Objective fronts

Meteorological Applications - Tập 5 Số 1 - Trang 37-65 - 1998
Tim Hewson1
1Joint Centre for Mesoscale Meteorology, Department of Meteorology, University of Reading, PO Box 243, Reading RG6 6BB, UK

Tóm tắt

AbstractThis paper addresses the long‐standing problem of plotting atmospheric fronts objectively. A thermodynamic definition of a front is proposed. Time‐independent diagnostic quantities are then devised according to this definition. These can be computed from any gridded dataset. Fronts are then plotted, without human intervention, by utilising standard graphics package facilities, such as contouring, to represent the diagnostics. The methodology includes applying threshold criteria to erase automatically fronts which are thermally weak. By tuning these criteria a good match with subjective fronts is obtained. In addition, the objective surface fronts very often coincide with troughs in surface pressure, implying that a thermodynamic definition is sufficient. The objective front‐plotting is further developed to recognise split fronts, and ana‐ and kata‐front characteristics. Many examples are presented; these illustrate how objective fronts are potentially a very powerful tool for both forecasting and research. At the Joint Centre for Mesoscale Meteorology plots and animations showing objective fronts have been produced on a daily basis for many months now. Copyright © 1998 Royal Meteorological Society

Từ khóa


Tài liệu tham khảo

10.1175/1520-0469(1994)051<0874:FWSDMD>2.0.CO;2

Bjerknes J., 1922, Life cycles of cyclones and the polar front theory of atmospheric circulation, Geofys. Publ., 3, 1

10.1007/978-1-944970-33-8_8

10.1002/qj.49710845609

Browning K. A., 1994, Structure of a frontal cyclone, Q. J. R. Meteorol. Soc., 120, 1535

Cahir J. J.&Lottes W. D.(1982).An objective diagnostic aid in locating meteorologically significant boundaries. InPreprints of 9th Conference on Weather Forecasting and Analysis Seattle Washington June 28–July 1 1982. American Meteorological Society Boston MA 296–299.

Carlson P. E., 1966, A note on the objective location of frontal zones, Meteorol. Mag., 95, 218

10.1175/1520-0450(1966)005<0764:TUSNNF>2.0.CO;2

10.1002/qj.49712253610

10.1007/BF01314825

10.1007/BF01029564

10.1007/BF01029565

10.1007/BF01029559

Holton J. R., 1992, An Introduction to Dynamic Meteorology, 391

Huber‐Pock F.&Kress Ch.(1981).Contributions to the problem of numerical frontal analysis.Proceedings of the Symposium on Current Problems of Weather‐Prediction. Vienna June 23–26 1981. Publications of the Zentralanstalt für Meteorologie und Geodynamik 253.

10.1007/BF01032457

Japan Meteorological Agency, 1988, On the improvement of the significant weather chart, Weather Serv. Bull., 55, 1

10.1175/1520-0477(1997)078<1917:TFAAST>2.0.CO;2

10.1175/1520-0493(1988)116<0762:AGOPFF>2.0.CO;2

Kirk T. H., 1965, A parameter for the objective location of frontal zones, Meteorol. Mag., 94, 351

10.1175/1520-0477(1991)072<0348:SFATFA>2.0.CO;2

Meteorological Office, 1991, Meteorological Glossary, 335

Monk G.A., 1992, Synoptic and mesoscale analysis of intense mid‐latitude cyclones, Meteorol. Mag., 121, 269

10.1175/1520-0493(1965)093<0547:EINOFA>2.3.CO;2

10.1007/BF01025611

10.1175/1520-0477(1995)076<0505:ACFDSA>2.0.CO;2

Saucier W.J., 1955, Principles of Meteorological Analysis

10.1007/978-1-944970-33-8_10

10.1007/BF01029561

Thorpe A. J.(1994).Dynamics of mesoscale sub‐structure at fronts. InThe Life Cycles of Extratropical Cyclones Proceedings of an International Symposium Bergen Norway 27 June–1 July 1994 vol.I 220–228. Alma Mater Forlag AS Bergen.

10.1002/qj.49711750103

10.1175/1520-0477(1989)070<1412:APFGCI>2.0.CO;2

10.1007/BF01025614

10.1007/BF01030580

Zwatz‐Meise V.&Mahringer G.(1988).Use of satellite imagery combined with numerical model diagnostics to locate fronts and predict their activity: methods and examples. InSatellite and Radar Imagery Interpretation Preprints for a Workshop in Reading England 20–24 July 1987. ed. M. Bader and T. Waters Eumetsat 143–162.

10.1175/1520-0434(1990)005<0233:SAISCS>2.0.CO;2

Thông tin
Thông tin xuất bản

Meteorological Applications

Tập 5 Số 1

37-65

Thông tin tác giả