Fig. 1From: Thermospheric inter-annual variability and its potential connection to ENSO and stratospheric QBOTime series during 1967–2012. a The observed (black line) and NRLMSISE-00 modeled (green line) values of the global mean thermospheric density at 400 km altitude. b The density residual (thin line) and its yearly running mean (thick line). c Nino3 index and its yearly running mean. d QBO and its yearly running meanBack to article page