Extended Data Figure 3 : Evolution of stratospheric HCl from satellite observations.

From: Recent Northern Hemisphere stratospheric HCl increase due to atmospheric circulation changes

Extended Data Figure 3

Comparison of merged GOZCARDS satellite HCl observations (by HALOE, ACE-FTS and Aura/MLS) with KASIMA model results for Northern and Southern Hemisphere mid-latitude lower (46 hPa) and upper (7 hPa) stratosphere. GOZCARDS monthly mean observations are shown as red dots. Linear fits to the GOZCARDS data and the KASIMA run are displayed as red and blue lines, respectively, for periods before and after 2005. An upward trend is observed and modelled in the Northern Hemisphere lower stratosphere (d) while HCl is decreasing in the southern and northern upper stratosphere (a, b); volume mixing ratio in parts per billion.