Global Modeling

1
Global Modeling

• The climate in the VOCALS region is a tightly
  coupled atmosphere-ocean-land system

2
Scale interaction

• Downscaling large-scale forcing to regional
  domain. How much improvement can be gained from
  it?
• Upscaling regional effects to global domain. How
  strong are they?

Key role of VOCALS is to clarify relative
emphasis on regional (nested) vs. global framework
3
Regional Modeling Processes VOCALS Data
4
VOCALS Data to Verify Model Improvements
5
Consensus

• In the ocean, coastal upwelling develops directly
  affecting a narrow region (50-100 km width),
  suggesting a resolution requirement for models.
• - Upwelling brings cold water to surface
• - Eddies develop and transport heat (nutrients)
  etc. offshore
• The uncoupled global AGCMs and OGCMs still have
  systematic errors and the impact of correcting
  those errors is uncertain at the moment.

6
Key role of VOCALS is to clarify relative
emphasis on regional (nested) vs. global
framework
VOCALS strategy is to follow the two approaches
using a model hierarchy (LES, MMF, Mesoscale,
GCMs)
7
VOCALS issues

• How to systematically eliminate sources of error
  (e.g. trade winds, upwelling and oceanic eddies,
  physical properties of Scu)
• Resolution requirement for atmospheric and
  oceanic models.
• Readiness of regional models to handle PBL cloud
  issues, including microphysics?
• Need for a dry run prediction period to be made
  by the operational centers in preparation for the
  actual VOCALS Rex period.

8
Atmosphere

• Diurnal cycle (circulation, air temperature). Do
  the models capture mechanism for diurnal
  variation of stratus? Linkage with observations?
• Upsidence wave Rectification effect on the ABL
  (and oceanic mixed layer)? Need to examine time
  series of ocean temperature.
• Very-near upstream influence of the Andes
  Subsidence due to convection over mountain and
  coupled land-atmosphere processes

9
Ocean

• What, if any, model development needs to occur to
  do ocean modeling in the VOCALS region?
• What is the state of lateral boundary conditions?
• Could recent developments in parameterization of
  horizontal eddy mixing be leveraged for VOCALS?

10
Organizational Issues

• Need to establish a coherent implementation of
  modeling projects
• Should we try to obtain dedicated CP time for
  VOCALS modeling? If so, from where?
• Are we missing any group?