Barometric pressure measurements from buoys during AIDJEX 1972

Electrical readout aneroid pressure sensors were used on two types of buoys which were deployed in an array around the main camp during AIDJEX 1972 to obtain barometric pressure measurements. Laboratory tests prior to the field experiment showed that the calibration of the sensors shifted when they were exposed to normal handling and room temperatures. Corrections for these shifts were obtained by visiting the buoys after installation with portable pressure standards which were referenced to a mercury barometer in the main camp. The corrections ranged from a few tenths of a millibar up to, in one case, 17 mb. Comparison of the portable standards and the mercury barometer revealed significant errors in the mercury barometer readings caused by temperature fluctuations, and a calibration drift in one of the portable standards. The calibrations are probably accurate to a few tenths of a millibar. Comparison of duplicate pressure observations when both types of buoys were at each site shows a relative precision of about 0.1 mb, which is better than the relative precision of the standards. An observation of an unusual pressure feature was confirmed by duplicate buoys at one site. Accuracies better than a few tenths of a millibar will require more work to improve the stability of sensors, to improve the field use of the standards, and possibly to eliminate the effects of dynamic pressure due to wind. An analysis of other error sources introduced in the use of pressure data should precede any effort to improve the measurement accuracy.