Abstract
An atypical occlusion process that occurred in North China on 14 July 2011 is studied based on both observations and a real-data Weather Research and Forecasting (WRF) model simulation. The results show that this atypical occlusion process was significantly different from the traditional, synoptic-scale occlusion process that occurs within extratropical cyclones. It was caused by the merger of two cold-type mesoscale fronts. One of the fronts developed from the gust front of convective storms, while the other was a sea-breeze front. As the two fronts moved towards each other, the warm air between them was squeezed and separated from the surface. An atypical occluded front was formed when the two fronts merged, with the warm air forced aloft. This kind of occlusion is termed a “merger” process, different from the well-known “catch-up” and “wrap-up” processes. Moreover, local convection was found to be enhanced during the merger process, with severe convective weather produced in the merger area.
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References
Bjerknes, J., 1919: On the structure of moving cyclones. Geofys. Publ., 1(2), 1–8.
Bjerknes, J., and H. Solberg, 1921: Meteorological conditions for the formation of rain. Geofys. Publ., 2(3), 3–61.
Bjerknes, J., and H. Solberg, 1922: Life cycle of cyclones and the polar front theory of atmospheric circulation. Geofys. Publ., 3(1), 1–18.
Byers, H. R., and H. R. Rodebush, 1948: Causes of thunderstorms of the Florida peninsula. J. Meteor., 5, 275–280.
Carbone, R. E., J. W. Wilson, T. D. Keenan, and J. M. Hacker, 2000: Tropical island convection in the absence of significant topography. Part I: Life cycle of diurnally forced convection. Mon. Wea. Rev., 128, 3459–3480.
Dudhia, J., 1989: Numerical study of convection observed during the winter monsoon experiment using a mesoscale twodimensional model. J. Atmos. Sci., 46, 3077–3107.
Fankhauser, J. C., N. A. Crook, J. Tuttle, L. J. Miller, and C. G. Wade, 1995: Initiation of deep convection along boundary layer convergence lines in a semitropical environment. Mon. Wea. Rev., 123, 291–313.
Fovell, R. G., 2005: Convective initiation ahead of the sea-breeze front. Mon. Wea. Rev., 133, 264–278.
Hong, S.-Y., Y. Noh, and J. Dudhia, 2006: A new vertical diffusion package with an explicit treatment of entrainment processes. Mon. Wea. Rev., 134, 2318–2341.
Kingsmill, D. E., 1995: Convection initiation associated with a sea breeze front, a gust front, and their collision. Mon. Wea. Rev., 123, 2913–2933.
Kingsmill, D. E. and N. A. Crook, 2003: An observational study of atmospheric bore formation from colliding density currents. Mon. Wea. Rev., 131, 2985–3002.
Krain, J. S., 2004: The Kain-Fritsch convective parameterization: An update. J. Appl. Meteor., 43, 170–181.
Liang, Z. M., S. T. Gao, and Y. Wang, 2013: Data analysis of collision-type sea-breeze front in the Bohai Bay region. Climatic and Environmental Research, 18(5), 607–616. (in Chinese)
Lim, K.-S. S., and S.-Y. Hong, 2010: Development of an effective double-moment cloud microphysics scheme with prognostic cloud condensation nuclei (CCN) for weather and climate models. Mon. Wea. Rev., 138, 1587–1612.
Lu, H. Z., Y. W. Liu, A. X. Liu, N. Zhang, and M. N. Sun, 2012: Study of thunderstorm initiation and intensification rules associated with sea breeze fronts. Meteorological Monthly, 38(9), 1078–1086. (in Chinese)
Miller, S. T. K., B. D. Keim, R. W. Talbot, and H. Mao, 2003: Sea breeze: Structure, forecasting, and impacts. Rev. Geophys., 41(3), 1011, doi: 10.1029/2003RG000124.
Mlawer, E. J., S. J. Taubman, P. D. Brown, M. J. Iacono, and S. A. Clough, 1997: Radiative transfer for inhomogeneous atmospheres: RRTM, a validated correlated-k model for the longwave. J. Geophys. Res., 102, 16 663–16 682.
Nicholls, M. E., R. A. Pielke, and W. R. Cotton, 1991: A twodimensional numerical investigation of the interaction between sea breezes and deep convection over the Florida Peninsula. Mon. Wea. Rev., 119, 298–323.
Paulson, C. A., 1970: The mathematical representation of wind speed and temperature profiles in the unstable atmospheric surface layer. J. Appl. Meteor., 9, 857–861.
Pielke, R. A., 1974: A three-dimensional numerical model of the sea breezes over south Florida. Mon. Wea. Rev., 102, 115–138.
Rotunno, R., J. B. Klemp, and M. L. Weisman, 1988: A theory for strong, long-lived squall lines. J. Atmos. Sci., 45, 463–485.
Schultz, D. M., 2005: Review of cold fronts with prefrontal troughs and wind shifts. Mon. Wea. Rev., 133, 2449–2472.
Schultz, D. M., and G. Vaughan, 2011: Occluded fronts and the occlusion process: A fresh look at conventional wisdom. Bull. Amer. Meteor. Soc., 92, 443–466.
Simpson, J. E., 1994: Sea Breeze and Local Wind. Cambridge University Press, 234 pp.
Skamarock, W. C., and Coauthors, 2008: A description of the Advanced Research WRF version 3. NCAR Technical Note NCAR/TN-475+STR, 113 pp.
Tewari, M., and Coauthors, 2004: Implementation and verification of the unified NOAH land surface model in the WRF model. 20th Conference on Weather Analysis and Forecasting/16th Conference on Numerical Weather Prediction, 11–15.
Wang, Q., and J. H. Fan, 2012: Mesoscale analysis of a local severe convective weather triggered by sea-breeze front. Proc. 29th Annual Conference of Chinese Meteorology Society on Research and Forecasting of Severe Weather. Shenyang, Chinese Meteorological Society, P458. (in Chinese)
Wang, Y., S. T. Gao, and Z. M. Liang, 2014: Analysis on the observation and simulation of thunderstorms triggered by sea breeze front in Bohai Bay. Plateau Meteorology, 33(3), 848–854. (in Chinese)
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Abulikemu, A., Xu, X., Wang, Y. et al. Atypical occlusion process caused by the merger of a sea-breeze front and gust front. Adv. Atmos. Sci. 32, 1431–1443 (2015). https://doi.org/10.1007/s00376-015-4260-2
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DOI: https://doi.org/10.1007/s00376-015-4260-2