On Scale Interactions in the Tropics During Northern Summer

Kanamitsu, Masao; Krishnamurti, T. N.; Depradine, Colin

doi:10.1175/1520-0469(1972)029<0698:osiitt>2.0.co;2

Cited by 52 publications

(26 citation statements)

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“…West phase years 1953, 1955, 1957, 1961, 1966, 1969, 1971, 1973, 1975, 1978, 1980, 1985, 1990, 1995, 1997, 1999, 2002, 2006, 2008East phase years 1954, 1956, 1958, 1960, 1962, 1963, 1965, 1968, 1970, 1972, 1974, 1976, 1977, 1979, 1981, 1982, 1984, 1986, 1987, 1989, 1991, 1992, 1994, 1996, 1998, 2000, 2001, 2003, 2005, 2010, 2012 methods, EMD is empirical, intuitive, direct and adaptive (Wu and Huang, 2009). The main idea of EMD is to decompose the data locally into different oscillatory components called IMF.…”

Section: Qbo Phases Yearsmentioning

confidence: 99%

“…Owing to its synoptic nature, changes in strength of TEJ are considered as one of the indicators of long-term changes in atmospheric general circulation (Pielke et al, 2001). A study by Kanamitsu et al (1972) on the TEJ intensity during the summers of 1967 and 1972 found a weaker jet prevailing during 1972, which resulted to a drought condition over India. Various studies hint that the size of TEJ has reduced in the recent years (Pattanaik and Satyan, 2000;Rao et al, 2004).…”

Section: Introductionmentioning

confidence: 99%

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Effect of changing tropical easterly jet, low level jet and quasi‐biennial oscillation phases on Indian summer monsoon

Rai

Dimri

2017

Atmospheric Science Letters

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Section: Qbo Phases Yearsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Effect of changing tropical easterly jet, low level jet and quasi‐biennial oscillation phases on Indian summer monsoon

Rai

Dimri

2017

Atmospheric Science Letters

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“…It is possible to examine energy exchanges among harmonic wave components. A study along these lines for the 200-mb observations during the northern summer was carried out by Kanamitsu et al (1972) The decomposition is illustrated for the kinetic and potential energy and the heating H during northern summer, of which we regard the long wave heating HL as a primary heating function arising from land-ocean contrasts. It should be noted that HL is a net heating of the troposphere, e.g., sensible and evaporative fluxes from ocean and from land areas, long and short wave radiative effects, shallow and deep cumulus convection and large-scale condensation heating.…”

mentioning

confidence: 99%

“…Most of this generation of KL is thus related to large east-west differential net heating primarily associated with zonal wavenumbers 1 and 2. The diagram furthermore indicates that zonal flows receive kinetic energy, Kz , from the long waves and lose to shorter waves, Ka (see Kanamitsu et al, 1972, andKrishnamurti et al, 1973). This diagram is to be regarded as somewhat schematic because of uncertainties in most elements.…”

mentioning

confidence: 99%

Tibetan High and Upper Tropospheric Tropical Circulations during Northern Summer

Krishnamurti

Daggupaty

Fein

et al. 1973

Bulletin of the American Meteorological Society

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107

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The zonally asymmetric climatology of the tropical largescale motion field is an interesting GARP topic. Understanding of the maintenance of various quasi-stationary features will be a challenging problem during the FGGE (the First GARP Global Experiment) and Monex (the Monsoon Experiment). In this paper we present some current thoughts that are relevant to the climatology of the tropical upper troposphere during the northern summer.A review of some of the results from various numerical general circulation models and theoretical studies is presented for northern summer conditions. The relative success or failure of simulations of 200-mb climatology is discussed. It is pointed out that a proper simulation of the belt of anticyclones over the Asian highlands is somewhat crucial for a proper simulation of the summer climatology over the rest of the tropics.Observations of the semipermanence of the Tibetan high pressure cell during northern summer at 200 mb suggests that it acts somewhat like a barrier. In order to illustrate this we consider a problem related to the evolution of barotropic non-divergent flows past a barrier. The flows are initially zonal, with speeds varying in the north-south direction according to northern summer ob-1 Present affiliation: National Center for Atmospheric Research, Boulder, Colo. 80302.2 Present affiliation: Department of Meteorology, University of Oklahoma, Norman, Okla. 73069. 1234servations. The barrier, whose shape is based on observations of a blocking thermal high, is impulsively introduced at initial time. The flows are kept zonal at frictionless walls at 25S and 45N. The initial north-south distribution of the zonal flows is shown to have no inflection point in its profile, thus it does not satisfy the necessary condition for barotropic instability. The presence of an impulsively introduced barrier, however, results in the evolution of transient as well as steady wave motions in long term numerical integrations. It is shown that a 30-day mean motion field contains many of the well known climatological features such as the African high, the mid-Atlantic trough, the mid-Pacific trough, the Mexican high and a weak easterly jet south of the Tibetan high. Calculations of kinetic energy exchanges between waves and zonal flow in this simple experiment is compared with corresponding calculations for tropical observations and recent general circulation experiments carried out by Abbott. The impulsively introduced barrier simulates an energy source for zonal wavenumber 1, quite similar to observations in a tropical belt. Although this experiment is fairly crude, it is found to be very illustrative in many respects. Many diverse experiments along these lines can be carried out to reveal various aspects of atmospheric circulations.

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“…A detailed review of these works up to 1974 is given in Kung and Smith (1974). After a number of tropical experiments i. e. IIOE, GATE, MONSOON-77 AND FGGE, a few studies related to the selected regions of the tropics (Chen, c 1989, Meteorological Society of Japan 1980; Krishnamurti et al, 1973;Kanamitsu et al, 1972;Depradine, 1980;Kung et al, 1974Kung et al, , 1978Kung et al, and 1981 are found in the literature. These studies have demonstrated that the circulation features in the tropics differ considerably from that of the mid-latitudes.…”

Section: Introductionmentioning

confidence: 99%

Energy Transformations in the Tropical Circulation During the FGGE Winter

Mohanty

Ramesh

Dash

1989

Journal of the Meteorological Society of Japan

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FGGE level-IIIb data produced by the European Centre for Medium Range Weather Forecasts (ECMWF) for the DJF 1978-79 is used to analyse the kinetic energy budget over the global tropical belt. A detailed energetics of the mean and transient fluctuations, in particular, the generation, the exchange between the mean flow and the transients and the dissipation of kinetic energy are estimated for the tropics and compared with the earlier studies.It is found that about 60% of the kinetic energy generated in the tropics is dissipated by the frictional mechanisms and remaining 40% is transported to the middle latitudes of both the hemispheres. The subtropical westerly jet stream of the winter hemisphere plays a dominant role in the process of kinetic energy flux transport. It is observed that the inter-hemispheric exchange of kinetic energy is negligible. Further, the study confirms the fact that the tropical circulation is mainly maintained by the mean flow while in the extra tropics (beyond 30* latitude) the transients are quite important.

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On Scale Interactions in the Tropics During Northern Summer

Cited by 52 publications

References 0 publications

Effect of changing tropical easterly jet, low level jet and quasi‐biennial oscillation phases on Indian summer monsoon

Effect of changing tropical easterly jet, low level jet and quasi‐biennial oscillation phases on Indian summer monsoon

Tibetan High and Upper Tropospheric Tropical Circulations during Northern Summer

Energy Transformations in the Tropical Circulation During the FGGE Winter

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