As altitude increases, pressure decreases.
A millibar is a unit of pressure that is most commonly seen in the context of meteorology, where atmospheric pressure is sometimes given in millibars. As the name suggests, one millibar is equal to one thousandth of a bar. The bar is a unit of measurement introduced in the early 1900s, based on a system of measurement that uses dynes. Dynes are part of the now outdated centimeter-gram-second (CGS) measurement system.
Drops in pressure, measured in millibars, indicate storms are coming.
Measurements can be a little confusing. Several conflicting measurement systems are in use today, and sometimes nations using one official system may periodically reference another, adding to the confusion. Millibars are widely accepted as a unit of measurement in meteorology, but are rarely seen outside of this field. Slashes and the related system of pascals are closely linked, and sometimes used interchangeably, with a single hectopascal being equivalent to a millibar.
At sea level, the standard pressure is about 1013 millibars. Atmospheric pressure decreases as people rise in altitude and increases as people go below sea level. The rates of rise and fall are quite stable, and there are calculations that can be used to track changes in atmospheric pressure and to determine pressure at a known altitude, with the millibar being a unit of measurement that can be used in such a way. calculations. As many people know, moving between areas of high and low pressure too quickly can be dangerous as the body may not be able to adapt quickly enough.
Local variations in atmospheric pressure occur in response to weather systems moving across the Earth’s surface. When meteorologists provide weather reports, they provide information about air pressure in millibars that people can use to learn more about the weather in the coming days. If the pressure is increasing, the weather should be good, while drops in pressure indicate that storm systems are on their way. Rapid fluctuations in atmospheric pressure can be warning signs that a storm system is approaching.
One place you can see millibars is in a weather report on the news or in the newspaper. Sometimes the reporter gives the measurement in hectopascals, abbreviated as hPa, and it may be helpful to remember that the terms “millibar” and “hectopascal” are equivalent. The term can also be seen in books dealing with climate issues and can come up in safety classes for people who work outdoors and are therefore vulnerable to changes in the weather. Sailors, for example, need to be aware of changes in air pressure and good at reading weather reports for safety reasons.