# Presentation: 806979

## Multi-scale Interactions & Tropical convection

*Duane Waliser*
*Jet Propulsion Laboratory/Caltech*
*Pan-WCRP, Beijing, 2008*

*Some Figures *
*for discussion*

## A Typical MJO in N.H. Winter

*Rainfall anomalies propagate in a eastward fashion and mainly affect the Tropical eastern hemisphere.*
*These anomalies are accompanied by anomalies in wind, solar radiation, sea surface temperature, etc.*

- A Typical MJO in N.H. Winter

**Notes:**

5 stages of the wet/dry anomalies of the MJO in boreal winter: (1) initiation, (2) eastward propagation in the Indian Ocean, (3) weakening over the Marine Continent, (4) formation of new convection in the western equatorial Pacific and propagates eastward, and (5) die out n the central Pacific. Each stage lasts about 8 days.

## A Typical MJO in N.H. Summer

*Composite rainfall maps derived from merged satellite and in-situ measurements are separated by 10 days.*
*Rainfall anomalies propagate in a *_***northeast***_* fashion and mainly affect the Tropical eastern hemisphere.*
*These anomalies are accompanied by anomalies in wind, solar radiation, sea surface temperature, etc.*

- A Typical MJO in N.H. Summer

**Notes:**
The MJO undergoes a strong seasonal cycle in both its strength and latitudinal locations [Madden, 1986; Gutzler and Madden, 1989; Salby and Hendon, 1994; Zhang and Dong, 2004], as illustrated in Figures 9 and 10. Its primary peak season is austral summer/fall when the strongest MJO signals are immediately south of the equator; the second peak season is boreal summer when its strongest signals are north of the equator. The primary peak season in austral summer is related to the Australian summer monsoon [Hendon and Liebmann, 1990], while the secondary peak season in boreal summer is related to the Asian summer monsoon [e.g., Lawrence and Webster, 2002].

## Local Synoptic

_**Local Synoptic**_
_**Organization**_
_**By ISO**_

**Goswami et al. 2003**

## Remote

- Organization
- Of Tropical
- Cyclones

**Higgins et al. 2000**

**CPC**
**NCEP**
**NOAA**

-  The green (brown) shading roughly corresponds to regions where convection is favored (suppressed) as represented by 200-hPa velocity potential anomalies Composites are based on 21 events over a 35 day period. Hurricane track data is for the period JAS 1979-1997.  Points of origin in each panel are for different storms. Contour interval is 0.5x106 m2 s-1, negative contours are dashed, and the zero contour is omitted for clarity.

## MJO & ENSO

- MJO & ENSO

**1996/97 **
**Event**

**Notes:**
While the relation between the MJO and Ocean Kelvin waves will undoubtedly be treated many times over the course of this workshop, for completeness sake, I am including this figure which shows the close relationship between MJO and wind variability in the western Pacific, and then the development of the ocean kelvin wave activity as depicted by the depth of the 20C isotherm, and then of course in this particular case, the development of an El Nino.  A case, which probably had a good deal to do with us being here.

## MJO Influence on 

**US West Coast Rainfall**

**CPC**
**NCEP**
**NOAA**

## Extra-Tropical Weather : US West Coast

- Same, except for mid-tropospheric (500 hPa) geopotential height over the Pacific/North American region during northern hemisphere winter. Solid contours indicate regions of anti-cyclonic (clockwise) circulation, dashed contours indicate regions of cyclonic (counterclockwise) circulation.

- Composite tropical convection for three Phases of the Madden Julian Oscillation (MJO). Blue shading indicates increased atmospheric convection. On average each phase lasts 7 days, and these three phases span about one half of a complete MJO cycle.

- Composite Pacific Nortwest wintertime precipitation for three Phases of the Madden Julian Oscillation (MJO). Blue shading indicates increased rainfall.

