Boundary Layer Radar Observations of the Passage of the Convection Center over Serpong, Indonesia (6&amp;deg;S, 107&amp;deg;E) during the TOGA COARE Intensive Observation Period

Journal of the Meteorological Society of Japan

Hashiguchi

et al. 1999

Self Cite

A spectral analysis of lower tropospheric winds, observed by the Boundary Layer Radar (BLR) at Serpong (60S, 1070E) in West Java, Indonesia during 1992/93, 1993/94, and 1994/95 rainy seasons reveals a pronounced spectral peak, at a period near 4 days. Filtered analysis of this quasi 4 day mode (Q4DM) shows almost an in-phase structure in the vertical. The CANAL (Global Objective Analysis by Japan Meteorological Agency) data for 1992/93 rainy seasons shows that in general the meridional wind component, at the altitude 700 hPa, has a westward phase propagation.

Section: Results Of Blr Data Analysissupporting

confidence: 84%

Section: Introductionmentioning

confidence: 99%

Quasi 4 Day Mode Observed by a Boundary Layer Radar at Serpong (6°S, 107°E), Indonesia

Widiyatmi

Journal of the Meteorological Society of Japan

Hashiguchi

et al. 1999

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“…They are consistent with the activity of eastward moving super cloud clusters (Hashiguchi et al, 1995c) which have Kelvin-wavelike structures and behavior (particularly near the tropopause; cf. Tsuda et al, 1994bTsuda et al, , 1995.…”

Section: Frequency Power Spectra Of Wind Velocity Fluctuationssupporting

confidence: 83%

Frequency Spectra of Wind Velocity Fluctuations between 1 hour and 1 month in the Atmospheric Boundary Layer over Equatorial Indonesia

Hashiguchi

Fukao

et al. 1997

J. geomagn. geoelec

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Frequency power spectra are analyzed from zonal and meridional wind velocities observed continuously in a height range below 2.5 km with the Kyoto University Boundary Layer Radar (BLR) in Serpong, Indonesia (6.4°S, 106.7°E). We find that (i) the spectral slope in a period range from a few hours to a few days is approximately -1; (ii) the power spectral densities in the rainy season are at least about two times larger than those in the dry season; (iii) the diurnal component is dominant both in dry and rainy seasons; (iv) components with periods of about 4 and 10 days are probably associated with mixed Rossbygravity wavelike cloud clusters and Kelvin wavelike super cloud clusters, respectively; and (v) the power spectral amplitudes increase at least one order of magnitude from the bottom to the top of the equatorial Planetary Boundary Layer (PBL), and the values at the top of the PBL are comparable to those in the upper troposphere over mid-latitudes. The last feature suggests that the equatorial PBL is probably a major source of kinetic energy of the earth's atmosphere.

“…Variations were especially pronounced during the dry season (Hashiguchi et al 1995(Hashiguchi et al , 1996. Hadi et al (2000Hadi et al ( , 2002 confirmed similar diurnal variations, and depicted cloud movements that accompanied sea-breeze intrusions.…”

Section: Introductionmentioning

confidence: 76%

Diurnal Cycle of Cloud System Migration over Sumatera Island

Sakurai

Murata

Journal of the Meteorological Society of Japan

et al. 2005

Self Cite

101

This paper describes a diurnal cycle in systematic cloud system migration observed with the GMS IR1 sensor over Sumatera (approximately 1,500 km in length) from May 2001 to April 2002. Convective clouds developed over mountainous areas in the afternoon, and migrated westward and/or eastward for several hundred kilometers (@500 km) from midnight to morning. Westward migration occurred in almost every month except August over southernmost Sumatera Island. Eastward migration occurred when lower-tropospheric winds were westerly and/or when super cloud clusters moved eastward along the Intertropical Convergence Zone (ITCZ), which moves northward and southward with an annual cycle.