NSSL-MP scheme updates

[MicroTed]

This NSSL-MP update makes some improvements under the hood. No changes to the public subroutine calls. The same update is being submitted for CCPP, as well.

TYPE: enhancement

KEYWORDS: NSSL microphysics scheme; rain breakup

SOURCE: Ted Mansell (NOAA/NSSL) (@MicroTed )

DESCRIPTION OF CHANGES:

• More accurate saturation mixing ratio calculation (iqvsopt=1)
• Changed default droplet renucleation to irenuc=5, which allows extra nucleation at high supersaturation
• A default explicit rain breakup for 3-moment rain (irainbreak=2) has been added to reduce excessive median drop diameters in rain cores, which in turn increases evaporation and cool pool temperature deficits (were too warm).
• Imposed reflectivity conservation in graupel->hail conversion (ihlcnh=3) and Bigg freezing (both 2- and 3-moment)
• Two optional diagnostic outputs for supersaturation (wrt liquid/ice)
• Changed nssl_hail_on from max_dom array to singe value, because it can't be different for different domains, anyway.

LIST OF MODIFIED FILES:

Registry/Registry.EM_COMMON
doc/README.NSSLmp
dyn_em/solve_em.F
phys/module_microphysics_driver.F
phys/module_mp_nssl_2mom.F
phys/module_physics_init.F

TESTS CONDUCTED:
2. Are the Jenkins tests all passing? Yes

RELEASE NOTE: NSSL microphysics scheme updates include 1. An explicit rain breakup for 3-moment rain (addresses issue of cold pools being too warm and drops being too large in rain cores), 2. Improved reflectivity conservation for graupel->hail conversion and drop freezing, 3. More accurate saturation mixing ratio calculation, 4. New default droplet nucleation that controls excess supersaturation much better than previously (and default is to always predict the number of activated CCN).

[weiwangncar]

@MicroTed Not sure if you received email from our Jenkins tests (check your spam folder too). But it looks like the compilation failed for all builds. If you need a output, let me know.

[MicroTed]

@weiwangncar I missed a final couple minor fixes. It should compile now -- I hope!

[weiwangncar]

The regression test results:

Test Type              | Expected  | Received |  Failed
= = = = = = = = = = = = = = = = = = = = = = = =  = = = =
Number of Tests        : 23           24
Number of Builds       : 60           57
Number of Simulations  : 158           150        0
Number of Comparisons  : 95           86        0

Failed Simulations are: 
None
Which comparisons are not bit-for-bit: 
None

[weiwangncar]

@MicroTed Can you summarize the updates in the RELEASE NOTE section? This is what we use to prepare the release description. Thanks!