H2O and CO2 are both important greenhouse gases, currently contributing to roughly 70% of the total greenhouse effect. H2O affects our climate and plays a key role in the chemistry and dynamics of the atmosphere. It is of particular significance in the upper troposphere and lower stratosphere (UTLS), where it increases global warming through the water vapour feedback loop and plays an important role in stratospheric ozone loss. Despite the importance of H2O and CO2 in this region of the atmosphere, very few in situ measurements of both species have been done near or above the tropopause. The Canadian Laser Absorption Experiment Testbed (CALASET) is a collaborative project to design innovative technology for stratospheric balloon-based research. This presentation will discuss the first two deployments of CALASET-SE, a new instrument designed to make CO2 and H2O concentration measurements from the surface up to the mid stratosphere. This instrument utilizes a commercial non-dispersive infrared (NDIR) sensor that has been adapted for use in low pressure environments. An earlier version of CALASET-SE was launched as part of an August 2023 stratospheric balloon campaign in Timmins, Ontario, and was tested up to an altitude of 34 km over the 14 hour long flight. An upgraded version of the instrument flew as part of the 2024 TRANSAT campaign, a collaboration between the Centre National D’Etudes Spatiales (CNES), the Canadian Space Agency (CSA) and the Swedish Space Corporation (SSC). This campaign involved a long duration stratospheric balloon flight that launched from the ESRANGE Space Center in northern Sweden and traversed the Atlantic ocean at altitudes between 36 and 40 km before landing near Pond Inlet on Baffin Island. The instrument took measurements throughout the ascent and the roughly four day journey to Canada. Preliminary results from the TRANSAT flight will be discussed, including the work that has been done to analyze the data and compare it with nearby balloon-borne, and satellite measurements.
A Balloon-Borne CO2 and H2O Analyzer using NDIR Technology: Greenhouse Gas Measurements in the Northern Atlantic Stratosphere.
Host: Eylon Vakrat