Micrometeorological Observations and Comparison of Pasquill to Smith Stability Classes in Conditions of Land / Sea Breezes and of Strong Wind Using Data Obtained with an Ultrasonic Anemometer Thermometer, an Acoustic Sound

Abstract

A THREE-DIMENSIONAL ULTRASONIC ANEMOMETER/THERMOMETER, A MONOSTATIC ACOUSTIC SOUNDER WITH A FACSIMILE CHART, A MICROBAROMETER AND RADIO- METERS WERE INSTALLED AT A DISTANCE OF 1 KM FROM THE SHORE OF THE BERRE POND DURING THE VITH EUROPEAN AIR POLLUTION MEASURING CAMPAIGN NEAR FOS, FRANCE, IN JUNE 1983. TWENTY SECOND AND THIRTY MINUTE AVER- AGES AND CORRELATION PRODUCTS OF MICROMETEOROLOGICAL VARIABLES WERE CALCULATED IN REAL TIME AFTER CORRECTION OF THE TEMPERATURE FOR DIS- TORSIONS DUE TO THE WIND. THESE DATA WERE THEN TRANSFERRED TO AN IBM- COMPATIBLE MAGNETIC TAPE. GRAPHS OF SELECTED DATA OF THREE DAYS OF A TEN DAY MEASURING CAM- PAIGN ARE SHOWN TOGETHER WITH THE ACOUSTIC SOUNDER RECORDS. THE STABILITY CLASSES OF PASQUILL (FROM RADIATION AND WIND) AND OF SMITH (FROM HEAT AND MOMENTUM FLUXES) ARE COMPARED DURING A PERIOD OF STRONG AND DRY WIND (MISTRAL) AND DURING A LAND-SEA BREEZE REGIME. BOTH STABILITY VALUES DISAGREE DURING NIGHTS WITH AN OSCILLATING AND STRATIFIED STABLE ATMOSPHERE WHEN THE MOMENTUM FLUX ALSO CHANGES DI- RECTION. IT IS CONCLUDED THAT, IN THIS CASE, THE THEORY APPLIED AND THE RELATED POLLUTANT DIFFUSION MODELS CANNOT DESCRIBE THE DYNAMICS OF THE ATMOSPHERE.