Fig. 3
From: The influences of El Nino and Arctic sea-ice on the QBO disruption in February 2016
El Nino and Arctic sea-ice in relation to the lower stratospheric circulations. a A scatter plot of NINO3.4 and the sea-ice over the Barents and Kara Sea (30–90°E, 65–85°N) for February 1980–2016 (values are normalized). b A multiple regression map of the stream function (shading; 106 m2 s−1; zonal mean is removed) and WAF (vector; m2 s−2) at 40 hPa with respect to NINO3.4 and the sea-ice. The hatchings denote a significance level of 90% based on the bootstrap method. The regression coefficients are weighted by the respective values of NINO3.4 (1.7) and the sea-ice (−2.0) in February 2016 for a comparison with the anomaly of February 2016. The vectors equatorward of 30°N are multiplied by a factor of 10
