SuperParameterized CESM: Multi-Instance Land

Ian Baker, Mark Branson, Don Dazlich, Dave Randall, Scott Denning, Cheryl Craig, Jim Edwards, Mariana

Vertenstein, Brian Eaton, and many more

NCAR LMWG meeting, Boulder CO, 24-26 Feb 2014Friday, February 21, 14

Superparameterization

• GCM timestep; tens of minutes

• CRM timestep; seconds

Friday, February 21, 14

Superparameterization• ‘Curtain’ of CRMs in a single GCM gridcell

• Current Version: CAM/SAM/CLM

• How do we represent land in this configuration?

Friday, February 21, 14

Superparameterized CESM (SP-CESM)

Multiple atmospheres, single land

Multiple atmospheres, multiple land

From this To this

Friday, February 21, 14

TESTING: Superparameterized

Single Column Model (Super-SCM)

(NOT CESM)

From this

To thisTo this

Atmosphere

Land

‘SASL’

‘MASL’ ‘MAML’

Friday, February 21, 14

SCM Testing:

K83• Precip similar in all configurations

• SASL: larger LE (wet season), H

• SASL: Radiation

• Diurnal precip patterns similar (not shown)

Friday, February 21, 14

SCM Testing:

K83: PBL

• ‘Apples and Oranges’: meters vs. pressure height

• SASL: deeper mean PBL in wet season - no nocturnal collapse

• MASL/MAML : Similar behavior, larger annual ‘peak’ amplitude than SASL

Friday, February 21, 14

SCM Testing: K83:

carbon cycle

• SASL: most radiation, smallest GPP• MASL: Larger GPP, less midday reduction• SASL: if precip is similar, why so much stress?

Friday, February 21, 14

SCM Testing: K83:

canopy• SASL: water evaporates off leaves, not available to roots

• MASL: Less leaf water than SASL, more than MAML

• Re-partitioning of canopy processes can have large influence on overall behavior

• Other sites (ARM)?Friday, February 21, 14

Global Runs-Sanity ChecksGlobal Mean Surface Sensible Heat Flux

0 20 40 60 80 100 120Month

16

18

20

22

24

26

W/m

2

Multi-Instance Non-MI

Global Mean Surface Latent Heat Flux

0 20 40 60 80 100 120Month

76

78

80

82

84

86

88

90

W/m

2

Multi-Instance Non-MI

Global Mean Surface Air Temperature

0 20 40 60 80 100 120Month

284

286

288

290

292

K

Multi-Instance Non-MI

Global Mean Water Equivalent Snow Depth

0 20 40 60 80 100 120Month

0.030

0.035

0.040

0.045

0.050

m

Multi-Instance Non-MI

Friday, February 21, 14

Global Runs - Surface Temperature

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Global Runs - DJF

LE

H

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Global Runs - 300mb Height

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Hotter Land: Bug or a Feature?

Friday, February 21, 14

Summary• We have distributed land working in SP-

CESM

• We still have work to do

- Tracers (CO2)

- code compliance

- testing

• Code should be available for checkout within 1 year

Friday, February 21, 14