Verhaegen Yoni
Enthusiast
Hi all,
I have been doing some self-research on internet concerning thunderstorms and their initiation. I do, however, have some questions that are still not clear to me. Can anyone help me out and/or confirm that I got things right? Thanks!
First:
So, given an unstable atmosphere, thunderstorm initiation can occur when (a) the convection temperature is reached or (b) CIN is absent. However, in some situations deep moist convection still will not occur given that one of these 2 requirements is fulfilled (e.g. with high vertical wind shear beneath the cloud base or entrainment of dry air). Sometimes, initiation does occur when there is still some CIN left (e.g. with elevation convection). Can anyone confirm that I got things right?
Second:
When a rising parcel does not come across CIN, it will spontaneously rise from the surface to the LCL and further until hitting the equilibrium level. However, I was thinking that the LCL is only used for lifted air parcels (contrary to the CCL). So isn't this some kind of contradiction: with no CIN, the parcels rise "spontaneously" to the LCL, which actually is a level that requires "forced lifting" to be reached?
Third:
When CIN is present, it can be reduced by (a) heating below (until convection temperature reached), (b) moistening below, and (c) vertical motion, which then cools air adiabatically (cool the cap layer). However, for some mechanical lifting mechanisms, CIN does not need to be reduced for thunderstorm initiation, as the air can be lifted mechanically to a level above (or "through") the CIN (orographic lifting, lifting with fronts/outflow boundaries).
Thanks for your time and effort! I would really appreciate it!
I have been doing some self-research on internet concerning thunderstorms and their initiation. I do, however, have some questions that are still not clear to me. Can anyone help me out and/or confirm that I got things right? Thanks!
First:
So, given an unstable atmosphere, thunderstorm initiation can occur when (a) the convection temperature is reached or (b) CIN is absent. However, in some situations deep moist convection still will not occur given that one of these 2 requirements is fulfilled (e.g. with high vertical wind shear beneath the cloud base or entrainment of dry air). Sometimes, initiation does occur when there is still some CIN left (e.g. with elevation convection). Can anyone confirm that I got things right?
Second:
When a rising parcel does not come across CIN, it will spontaneously rise from the surface to the LCL and further until hitting the equilibrium level. However, I was thinking that the LCL is only used for lifted air parcels (contrary to the CCL). So isn't this some kind of contradiction: with no CIN, the parcels rise "spontaneously" to the LCL, which actually is a level that requires "forced lifting" to be reached?
Third:
When CIN is present, it can be reduced by (a) heating below (until convection temperature reached), (b) moistening below, and (c) vertical motion, which then cools air adiabatically (cool the cap layer). However, for some mechanical lifting mechanisms, CIN does not need to be reduced for thunderstorm initiation, as the air can be lifted mechanically to a level above (or "through") the CIN (orographic lifting, lifting with fronts/outflow boundaries).
Thanks for your time and effort! I would really appreciate it!