Atmosphere (대기)

Korean Meteorological Society (한국기상학회)
권호 표지
DOI QR코드

DOI QR Code

Predictability of Northern Hemisphere Blocking in the KMA GDAPS during 2016~2017

기상청 전지구예측시스템 자료에서의 2016~2017년 북반구 블로킹 예측성 분석

  • Roh, Joon-Woo (The Research Institute of Basic Sciences, Seoul National University) ;
  • Cho, Hyeong-Oh (School of Earth and Environmental Sciences, Seoul National University) ;
  • Son, Seok-Woo (School of Earth and Environmental Sciences, Seoul National University) ;
  • Baek, Hee-Jeong (Numerical Data Application Division, Numerical Modeling Center, Korea Meteorological Administration) ;
  • Boo, Kyung-On (Numerical Model Development Division, Numerical Modeling Center, Korea Meteorological Administration) ;
  • Lee, Jung-Kyung (Research Institute of Oceanography, Seoul National University)
  • 노준우 (서울대학교 기초과학연구원) ;
  • 조형오 (서울대학교 지구환경과학부) ;
  • 손석우 (서울대학교 지구환경과학부) ;
  • 백희정 (기상청 수치모델링센터 수치자료응용과) ;
  • 부경온 (기상청 수치모델링센터 수치모델개발과) ;
  • 이정경 (서울대학교 해양연구소)
  • Received : 2018.10.05
  • Accepted : 2018.12.22
  • Published : 2018.12.31
Download PDF
⟨ Previous Next ⟩

Abstract

Predictability of Northern Hemisphere blocking in the Korea Meteorological Administration (KMA) Global Data Assimilation and Prediction System (GDAPS) is evaluated for the period of July 2016 to May 2017. Using the operational model output, blocking is defined by a meridional gradient reversal of 500-hPa geopotential height as Tibaldi-Molteni Index. Its predictability is quantified by computing the critical success index and bias score against ERA-Interim data. It turns out that Northwest Pacific blockings, among others, are reasonably well predicted with a forecast lead time of 2~3 days. The highest prediction skill is found in spring with 3.5 lead days, whereas the lowest prediction skill is observed in autumn with 2.25 lead days. Although further analyses are needed with longer dataset, this result suggests that Northern Hemisphere blocking is not well predicted in the operational weather prediction model beyond a short-term weather prediction limit. In the spring, summer, and autumn periods, there was a tendency to overestimate the Western North Pacific blocking.

Keywords

KSHHDL_2018_v28n4_403_f0001.png 이미지

Fig. 1. 500-hPa geopotential height fields from 2017020600 UTC to 2017021100 UTC. Red color curves indicate 5400 gpm.

KSHHDL_2018_v28n4_403_f0002.png 이미지

Fig. 2. Hovmöller diagram of blocking occurrence distribution in Northern Hemisphere from 2017020200 UTC to 2017021400 UTC. Red color shading indicate the distribution of blocking based on TM index.

KSHHDL_2018_v28n4_403_f0003.png 이미지

Fig. 3. Blocking distributions computed from ECMWF reanalysis data (shading in Fig. 3a and black lines in Figs. 3b to 3g) and KMA GDAPS initialized at differenct times from 2017020600 UTC to 2017021100 UTC (red shadings in Figs. 3b to 3g).

KSHHDL_2018_v28n4_403_f0004.png 이미지

Fig. 4. CSI values of forecated blocking over 120°E-120°W in KMA GDAPS for different times: 0000 UTC 1 (violet line), 0000 UTC 2 (blue line), 0000 UTC 3 (green line), 0000 UTC 4 (yellow line), 0000 UTC 5 (orange line), and 0000 UTC 6 (red line) February.

KSHHDL_2018_v28n4_403_f0005.png 이미지

Fig. 6. Same to ‘Fig. 5’ except for September, October, and November 2016.

KSHHDL_2018_v28n4_403_f0006.png 이미지

Fig. 7. Same to ‘Fig. 5’ except for December 2016, January 2017, and February 2017.

KSHHDL_2018_v28n4_403_f0007.png 이미지

Fig. 8. Same to ‘Fig. 5’ except for March, April, and May 2017.

KSHHDL_2018_v28n4_403_f0008.png 이미지

Fig. 5. (a) Distribution of CSI for forecasted blocking from KMA GDAPS (longitude on the x-axis and lead times [day] on the y-axis), (b) mean CSI of forecasted blocking from KMA GDAPS over the Western North Pacific (120°E-180°E) (lead times [day] on the x-axis), (c) distribution of BIA for forecasted blocking from KMA GDAPS (longitude on x-axis and lead times [day] on y-axis), and (d) mean BIA of forecasted blocking from KMA GDAPS over the Western North Pacific (lead times on the x-axis) in July and August 2016.

Table 1. Averaged TM index over the Western North Pacific for the period in summer (July~August 2016), Autumn (Sep~Nov 2016), Winter (Dec 2016~Feb 2017), and Spring (Mar~May 2017).

