Physical Therapy Assistant Guide. Welcome to the PTA Guide, a physical therapy assistant education & career resource. We have everything you need to become a licensed PTA in your state. A few of the helpful things that you'll find here are information resources by state such as tools and info on PTA Schools, PTA license requirements, PTA Jobs, PTA salary data for states & major cities.
A dust devil in Ramadi, Iraq. Atmospheric instability is a condition where the Earth's atmosphere is generally considered to be unstable and as a result the weather is subjected to a high degree of variability through distance and time.hese indices, as well as atmospheric instability itself, involve temperature changes through the troposphere with height, or lapse rate. Effects of atmospheric instability in moist atmospheres include thunderstorm development, which over warm oceans can lead to tropical cyclogenesis, and turbulence.
DEFINITION of 'Variability'. The extent to which data points in a statistical distribution or data set diverge from the average or mean value.Variability also refers to the extent to which these data points differ from each other. There are four commonly used measures of variability: range, mean, variance and standard deviation.The risk perception of an asset class is directly proportional to the variability of its returns.he extent to which data points in a statistical distribution or data set diverge from the average or mean value. Variability also refers to the extent to which these data points differ from each other.