The Madden–Julian Oscillation Observed during the TOGA COARE IOP: Global View

Yanai, Michio; Chen, Baode; Tung, Wen‐wen

doi:10.1175/1520-0469(2000)057<2374:tmjood>2.0.co;2

Cited by 127 publications

(149 citation statements)

References 84 publications

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“…1 depicts the zonal and vertical flow and heating contours along the equator, y ϭ 0. Note the pronounced upward vertical and westward tilt to this synoptic-scale wave train of circulations; this is the crucial observational feature of the supercluster wave trains from H captured by these balanced SEWTG solutions (22,25); for ␣ ϭ 0 or 0 ϭ 0, all of the synoptic-scale wave trains are upright, having no tilt. With the explicit solution formulas in Eq.…”

Section: [7]mentioning

confidence: 89%

A multiscale model for tropical intraseasonal oscillations

Majda

Biello

2004

Proc. Natl. Acad. Sci. U.S.A.

150

107

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The tropical intraseasonal 40-to 50-day oscillation (TIO) is the dominant component of variability in the tropical atmosphere with remarkable planetary-scale circulation generated as envelopes of complex multiscale processes. A new multiscale model is developed here that clearly demonstrates the fashion in which planetary-scale circulations sharing many features in common with the observational record for the TIO are generated on intraseasonal time scales through the upscale transfer of kinetic and thermal energy generated by wave trains of organized synoptic-scale circulations having features in common with observed superclusters. The appeal of the multiscale models developed below is their firm mathematical underpinnings, simplicity, and analytic tractability while remaining self-consistent with key features of the observational record. The results below demonstrate, in a transparent fashion, the central role of organized vertically tilted synoptic-scale circulations in generating a planetary circulation resembling the TIO.T he dominant component of intraseasonal variability in the tropics is the 40-to 50-day tropical intraseasonal oscillation (TIO), often called the Madden-Julian oscillation (MJO) after its discoverers (1). In the troposphere, the MJO is an equatorial planetary-scale wave envelope of complex multiscale convective processes that begins as a standing wave in the Indian Ocean and propagates across the Western Pacific at a speed of Ϸ5 ms Ϫ1 (2-5). The planetary-scale circulation anomalies associated with the MJO significantly affect monsoon development and intraseasonal predictability in mid-latitudes and impact the development of the El Niño southern oscillation (ENSO) in the Pacific Ocean, which is one of the most important components of seasonal prediction (6-8). Present-day computer general circulation models (GCMs) typically poorly represent the MJO (9). One conjecture for the reason for this poor performance of GCMs is the inadequate treatment across multiple spatial scales of the interaction of the hierarchy of organized structures that generate the MJO as their envelope.There have been a large number of theories attempting to explain the MJO through a specific linearized mechanism such as evaporation wind feedback (10, 11), boundary layer frictional convective instability (12), stochastic linearized convection (13), radiation instability (14), and the planetary-scale linear response to moving heat sources (15). Moncrieff (16) recently developed an interesting phenomenological nonlinear theory for the upscale transport of momentum from equatorial mesoscales [O (300 km)] to planetary scales and applied this theory to explain the ''MJO-like'' structure in recent ''super-parametrization'' computer simulations (17) with a scale gap (no resolution at all) on scales between 200 and 1,200 km. Despite all of these interesting contributions, the problem of explaining the MJO has recently been called the search for the Holy Grail of tropical atmospheric dynamics (14). Here we contribute to this sear...

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Section: [7]mentioning

confidence: 89%

A multiscale model for tropical intraseasonal oscillations

Majda

Biello

2004

Proc. Natl. Acad. Sci. U.S.A.

150

107

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“…Analysis of observational data from TOGA-COARE (Tropical Ocean Global Atmosphere Coupled Ocean Atmosphere Response Experiment) provides a revealing look into the multicloud and multiscale structure of convection in the Tropics (22) and, in particular, the MJO (23)(24)(25). These observations reveal a central role of three cloud types above the boundary layer in the MJO: lower-middle troposphere congestus cloud decks that moisten and precondition the lower troposphere in the initial phase, followed by deep convection and a trailing wake of upper troposphere stratiform clouds (23,25).…”

Section: T He Dominant Component Of Intraseasonal Variability In Thementioning

confidence: 99%

Madden–Julian Oscillation analog and intraseasonal variability in a multicloud model above the equator

Majda

Stechmann

Khouider

2007

Proc. Natl. Acad. Sci. U.S.A.

