Add time-maximum precipitation and reflectivity to output #145
Description
While instantaneous precipitation rate is already output from MPAS, there is currently no time-maximum value akin to hourly-max updraft helicity. Likewise, time-maximum reflectivity is hit-and-miss in the model.
This code update adds five total fields to be output from MPAS, with the most critical being maximum instantaneous precipitation rate since the last output time. The additional output fields are
- Maximum composite reflectivity since the last output time
- Maximum 1-minute, 5-minute, and 10-minute average precipitation rate since the last output time
There is already code in the microphysics driver to compute hourly maximum 1-km AGL reflectivity. However, the subroutine to compute reflectivity in general is contained within an IF statement such that it only runs when the model is at an output time step. Thus, even the existing hourly-max 1-km AGL reflectivity array looks weird since it is only the maximum over two time steps (the current time and the previous hour). My code change comments out this IF statement so that reflectivity is calculated at each time step. This enables an accurate reflection of the time-maximum composite (vertical max) reflectivity.
The time-maximum (1/5/10)-minute average precipitation rate fields were added to supplement the information contained with the time-maximum instantaneous precipitation rate. After talks with folks in the FFaIR experiment, it was made apparent that instantaneous precipitation rate may not be the most useful field for depicting regions of impactful extreme precipitation. Thus I made the choice to compute precipitation rates over longer time intervals that still generally fall between typical history intervals. I do not currently know which of the three lengths will prove most useful, but the code changes do not include these fields to be output by default. MPAS model users still must add these to an output stream.