京都 大 学 防 災 研 究 所 年 報 第 50 号 B 平 成 19 年 4 月
Annualsof Disas. Prev. Res. Inst., Kyoto Univ., No. 50 B, 2007ᚑጀ࿤⓭ὼ᣹᷷⃻⽎⊒↢ᦼߦ߅ߌࠆᚑጀ࿤ኻᵹ࿤⚿วߩ੍᷹น⢻ᕈߦ㑐ߔࠆᢙ୯ታ㛎ะᎹဋ࡮ᑝጟବᒾ ࡮㤥↰෹ੑ ਻Ꮊᄢቇᄢቇ㒮ℂቇ⎇ⓥ㒮᳇⽎⎇ⓥᚲⷐᣦ᳇ᚑጀ࿤⓭ὼ᣹᷷ (SSW) ⊒↢ᦼߦ߅ߌࠆᚑጀ࿤-ኻᵹ࿤⚿วߩ੍᷹น⢻ᕈࠍ⺞ߴࠆߚ߼㧘2001ᐕ12᦬ߦ↢ߓߚSSWߦߟ޿ߡ㧘᳇⽎⎇ⓥᚲ-᳇⽎ᐡ⛔৻ᄢ᳇ᄢᓴⅣࡕ࠺࡞ࠍ↪޿ߚ੍ႎታ㛎ࠍⴕߞߚ‫⚿ߩߘޕ‬ᨐ㧘Mukougawa et al. (2005) ߣห᭽ߦ㧘SSW⊒↢ᦼߦSSWߩ੍ႎ߇ೋᦼ୯ߦ
ኻߔࠆ㍈ᢅᕈ߇ᄢ߈ߊߥࠆߎߣ߿㧘ኻᵹ࿤ߦ߅ߌࠆ೨㚟⃻⽎ࠍ⏕⹺ߔࠆߎߣ߇ߢ߈ߚ‫ߚ߹ޕ‬㧘೨㚟⃻⽎ߩᄢ߈ߐߦኻߔࠆᚑጀ࿤ᓴⅣߩᔕ╵ߪ㕖✢ဳ⊛ߢ޽ࠆߎߣ߽ಽ߆ߞߚ‫ޕ‬ࠠ࡯ࡢ࡯࠼㧦੍᷹น⢻ᕈ㧘ᚑጀ࿤⓭ὼ᣹᷷㧘ࡉࡠ࠶ࠠࡦࠣ㧘ࠕࡦࠨࡦࡉ࡞੍ႎ ߪߓ߼ߦSSW ߪዋߥߊߣ߽ 2 ㅳ㑆೨߆ࠄ੍᷹น⢻ߢ޽ࠆߎߣࠍ⷗޿಴ߒߚ‫ߚ߹ޕ‬㧘SSW ߩ੍᷹น⢻ᕈߪ੍᷹ߩೋᦼᤨᄢ᳇ᄢⷙᮨㆇേߩ੍᷹น⢻ᕈߦ㑐ߔࠆ⎇ⓥߪ㧘ߎࠇೞߦᄢ߈ߊଐሽߒ㧘SSW ߇ࠝࡦ࠮࠶࠻ߔࠆᤨᦼߦߪ,߹ߢਥߣߒߡኻᵹ࿤ᓴⅣࠍኻ⽎ߦߒߡⴕࠊࠇߡ߈ߚ

SSW ߩ੍᷹ߩೋᦼ୯ߦኻߔࠆ㍈ᢅᕈ߇ᄢᄌᄢ߈ߊߥ

(e.g., Kimoto et al., 1992)‫৻ޕ‬ᣇߢ㧘ᚑጀ࿤ᓴⅣߩ੍᷹นࠆߎߣࠍ⊒⷗ߒߚ‫ޕ‬ห᭽ߩ੍᷹น⢻ᕈߩᄌേߪ㧘ኻᵹ⢻ᕈߦ㑐ߔࠆ⎇ⓥߪ㧘ᚑጀ࿤⓭ὼ᣹᷷(Stratospheric࿤ߢߩࡉࡠ࠶ࠠࡦࠣߩ੍᷹ߦኻߒߡ߽↢ߓࠆߎߣࠍ㧘Sudden Warming; SSW)ߩౣ⃻ࠍ⋡⊛ߣߒߚೋᦼߩ⎇ⓥ

