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This paper presents a review of the factor separation (FS) technique and its fractional approach. The work focuses on two points. First, the FS methodology is applied to some fundamental mathematical functions. For each function we define the constrains for the factor values, by investigating the function under three different synergy states: synergy term equals zero; is opposite in its sign to the factors' contributions, or is dominant. Second, the application of the method is demonstrated with a simplified atmospheric problem with an analytical solution, i.e., the Haurwitz sea-breeze (SB) model. The FS method also assists in analyzing the effects of the dominant and secondary factors in given physical models that have analytical solutions. Study of factors with the FS methodology allows a better understanding of the various mechanisms and particularly the role of their interactions-synergies in atmospheric dynamics.


Heat Flux Factor Separation Coriolis Force Western Pacific Warm Pool Marine Atmospheric Boundary Layer 
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  1. Ackerman S.A., Knox J., 2002, Meteorology: Understanding the Atmosphere, Brooks/Cole. Publishing Co.Google Scholar
  2. Alpert, P., Krichak, S. O., Krishnamurti, T. N., Stein, U., and Tsidulko, M., 1996, The Relative Roles of Lateral Boundaries, Initial Conditions and Topography in Mesoscale Simulations of Lee Cyclogenesis, J. Appl. Meteor. 35: 1091–1099, 1996.CrossRefGoogle Scholar
  3. Alpert, P., D. Niyogi, R.A. Pielke Sr., and J.L. Eastman, 2006, ȜFirst evidence for carbon dioxide and moisture synergies from the leaf cell to global scale - Implications to human-caused climate changeȝ, J. Global Planetary Change (in press).Google Scholar
  4. Alpert. P., U. Stein and M. Tsidulko, 1995, Role of sea fluxes and topography in eastern Mediterranean cyclogenesis, The Global Atmosphere-Ocean System 3: 55–79.Google Scholar
  5. Alpert. P., U. Stein, M. Tsidulko and B.U. Neeman, 1993, Synergism in Weather and climate, unpublished.Google Scholar
  6. Alpert, P., and M. Tsidulko, 1994, Project WIND-numerical simulations with Tel-Aviv PSU/NCAR model at Tel-Aviv University 1994, Mesoscale Modeling of the Atmosphere, in: Meteor. Monogr., No.25, Amer. Meteor. Soc., pp. 81–95.Google Scholar
  7. Alpert, P., M. Tsidulko and U. Stein, 1995: Can sensitivity studies yield absolute comparisons for the effects of several processes?, J. Atmos. Sci., 52, pp. 597–601.CrossRefGoogle Scholar
  8. Alpert. P., M. Tzidulko and D. Izigsohn, 1999: A shallow short-lived meso-beta cyclone over the gulf of Antalya, eastern Mediterranean, Tellus, 51A, pp. 249–262.Google Scholar
  9. Alpert. P., M. Tzidulko, S. Krichak and U. Stein, 1996: A multi-stage evolution of an ALPEX cyclone, Tellus, 48A, pp. 209–220.Google Scholar
  10. Berger A., 1998, The role of CO2, sea level and vegetation during the Milankovitch-forced glacial-interglacial cycles, in: Geosphere-Biosphere Interactions and Climate, L. Bengtsson and C.U. Hammer (eds.), Geosphere-Biosphere Interactions and Climate. New-York, Cambridge University Press.Google Scholar
  11. Berger A., Claussen M. and Kubatzki Ci., 2005, Identifying the individual contribution of climatic factors and of their synergism, submitted.Google Scholar
  12. Doswell, C. A. III, C. Ramis, R. Romero, and S. Alonso, 1998: A diagnostic study of three heavy precipitation episodes in the western Mediterranean region, Wea. Forecasting, 13, pp. 102–124.CrossRefGoogle Scholar
  13. Guan S. and G. W. Reuter, 1996: Numerical simulation of an industrial cumulus affected by heat, moisture and CCN released from an oil refinery, J. Applied Meteor., 35, 1257–1264.CrossRefGoogle Scholar
