User:Wmla

I am currently an undergraduate student at the University of Utah. I am studying Meteorology.

Marty Booth   http://www.met.utah.edu/people/undergraduate

Convective Inhibition (CIN) is the amount of energy required to overcome the negatively bouyant energy the environment exerts on an air parcel. In most cases, when CIN exists, it covers a layer from the ground to the level of free convection (LFC). The negatively bouyant energy exerted on an air parcel is a result of the air parcel being cooler (more dense) than the air which surrounds it, which causes the air parcel to accelerate downward. The layer of air dominated by CIN is warmer and more stable than the layers above or below it.

CIN hinders updrafts necessary to produce convective weather, such as thunderstorms. Although, when large amounts of CIN are reduced by heating and moistening during a convective storm, the storm will be more severe than in the case if no CIN was present.

CIN is strengthened by low altitude dry air advection and surface air cooling. Surface cooling causes a small capping inversion to form aloft allowing the air to become stable. Incoming fronts and short waves influence the strengthening or weaking of CIN.

CIN is calculated by measurements recorded electronically by a rawinsonde (weather balloon) which carries devices which measure weather parameters, such as air temperature and pressure. A single value for CIN is calculated from one balloon ascent by use of the equation below. The z-bottom and z-top limits of integration in the equation represent the bottom and top altitudes (in meters) of a single CIN layer. In many cases, the z-bottom value is the ground and the z-top value is the LFC. CIN is an energy per unit mass and the units of measurement are Joules per kilogram (J/kg). CIN is expressed as a negative energy value. CIN values greater than 200 J/kg are sufficient enough to prevent convection in the atmosphere.

$$CIN = \int_{z_{bottom}}^{z_{top}} g \left(\frac{T_{parcel} - T_{env}}{T_{env}}\right) \, dz$$

The CIN energy value is an important figure on a skew-T log-P diagram and is a helpful value in evaluating the severity of a convective event. On a skew-T log-P diagram, CIN is any area between the warmer environment temperature profile and the cooler parcel temperature profile.