UPPER TROPOSPHERIC DYNAMICS AS REFLECTED IN NIMBUS-4 THIR 6.7-µm DATA

摘要

In order to determine if a quantifiable relationship exists between the 6.7-um radio metric patterns observed by the Nimbus-4 temperature-humidity infrared radiometer (THIR) and tropospheric dynamics a 10-level diagnostic model is employed. The model is used to show the spatial and temporal relationships existing between radio metrically observed water vapor patterns and conventionally derived water vapor patterns, and to examine the upper and middle tropospheric water vapor budget and associated dynamics in order to assess the causes behind the spatially-and temporally varying water vapor radiometric patterns. A particular situation involving a confluent trough located to the lee of the Rockies over the Central United States is examined. The THIR observations over the trough extend from 0538 GMT on April 30, 1970, to 1850 GMT on May 1, 1970, in approximately 12-hr increments. They reveal a tongue of warm equivalent blackbody temperature (T B B ) greater than 250K that advanced around and ahead of the trough. The movement of this warm tongue implies significant changes in the upper and middle tropospheric dynamics that characterize the different stages of the trough's life cycle.