Low-pressure area most active tropical cyclone basin on Earth. Wind is initially accelerated from areas of high pressure to areas of low pressure. This is due to density (or temperature and moisture) differences between two air masses. Since stronger high-pressure systems contain cooler or drier air, the air mass is denser and flows towards areas that are warm or moist, which are in the vicinity of low-pressure areas in advance of their associated cold fronts. The stronger the pressure difference, or pressure gradient, between a high-pressure system and a low-pressure system, the stronger the wind. Thus, stronger areas of low pressure are
Pressure exchanger low membrane performance, pressure drop limitations and the absence of energy recovery devices. An example where a pressure exchange engine finds application is in the production of potable water using the reverse osmosis membrane process. In this process, a feed saline solution is pumped into a membrane array at high pressure. The input saline solution is then divided by the membrane array into super saline solution (brine) at high pressure and potable water at low pressure. While the high pressure brine is no longer useful in this process as a fluid, the pressure energy that it contains has high value.