Neutral air temperatures at 90 km and 70°N and 78°N

Meteor radars are employed to determine neutral air temperatures at 90 km altitude above Adventdalen, Spitsbergen (78°N, 16°E) and Ramfjordmoen, mainland Norway (70°N, 19°E). The philosophy underlying the temperature derivation including choice of appropriate pressure model and calibration against independent observations is discussed. Average annual variations at each of the two geographic locations are presented, indicating that current models overestimate the summer temperatures by as much as 20 K. The seasonal variation of variability of these temperatures, indicative of corresponding variation in planetary wave activity, is investigated, and in particular, we see that wave activity at 78°N is largely suppressed during summer and is otherwise characterized by a quasi 27‐day oscillation during late autumn and winter. The monthly average temperatures for 78°N presented here are proposed as a viable alternative to current semiempirical models.