Previous: Ext. Abst. Next: Introduction Up: Ext. Abst.

1. Introduction

Radiosonde observations of temperature and horizontal winds have been made at many stations in the world operationally over decades mostly for the purpose of weather prediction. Horizontal wind and temperature data obtained from operational high-resolution radiosonde observation in Japan have recently been available. By analyzing the data over 4 years at all 18 stations, it is discovered that clearly layered and long lasting structure in horizontal winds appears frequently in winter at several stations simultaneously. In this study, appearance patterns and sources of the layered disturbances are also examined by EOF analysis and backward trajectory analysis, respectively.