Low-pressure area This generates a steady wind blowing toward the land, bringing the moist near-surface air over the oceans with it. Similar rainfall is caused by the moist ocean-air being lifted upwards by mountains, surface heating, convergence at the surface, divergence aloft, or from storm-produced outflows at the surface. However the lifting occurs, the air cools due to expansion in lower pressure, which in turn produces condensation. In winter, the land cools off quickly, but the ocean keeps the heat longer due to its higher specific heat. The hot air over the ocean rises, creating a low-pressure area and a breeze from
Coronary perfusion pressure Coronary perfusion pressure Coronary perfusion pressure (CPP), also known as simply perfusion pressure, refers to the pressure gradient that drives coronary blood pressure, meaning the difference between the diastolic aortic pressure and the right atrium end diastolic pressure. It is a term used mainly in research concerning cardiac arrest. In this context, it is assumed that the minimum CPP needed for a successful outcome is 15mm Hg. CPP is a part of normal blood pressure that is specifically responsible for coronary blood flow. CPP is also, generally, a surrogate term for coronary blood flow. During cardiac arrest, CPP is one