We have made measurements with hand-held sensors on deck but any marine meteorologist can tell you how thoroughly a ship modifies the air flowing past it. The presence of the ship disturbs wind speed and direction and barometric pressure. Our manual measurements have usually been a source of frustration since the buoy measurements are much more accurate. Accurate meteorological measurements can be made from a ship, however. If the relative wind is within 45-90 degrees of dead ahead and if the sensors are in the bow well above rail level, the presence of the ship has little effect.
All ships have a jack staff in the peak of the bow which meets the requirements.
During April 1995, the Upper Ocean Processes Group is redeploying some moorings in the Arabian Sea. For this cruise on the RV Thompson , we developed a compact package for mounting on the jack staff which contains wind speed and direction, air temperature, relative humidity, and barometric pressure sensors. The barometer and CR10 data logger are housed in a cylinder beneath the Gill port. The air temperature, relative humidity and barometric pressure sensors were calibrated shortly before the system was shipped to Oman. We have had much experience with other CSI data loggers in the laboratory and have confidence in them.