6-1기후.2정일웅c

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1 Observed Change of Climatic Regions and Desertification during the 20th Century Il-Ung Chung* Sang-Hye Shin** *Department of Atmospheric & Environmental Sciences, Gangneung-Wonju National University **Department of Atmospheric Sciences, Yonsei University (Received 13 December 2010, Revised 23 December 2010, Accepted 28 December 2010) 20 Köppen 5 A E C/D 1960 B (BW) km 2 (BS) Abstract : In this study, the characteristic features in both global change of the Köppen climate regions and desertification during the 20th century were investigated using observed data. The results of the analyses for the areal changes of Köppen climate regions show that the warmer climate areas and the colder climate areas were continually expanded and shrunk, respectively, over the entire period. Areas of C and D climate types show distinct increase and decrease, respectively, since 1960s. These changes seem to be understood by the direct consequences of global warming. Area of the dry climate was considerably expanded since 1970s so that its areal percentage during 1990s was increased by about 2% compared to during 1960s. Especially, area of the desert climates was increased by about km 2 during the last decade, relative to the average for 1961~1990. This expansion can be interpreted as a desertification because most of the expansion (more than 98%) Correspondence: Il-Ung Chung, Department of Atmospheric & Environmental Sciences, Gangneung-Wonju National University, 120 Gangneung Daehagno, Gangneung, Gangwon, , Republic of Korea, Phone: , Fax: , iuchung@gwnu.ac.kr

1970 1960 1990 2 (BW) 20 1991 2000 1961 1990 1 320 10 3 km 2 (BS) 1950 1960 Abstract : In this study, the characteristic features in both global change of the Köppen climate regions and

2 24 was from BS climate regions around deserts. Analysis for the regional desertification reveals that the most prominent expansion occurred in the northern Africa and in the central Asia since 1950s. The possibility of global warming as a cause of the desertification was prudently examined by inquiring intensification of the wintertime Hadley circulation. We found that Hadley circulation in boreal winter was significantly strengthened since 1960s. Key Words : Global Warming, Climate Change, Köppen Climate Classification, Climate Region, Hadley Circulation 50 IPCC (Intergovernmental Panel on Climate Change) 4 (IPCC, 2007) 280ppm ppm 715ppb 1774ppb 270ppb 319ppb (sea ice) mm cm Suckling and Mitchell(2000) 20 Köppen C/D Fraedrich et al.(2001) Diaz and Eischeid(2007)

We found that Hadley circulation in boreal winter was significantly strengthened since 1960s.

3 25 Köppen 20 Beck et al.(2006) Fraedrich et al.(2001) Beck et al.(2006) IPCC(2007) UNCCD(United Nations Convention to Combat Desertification) 2 5 (WMO, 2005) (Fraedrich et al., 2001; Beck et al., 2006; Kim et al., 2008) 1997 Charney(1975) 1998 Nicholson et al.(1998) NDVI(Normalized Difference Vegetation Index) Piao et al.(2005) NDVI Mahowald(2007) Zeng and Yoon(2009) IPCC

(Fraedrich et al., 2001; Beck et al., 2006; Kim et al., 2008) 1997 Charney(1975) 1998 Nicholson et al.

4 26 20 A B C D E f m w S W w s f w s f T F 18 6cm 10 R/25 R cm 10 R/25 R<2T R<2T 70 6 R<2T R (cm) T BS-BW w s 3 10 C C C

5 27 Köppen Köppen 1 5 (A, B, C, D, E) (B) (BS) (BW) Martonne 1999 AI(aridity index) (P) (T) AI P(mm) T( C)+10 (1) Charney(1975) Tanaka et al.(2004) 200hPa V fl V fl (Krishnamurti, 1971) V fl V fl V fl kfi fl fl (2) (streamfunction) (velocity potential) D D fl V fl 2 (3) D Poisson (2) D(spherical harmonic expansion) Tanaka et al.(2004)

(2004) 200hPa V fl V fl (Krishnamurti, 1971) V fl V fl V fl kfi fl fl (2)

6 28 max 200hPa 3 3 Tanaka et al.(2004) 3 (orthogonal spatial patterns) [ (t,y)] *(t,x,y) [ (t,y)] *(x,y) * (t,x,y) (4) x, y, t 4 Köppen (Climatic Research Unit, CRU) CRU TS 2.1 (Mitchell and Jones, 2005) Köppen 1 20 ECMWF 40 (Uppala et al., 2005) 200hPa hPa

7 29 (DJF) (JJA) 5 5

8 30

9 31 3a Köppen 4 13 Köppen (A) (B) km (C) (D)

20 28 73 1930 1970 50 27 43 30 1 8 29 27 1 8 2 638 1 10 3 km 2

10 32 (E) km 2 7 7

11 33 Köppen

12 34

13 35 A BS BW C D E km 2 3, km 2 1, km 2 2, km 2 1, km km 2 A BS BW C D E (A) km 2 BS A 31 7 BW BW km 2 BS BW 98 3 BW BS BW BS BW BS A C D BW E 1 7 BW E BW 5 5 7a

3 30.8 0.0-1.5 0.0 D 0.0 22.4 0.0 76.7-88.2 E 0.0 0.7 1.7 3.5 91.

