What are the key differences between warm and cold core cyclones?

Question

What are the key differences between warm and cold core cyclones? What is an example of each?

Answer 1

Warm and cold core cyclones differ in a few ways:

1. Fronts - Cold core lows will have fronts due to baroclinic zones (clashing of air masses) where warm core lows do not have fronts due to the lack of differing air masses.
2. Structure - Cold core lows tend to be less symmetrical with the typical "comma" cloud shape around the center of low pressure with long tails along the frontal boundaries. Warm core lows are more symmetrical such as tropical cyclones.
3. Centralized Temperature - Warm core lows form with strong surface heating either over land or the ocean. They can be broken down into 2 categories: continental and tropical. Continental warm core lows are formed through strong daytime heating of the ground whereas tropical warm core lows are formed from warm ocean waters. These two scenerios create instability (warm air below cooler air) and causes air to rise. Clouds then form and latent heat is released through condensation which, in turn, warms the core of the cyclone. Cold core lows are coldest at their centers when looking at heights above the surface.
4. Wind shear - Warm core lows are not associated with the jet-stream, so the wind speed at the surface often does not differ much from wind speeds aloft. Cold core lows are often associated with a jet streak (strong section of winds within the jet stream) which makes wind speeds at the surface and aloft differ substantially.

An example of a warm core low is a hurricane because it does not have fronts and is driven by latent heat release from warm ocean waters. An example of a cold core low is a typical mid-latitude cyclone because the clash of air masses creates fronts or baroclinic zones.