Update on AMWG/CAM ActivitiesPhil Rasch

• Report on last meeting & where we are going• Answer questions• Focus over last year on reducing systematic biases in CAM/CCSM• I view the last years effort as extremely successful, and am very

optimistic about accomplishments over the next year

• Working group web page http://www.ccsm.ucar.edu/working_groups/Atmosphere

• Talks from last meeting http://www.ccsm.ucar.edu/working_groups/Atmosphere/Agendas/amwgmeetingagenda2006Jan.html

• WIKI at http://swiki.ucar.edu/cam-dev (contact Andrew Gettelman for access)

What was discussed• Convection, Convection, Convection, ….• PBL and Shallow convection• Polar Clouds• Gravity Wave Drag• Aerosols & Microphysics• Diagnostics

– extratropical cloud/cyclones– Extratropical dynamics– CAPT

• Dynamical Cores• Data Assimilation• See http://swiki.ucar.edu/cam-dev for developments in these areas

(contact Andrew Gettelman for passwords if you need one)

What was missing

• Cloud fraction, subgrid variability, cloud overlap, independent column approximations

• Gravity Wave Drag• Flow dependent horizontal diffusion (e.g.

Smagorinsky)• Microphysics within vigorous convection• Radiation• Extra-terrestrial CAM• New grids/numerical techniques for CAM

– HOMME– Conservative remapping

What is happening in other components of CCSM

• Software engineering efforts relevant to the development of CCSM– Subversion repository maturing– Sequential CCSM development (significant refactoring of CAM as first stage. No

re-griding yet)– Removed dependencies within CAM assuming rectangular lat/lon grids (opens

path for cubed sphere and triangular grids)– Coupling Frameworks: We plan to exploit two frameworks

• Much of the development has been done using MCT • Nearing complete ESMF capability. Stage 1 effectively complete. Stage 2 begins.

– Unification of FV core with NASA GEOS-5 modeling effort– Fixed OMEGA (pressure velocity) in CAM– Much improved regression testing procedures for CAM, constantly evolving, to

exercise new functionality– Database of experiments and control simulations (currently most relevant for

CCSM rather than CAM)– Tropospheric MOZART/Chem, WACCM, UW Physics, Emanuel convection,

Offline CAM & CGD aerosols on development trunk as options– Massively parallel issues [I/O, dynamical core, memory (particularly lookup

tables in chemistry)]

What is happening in other components of CCSM part II

• Exploratory– Regional Cloud Resolving Model (NRCM, WRF run in a channel

driven by either analyses or CCSM)• The path forward

– New land model (revisions to hydrology)– Chemistry [w/aerosols (simple and more complex)]– More Biogeochemistry

• (Carbon, Nitrogen cycles)• C4MIP -> C-LAMP

(compare CASA, CN, IBIS w/in SciDAC)– Substantially revised ocean model (POP-2 code, vertical

resolution, horizontal viscosity, GM modifications, new advection)

– New Sea Ice Model (CSIM -> CICE4, ridging, albedo, meltponds)

Feb 27-28

Interim model (CCSM3.5)• Will combine all model component improvements available as of about 1

March, 2007• Goal to allow exploration of Carbon Cycle early in the evolution of CCSM4

(spinups of as much as a thousand years are necessary to equilibrate biogeochemical models)

• Strategy is starting to evolve to produce controls for the CC experiments– Balance CCSM at TOA at 1870 conditions– Run model forward in time with transient forcing, look at present day simulation

to make sure it looks like today’s planet earth.– Iterate until physical system acceptable– Start BGC simulations with CCSM 3.5

• Improvements continue within components at least until early 2008 (phase II)

• In 2008 we put models together again and start phase III “test, finalize, and thoroughly understand the CCSM4 that includes the new physical components, the final carbon cycle component, aerosol indirect effects, and the new land ice component. Includes obtaining the very long spinups required for the biogeochemistry and land ice components, and determining the final parameter settings for the CCSM, such as the sea ice albedos, etc. “

• Goal is to have a model we have some confidence in by early 2009.

Deep Convection Modifications

• Neale and Richter– Convective momentum transports– Dilute instead of undilute plume calculation, with

freezing of cloud water• Zhang

– Convective inhibition (no conv CIN>400 J/kg)– d(CAPE)/dt from large-scale > 0 J/kg/hr

• Wu– Convective momentum transports– Convective inhibition (no conv CIN>400 J/kg)– d(CAPE)/dt from large-scale > 20 J/kg/hr

Control Neale+Richter

Zhang Wu

Annual

Rainfall

Neale, Wu, Zhang, Richter

Control Neale+Richter

Zhang Wu

JJA

Rainfall

Neale, Wu, Zhang, Richter

Control Neale+Richter

Zhang Wu

ANN Surface Stress

Neale, Wu, Zhang, Richter

Control Neale+

Richter

Zhang Wu

Neale, Wu, Zhang, Richter

Control Neale+Richter

Zhang Wu

20-100 day

[U] 200mb

Variance

MJO

INDEX

Neale etal

Control Neale+Richter

Zhang Wu

NCEP RAW OMEGA 500mb

Neale etal

Control Neale+Richter

Zhang Wu

HadiSST nino3.4 SST

Neale etal

Control Neale+Richter

Zhang Wu

Lag 0 Nino 3 SST Correlation

Neale etal

ITCZ regime, forecast T error, July 1998

ITCZ region: forecast error is set within 1 day

Control

Warm bias

Neale+Richter

Zhang Wu

Cold bias

Hannay etal

ITCZ regime, Precipitation, July 1998--- GPCP--- Control --- Neale+Richter --- Zhang--- Wu

- GPCP DatasetDaily precipitation

- Control Loses water very quickly during day 1.

- Wu and Zhang Strong diurnal cycle.

Total precipitation

Omega Hannay etal

Precipitation at ARM SGPD. Williamson etal

• Composite picture is somewhat misleading– All variants are a substantial

improvement on control– Rainfall is episodic

• Variants fire when they shouldn’t, don’t fire when they should

• Wu format fires correctly in afternoon when primed with observations

• Other problems with Brazilian rainfall