Kimoto et al. (1992) ߇␜ߒߡ޿ࠆ‫ޕ‬(e.g. Miyakoda et al., 1970; Mechoso et al., 1985) ߩઁߦ৻ᣇ㧘SSW ߩၮᧄ⊛ߥࡔࠞ࠾࠭ࡓߪ㧘Matsuno (1971)ߪ㧘߶ߣࠎߤሽ࿷ߒߥ޿‫ ޕ‬SSW ߪ౻ቄᚑጀ࿤ᓴⅣߦߩ⎇ⓥߦࠃࠅ㧘ኻᵹ࿤߆ࠄ਄ᣇવ᠞ߔࠆᖺᤊⷙᮨᵄߣ߅ߌࠆᦨ߽㗼⪺ߥᖺᤊⷙᮨߢߩᄌേ⃻⽎ߢ޽ࠆ‫ߚ߹ޕ‬㧘ᚑጀ࿤Ꮺ⁁ᵹߣߩജቇ⊛⋧੕૞↪ߦࠃࠅ߁߹ߊℂ⸃ߢㄭᐕ㧘ᚑጀ࿤ᓴⅣᄌേ߇ᒁ߈⿠ߔኻᵹ࿤߳ߩਅᣇᓇ㗀߈ࠆߎߣ߇␜ߐࠇߡ޿ࠆ‫ࠄ߇ߥߒ߆ߒޕ‬㧘SSW ߩࠝࡦߦኻߔࠆ㑐ᔃ(Christiansen, 2003; Reichler et al., 2005)ߩ

