Barometer Simultaneous barometric readings from across a network of weather stations allow maps of air pressure to be produced, which were the first form of the modern weather map when created in the 19th century. Isobars, lines of equal pressure, when drawn on such a map, give a contour map showing areas of high and low pressure. Localized high atmospheric pressure acts as a barrier to approaching weather systems, diverting their course. Atmospheric lift caused by low-level wind convergence into the surface brings clouds and sometimes precipitation. The larger the change in pressure, especially if more than 3.5 hPa (0.1 inHg),
Mean arterial pressure Mean arterial pressure In medicine, the mean arterial pressure (MAP) is an average blood pressure in an individual during a single cardiac cycle. Total Peripheral Resistance (TPR) is represented mathematically by the formula:mean arterial pressure R = ΔP/Q R is TPR. ΔP is the change in pressure across the systemic circulation from its beginning to its end. Q is the flow through the vasculature (equal to cardiac output) In other words: Total Peripheral Resistance = (Mean Arterial Pressure - Mean Venous Pressure) / Cardiac Output Therefore, Mean arterial pressure can be determined from: where: While MAP can only be measured