Key points are not available for this paper at this time.
Abstract Upper-air observations with kites, aircraft, and radiosondes were performed in the United States operationally since the 1890s. In this paper, the authors present a reevaluation of newly digitized monthly mean values from the Monthly Weather Review back to 1922. Data from 46 U.S. weather stations are presented with a focus on early kite and aircraft observations during the 1922–38 period. A quality assessment of the data, based on reconstructed reference series, is carried out and the quality of the monthly mean data is found to be sufficient for analysis of variability in upper-level circulation. Anomalies of upper-level temperatures from the reevaluated station data, together with surface fields, are shown for selected periods.
Ewen et al. (Thu,) studied this question.