Retreive the geopotential height at 500 hPa from lbfd files – in #9: CCLM

in #9: CCLM

<p> Hello, <br/> I would like to compute the geopotential height at 500 hPa from lbfd files that I have generated using the INT2LM software. In principle, it should be possible using PP, but I do not know how to compute the pressure profile of the reference state. irefatm=2 with delta_t=75, h_scal=10000, posl=100000 and tosl=288.15. <br/> Then I can approximatively estimate the height for which P is 500 hPa. As the height will likely fall between 2 vertical levels, which kind of interpolation do you suggest if I want to refine this first estimate? Using <span class="caps"> CDO </span> for doing that? <br/> Thank you for your input, <br/> Sylvain </p>

  @sylvainmarchi in #1c697bf

<p> Hello, <br/> I would like to compute the geopotential height at 500 hPa from lbfd files that I have generated using the INT2LM software. In principle, it should be possible using PP, but I do not know how to compute the pressure profile of the reference state. irefatm=2 with delta_t=75, h_scal=10000, posl=100000 and tosl=288.15. <br/> Then I can approximatively estimate the height for which P is 500 hPa. As the height will likely fall between 2 vertical levels, which kind of interpolation do you suggest if I want to refine this first estimate? Using <span class="caps"> CDO </span> for doing that? <br/> Thank you for your input, <br/> Sylvain </p>

Retreive the geopotential height at 500 hPa from lbfd files

SM wrote

Hello,
I would like to compute the geopotential height at 500 hPa from lbfd files that I have generated using the INT2LM software. In principle, it should be possible using PP, but I do not know how to compute the pressure profile of the reference state. irefatm=2 with delta_t=75, h_scal=10000, posl=100000 and tosl=288.15.
Then I can approximatively estimate the height for which P is 500 hPa. As the height will likely fall between 2 vertical levels, which kind of interpolation do you suggest if I want to refine this first estimate? Using CDO for doing that?
Thank you for your input,
Sylvain

View in channel
<p> I think the easiest way to get the reference atmosphere is just to run <span class="caps"> CCLM </span> for a few timesteps and write out both full pressure (P) and perturbation pressure (PP) on model levels. The reference atmosphere would then be obtained by subtracting PP from P. Alternatively, you can copy the code from vgrid_refatm_utils.f90. </p>

  @edmundmeredith in #972e3de

<p> I think the easiest way to get the reference atmosphere is just to run <span class="caps"> CCLM </span> for a few timesteps and write out both full pressure (P) and perturbation pressure (PP) on model levels. The reference atmosphere would then be obtained by subtracting PP from P. Alternatively, you can copy the code from vgrid_refatm_utils.f90. </p>
EM replied

I think the easiest way to get the reference atmosphere is just to run CCLM for a few timesteps and write out both full pressure (P) and perturbation pressure (PP) on model levels. The reference atmosphere would then be obtained by subtracting PP from P. Alternatively, you can copy the code from vgrid_refatm_utils.f90.

View in channel