Questions & Answers

Questions from Paul Joe ...

Questions from Paul Joe ...

by David Ball -
Number of replies: 3
Hi everyone ...

Paul Joe has some questions for you that might help deal with the AP issue ...
  1. Can sub and super - refraction happen at the same time?
  2. Here are two scenarios, what are the implications?
  • It is possible that the top of the beam is sub-refracting and the bottom of the beam is super-refracting? Or is it? Draw a picture.. What is the implication of this? Is the opposite also possible?
  • It is possible that the center of the beam is sub/super - refracting as it propagates along. What are the implications of this?
Is the problem more evident at low or high elevation angles and why?

In reply to David Ball

Re: Questions from Paul Joe ...

by Julie Deshaies -
Hi,

I'll try to answer these questions but I really don't know if I'm right. So Paul or others, feel free to correct me because I really want to know if I'm wrong.

1. I don't think it's possible if we talk about the same place (same time). Sub-refraction happens when you have a more unstable environment (dry adiabatic) than Stardard Atmosphere and super-refraction when the environment is more stable (inversion).

2. a) I think it's possible when the radar beam becomes wider and if you have a strong and narrow inversion with an unstable layer above the inversion.

I think that the opposite is also possible with an unstable environment near surface and a strong cap (inversion).

b) ?????

3. low elevation the stratification of the low atmosphere is more important than aloft.

Am I right?
In reply to Julie Deshaies

Re: Questions from Paul Joe ...

by Julie Deshaies -
I think that I misunderstood the first question... it is possible for different part of the beam.
In reply to David Ball

Re: Questions from Paul Joe ...

by Birgitte Knudsen -

Regarding question 2B:

What exactly is meant? That the centre of the beam will both sub- and superrefract during its propagation?

If so, I think it should be possible as well as for the top and bottom of the beam. If the centre of the beam starts propagating through an unstable airmass (subrefraction) and then hits an overlying inversion and superrefracts.

Regarding the rest of the questions: I agree with Julie.