Summary

The 1977 South Park Area Cumulus Experiment (SPACE-77) was a comprehensive summertime meteorological field program conducted in the Colorado mountains (July and August 1977) by Colorado State University (CSU) and NCAR. The location of the project was South Park, a high altitude broad basin (approximately 50-km wide, east-west) between the Mosquito Range and the Front Range of the Rocky Mountains about 100 km SW of Denver. The main area of interest were the valleys of the South Platte River and its tributaries, several of which flow through this region identified by “Central South Park”. Thus, upslope or up-valley winds are generally from a southerly through easterly direction, while downslope or down-valley winds blow from the north or west. Cumulus and cumulonimbus clouds form with great regularity within this relatively small area.

The primary objective of SPACE-77 (as a follow-on to earlier similar but smaller campaigns in this area conducted by CSU in 1973, 1974, and 1975) was to investigate the initiation, development, and propagation of cumulus congestus and cumulonimbus clouds in the mountains and the subsequent organization of these clouds into mesoscale systems. Another objective was to study aspects of the mountain boundary layer (which becomes the sub-cloud layer when clouds form) and the dry-convective mesoscale circulations which contribute to the initiation, growth, and movement of cumulus clouds. A third objective was to provide data for developing and testing numerical models of the boundary layer, cumulus clouds, and mesoscale systems over mountainous terrain.