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The Madden-Julian Oscillation (MJO) is the dominant component of tropical intraseasonal variability, and a theory explaining its structure and successful numerical simulation remains a major challenge. A successful model for the MJO should have a propagation speed of 4 -7 m/s predicted by theory; a wavenumber-2 or -3 structure for the planetary-scale, low-frequency envelope with distinct active and inactive phases of deep convection; an intermittent turbulent chaotic multiscale structure within the planetary envelope involving embedded westward-and eastward-propagating deep convection events; and qualitative features of the low-frequency envelope from the observational record regarding, e.g., its zonal flow structure and heating. Here, such an MJO analog is produced by using the recent multicloud model of Khouider and Majda in an appropriate intraseasonal parameter regime for flows above the equator so that rotation is ignored. Key features of the multicloud model are (i) systematic low-level moisture convergence with retained conservation of vertically integrated moist static energy, and (ii) the use of three cumulus cloud types (congestus, stratiform, and deep convective) together with their differing vertical heating structures. Besides all of the above structure in the MJO analog waves, there are accurate predictions of the phase speed from linear theory and transitions from weak, regular MJO analog waves to strong, multiscale MJO analog waves as climatological parameters vary. With all of this structure in a simplified context, these models should be useful for MJO predictability studies in a fashion akin to the Lorenz 96 model for the midlatitude atmosphere.coherent planetary intraseasonal variability ͉ multiscale structure ͉ intermittency in convection ͉ nonlinear analog model T he dominant component of intraseasonal variability in theTropics is the 40-to 50-day tropical intraseasonal oscillation, often called the Madden-Julian Oscillation (MJO) after its discoverers (1). In the troposphere, the MJO is an equatorial planetary-scale wave envelope of complex multiscale convective processes that begins as a standing wave in the Indian Ocean and propagates across the western Pacific at a speed of Ϸ5 m⅐s Ϫ1 (2-5). The planetary-scale circulation anomalies associated with the MJO significantly affect monsoon development and intraseasonal predictability in midlatitudes and the development of the El Niño southern oscillation in the Pacific Ocean, which is one of the most important components of seasonal prediction (6, 7). Present-day computer general circulation models typically poorly represent the MJO (8, 9). One conjectured reason for the poor performance of general circulation models is the inadequate treatment across multiple spatial scales of the interaction of the hierarchy of organized structures that generate the MJO as their envelope.There have been a large number of theories attempting to explain the MJO through a specific linearized mechanism, such as evaporation-wind feedback (10, 11), boundary layer...

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“…Q 1 and Q 2 have been widely used to reveal the role of diabatic heating in atmospheric processes such as the Madden-Julian Oscillation [e.g., Yanai et al, 2000;Lin et al, 2004], monsoons [e.g., Hung and Yanai, 2004;Garcia and Kayano, 2011], and energy and moisture budgets [e.g., Lin and Johnson, 1996b;Yang and Smith, 1999;Katsumata et al, 2011]. Neglecting ice processes, the equations of Q 1 and Q 2 can be written as…”

Section: Introductionmentioning

confidence: 99%

Three‐dimensional constrained variational analysis: Approach and application to analysis of atmospheric diabatic heating and derivative fields during an ARM SGP intensive observational period

Tang

Zhang

2015

JGR Atmospheres

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Atmospheric vertical velocities and advective tendencies are essential large-scale forcing data to drive single-column models (SCMs), cloud-resolving models (CRMs), and large-eddy simulations (LESs). However, they cannot be directly measured from field measurements or easily calculated with great accuracy. In the Atmospheric Radiation Measurement Program (ARM), a constrained variational algorithm (1-D constrained variational analysis (1DCVA)) has been used to derive large-scale forcing data over a sounding network domain with the aid of flux measurements at the surface and top of the atmosphere (TOA). The 1DCVA algorithm is now extended into three dimensions (3DCVA) along with other improvements to calculate gridded large-scale forcing data, diabatic heating sources (Q 1 ), and moisture sinks (Q 2 ). Results are presented for a midlatitude cyclone case study on 3 March 2000 at the ARM Southern Great Plains site. These results are used to evaluate the diabatic heating fields in the available products such as Rapid Update Cycle, ERA-Interim, National Centers for Environmental Prediction Climate Forecast System Reanalysis, Modern-Era Retrospective Analysis for Research and Applications, Japanese 55-year Reanalysis, and North American Regional Reanalysis. We show that although the analysis/reanalysis generally captures the atmospheric state of the cyclone, their biases in the derivative terms (Q 1 and Q 2 ) at regional scale of a few hundred kilometers are large and all analyses/reanalyses tend to underestimate the subgrid-scale upward transport of moist static energy in the lower troposphere. The 3DCVA-gridded large-scale forcing data are physically consistent with the spatial distribution of surface and TOA measurements of radiation, precipitation, latent and sensible heat fluxes, and clouds that are better suited to force SCMs, CRMs, and LESs. Possible applications of the 3DCVA are discussed.

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The Madden–Julian Oscillation Observed during the TOGA COARE IOP: Global View

Cited by 127 publications

References 84 publications

A multiscale model for tropical intraseasonal oscillations

A multiscale model for tropical intraseasonal oscillations

Madden–Julian Oscillation analog and intraseasonal variability in a multicloud model above the equator

Three‐dimensional constrained variational analysis: Approach and application to analysis of atmospheric diabatic heating and derivative fields during an ARM SGP intensive observational period

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