14 36 7b mm 231mm 72mm mm mm 39mm BS BW BS

15 km 2 BW km Nicholson et al.(1998) 8b BS km 2 BW km BW 20 8c BS km 2 BW km BW BS BS BW 8d BS km 2 BW BS km BS BW BS km 2 BW km km 2 BW

1950 50 191 4 10 3 km 2 1950 2 4 BW BS BS BW 8d BS 1970 80 20 20 1 036 1 10 3 km 2 BW BS 1970 80 20 20 1 084 5 10

16 38

17 39 20 Chen et al.(2002) 1990 Hu and Fu(2007) 1979 IPCC 4 (IPCC, 2007) 21 Lu et al.(2007) 9 ECMWF (DJF) (Tanaka et al. 2004, Mitas and Clement, 2005; Song and Zhang, 2007; Takemoto and Tanaka, 2007)

(2007) 9 ECMWF 40 200 1961 2000 40 4 10 27 5 12 15 1960 1990

18 40

19 41

20 42 20 Köppen A E C/D 1960 B (BW) km 2 (BS) 20 BS BW 1950 Charney(1975) IPCC

21 43 Kalvova et al Beck, C., Grieser, J., Kottek, M., Rubel, F., and Rudolf, B., 2006, Characterizing global climate change by means of Köppen climate classification. DWD, Klimastatusbericht 2005, Deutscher Wetterdienst, ISBN Charney, J. G., 1975, Dynamics of deserts and drought in Sahel, Quart. J. Roy. Meteor Soc., 101, Chen, J., Carlson, B. E., and Del Genio, A. D., 2002, Evidence for strengthening of the tropical general circulation in the 1990s, Science, 295, Diaz, H. F. and Eischeid, J. K., 2007, Disappearing alpine tundra Köppen climatic type in the western United States, Geophys. Res. Lett., 34, L18707, doi: / 2007GL Fraedrich, K., Gerstengarbe, F. W., and Werner, P. C., 2001, Climate shifts in the last century, Climatic Change, 50, Hu, Y. and Fu, Q., 2007, Observed poleward expansion of the Hadley circulation since 1979, Atmos. Chem. Phys., 7, IPCC, 2007, Climate Change, 2007: The Physical Science Basis. Contributions of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [Solomon, S., Qin, D., Manning, M., Chen, Z., Marquis, M., Averyt, K. B., Tignor, M., Miller, H. L. (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, 996 pp. Kalvova, J., Halenka, T., Bezpalcova, K., and Nemesova, I., 2003, Köppen climate types in observed and simulated climates, Stud. Geophys. Geod., 47, Kim, H. -J., Wang, B., Ding, Q., and Chung, I. -U., 2008, Changes in arid climate over North China detected by the Köppen climate classification, J. Meteor. Soc. Japan, 86(6), Köppen, W., 1936, Das geographische System der Klimate (Handbuch der Klimatologie, Bd. 1, Teil C). Krishnamurti, T. N., 1971, Tropical east-west circulations during the northern summer, J. Atmos. Sci., 28, Lu, J., Vecchi, G. A., and Reichler, T., 2007, Expansion of the Hadley cell under global warming, Geophys. Res. Lett., 34, L06805, doi: /2006gl

22 44 Mahowald, N. M., 2007, Anthropocene changes in desert area: Sensitivity to climate model predictions, Geophys. Res. Lett., 34, L18817, doi: /2007gl Mitas, C. M. and Clement, A., 2005, Has the Hadley cell been strengthening in recent decades?, Geophys. Res. Lett., 32, L03809, doi: /2004gl Mitchell, T. and Jones, P., 2005, An improved method of constructing a database of monthly climate observations and associated high-resolution grids, Int. J. Climatol., 25, Nicholson, S. E., Tucker, C. J., and Ba, M. B., 1998, Desertification, drought, and surface vegetation: An example from the West African Sahel, Bull. Amer. Meteor. Soc., 79, Piao, S., Fang, J., Liu, H., and Zhu, B., 2005, NDVI-indicated decline in desertification in China in the past two decades, Geophys. Res. Lett., 32, L06402, doi: / 2004GL Song, H. and Zhang, M. 2007, Changes of the boreal winter Hadley circulation in the NCEP-NCAR and ECMWF reanalyses: A comparative study, J. Climate, 20, Suckling, P. W. and Mitchell, M. D., 2000, Variation of the Köppen C/D climate boundary in the central United States during the 20th century, Phys. Geog., 21, Takemoto, M. and Tanaka, H. L., 2007, Intensities of Hadley, Walker, and monsoon circulations compared in the upper and lower troposphere, J. Korean Meteor. Soc., 43, Tanaka, H. L., Ishizaki, N., and Kitoh, A., 2004, Trend and interannual variability of Walker, monsoon and Hadley circulations defined by velocity potential in the upper troposphere, Tellus, 56A, Uppala, S. M. and Coauthors, 2005, The ERA-40 Reanalysis, Quart. J. Roy. Meteor. Soc., 131, WMO, 2005, Climate and Land Degradation, Report No Geneva, Switzerland, 32pp. Zeng, N. and Yoon, J., 2009, Expansion of the world s deserts due to vegetation-albedo feedback under global warming, Geophys. Res. Lett., 36, L17401, doi: / 2009GL

03이경미(237~248)ok

03이경미(237~248)ok The recent (2001-2010) changes on temperature and precipitation related to normals (1971-2000) in Korea* Kyoungmi Lee** Hee-Jeong Baek*** ChunHo Cho**** Won-Tae Kwon*****. 61 (1971~2000) 10 (2001~2010).