장기간 지속되는 이상고온기의 종관패턴: 미국을 사례로

Prevailing Synoptic Patterns for Persistent Positive Temperature Anomaly Episodes in the United States

  • 최종남 (미국 일리노이주 메콤 서일리노이대학 지리학과) ;
  • 최광용 ;
  • Choi, Jong-Nam (Department of Geography, Western Illinois University) ;
  • Choi, Gwang-Yong (Climate Research Laboratory, National Institute of Meteorological Research, Korea Meteorological Administration) ;
  • Williams, Thomas (Department of Geography, Western Illinois University)
  • 발행 : 2008.12.31

초록

본 연구는 미국 지역을 사례로 겨울철 및 여름철에 장기간 지속되는 이상고온기 발생에 유리한 종관 규모의 매커니즘을 밝힌다. 여름철 이상고온기는 주로 미국의 남중부 지역에서 발생하는 반면, 겨울철 이상고온기는 미서부 지역에서 발생한다. 지상 및 상층 기압장 자료 분석 결과, 이러한 이상고온기는 태평양과 대서양의 아열대 고기압들의 활동과 밀접하게 관련되어있다. 장기간 지속되는 여름철 이상고온기는 중층 및 상층 블러킹 고기압의 활동에 의해 형성되는 매우 안정된 대기 조건하에서 주로 발생한다. 또한 이 시기에는 지표강제력으로 상대적으로 높은 보웬비(Bowen ratio)가 나타나지만, 따뜻한 공기의 이류의 영향은 크지 않다. 반면, 장기간 지속되는 겨울철 이상고온기는 블러킹 고기압에 의한 단열 기온 상승뿐만 아니라 따뜻한 공기의 이류의 복합적인 작용에 의해 나타난다. 그러나 이 시기의 지표 강제력의 영향은 약하다.

This study examines the prevailing synoptic-scale mechanisms favorable for long-lived summer Persistent Positive Temperature Anomalies (PPTAs) as well as winter PPTAs in the United States. Such long-lived PPTAs usually occur in the south-central region of the United States in summer, but in the southwestern part of the United States in winter. Composite analyses of surface and pressure level data demonstrate that the formation of both winter and summer PPTAs is closely related to the movement of subtropical high pressure systems in the Pacific Ocean and Atlantic Ocean, respectively. The occurrence of long-lived summer PPTAs usually coincides with an extremely stable atmospheric condition caused by persistent blocking by mid- to upper-tropospheric anticyclones. Significant surface forcing is also easily identified through relatively high Bowen ratios at the surface. Warm air advection is, however, weak and appears to be an insignificant element in the formation of long-lived summer PPTAs. On the other hand, synergistic warming effects associated with adiabatic heating under an anticyclonic blocking system as well as significant warm air advection characterize the favorable synoptic environments for long-lived winter PPTAs. However, the impact of surface forcing mechanisms on winter PPTAs is insignificant.