KSHHDL_2018_v28n4_403_t0001.png 이미지

References

  1. Austin, J. F., 1980: The blocking of middle latitude westerly winds by planetary waves. Quart. J. Roy. Meteor. Soc., 106, 327-350. https://doi.org/10.1002/qj.49710644807
  2. Brezowsky, H., H. Elohn, and P. Hess, 1951: Some Remarks on the Climatology of Blocking Action. Tellus, 3, 191-194.
  3. Charney, J. G., and J. G. DeVore, 1979: Multiple flow equilibria in the atmosphere and blocking. J. Atmos. Sci., 36, 1205-1216. https://doi.org/10.1175/1520-0469(1979)036<1205:MFEITA>2.0.CO;2
  4. D'Andrea, F., and Coauthors, 1998: Northern Hemisphere atmospheric blocking as simulated by 15 atmospheric general circulation models in the period 1979-1988. Climate Dyn., 14, 385-407. https://doi.org/10.1007/s003820050230
  5. Dee, D., and Coauthors, 2011: The ERA-Interim reanalysis: configuration and performance of the data assimilation system. Quart. J. Roy. Meteoro. Soc., 137, 553-597, doi:10.1002/qj.828.
  6. Dole, R. M., 1986: Persistent anomalies of the extratropical Northern Hemisphere wintertime circulation: structure. Mon. Wea. Rev., 114, 178-207. https://doi.org/10.1175/1520-0493(1986)114<0178:PAOTEN>2.0.CO;2
  7. Elliott, R. D., and T. B. Smith, 1949: A study of the effects of large blocking highs on the general circulation in the Northern-Hemisphere Westerlies. J. Meteor., 6, 67-85.
  8. Galarneau, T. J., T. M. Hamill, R. M. Dole, and J. Perlwitz, 2012: A multiscale analysis of the extreme weather events over Western Russia and Northern Pakistan during July 2010. Mon. Wea. Rev., 140, 1639-1664, doi:10.1175/MWR-D-11-00191.1.
  9. Hamill, T. M., and G. N. Kiladis, 2014: Skill of the MJO and Northern Hemisphere blocking in GEFS mediumrange reforecasts. Mon. Wea. Rev., 142, 868-885, doi:10.1175/MWR-D-13-00199.1.
  10. Jung, T., and Coauthors, 2012: High-resolution global climate simulations with the ECMWF model in project Athena: Experimental design, model climate, and seasonal forecast skill. J. Climate, 25, 3155-3172. https://doi.org/10.1175/JCLI-D-11-00265.1
  11. Kimoto, M., H. Mukougawa, and S. Yoden, 1992: Mediumrange forecast skill variation and blocking transition. a case study. Mon. Wea. Rev., 120, 1616-1627. https://doi.org/10.1175/1520-0493(1992)120<1616:MRFSVA>2.0.CO;2
  12. Lejenas, H., and H. okland, 1983: Characteristics of northern hemisphere blocking as determined from a long time series of observational data. Tellus A, 35A, 350-362. https://doi.org/10.1111/j.1600-0870.1983.tb00210.x
  13. Liu, Q., 1994: On the definition and persistence of blocking. Tellus A, 46, 286-298. https://doi.org/10.3402/tellusb.v46i4.15803
  14. Mauritsen, T., and E. Kallen, 2004: Blocking prediction in an ensemble forecasting system. Tellus A, 56, 218-228. https://doi.org/10.1111/j.1600-0870.2004.00052.x
  15. Rex, D. F., 1950a: Blocking action in the middle troposphere and its effect upon regional climate. Tellus, 2, 196-211.
  16. Rex, D. F., 1950b: Blocking action in the middle troposphere and its effect upon regional climate. Tellus, 2, 275-301.
  17. Schaefer, J. T., 1990: The critical success index as an indicator of warning skill. Wea. Forecasting, 5, 570-575. https://doi.org/10.1175/1520-0434(1990)005<0570:TCSIAA>2.0.CO;2
  18. Sumner, E. J., 1954: A study of blocking in the Atlantic- European of the northern hemisphere. Quart. J. Roy. Meteor. Soc., 80, 402-416. https://doi.org/10.1002/qj.49708034510
  19. Tibaldi, S., and F. Molteni, 1990: On the operational predictability of blocking. Tellus A, 42, 343-365. https://doi.org/10.3402/tellusa.v42i3.11882
  20. Treidl, R. A., E. C. Birch, and P. Sajecki, 1981: Blocking action in the northern hemisphere: A climatological study. Atmos.-Ocean, 19, 1-23. https://doi.org/10.1080/07055900.1981.9649096
  21. Watson, J. S., and S. J. Colucci, 2002: Evaluation of ensemble predictions of blocking in the NCEP Global Spectral Model. Mon. Wea. Rev., 130, 3008-3021. https://doi.org/10.1175/1520-0493(2002)130<3008:EOEPOB>2.0.CO;2