LOGIN TO YOUR ACCOUNT

Username
Password
Remember Me
Or use your Academic/Social account:

Congratulations!

You have just completed your registration at OpenAire.

Before you can login to the site, you will need to activate your account. An e-mail will be sent to you with the proper instructions.

Important!

Please note that this site is currently undergoing Beta testing.
Any new content you create is not guaranteed to be present to the final version of the site upon release.

Thank you for your patience,
OpenAire Dev Team.

Close This Message

CREATE AN ACCOUNT

Name:
Username:
Password:
Verify Password:
E-mail:
Verify E-mail:
*All Fields Are Required.
Please Verify You Are Human:

OpenAIRE is about to release its new face with lots of new content and services.
During September, you may notice downtime in services, while some functionalities (e.g. user registration, login, validation, claiming) will be temporarily disabled.
We apologize for the inconvenience, please stay tuned!
For further information please contact helpdesk[at]openaire.eu

fbtwitterlinkedinvimeoflicker grey 14rssslideshare1
KRISHNAMURTI, T. N.; PASCH, RICHARD J.; ARDANUY, PHILIP (2011)
Publisher: Co-Action Publishing
Journal: Tellus A
Languages: English
Types: Article
Subjects:
This paper is part of a sequence of numerical weather prediction efforts utilizing the special observations from the GARP Atlantic Tropical Experiment (GATE). These observations, along with those available from the World Weather Watch, provide a unique opportunity to carry out numerical weather prediction (NWP) studies over portions of West Africa and the eastern Atlantic ocean utilizing high resolution limited area models. The present study reports on the results of 34 short-range numerical weather prediction experiments, with two simple models, designed to study the westward propagation of African waves. In the time frame of 24 to 48 hours, predictions at 700 mb (the level of maximum amplitude of these waves, and the level of non-divergence) show extremely promising results. These results are comparable to fine-mesh predictions in higher latitudes. Errors in phase speed and vector root mean square (RMS) wind errors are summarized for the third phase of GATE. A second part of this study deals with the problem of specification of the West African squall line with respect to the position of the predicted trough line of the African wave. A body of recent literature provides useful observational statistics relating the position of African waves, certain geographical regions, the time of day and the formation of line squall systems. These studies also provide information on the relative speeds of westward motion of the squall line and the wave trough. The decay of the squall lines during their westward propagation away from the trough is also a part of these observational statistics. Based on these observations, an empirical set of selection rules may be defined to specify the squall lines with respect to the predicted motion field. Successful results were obtained in the time frame of 24 to 48 hours for these experiments, the results of which are summarized below.DOI: 10.1111/j.2153-3490.1980.tb00949.x
  • The results below are discovered through our pilot algorithms. Let us know how we are doing!

    • Arakawa, A. 1966. Computational design for long term numerical integration of the equations of atmospheric motion. J. Comp. Phys. 1, 119-143.
    • Aspliden, C. I., Tourre, Y.and Subine, J. B. 1976. Some climatological aspects of West African squall lines during GATE. Mon. Wea.Rev. 104, 1029-1035.
    • Cocheme, J. and Franquin, R. 1967. An agroclimatology survey of a semi-arid area in Africa south of the Sahara. WMO Tech. Note No. 86, 136 pp.
    • Cressman, G. P. 1959. An operational objective analysis system. Mon. Wea.Rev. 87,367-374.
    • Eldridge, R. H. 1957. A synoptic study of West African disturbance lines. Quart. J . Roy. Met. SOC.83, 303- 314.
    • Gates, W. L. and Nelson, A. B. 1975. A new (revised) tabulation of the Scripps topography on a l o global grid. Part 1. Terrain heights. Rept. No. R-1276-1- ARPA-Rand Corporation,Santa Monica, California.
    • Hamilton, R. A. and Archibald,J. W. 1945.Meteorology of Nigeria and adjacent territories. Quart. J. Roy. Met. SOC.71,23 1-264.
    • Hockney, R. W. 1965. A fast direct solution of Poisson's equation using Fourier analysis. J. Assoc. Compuf. Mach. 12,95-113.
    • Kanamitsu, M. 1975. On numerical prediction over a global tropical belt. Rept. No. 75-1, Department of Meteorology, Florida State University, Tallahassee, Florida 32306.282 pp.
    • Krishnamurti, T. N. 1969. An experiment in numerical prediction in equatorial latitudes. Quart. J . Roy. Met. SOC9.5,594-620.
    • Krishnamurti, T. N. and Pearce R. P. 1977. The fundamentalsof numerical weather prediction and the filtered barotropic model. Proceedings of WMO seminar, Dakar, November, 1976. WMO Rept. No. 492. Geneva, Switzerland.
    • Krishnamurti, T. N., Pan, H.L., Chang, C. B., Ploshay, J., Walker, D. and Oodally, A. W. 1979a. Numerical weather prediction for GATE. To appear in the October issue of the Quart. J. Roy. M e f .SOC.
    • Krishnarnurti,T. N., Pasch, R. J. and Ardanuy, P. 1979b. Prediction of African waves and specification of squall lines. Rept. No. 79-2, Dept. of Meteorology, Florida State U., Tallahassee, Florida 32306. 55 pp.
    • Martin, D. W. 1975. Characteristics of West African and Atlantic cloud clusters based on satellite data. GATE Rept. No. 14, Preliminary scientific results of the GARP Atlantic Tropical Experiment, Vol. I., 182- 190.
    • Mathur, M. B. 1970. A note on an improved quasiLagrangian advective scheme for primitive equations. Mon. Wea.Rev. 98,214-219.
    • Matsuno, T. 1966. Numerical integration of primitive equations by a simulated backward difference method. J. Met. SOCJ.apan 44, 76-84.
    • McGarry, M. M. and Reed, R. J. 1978. Diurnal variations in convective activity and precipitation during phases I1 and 111 of GATE. Mon. Wea. Rev. 106, 101-113.
    • Payne, S. W. and McGarry, M. hl. 1977. The relationship of satellite infrared convective activity to easterly waves over West Africa and the adjacent ocean during phase 111 of GATE. Mon. Wea.Rev. 105,413-420.
    • Pedgley, D. E. and Krishnamurti, T. N. 1976. Structure and behavior of a monsoon cyclone over West Africa. Mon. Wea.Rev. 104, 149-167.
    • Ramanathan, Y. and Bansal, R. K. 1976. The NHAC operational quasi-geostrophic model. IMD Scientific Rept. No. 7611. pp. 1-12. India Meterological Department, Lodi Road, New Delhi, India.
    • Reed, R. J., Norquist, D. C. and Recker, E. E. 1977. The structure and properties of African wave disturbances as observed during phase Ill of GATE. Mon. Wea. Rev. 105,317-333.
    • Thompson, R. M., Payne, S.W., Recker, E. E. and Reed, R. J. 1979. Structure and properties of synoptic-scale wave disturbances in the intertropical convergence zone of the Eastern Atlantic. J . Atmos. Sri.36, 53-72, Tripoli, G. and Krishnamurti, T. N. 1975. Low level flows over the GATE area during summer 1972. Mon. Wea.Rev. 103, 197-216.
    • Vanderman, L. W. and Collins, W. G. 1967. Operational experimental numerical forecasting for the tropics. Mon. Wea.Rev. 95,950-953.
  • No related research data.
  • No similar publications.

Share - Bookmark

Funded by projects

Cite this article

Collected from

Cookies make it easier for us to provide you with our services. With the usage of our services you permit us to use cookies.
More information Ok