Hail variables in output – in #9: CCLM

in #9: CCLM

<p> Dear Vladimir, </p> <p> To produce <span class="caps"> HAIL </span> output, you need to use the second moment scheme. This is not a namelist option. It requires the model to be compiled with this scheme (including the second moment scheme code and the flag - <span class="caps"> DTWOMOM </span> _SB). </p> <p> However, if you want to produce realistic amount of hail, you also need to use a relevant resolution (same is true for the “graupel scheme”). <br/> At the resolution you use, the convective plumes are not resolved enough to produce realistic vertical wind speeds. This results in an severe underestimation of your graupel estimation. </p> <p> To summarise, if you want to produce graupel output, increase the resolution of your model to the convection-permitting scale (e.g. 0.0275°) (this will be very very expensive for your domain) and include the second moment scheme (about 40% increase in computational cost). </p> <p> If you want more information on this or have some more questions, do not hesitate to contact me directly. </p> <p> Kind regards, <br/> Erwan </p>

  @redc_migration in #ff4a66c

<p> Dear Vladimir, </p> <p> To produce <span class="caps"> HAIL </span> output, you need to use the second moment scheme. This is not a namelist option. It requires the model to be compiled with this scheme (including the second moment scheme code and the flag - <span class="caps"> DTWOMOM </span> _SB). </p> <p> However, if you want to produce realistic amount of hail, you also need to use a relevant resolution (same is true for the “graupel scheme”). <br/> At the resolution you use, the convective plumes are not resolved enough to produce realistic vertical wind speeds. This results in an severe underestimation of your graupel estimation. </p> <p> To summarise, if you want to produce graupel output, increase the resolution of your model to the convection-permitting scale (e.g. 0.0275°) (this will be very very expensive for your domain) and include the second moment scheme (about 40% increase in computational cost). </p> <p> If you want more information on this or have some more questions, do not hesitate to contact me directly. </p> <p> Kind regards, <br/> Erwan </p>
re replied

Dear Vladimir,

To produce HAIL output, you need to use the second moment scheme. This is not a namelist option. It requires the model to be compiled with this scheme (including the second moment scheme code and the flag - DTWOMOM _SB).

However, if you want to produce realistic amount of hail, you also need to use a relevant resolution (same is true for the “graupel scheme”).
At the resolution you use, the convective plumes are not resolved enough to produce realistic vertical wind speeds. This results in an severe underestimation of your graupel estimation.

To summarise, if you want to produce graupel output, increase the resolution of your model to the convection-permitting scale (e.g. 0.0275°) (this will be very very expensive for your domain) and include the second moment scheme (about 40% increase in computational cost).

If you want more information on this or have some more questions, do not hesitate to contact me directly.

Kind regards,
Erwan

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