Abstract
An analysis is made, with the aid of ECMWF operational data, of medium-scale, eastward-traveling waves in the mid-latitude upper troposphere over the north Atlantic area as a counterpart of the similar analysis of Sato et al. (1993) for the medium-scale waves over Japan.
It is shown that the waves dominate in wintertime (January and February of 1990) over the north Atlantic centered around 50°N, with the typical wavelength of 2400km, a period of 33 hours, and hence an eastward phase velocity of about 20ms-1.
In view of their vertical structure and relationship to the background zonal flow, it is concluded that the wave character obtained in this analysis is the same in essence as that shown by Sato et al. (1993).
