1. Experimental tag for cesm1.5
Tag for 28 (mini-breck code)
28 code is 4-month old
Tag for 36 (modern version of the code base)
Purpose: Up-to-date code base
We expect differences in climate because there are differences in the code.

2. What are the differences 28  36 ?
28 code
36 code
Differences
cime
cime4.2.3_cntlexp.06
cime4.4.5_cntlexp.06
cam
cam5_4_29
cam5_4_51
mods to energy conservation fixer WACCM updates (se grid, gravity wave drag consistent with CCMI, fix for troposphere/stratosphere heterogeneous chemistry rates)
clm
respmods_n06_clm4_5_7_r162
respmods_n11_clm4_5_7_r169
minor updates to the nitrogen code
bug fix to the methane code
Both affect plant productivity and biogeophysical properties of the surface
cice
cice5_
cice5_
SW bug fix
pop
cesm_pop_2_1_
cesm_pop_2_1_
compute the surface layer depth to be 10% of the boundary layer
cism
cism2_1_10
cism2_1_13
Nothing important ;)
ww3
ww3_151016
mosart
mosart1_0_14
mosart1_0_16
bug fixes which could change discharge for some rivers. Expected to be similar to 28.

3. 36 versus 28 diagnostics pi_control 36 20-year run
Initialized same way as 28 (spunup ocean)
Could be extended to 50 years
All diags are on the CESM1.5 webpage at:

4. 36 versus 28 diagnostics
36 decently balanced: RESTOM =-0.08 W/m2 For the same period: for 28, RESTOM = 0.03W/m2
36 is warmer than 28
Impact on sea-ice ? Sea-ice already was too low in 28)

5. 36 versus 28 (AMWG diags) Surface Temperature (TS) TS is warmer in 36.
Global: ΔTS = 0.23K
Ocean: ΔTS = 0.15K
Land: ΔTS = 0.46K
TS is warmer in 36.
Largest differences are over land

6. 36 versus 28 (AMWG diags) Precipitable water
28: PREH20 = mm
36: PREH20 = mm
ΔPREH20 = 0.23 mm
36 is moister than 28 Consistent with 36 warmer than 28

7. Energy conservation issue (slide from Feb 9)
Something happened between panel 1 and 2
Something happened with new autoconversion
Pete’s fix for energy conservation

8. Energy conservation: RESTOM-RESSURF
Abs( RESTOM – RESSURF)
RESTOM - RESSURF is improved in 36 but not as much as when using new autoconversion

9. 36 versus 28 (land diags)
From Keith Oleson: it seems to be a bit different in 36 from the land perspective, warmer overall. We anticipated the climate to be different because of changes to the nitrogen cycle (including methane) that are in the tag you are using.

10. 36 versus 28 (ice diags)
From Dave B: These are different and with only 20 years it is hard to say, but overall they appear to be within the variability.

11. 36 versus 28 (ocean diags) From
RUNOFF
HBLT
From

12. Instructions to run cesm1.5
Tag for 28 (mini-breck code)
Tag
+ use modifications in (you REALLY need these !!!!)
Tag for 36 (modern version of the code)
Tag:
Create new case command
./create_newcase -case $yourcasename -compset B1850 -res f09_g16 -mach yellowstone -user_mods_dir b1850 -pecount X -project $project_number
This only works for B1850. For other compsets (F), use modifications in :

13. Instructions to run cesm1.5
Living document As of today (March 9, 2016)
B1850 out of the box