Atmospheric pressure is often measured in atmospheres (atm), especially when discussing meteorological events like hurricanes. The atmosphere unit is based on the average pressure at sea level on Earth, which is approximately 1013.25 millibars (mbar). This value serves as a standard reference point for other pressure units.
To convert from millibars to atmospheres, you divide the pressure value in millibars by 1013.25. In this way, you can determine how many times the given pressure fits into the standard atmospheric pressure. For instance, converting 882 mbar to atmospheres, as seen for Hurricane Wilma, results in about 0.8707 atm.
Here's the formula used:
- Atmospheres: \( \text{atm} = \frac{\text{mbar}}{1013.25} \)
The value reveals that Wilma's pressure dropped significantly below the average sea level pressure, indicating its extreme intensity.