Fig. 4From: Geomagnetic activity dependence and dawn-dusk asymmetry of thermospheric winds from 9-year measurements with a Fabry–Perot interferometer in Tromsø, NorwayPolar plot of the quiet-time wind. MLT, solar local time (SLT) and universal time (UT) are marked in black, blue, and gray, respectively. A reference vector magnitude is presented at the topBack to article page