A Low-Level Jet in the Tropics

DeSOUZA, R. L.; Aspliden, C. I.; Garstang, Michael; LaSeur, N. E.; Hsueh, Y.

doi:10.1175/1520-0493(1971)099<0559:aljitt>2.3.co;2

Mon. Wea. Rev.

1971

DOI: 10.1175/1520-0493(1971)099<0559:aljitt>2.3.co;2

|View full text |Cite

A Low-Level Jet in the Tropics

R. L. DeSOUZA¹,

C. I. Aspliden²,

Michael Garstang³

et al.

Abstract: A temporary mesoscale network of pilot balloon stations on a tropical island (Barbados, West Indies) revealed the existence of a low-level jet a t 700 m above mean sea level, with a maximum wind near 40 m/s and a duration of at least 2 hr. The phenomenon appears to be associated with the Venturi effect produced in the low levels by a traveling gravity wave at the inversion. It is suggested that jets of this kind probably exist over other tropical islands.

Help me understand this report

Search citation statements

Order By: Relevance

Paper Sections

Select...

Citation Types

Supporting

Mentioning

Contrasting

Year Published

1975

1994

Publication Types

Select...

Article5

Relationship

Self Cite1

Independent4

Authors

Journals

Cited by 6 publications

(1 citation statement)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, little evidence is available to establish this fact in comparison with conditions over the city. Some observations [DeSouza et al, 1971] suggest intensification of an inversion due to subsidence over an island at a time of strong heating. This condition would be the reverse of the situation discussed above for generation of a rural inversion induced by subsident outflow from the city.…”

mentioning

confidence: 99%

The structure of Heat Islands

Garstang¹,

Tyson²,

Emmitt³

1975

Reviews of Geophysics

Self Cite

View full text Add to dashboard Cite

Cities as well as ocean islands create mesoscale circulations in the atmosphere on a horizontal scale closely related to the size of the city or island. Contrast in albedo, heat capacity, and hence heating and cooling rates, heat generation, and surface roughness between the ‘island’ and its more uniform surroundings results in the generation of localized weather processes. Ocean islands, which may be simple in relief, free of pollution, and embedded in a uniform surface ocean temperature field, provide an excellent contrast to cities, which may be situated in complex topography and generate heat and pollution. The juxtaposition of the ocean and city islands is used to compare and contrast the induced atmospheric fields and the observed behavior of the atmosphere. The observed fields are then presented in terms of various numerical models. The simpler conditions prevailing over an ocean heat island lead to a more nearly complete three‐dimensional delineation of the thermodynamic and kinematic fields. These data for the ocean islands demonstrate significant deficiencies in the counterpart descriptions that exist for the atmosphere over the city. Complexities of modeling increase over both ocean and city heat islands as velocity fields change from zero to flow with strong vertical shear of the horizontal wind. Steady state models fare poorly under these conditions, whereas models that have attempted to account for the vertical redistribution of the horizontal momentum field show promise.

show abstract

mentioning

confidence: 99%

The structure of Heat Islands

Garstang¹,

Tyson²,

Emmitt³

1975

Reviews of Geophysics

Self Cite

View full text Add to dashboard Cite

show abstract

Enhancement and suppression of urban heat plumes over Johannesburg

Goldreich

Tyson

Gogh³

et al. 1981

Boundary-Layer Meteorol

View full text Add to dashboard Cite

Observations of the atmospheric temperature structure over Johannesburg have revealed the existence of both well-developed and suppressed heat plumes. Suppressed plumes appear to be associated with the incidence in a stable atmosphere of positive wind shear and well-developed katabatic flow away from the city. A localised cool region in the atmosphere above the central city is invariably associated with suppressed plume development. A tentative identification of wind shear and katabatic flow as the major influences on such structures is strengthened by the observation that during conditions of negative windshear and reduced katabatic advection, significant heat plumes are developed. It is at present not possible to assess the extent to which the observations and causative processes are sitespecific.

show abstract

Low-level nocturnal wind maximum over the central Amazon basin

Greco

Ulanski

Garstang³

et al. 1992

Boundary-Layer Meteorol

View full text Add to dashboard Cite

A low-level nocturnal wind maximum is shown to exist over extensive and nearly undisturbed rainforest near the central Amazon city of Manaus. Analysis of meteorological data collected during the 1985 and 1987 Amazon Boundary Layer Experiments (ABLE 2A and 2B) indicates the presence of this nocturnal wind maximum during both the wet and dry seasons of the Central Amazon Basin. Daytime wind speeds which are characteristically 3-7 m s-' between 300 and 1000 m increase to lo-15 m s-l shortly after sunset. The wind speed maximum is reached in the early evening, with wind speeds remaining high until several hours after sunrise. The nocturnal wind maximum is closely linked to a strong low-level inversion formed by radiational cooling of the rainforest canopy. The night-time inversion extends up to 300 m with strong vertical shear of the horizontal wind below the inversion top and uniformly strong horizontal winds above the inversion top. Frictional decoupling of the air above the inversion from the rough forest below, however, is responsible for only part of the observed increase. Surface and low-level pressure gradients between the undisturbed forest and the large Amazon river system and the city of Manaus are shown to be responsible for much of the nocturnal wind increase. The pressure gradients are interpreted as a function of the thermal differences between undisturbed forest and the river/city. The importance of both the frictional decoupling and the horizontal pressure gradient suggest that the nocturnal wind maximum does not occur uniformly over all Amazonia. We suspect that stronger low-level winds are pervasive under clear skies and strong surface cooling and that, in many places (i.e., near rivers), local pressure gradients enhance the low-level nocturnal winds.

show abstract

scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.

Contact Info

customersupport@researchsolutions.com

10624 S. Eastern Ave., Ste. A-614

Henderson, NV 89052, USA

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

Blog Terms and Conditions API Terms Privacy Policy Contact Cookie Preferences Do Not Sell or Share My Personal Information

Made with 💙 for researchers

Part of the Research Solutions Family.

A Low-Level Jet in the Tropics

Cited by 6 publications

References 5 publications

The structure of Heat Islands

The structure of Heat Islands

Enhancement and suppression of urban heat plumes over Johannesburg

Low-level nocturnal wind maximum over the central Amazon basin

Contact Info

Product

Resources

About