Adding udm microphysics as option 27

[dudhia]

TYPE: new feature

KEYWORDS: UFS Double Moment Microphysics scheme (UDM)

SOURCE: Songyou Hong via internal

DESCRIPTION OF CHANGES:
The new microphysics option is based on 7-class WDM7 and will be mp_physics=27. UDM mp largely adopts microphysical processes in WDM7, but with bug fixes or revisions based on literature and accumulated realism. UDM mp utilizes the in-cloud microphysics concept (Kim and Hong 2018), with the addition of water-friendly aerosols for CCN initialization. Semi-lagrangian sedimentation of Juang and Hong (2010) is also re-configured for computational efficiency and numerical accuracy. All production terms are optimized by introducing a cloud-top definition for hydrometeors.

LIST OF MODIFIED FILES:
M Registry/Registry.EM_COMMON
M phys/Makefile
M phys/module_microphysics_driver.F
M phys/module_physics_init.F
M phys/module_mp_udm.F

TESTS CONDUCTED:

1. Compilation on derecho Cray Intel (ftn) seems to need -O2.
2. squall2d_x test case runs OK.
3. Are the Jenkins tests all passing? Yes.

RELEASE NOTE: UFS Double Moment (UDM) 7-class microphysics from Songyou Hong added (mp_physics=27).

[dudhia]

It has failed the tests, so I need to know what happened.

[dudhia]

forgot to add new module, done now.

[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

[smileMchen]

@dudhia
Jimy,
The codes look fine to me and I will approve this PR later.
By the way, is there any information regarding the UDM performance/improvement compared to WDM7? Thanks.

[weiwangncar]

Do we still check all these variables' presence if we only have one dynamic core?

[dudhia]

I think this is part of a bigger question, but if they are optional in the driver we need these.

[weiwangncar]

@dudhia Can you or Songyou add some more description to the scheme, especially for its difference and improvements over WDM7? Is the computation speed improved?

[Songyou184]

UDM mp largely adopts microphysical processes in WDM7, but with
bug fixes or revisions based on literature and accumulated realism.
UDM mp utilizes the in-cloud microphysics concept (kim and hong 2018), with the addition of water-friendly aerosols for CCN initialization. Semi-lagrangian sedimentation of juang and hong (2010) is also re-configured for computational efficiency and numerical accuracy. All production terms are optimized by introducing a cloud-top definition for hydrometeors.

[weiwangncar]

@dudhia @Songyou184 I took the liberty and added it to the PR itself. It may be useful to add it to the release notes too.