Extended Data Figure 2 : HCl relative rates of change at eight NDACC sites.

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

Extended Data Figure 2

a and b provide the rates of change (per cent per year) for the 1997–2007 (1999–2007 for Thule and Izana, 1998–2007 for Tsukuba) and 2007–2011 time periods, respectively. They were derived from the FTIR and GOZCARDS observational data sets and from the SLIMCAT and KASIMA simulated time series (see colour key). The error bars correspond to the 2σ level of uncertainty.