed as a temporary solution to reduce the impacts of climate change. Having a network of observations to detect any artificial injection and trace back its origin is critical.While stratospheric optical properties have been monitored for more than 4 decades with satellite observations quasi-globally (Fig.1), they suffer of limited vertical, horizontal and temporal resolutions and requires several assumptions to derive aerosol concentrations. In situ measurements of aerosol concentration have focused mostly on the Northern Hemisphere with less coverage over the tropical region.The Balloon Network for stratospheric aerosol Observations (BalNeO) aims to fill those gaps. BalNeo brings together research laboratories from USA (NASA Langley Research Center, The National Insitute of Aerospace), Brazil (IPMet – Centro de Meteorologia de Bauru, Instituto de Pesquisas Energéticas e Nucleares), France (Groupe de Spectroscopie Moléculaire et Atmosphérique-Université de Reims Champagne-Ardenne …