Pallav Ray, Joe Tenerelli and Chidong Zhang

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Study of the Tropical Atmosphere
Introduction of a New Tool

• Pallav Ray, Joe Tenerelli and Chidong Zhang
• MPO, RSMAS, University of Miami
• 14 April, 2004

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Outline

• Background and Motivations
• Model set up and Data
• Results
• Conclusions and Future Work

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Background
Mesoscale Model
GCM
1. Small area coverage 1. Global coverage 2.
Finer resolution 2. Coarse resolution 3.
Prescribed boundary condition 3. No lateral
boundaries 4. Synoptic scale 4. Seasonal to
Climate
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Motivation

• To fill the gap between mesoscale model and
  global model in terms of area coverage and
  resolution.

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Tropical MM5
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Is such a model applicable for tropics ?
Zhang et al. (2004)
Gustafson and Weare (2004)
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Model Domains
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Model Physics and Data

• Betts-Miller (1986) Grell et al. (1991)
  convective parameterization
• Goddard moisture scheme (Lin et al., 1983) .
• Mellor Yamada PBL scheme (Janjic, 1990, 1994).
• 28 vertical levels (unevenly spaced)
• 240 sec integration time step
• NCEP-NCAR Reanalysis data for initialization and
  boundary conditions.
• TMI wind and precipitable water

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Wind at 200 mb (m/s)
D2
D1
D1D3
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Surface wind (m/s)
D2
D1
D1D3
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Atmospheric Water Vapor (Kg/m2)
D2
D1
D1D3
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V wind at 95 W
Zhang et al. (2004)
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Conclusions

• Tropical MM5 has the potential to fill the much
  needed gap between conventional mesoscale model
  and GCM.
• The model is able to capture the large-scale
  features of the tropics, and can be used for a
  variety of studies. Higher resolution improves
  the model output to a great extent.

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Future Work
On the model

• 12 hourly (2.5ox2.5o) NCEP-NCAR data were used.
  We plan to use different data for initialization
  (e.g., ECMWF data).
• Model output was taken every 12 hours. Diurnal
  variation could be important (Chen and Houze,
  1997).
• To run the model with finer resolution (e.g.,
  Colle et al. 1999)
• ..

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Future Work
Scientific Problem

• Monsoonal Circulation
• Equatorial Waves
• MJO (Slingo et al., 1996 Gustafson and Weare,
  2004).
• Double ITCZ (Mechoso et al., 1995).
• Water Vapor Transport
• Shallow meridional circulation in the eastern
  Pacific (Zhang et al., 2004).
• Atmospheric Teleconnection in the Tropics

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Thank you