THE GLOBAL CIRCUIT - GLOBAL THERMOMETER, WEATHER BY-PRODUCT OR CLIMATIC MODULATOR

This paper will review progress on the fair weather global circuit and its coupling to the upper atmosphere. The paper will confine its focus to work done by scientists working in the United States of America during the last four years. The global circuit is an old and familiar topic thought by many to have been well understood many years ago. The recent developments to be reviewed here suggest that this opinion is optimistic and possibly incorrect. Improvements in technology have permitted the deployment of new instruments with unprecedented capabilities that have produced data which have, in their turn, reopened a host of old questions and posed some fascinating new ones. Copyright 1995 by the American Geophysical Union.