Aspects of the 40–50 Day Oscillation during the Northern Winter as Inferred from Outgoing Longwave Radiation

Lau, K.-M.; Chan, Paul H.

doi:10.1175/1520-0493(1985)113<1889:aotdod>2.0.co;2

Cited by 211 publications

(133 citation statements)

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“…It has also been shown that the "westerly wind burst" is closely related to and may be instrumental to the onset of ENSO (Murakarni andSumathipala, 1988 andLukas, 1987). Independent of the above observations, many recent studies have shown that strong convective activities associated with the 30-60 day oscillations are confined to the Indian Ocean/Wester Pacific region (Knutson and Weickmann, 1987, Lau and Chan, 1985, 1986a. In particular, Lau and Chan (1985) found that as the 30-60 day oscillation propagates into the equatorial western Pacific region, it seems to stall and spawn additional convection before the convection dies off as the waves propagate into the eastern Pacific.…”

Section: Introductionmentioning

confidence: 85%

Dynamics of Super Cloud Clusters, Westerly Wind Bursts, 30-60 Day Oscilations and ENSO: An Unified View

Lau

Sui

et al. 1989

Journal of the Meteorological Society of Japan

115

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Section: Introductionmentioning

confidence: 85%

Dynamics of Super Cloud Clusters, Westerly Wind Bursts, 30-60 Day Oscilations and ENSO: An Unified View

Lau

Sui

et al. 1989

Journal of the Meteorological Society of Japan

115

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“…Moreover, previous analysis of the life cycle of the eastward-propagating MJO, as depicted from distinct empirical and modelling methods, evidenced largest amplitudes of the intraseasonal anomalies extending across the warm pool region between the Indian and western Pacific Oceans (Weickmann et al, 1985;Lau and Chang, 1985;Rui and Wang, 1990;Hendon and Salby, 1994;Kayano and Kousky, 1999;Matthews, 2000). Nevertheless, there are also close relationships between the propagation of MJO and the large-scale moist convection and atmospheric circulation patterns associated with monsoon regimes in North America (Mo, 2000), South America and Africa (Matthews, 2004a) on subseasonal timescales.…”

Section: Introductionmentioning

confidence: 93%

Modulation of the intraseasonal rainfall over tropical Brazil by the Madden–Julian oscillation

Souza¹,

Ambrizzi

2006

Int. J. Climatol.

101

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Fifteen years (1987)(1988)(1989)(1990)(1991)(1992)(1993)(1994)(1995)(1996)(1997)(1998)(1999)(2000)(2001) of rain gauge-based data are used to describe the intraseasonal rainfall variability over tropical Brazil and its associated dynamical structure. Wavelet analysis performed on rainfall time series showed significant peaks centered roughly in periods of 30-70 days, particularly in the eastern southeastern Amazon and northern northeast Brazil. A significant enhancement of precipitation with maximum anomalies in a northeastward oriented band over tropical Brazil is evidenced from empirical orthogonal function (EOF) analysis of 30-70-day filtered rainfall anomalies during rainy season (January to May). Lagged/lead composites revealed that, on a global scale, the Madden-Julian oscillation (MJO) is the main atmospheric-mechanism modulator of the pluviometric variations on intraseasonal timescale in the eastern Amazon and northeast Brazil. A coherent northward expansion of rainfall across tropical Brazil is evident during the passage of MJO over South America. Regionally, the establishment of a quasi-stationary deep convection band triggered by the simultaneous manifestation of south Atlantic convergence zone (SACZ) and intertropical convergence zone (ITCZ) explains the intensified rainfall over these regions. Such regional mechanisms are dynamically embedded within the eastward-propagating MJO-related large-scale convective envelope along tropical South America/the Atlantic Ocean. These features occur in association with a significant intraseasonal evolution of the lower-level wind and seasurface temperature (SST) patterns, particularly in the Atlantic Ocean, including a coherent dynamical connection with atmospheric circulation, deep convective activity over South America and rainfall over tropical Brazil.

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“…In multivariate SSA (M-SSA: Weare and Nasstrom, 1982;Lau and Chan, 1985;Kimoto et al, 1991), the EOFs are normalized eigenvectors of a block [M x G'-by-M × C] lag-cross-correlation matrix between C time series -or channels, such as the leading S-PCs of the preceding S-EOF analysis -with lags ranging from 1 to M times At, the sampling interval. The EOFs in M-SSA contain elements of both spatial and temporal variability and are called space-time EOFs (ST-EOFs: Plaut and Vautard, 1994).…”

Section: Singular-spectrum Analysis (Ssa)mentioning

confidence: 99%

Interannual and interdecadal variability in United States surface-air temperatures, 1910-87

1995

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Abstract. Monthly mean surface-air temperatures at 870 sites in the contiguous United States were analyzed for interannual and interdecadal variability over the time interval 1910-87. The temperatures were analyzed spatially by empirical-orthogonal-function analysis and temporally by singularspectrum analysis (SSA). The dominant modes of spatio-temporal variability are trends and nonperiodic variations with time scales longer than 15 years, decadal-scale oscillations with periods of roughly 7 and 10 years, and interannual oscillations of 2.2 and 3.3 years. Together, these modes contribute about 18% of the slower-than-annual United States temperature variance. Two leading components roughly capture the mean hemispheric temperature trend and represent a long-term warming, largest in the southwest, accompanied by cooling of the domain's southeastern quadrant. The extremes of the 2.2-year interannual oscillation characterize temperature differences between the Northeastern and Southwestern States, whereas the 3.3-year cycle is present mostly in the Western States. The 7-to 10-year oscillations are rauch less regular and persistent than the interannual oscillations and characterize temperature differences between the western and interior sectors of the United States. These continental-or regionat-scale temperature variations may be related to climatic variations with similar periodicities, either global or centered in other regions; such variations include quasi-biennial oscillations over the tropical Pacific or North Atlantic and quasi-triennial oscillations of North Pacific sea-surface temperatures.

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Aspects of the 40–50 Day Oscillation during the Northern Winter as Inferred from Outgoing Longwave Radiation

Cited by 211 publications

References 0 publications

Dynamics of Super Cloud Clusters, Westerly Wind Bursts, 30-60 Day Oscilations and ENSO: An Unified View

Dynamics of Super Cloud Clusters, Westerly Wind Bursts, 30-60 Day Oscilations and ENSO: An Unified View

Modulation of the intraseasonal rainfall over tropical Brazil by the Madden–Julian oscillation

Interannual and interdecadal variability in United States surface-air temperatures, 1910-87

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