Before we go into why it’s important, just what is “Barometric Pressure” anyway?
Barometric pressure, also called atmospheric pressure, is the measure of the weight of Earth’s atmosphere. The atmosphere has five layers: exosphere, thermosphere, mesosphere, stratosphere, and troposphere, which is the layer closest to the Earth’s surface. Barometric pressure increases as altitude decreases, with air molecules in the upper layers compressing the layers below them. Barometric pressure fluctuates based on elevation levels, wind patterns, and temperatures.
The Evolution of the Barometer
Traditionally, a barometer was used for measuring barometric pressure. The barometer was first devised hundreds of years ago, in 1644. It consists of a glass tube that is closed at one end and open at the other. The tube sits vertically, with the open end sitting in a pool of mercury.
Changes in pressure will change the level of mercury in the tube. Increased air pressure pushes the mercury higher into the tube, whereas decreased air pressure allows the mercury in the tube to drop.
Now, the SWMP uses a more modern and accurate device called a capacitative pressure sensor. A SWMP barometric sensor is a high-precision, automated device used within the National Estuarine Research Reserve (NERR) System-wide Monitoring Program (SWMP) to measure atmospheric pressure. These sensors are part of a standardized, long-term monitoring network that collects meteorological and water quality data to evaluate the health of coastal ecosystems.
How is Barometric Pressure Measured?
Let’s get scientific. Barometric pressure is typically reported in inches of mercury or in millibars. 1 inch of mercury equals about 33.9 millibars, Inches of mercury is the traditional way of reporting air pressure. Greater air pressure pushes a column of mercury higher in a barometer. Millibars are a more direct measure of barometric pressure and are the units used in SWMP.
Why is Barometric Pressure Important to Predicting Weather?
Barometric pressure has important effects on water chemistry and weather conditions. It affects the amount of gas that can dissolve in water. More gas, such as oxygen, can dissolve in water under higher pressure when compared to lower air pressure. For instance, more oxygen is dissolved in water at sea level than at high altitudes.
The pressure of the overlying air forces more gas into solution. As the overlying pressure decreases, gas is released from solution. A common example of this is when someone opens a carbonated beverage. High barometric pressure supports sunny, clear, and favorable weather conditions, but lower levels promotes rainy and cloudy weather conditions.
Thus, higher pressure is indicative of calm weather, while low barometric pressure indicates poor weather. Meteorologists and sailors use fluctuations in barometric pressure to forecast weather conditions.
How does Barometric Pressure Affect Our Health?
According to Master Class, Ragged breathing at higher altitudes is a result of low barometric pressure. The air molecules in lower-pressure altitudes (for instance, on a mountaintop) are less dense because they’re not being pushed together by as much barometric pressure, resulting in fewer oxygen molecules per breath.
In high-pressure areas near sea level, it’s easier for your lungs to absorb oxygen because gravity forces the air down to you. In low-pressure areas, there’s less force pushing oxygen toward you, so your lungs may struggle to absorb it.
Barometric Pressure can be responsible for a wide range of health issues, including:
- Joint Pain and Arthritis: As pressure drops, air pressure against the body decreases, allowing muscles, tendons, and tissues around joints to expand, causing stiffness and pain.
- Headaches and Migraines: A drop in pressure can reduce oxygen flow to the brain and cause tissues to swell, triggering migraines or headaches.
- Sinus and Ear Pressure: Similar to airplanes ascending, rapid pressure changes can cause ear popping, pain, or sinus discomfort.
- Fatigue and Breathing Issues: Lower pressure means less oxygen is available, leading to potential fatigue or breathing difficulties for people with respiratory conditions.
- Vertigo and Dizziness: Changes in pressure can disturb the fluid levels in the inner ear, affecting balance.
- Mood Fluctuations: Changes in atmospheric pressure, particularly falling pressure, can impact serotonin levels, causing irritability or, in some, depression
Barometric Pressure and your Chocolate Cake
Barometric pressure even affects your attempt at being the next Martha Stewart. It directly impacts how quickly fluids evaporate, which has a significant effect on baking. Evaporation slows under high pressure, meaning that cakes and breads take longer to rise and require more time in the oven before they’re finished baking. In lower-pressure environments, evaporation happens quicker, so cakes and breads rise more quickly and finish baking faster.
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