b.e23_alpha16g.BLT1850.ne30_t232.082b

[cecilehannay]

Purpose: Test new gustiness formulation to align with Redelsperger et al (2000) with alpha = 1x

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Description: Same as 78b except use new formulation for gustiness with alpha = 1x

vmag   = max(seq_flux_atmocn_minwind, sqrt( (ubot(n)-us(n))**2 + (vbot(n)-vs(n))**2 + (1.0_R8*ugust(min(rainc(n),6.94444e-4_r8))**2)) )

in shr_flux_mod.F90

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Case directory:

• Locally (if still available): /glade/campaign/cesm/cesmdata/cseg/runs/cesm2_0/b.e23_alpha16g.BLT1850.ne30_t232.082b

• On github: https://github.com/NCAR/amwg_dev/tree/b.e23_alpha16g.BLT1850.ne30_t232.082b

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  Sandbox:

• Locally (if still available): /glade/work/hannay/cesm_tags/cesm2_3_alpha16g

• On github: https://github.com/ESCOMP/cesm/tree/cesm2_3_alpha16g

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  Diagnostics:

• Diags (if available): https://webext.cgd.ucar.edu/BLT1850/b.e23_alpha16g.BLT1850.ne30_t232.082b/

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  Output:

• Raw output on derecho (if still available): /glade/derecho/scratch/hannay/archive/b.e23_alpha16g.BLT1850.ne30_t232.082b/

• CAM Climos: /glade/campaign/cgd/amp/amwg/climo/b.e23_alpha16g.BLT1850.ne30_t232.082b

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  Contacts: @cecilehannay, @megandevlan, @swrneale, @PeterHjortLauritzen, @adamrher, @JulioTBacmeister, @gustavo-marques

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  Extra details:

[megandevlan]

It's still early, but the good news is that years 2-14 here confirm that the coupled runs are similar to what we saw in AMIP tests.

The fix weakens the LHFLX enhancement we saw in DJF for the Indian Ocean, and there's a large response in the western and central Pacific (top plot). Tropical precip generally decreases relative to 78b (without the fix), especially in equatorial west Pacific. IndIan Ocean shows some increases though (bottom plot).

DJF LHFLX (Years 2-14)

DJF PRECT (Years 2-14)

[megandevlan]

Adding ten years to plots above here. For years 2-24 the DJF differences are weaker, which is good. For the Indian Ocean precip signal, it's nice to see that increases in the eastern part of the basin aren't erased and are possibly even enhanced a bit. There's still a pretty noticeable reduction in LHFLX over the Central Pacific and NE Atlantic though.

[swrneale]

Quick analysis of El Nino. Basically the magnitude of gustiness still controls the magnitude of ENSO (3x (82b) has a greater reduction than 1x (81b) however the baseline 78b was already on the low side so it is arguable 3x hits it too hard. Usual figures below. There may also be some mean state trend that is giving rise to a trend a reduced variability and gust runs are only ~30 years.

[adamrher]

Dropping this comparison here of DJF means wrt to obs. I'm looking at this Large & Yeager product in the amwg diags, which has QFLX (the water vapor flux in mm/day), but not LHFLX.

CNTL = #66 which is the pre-gust version of the current track (different clubb_c8 tuning than 78b)

The first panel is CNTL diff w/ obs. The other panels are differences from the CNTL.

[edit - it would be interesting to look at the Asian Monsoon in the gust runs. I see similar improvement in JJA in this region. Perhaps a Hovmoller plot in latitude?]