  14. Haurwitz, B., 1947, Comments on the sea-breeze circulation, J. Meteorol. 4, 1–8.Google Scholar
  15. Homar, V., C. Ramis, R. Romero, S. Alonso, J. A. Garcia-Moya and M. Alarcon, 1999: A case of convection development over the western Mediterranean sea: A study through numerical simulations, Meteorol. Atmos. Phys., 71, 169–188.CrossRefGoogle Scholar
  16. Khain A.P., D. Rosenfeld, and I. Sednev, 1993: Coastal effects in the E. Mediterranean as seen from Experiments using a cloud ensemble model with Detailed Description of Warm and Ice Microphysical Processes, Atmos. Reserch, 30, 295–319.CrossRefGoogle Scholar
  17. Krichak S. and P. Alpert, 2002: A fractional approach to the factor separation method, J. Atmos. Sci. 59: 2243–2252.CrossRefGoogle Scholar
  18. Krichak. S., P. Alpert and T.N. Krishnamurti, 1997: Red Sea trough/cyclone development numerical investigation, Meteor. Atmos. Phys. 63, pp. 159–170.CrossRefGoogle Scholar
  19. Krichak. S., and P. Alpert, 1998: Role of the Large-Scale Moist Dynamics in Nov 1–5 1994 hazardous Mediterranean Weather, J. Geophy. Res., Vol. 103, No. D16, pp. 19453–19468.CrossRefGoogle Scholar
  20. Levy G. and M. Ek, 2001: The simulated response of the marine atmospheric boundary layer in the western Pacific warm pool region to surface flux forcing, J. Geophys. Res., 106, pp. 7229–7241.CrossRefGoogle Scholar
  21. Lindzen, R.S., 1990: Dynamics in atmospheric physics, Cambridge Univ. Press, p. 310.Google Scholar
  22. Morgenstern O., 1998: Alpine Southside Precipitation Events: Model Studies and Physical Concepts, PhD thesis, ETH Switzerland No. 12421.Google Scholar
  23. Pielke R.A.: “Mesoscale Meteorological Modeling”, Academic Press, Orlando, 1984.Google Scholar
  24. Ramis. C., R. Romero, 1995: A first numerical simulation of the development and structure of the sea breeze in the Island of Mallorca, Ann. Geophysicae, Vol. 13, pp. 981–994.CrossRefGoogle Scholar
  25. Ramis, R., R. Romero, V. Homar, S. Alonso, and M. Alarcon, 1998: Diagnosis and numerical simulation of a torrential precipitation event in Catalonia (Spain), Meteorol. Atmos. Phys., 69, pp. 1–21.CrossRefGoogle Scholar
  26. Romero, R: “Numerical simulation of mesoscale processes in the western Mediterranean: Environmental impact and natural hazards”, Ph. D. Thesis, Universitat de les Illes Balears, p. 164, 1998.Google Scholar
  27. R. Romero, C. A. Doswell III and C. Ramis: “Mesoscale Numerical Study of Two Cases of Long-lived Quasistationary Convective Systems over Eastern Spain”, Mon. Wea. Rev., vol. 128, no. 11, pp. 3731–3751, 2000.CrossRefGoogle Scholar
  28. Romero, R., C. Ramis, and S. Alonso, 1997: Numerical simulation of an extreme rainfall event in Catalonia: Role of orography and evaporation from the sea, Quart. J. Roy. Meteor. Soc., 123, pp. 537–559.CrossRefGoogle Scholar
  29. Romero, R., Ramis, C., Alonso, S., Doswell III, C. A., Stensrud, D. J., 1998, Mesoscale Model Simulations of Three Heavy Precipitation Events in the Western Mediterranean Region, Mon. Wea. Rev. 126: 1859–1881.CrossRefGoogle Scholar
  30. Rozoff, C.R., and Cotton, W. R., 2003, Simulation of St. Louis, Missouri, Land Use Impacts on Thunderstorms, J. Appl. Meteor. 42: 6,716–738.CrossRefGoogle Scholar
  31. Stein, U., and Alpert, P., 1993, Factor separation in numerical simulations, J. Atmos. Sci. 50: 2107–2115.CrossRefGoogle Scholar
  32. Tsidulko, M., and Alpert, P., 2001, Synergism of upper-level potential vorticity and mountains in Genoa lee cyclogenesis - A numerical study, Meteor. Atmos. Phys. 78: 261–285.CrossRefGoogle Scholar

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© Springer 2007

Authors and Affiliations

    • 1
    • 1
  1. 1.Dept. Geophysics & Planetary Sciences Tel-Aviv UniversityTel-AvivIsrael

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