- Bond and Vecchi, 2004

## Convectively-Coupled Waves

- Wheeler and Weickmann 2001

*Filtering for Tropical Wave Modes*

- Kelvin

- Rossby

- MJO

- Rossby-
- Gravity

**Notes:**
Chen, T.-C., and J. C. Alpert, 1990: Systematic errors in the annual and intraseasonal variations of the planetary-scale divergent circulation in NMC medium-range forecasts. J. Atmos. Sci., 118, 2607-2623.
Lau, K. M. and F. C. Chang, 1992: Tropical intraseasonal oscillation and its prediction by the NMC operational model. J. Climate, 5, 1365-1378.
Hendon, H. H., B. Liebmann, M. Newman, J. D. Glick, J. E. Schemm, 2000: Medium-Range Forecast Errors Associated with Active Episodes of the Madden–Julian Oscillation. Mon.Wea.Rev., 128, 69–86.
Jones, C., D. E. Waliser, J. K. Schemm, and W. K. Lau, 2000: Prediction skill of the Madden-Julian Oscillation in Dynamical Extended Range Forecasts. Climate Dynamics, 16, 273-289.
Krishnamurti, T. N., M. Subramaniam, D. K. Oosterhof, and G. Daughenbaugh, 1990: Predictability of Low-Frequency Modes. Meteorol. Atmos. Phys., 44, 63-83.
Krishnamurti, T. N., M. Subramaniam, G. Daughenbaugh, D. Oosterhof, and J. H. Xue, 1992: One-Month Forecasts of Wet and Dry Spells of the Monsoon. Mon. Weather Rev., 120, 1191-1223.

Lo, F., and H. H. Hendon, 2000: Empirical Prediction of the Madden-Julian Oscillation. Mon. Wea. Rev., 128, 2528-2543..
Mo, K. C., 2001: Adaptive Filtering and Prediction of Intraseasonal Oscillations. Monthly Wea. Rev. Submitted.
Waliser, D. E., C. Jones, J. K. Schemm and N. E. Graham, 1999b: A Statistical Extended-Range Tropical Forecast Model Based on the Slow Evolution of the Madden-Julian Oscillation. J. Clim., 12, 1918-1939.
Wheeler, M. and K. Weickmann, 2001: Real-time monitoring and prediction of modes of coherent synoptic to intraseasonal tropical variability. Mon. Wea. Rev., Submitted.

## Convectively-CoupledEquatorial Waves

**Kelvin Waves**

**Rossby Waves**

**MJOs**

- NH Winter
- MJO, Kelvin, Rossby

**Notes:**
The eastward moving convective center or active phase of the MJO can be viewed as a large-scale ensemble of myriad higher-frequency, small-scale convective systems moving in all directions [e.g., Nakazawa, 1988; Hendon and Liebmann, 1994] (Figure 8). The apparent eastward propagation of the large-scale convective center of the MJO is due to consecutive development of new convective systems, each on average slightly to the east of the previous one. Among others the most noticeable high-frequency variability within the large-scale ensemble of cloud clusters are eastward propagating synoptic-scale disturbances [Dunkerton and Crum, 1995] at the speed of the coupled Kelvin wave, which has been referred to as the supercluster or supercloud cluster [Nakazawa, 1988; Lau et al., 1989], and westward moving disturbances with apparent periods of 2 and 5 days. The 2-day disturbances are likely manifestations of the diurnal cycle of deep convection [Chen and Houze, 1997] and inertiogravity waves [Takayabu, 1994; Liebmann et al., 1997; Haertel and Kiladis, 2004]. The westward propagating 5-day waves might be related to equatorial Rossby waves and mixed Rossby-gravity waves [Wheeler and Kiladis, 1999]. In addition, other types of disturbances, such as easterly waves and tropical storms, also propagate westward. However, all can exist independently of the MJO [Clayson et al., 2002] (Figures 2b and 8).

## MJO & CCEWsMODELINGinIPCC Models

- Lin et al., 2005

- Difficult to get all
- Parts of the Variability Right

## MJO Simulation Diagnostics: Variance Precip & U850

- MJO Simulation Diagnostics: Variance Precip & U850

## MJO Simulation Diagnostics: W-F Precip & U850

- MJO Simulation Diagnostics: W-F Precip & U850

**Notes:**
- Variance map includes all of the zonal wavenumber components and it is not able to examine what is the prefer time scale for model’s subseasonal variability. (need for wavenumber-frequency diagram)
- In the case of models here, U850 is better than precipitation, consistent to Zhang et al. (2006).
- For precipitation, models (SNU, GEOS5, CAM3.5, ECHAM4/OPYC, CM2.1 and CFS) have spectral peak within the sub-seasonal time scale smaller than that in the low frequency (period longer than 80 day) part.
- General statement which has been used in many literature “model has faster and weaker MJO signal” seems not to be appropriate at least for U850.

