User:Hurricane Noah/sandbox

Structure
https://journals.ametsoc.org/configurable/content/journals$002fmwre$002f138$002f2$002f2009mwr2989.1.xml?t:ac=journals%24002fmwre%24002f138%24002f2%24002f2009mwr2989.1.xml https://www.sciencedirect.com/science/article/pii/S2225603218300365 https://books.google.com/books?hl=en&lr=&id=6gFiunmKWWAC&oi=fnd&pg=PA3&ots=f70Rb9MFfe&sig=J5lSabWMZUtStzyW9BDK4QEqDiU&redir_esc=y#v=onepage&q&f=false

Eye and center
At the center of a mature tropical cyclone, air sinks rather than rises. For a sufficiently strong storm, air may sink over a layer deep enough to suppress cloud formation, thereby creating a clear "eye". Weather in the eye is normally calm and free of convective clouds, although the sea may be extremely violent. The eye is normally circular and is typically 30 – in diameter, though eyes as small as 3 km and as large as 370 km have been observed.

The cloudy outer edge of the eye is called the "eyewall". The eyewall typically expands outward with height, resembling an arena football stadium; this phenomenon is sometimes referred to as the "stadium effect". The eyewall is where the greatest wind speeds are found, air rises most rapidly, clouds reach their highest altitude, and precipitation is the heaviest. The heaviest wind damage occurs where a tropical cyclone's eyewall passes over land.

In a weaker storm, the eye may be obscured by the central dense overcast, which is the upper-level cirrus shield that is associated with a concentrated area of strong thunderstorm activity near the center of a tropical cyclone.

The eyewall may vary over time in the form of eyewall replacement cycles, particularly in intense tropical cyclones. Outer rainbands can organize into an outer ring of thunderstorms that slowly moves inward, which is believed to rob the primary eyewall of moisture and angular momentum. When the primary eyewall weakens, the tropical cyclone weakens temporarily. The outer eyewall eventually replaces the primary one at the end of the cycle, at which time the storm may return to its original intensity.

Size
There are a variety of metrics commonly used to measure storm size. The most common metrics include the radius of maximum wind, the radius of 34 kn wind (i.e. gale force), the radius of outermost closed isobar (ROCI), and the radius of vanishing wind. An additional metric is the radius at which the cyclone's relative vorticity field decreases to 1×10−5 s−1. On Earth, tropical cyclones span a large range of sizes, from 100–2000 km as measured by the radius of vanishing wind. They are largest on average in the northwest Pacific Ocean basin and smallest in the northeastern Pacific Ocean basin. If the radius of outermost closed isobar is less than two degrees of latitude (222 km), then the cyclone is "very small" or a "midget". A radius of 3–6 latitude degrees (333 –) is considered "average sized". "Very large" tropical cyclones have a radius of greater than 8 degrees (888 km). Observations indicate that size is only weakly correlated to variables such as storm intensity (i.e. maximum wind speed), radius of maximum wind, latitude, and maximum potential intensity. Typhoon Tip is the largest cyclone on record, with tropical storm-force winds 2170 km in diameter. The smallest storm on record is Tropical Storm Marco (2008), which generated tropical storm-force winds only 37 km in diameter.