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titleKey questions and tasks using the control forecast

 

  1. Understand the weather situation over Africa.
  2. What is the role of large scale in this case (compare with N.America case).
  3. Look at the diurnal variation of key parameters (2m temperature, surface heat fluxes, precipitation, outgoing-longwave-radiation) for location 0N,25E.
  4. Compare differences in convection profiles between Central Africa and (i) open ocean, and (ii) Amazonia.

 

 

 

  1. Describe the phase and amplitude of (scaling) of the precipitation with the different experiments with respect to surface heat fluxes.
  2. What is it that scales precipitation flux? 
    Compare buoyancy flux with enthalpy. Think about the effect of local heating combined with atmospheric moisture.

  3. How important is the correct diurnal cycle of precipitation and radiation for 2m temperature and dewpoint forecast?

 

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Sensitivity experiments

The IFS is highly tuned to give the best forecast over a range of initial conditions. However, it is instructive to try some sensitivity experiments to understand the role of various physical and dynamical processes.

  • What's the impact of the different 'lead times' on the forecast of the convection (i.e. starting from different dates)? Note that this only makes sense for the North American convection

  • What's the impact of resolution on the forecast of the convection?

  • Does reducing the model timestep improve or worsen the forecast?

  • Increase the precipitation auto conversion rate - what impact does this have?

    Expand
    titleHow to change the code (click here to expand…)

    Edit the source code to increase the auto conversion rate by 20%

    File: ifs/phys_ec/sucldp.F90, change:

    Code Block
    line 123: RKCONV=1._JPRB/6000._JPRB   ! 1/autoconversion time scale (s)

    to:

    Code Block
    line 123: ! RKCONV=1._JPRB/6000._JPRB   ! 1/autoconversion time scale (s)
line 124: RKCONV=1.2_JPRB/6000._JPRB    ! default scaled by 20%: 1/autoconversion time scale (s)


Impact of the improved diurnal cycle of convection

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