Fig. 11

Meridional profiles of mean winds depending on local time (LT) and observation period. Zonal (a, c) and meridional (b, d) winds over December 2015–August 2016 (a, b) and October 2016–March 2017 (c, d). The winds are averaged over LTs (derived as in Fig. 7): 8–10 h (red), 11–13 h (black), and 14–16 h (blue). Thick error bars indicate ± the precision measures based on \(\left\langle {\varepsilon_{u} } \right\rangle\) (a, c) and \(\left\langle {\varepsilon_{v} } \right\rangle\) (b, d); specifically, they represent the RMS of \(\left\langle {\varepsilon_{u} } \right\rangle\) and \(\left\langle {\varepsilon_{v} } \right\rangle\) over each LT range divided by the square root of the effective degrees of freedom defined as the number of LT grid points (at maximum 10 over 2 h because of the 3° interval) divided by 3 to account for oversampling. Dotted thin bars show ± the standard deviation of the 10-day-bin means (within the LT and observation time ranges)