키워드

참고문헌

  1. Achtor, T. H. and Horn, L. H., 1986, Spring season Colorado cyclones. Part I: use of composites to relate upper and lower tropospheric wind fields, Journal of Climate and Applied Meteorology, 25, 732-743 https://doi.org/10.1175/1520-0450(1986)025<0732:SSCCPI>2.0.CO;2
  2. Blair, D., 1997, Short-period temperature variability at Winnipeg, Canada, 1872-1993: characteristics and trends, Theoretical and Applied Climatology, 58, 147-159 https://doi.org/10.1007/BF00865015
  3. Burnett, A. W., 1994, Regional-scale Troughing over the Southwestern U.S.: Temporal Climatology, Teleconnections, and Climatic Impact, Physical Geography, 15, 80-98
  4. Chang, F. and Wallace, J. M., 1987, Meteorological conditions during heatwaves and droughts in the U.S. plains, Monthly Weather Review, 115, 1253-1269 https://doi.org/10.1175/1520-0493(1987)115<1253:MCDHWA>2.0.CO;2
  5. Choi, J. N. and Meentemeyer, V., 2002, Climatology of persistent positive temperature anomalies for the contiguous United States (1950-1995), Physical Geography, 23, 175-195
  6. Davis, R. E., Hayden, B. P., Gay, D. A., Phillips, W. L., and Jones, G. V., 1997, The North Atlantic subtropical anticyclone, Journal of Climate, 10, 728-744
  7. Dickson, R. R., 1981, Weather and circulation of February 1981 - continued widespread drought, Monthly Weather Review, 109, 1130-1135 https://doi.org/10.1175/1520-0493(1981)109<1130:WACOF>2.0.CO;2
  8. Djuric, D., 1994, Weather Analysis, Prentice-Hall, New Jersey
  9. Henderson, K. G. and Muller, R. A., 1997, Extreme temperature days in the south-central U.S., Climate Research, 8, 151-162 https://doi.org/10.3354/cr008151
  10. Karl, T. R. and Quayle, R. P., 1981, The 1980 summer heat wave and drought in historical perspective, Monthly Weather Review, 109, 2055-2073
  11. Klein, W. H., 1952, The weather and circulation of June 1952: a month with a record heat wave, Monthly Weather Review, 80, 99-104 https://doi.org/10.1175/1520-0493(1952)080<0099:TWACOJ>2.0.CO;2
  12. Kunkel, K. E., 1989, A surface energy budget view of the 1988 mid-western U.S. drought, Boundary Layer Meteorology, 48, 217-225 https://doi.org/10.1007/BF00158325
  13. Meehl, G. A. and Tebaldi, C., 2004, More intense, more frequent, and longer lasting heat waves in the 21st Century, Science, 305, 994-997 https://doi.org/10.1126/science.1098704
  14. Namias, J., 1955, Some meteorological aspects of drought with special reference to the summers of 1952-54 over the U.S., Monthly Weather Review, 83, 199-205 https://doi.org/10.1175/1520-0493(1955)083<0199:SMAOD>2.0.CO;2
  15. Namias, J., 1962, Influences of abnormal surface heat sources and sinks on atmospheric behavior, Proceedings of the International Symposium on Numerical Weather Prediction in Tokyo, Meteorological Society of Japan
  16. Namias, J., 1966, Nature and Possible Causes of the Northeastern U.S. Drought during 1962-1965, Monthly Weather Review, 94, 543-554 https://doi.org/10.1175/1520-0493(1966)094<0543:NAPCOT>2.3.CO;2
  17. Namias, J., 1982, Anatomy of Great Plains protracted heat waves (especially the 1980 U.S. summer drought), Monthly Weather Review, 110, 824-838 https://doi.org/10.1175/1520-0493(1982)110<0824:AOGPPH>2.0.CO;2
  18. Namias, J., 1991, Spring and summer drought over the contiguous U.S.: causes and prediction, Journal of Climate, 4, 54-65 https://doi.org/10.1175/1520-0442(1991)004<0054:SASDOT>2.0.CO;2
  19. Shukla, J. and Mintz, Y., 1982, The influence of landsurface evaporation on the Earth's climate, Science, 215, 1498-1501 https://doi.org/10.1126/science.215.4539.1498
  20. Taubensee, R. E, 1981, Weather and circulation of December 1980 - a generally dry month with record warmth in the west, Monthly Weather Review, 109, 676-682 https://doi.org/10.1175/1520-0493(1981)109<0676:WACOD>2.0.CO;2
  21. Trenberth, K. E., Branstator, G. W., and Arkin, P.A.,1988, Origins of the 1988 North American drought, Science, 242, 1640-1645 https://doi.org/10.1126/science.242.4886.1640
  22. Trenberth, K. E. and Branstator, G. W., 1992, Issues in establishing causes of the 1988 drought over North-America, Journal of Climate, 5, 159-172 https://doi.org/10.1175/1520-0442(1992)005<0159:IIECOT>2.0.CO;2
  23. Trenberth, K. E. and Guillemot, C. J., 1996, Physical processes involved in the 1988 drought and 1993 floods in North America, Journal of Climate, 9, 1288-1298 https://doi.org/10.1175/1520-0442(1996)009<1288:PPIITD>2.0.CO;2
  24. Wagner, A. J., 1981, Weather and circulation of January 1981 - record warmth in the west, record cold in the southeast and widespread severe drought, Monthly Weather Review, 109, 920-928 https://doi.org/10.1175/1520-0493(1981)109<0920:WACOJ>2.0.CO;2
  25. Walsh, J. E., Jasperson, W. H., and Ross, B., 1985, Influences of snow cover and soil moisture on monthly air temperature, Monthly Weather Review, 113, 756-768 https://doi.org/10.1175/1520-0493(1985)113<0756:IOSCAS>2.0.CO;2
  26. Winkler, J. A.,1988, Climatological characteristics of summertime extreme rainstorms in Minnesota, Annals of the Association of American Geographers, 78, 57-73 https://doi.org/10.1111/j.1467-8306.1988.tb00191.x
  27. Wolfson, N., Atlas, R., and Sud, Y. C., 1987, Numerical experiments related to the summer 1980 United-States heat-wave, Monthly Weather Review, 115, 1345-1357 https://doi.org/10.1175/1520-0493(1987)115<1345:NERTTS>2.0.CO;2
  28. Zishka, K. M. and Smith, P. J., 1980, The climatology of cyclones and anticyclones over North America and surrounding ocean environs for January and July, 1950-77, Monthly Weather Review, 108, 387-401 https://doi.org/10.1175/1520-0493(1980)108<0387:TCOCAA>2.0.CO;2