Horizontal gradients of atmospheric pressure are the fundamental cause of almost all motions in the atmosphere. Very precise measurements of small pressure differences over distances of tens of kilometers are important for understanding of forcing functions responsible for extreme weather events. In general, present day operational instrumentation are not capable of measuring pressure gradients with sufficient accuracy for some research purposes. In previous research, the Principal Investigators demonstrated that high resolution airborne radar altimeters coupled with highly accurate navigational positioning, allow extremely accurate calculations of pressure gradient forces. These measurements are considered important to attack some classes of meteorological problems over the next decade. The Principal Investigators will continue to develop their measurement technique using data collected from their earlier experiment. The technique will then be applied to discern important physical processes associated with upper tropospheric jets, which have been shown to be associated with severe weather.//
