Correction to: ‘Stratospheric impact on tropospheric winds deduced from potential vorticity inversion in relation to the Arctic Oscillation’ by Yvonne Hinssen, Aarnout van Delden, Theo Opsteegh and Wouter de Geus

Abstract

By defining the reference state as the state of rest, two distinct potential vorticity (PV) anomalies are identified: the upper troposphere/lower stratosphere (UTLS) PV anomaly and the stratospheric PV-anomaly (Hinssen et al., 2010). Together with the surface temperature anomaly these PV anomalies determine the zonal average wind in the atmosphere. Some of our results are obtained from piecewise PV inversion of these anomalies. We have discovered an error in the application of the lower boundary condition in the PV inversion code. The main findings of the paper are not affected, but the correction of the code has led to a different view regarding the coupling of the UTLS PV anomaly and the surface temperature anomaly. Figure 1, which is the corrected version of Figure 6, shows that the new inverted wind deviates somewhat more from the ERA-40 wind, and that the influence of the surface temperature anomaly is much stronger in the corrected inversion. As a consequence of this, it is not possible to examine separately the influence, on the zonal wind, of the UTLS PV anomaly and of the boundary temperature anomaly by applying piecewise PV inversion. In other words, the UTLS PV anomaly is inextricably connected to the lower boundary. It is therefore not possible to make a corrected version of Figure 9(c) of Hinssen et al. (2010).Subtracting the wind field that is shown in Figure 1(c) from the wind field that is obtained from the inversion of the stratospheric PV anomaly including the observed boundary temperature anomaly yields a wind that is nearly identical to the wind that is obtained from inversion of the stratospheric PV anomaly with no boundary temperature anomaly. Therefore, it remains possible to examine the influence of the stratospheric PV anomaly on the tropospheric wind using piecewise PV inversion. As was stated before, this linear superposition does not apply to the UTLS PV anomaly and the boundary temperature anomaly. et al. (2010), demonstrates that the difference in lower boundary temperature between positive and negative AO cases is of greater importance than was thought previously. In other words, in order to explain fully the observed zonal wind differences between positive and negative AO cases by means of PV inversion, the difference in surface temperature between the two cases needs to be taken into account.

Stratosphere-troposphere exchange and its specific features at extratropical latitudes

“…The au thors of [47] cor rob o rated this fact. They studied the re la tion ship be tween the mean North At lan tic Os cil la tion in dex and the dis tri bu tion of zonal mean po ten tial vorticity and re vealed that the po ten tial vorticity anom aly in this layer af fects the ver ti cal wind shear and static sta bil ity at midlatitudes.…”