## Multi-Scale 

- Structure

- Nakazawa 1988

- How Important is
- This Finer Structure To
- The Phase Speed, Eastward Propagation, etc

- MJO

## Multi-scale StructureTime–longitude diagram of CLAUS Tb (2.5S–7.5N), January–April 1987

- Courtesy of G. Kiladis

**Notes:**
The eastward moving convective center or active phase of the MJO can be viewed as a large-scale ensemble of myriad higher-frequency, small-scale convective systems moving in all directions [e.g., Nakazawa, 1988; Hendon and Liebmann, 1994] (Figure 8). The apparent eastward propagation of the large-scale convective center of the MJO is due to consecutive development of new convective systems, each on average slightly to the east of the previous one. Among others the most noticeable high-frequency variability within the large-scale ensemble of cloud clusters are eastward propagating synoptic-scale disturbances [Dunkerton and Crum, 1995] at the speed of the coupled Kelvin wave, which has been referred to as the supercluster or supercloud cluster [Nakazawa, 1988; Lau et al., 1989], and westward moving disturbances with apparent periods of 2 and 5 days. The 2-day disturbances are likely manifestations of the diurnal cycle of deep convection [Chen and Houze, 1997] and inertiogravity waves [Takayabu, 1994; Liebmann et al., 1997; Haertel and Kiladis, 2004]. The westward propagating 5-day waves might be related to equatorial Rossby waves and mixed Rossby-gravity waves [Wheeler and Kiladis, 1999]. In addition, other types of disturbances, such as easterly waves and tropical storms, also propagate westward. However, all can exist independently of the MJO [Clayson et al., 2002] (Figures 2b and 8).

## Results from the Aqua-Planet Experiment (APE)

- Courtesy,
- Dave Williamson, NCAR

- NICAM Model
- Looks promising
- e.g., Matsuno talk

## How to address this problem?

- i.e. simultaneously address the large-to-global scale and the  scales of convective organization?
- What if we started from scratch?

- Winter 2005-6

- Kelvin Waves

- Rossby Waves

- MJOs

- Dominant Convectively-Coupled Tropical Waves Projected onto OLR Anomalies. Wheeler and Weickmann, 2001

## Invest in In-Situ Measurements for Diagnostic/process studies and data assimilation

- _Invest in In-Situ Measurements for Diagnostic/process studies and data assimilation_

- T-PARC

- AMY

## Add In-situ measurements over tropical oceans for Diagnostic/process studies and data assimilation

- PIRATA

- _Add In-situ measurements over tropical oceans for Diagnostic/process studies and data assimilation_

## TMI: sea surface temperature w/clouds

- TOPEX: sea surface height
- QuickScat: ocean surface winds
- TRMM: precipitation
- AIRS: temperature and water vapor profiles
- CloudSat: cloud profiles
- Calipso: aerosol/thin-cloud profiles
- AMSRE: ocean precip, water vapor, liquid water
- MLS: upper tropospheric water vapor, cloud ice, temperature
- CERES: TOA and surface radiative fluxes
- MODIS: cloud characteristics, ocean color, land characteristics
- AURA platform: atmospheric composition/chemistry
- MISR: aerosol and cloud structure

- _Build a robust satellite Observing system_

## Develop “high-Resolution” Regional & Global Modeling (& Analysis) Capabilities

- A CRM

- MMF; “superparameterization”

- A CRM

- A GCM cell

*Courtesy Satoh*

- (CSU, LLNL, GSFC, PNNL)

- Frontier Research Center for Global Change

- Global CSRM

- NCAR Tropical Chanel Momdel

## YoTC

**YoTC**

##  YOTC Programmtic Hypothesis: We can better exploit the observation infrastructure and modeling capabilities that we already have and achieve better understanding, simulations and predictions of tropical convection.

**Satellite Observations (**e.g., EOS**)**
**In-Situ Networks (**ARM, CEOP**)**
**GOOS (**e.g., TAO, PRADA, drifters**)**
**IOPs (**e.g., VOCALS, T-PARC, AMY**)**
**TIGGE**
**High-Resolution Deterministic Forecast Models & Global Analyses**
**Research Models **[e.g., Regional and Global Cloud(-System) Resolving Models]

- New/Improved Resources