UCCE Farm-Scale Temperature Inversion Study

Project Description

The UC Cooperative Extension conducted detailed evaluations of the springtime temperature inversion conditions at a future vineyard location in San Luis Obispo County and a partially-developed vineyard in Santa Barbara County in early 2011.

The purpose of this project was to quantify the strength and variability of the temperature inversion conditions that occurred on the spring frost nights at each location. The strength and reliability of such temperature inversions are required order for wind machines to provide effective frost protection. Detailed knowledge of the inversion characteristics of a given location is a key factor for deciding what type of active frost protection method (wind machine or sprinkler) will be most appropriate for that location.

Eleven 35 ft. tall meteorological towers were installed at the San Luis Obispo County location, and five towers were installed at the Santa Barbara County location. Each measured the temperature at heights of 5 ft. and 35 ft. throughout the spring. Detailed assessments of the minimum temperatures and inversion strength conditions throughout the night on all frost nights were prepared. This information will be extended to the public in an upcoming Grape Notes newsletter article.

Support for this work was provided by donations from the two cooperating vineyards.