Expert: Donald Rosenfeld - 1/29/2011

Question
Hi,

I have searched all over on google trying to find and answer and had no luck, hopefully you can help!  I am looking at atmospheric stability.  I know that stable conditions occur when the ELR is less than the dry adiabatic lapse rate and unstable conditions is the reverse.  But, my question is that since the dry adiabatic rate is constant, then it is the ELR is changing, so what causes the variations in the ELR.

Thanks,

Kia

Answer
Hi Kia

Variations in ELR are variations of temperature as the radiosonde rises. The cause are many for those variations including cooling with elevation, weather system structure, air mass structure, inversions, etc.

These sites should give you additional insight:

http://www.pilotfriend.com/av_weather/meteo/hm_temp.htm

http://geog-www.sbs.ohio-state.edu/courses/G230/hobgood/ASP230Lecture13.ppt#259,... Lapse Rate

http://cires.colorado.edu/~higginsm/atoc1050/ch05/chapter05.pdf

http://www.piercecollegeweather.com/stability.html