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.
Share. Air pressure is not uniform across the Earth however. The normal range of the Earth's air pressure is from 980 millibars (mb) to 1050 mb. These differences are the result of low and high air pressure systems which are caused by unequal heating across the Earth's surface and the pressure gradient force. low pressure system, or low, is an area where the atmospheric pressure is lower than that of the area surrounding it. Lows are usually associated with high winds, warm air, and atmospheric lifting.