࠮࠶࠻ᤨߦኻᵹ࿤ߢᖺᤊⷙᮨᵄࠍ↢ᚑߒ㧘ߘߩ਄ᣇવ㜞߹ࠅߣߣ߽ߦ㧘SSW ߩ੍᷹น⢻ᕈߦ㑐ߔࠆ⎇ⓥ߽ⴕ

᠞ࠍଦㅴߔࠆኻᵹ࿤ߢߩ೨㚟⃻⽎ߦߟ޿ߡߩℂ⸃ߪ੹ࠊࠇࠆࠃ߁ߦߥߞߡ߈ߚ‫ޕ‬ߛਇలಽߢ޽ࠆ‫ޕ‬᳇⽎ᐡ৻ࡩ᦬੍ႎ⚿ᨐߦ࿁Ꮻಽᨆࠍ

Mukougawa and Hirooka (2004) ߪ㧘ㅳ৻࿁ⴕࠊࠇߚⴕ߁ߎߣߦࠃࠅ㧘M05 ߪ㧘2001 ᐕ 12 ᦬ߩ SSW ߦߟ޿᳇⽎ᐡ৻ࡩ᦬੍ႎ⚿ᨐࠍ↪޿ߡ 1998 ᐕ 12 ᦬ߦ↢ߓߚߡ, ኻᵹ࿤ߢߩ೨㚟⃻⽎ࠍหቯߔࠆߎߣࠍ⹜ߺߡ޿ࠆ‫ޕ‬SSW ߇৻ࡩ᦬߽೨߆ࠄ੍᷹น⢻ߢ޽ࠆߎߣࠍ㧘ߪߓ߼ߘߩ⚿ᨐ㧘ᜬ⛯ᕈߩ㜞޿ኻᵹ࿤ࡉࡠ࠶ࠠࡦࠣߦ઻߁ኻߡႎ๔ߒߚ‫ߒ߆ߒޕ‬㧘ᓐࠄߩ⚿ᨐߪ㧘ೋᦼ୯ߦ៨േࠍᵹ࿤਄ጀߢߩ․ᓽ⊛ߥᏪ⁁㘑஍Ꮕ߇㧘᦭ᗧߦ SSW ߩ฽߹ߥ޿ࠦࡦ࠻ࡠ࡯࡞࡜ࡦߩ⚿ᨐߩߺߦၮߠߊ߽ߩߢ⊒↢ߣ㑐ㅪߒߡ޿ࠆߎߣࠍ⷗޿಴ߒߚ‫ࠄ߇ߥߒ߆ߒޕ‬㧘޽ࠅ㧘SSW ߩታ㓙⊛ߥ੍᷹น⢻ᕈࠍᱜ⏕ߦ⷗Ⓧ߽ࠆߎᓐࠄߩ⎇ⓥߪ⛔⸘⊛⸃ᨆߦߣߤ߹ߞߡ޿ࠆߚ߼㧘⛔⸘ߣߪߢ߈ߥ߆ߞߚ‫ߢߎߘޕ‬㧘Mukougawa et al. (2005) (એ⊛ߦᓧࠄࠇߚ೨㚟⃻⽎߇ታ㓙ߦᒁ߈⛯ߊ SSW ࠍ⺃⿠ਅߢߪ M05) ߪ㧘᳇⽎ᐡ৻ࡩ᦬੍ႎߩ៨േࠍ฽߻ోࠕߔࠆ߆ߤ߁߆⏕߆߼ࠆߎߣߪߢ߈ߥ޿‫ޕ‬ࡦࠨࡦࡉ࡞ࡔࡦࡃ࡯ࠍ↪޿ߡ㧘2001 ᐕ 12 ᦬ߦ↢ߓߚߘߎߢᧄ⎇ⓥߢߪ㧘2001 ᐕ 12 ᦬ߦ⊒↢ߒߚ SSW ߦSSW ߩታ㓙⊛ߥ੍᷹น⢻ᕈࠍี๧ߒߚ‫⚿ߩߘޕ‬ᨐ㧘ᵈ⋡ߒ㧘⛔⸘⊛ߦᓧࠄࠇߚኻᵹ࿤೨㚟⃻⽎ߣ SSW ߣ－ 427 －ߩജቇ⊛ 㑐ㅪ ࠍ⏕߆߼ ࠆߚ ߼㧘ᄢ᳇ ᄢᓴ Ⅳࡕ࠺࡞(MRI/JMA-GCM) ࠍ↪޿ߡ৻ㅪߩ੍ႎታ㛎ࠍⴕ߁‫߹ޕ‬ߚ㧘 M05 ߢᓧࠄࠇߚ SSW ࠝࡦ࠮࠶࠻ᦼߦ߅޿ߡ㧘
SSW ߩ੍᷹߇ೋᦼ୯ߦᄢ߈ߊଐሽߔࠆ⃻⽎߇㧘ߎߩ
GCM ੍ႎታ㛎ߢ߽ౣ⃻ߢ߈ࠆߩ߆ߤ߁߆߽ี๧ߔࠆ‫ޕ‬ߎߩࠃ߁ߥ੍ႎታ㛎ࠍታᣉߒߡ೨㚟⃻⽎ࠍ⹦⚦ߦᬌ⸛ߔࠆߎߣߦࠃߞߡߪߓ߼ߡ㧘ኻᵹ࿤ࡉࡠ࠶ࠠࡦࠣߣߘࠇߦᒁ߈⛯޿ߡ⊒↢ߔࠆ SSW ߣߩജቇ⊛㑐ㅪࠍ᣿ࠄ߆ߦߢ߈ࠆߣ⠨߃ࠆ‫ޕ‬ࡕ࠺࡞ᧄ⎇ⓥߢ↪޿ߚࡕ࠺࡞ߪ㧘᳇⽎ᐡ(JMA)ߣ᳇⽎⎇ⓥ
ᚲ(MRI)߇౒หߢ㐿⊒ߒߚ᳇⽎⎇ⓥᚲ/ ᳇⽎ᐡ⛔৻ᄢ᳇ᄢᓴⅣࡕ࠺࡞(MRI/JMA-GCM)ߢ޽ࠆ (Mizuta et al.,2006)‫ ߩߎޕ‬GCM ߪၮᧄ⊛ߦߪ㧘᳇⽎ᐡో⃿ᢙ୯੍ႎ
ࡕ࠺࡞(JMA-GCM0103) ߦၮߠ޿ߡ޿ࠆ‫߅ߥޕ‬㧘ߎߩో⃿ᢙ୯੍ႎࡕ࠺࡞ߪ㧘M05 ߢ૶↪ߒߚ 2001/2002 ౻ቄߩ᳇⽎ᐡ৻ࡩ᦬ࠕࡦࠨࡦࡉ࡞੍ႎߢ↪޿ࠄࠇߡ޿ߚ‫ޕ‬

Fig. 1 Time variation of 10-hPa T at 80N from 20 Nov

ߎߩࡕ࠺࡞ߩ᳓ᐔ⸃௝ߪ TL96 ߢ㧘㋦⋥ߦ 40 ጀ㧘ࡕ2001 through 20 Jan 2002 for the analysis (thick solid࠺࡞ߩ਄┵ߪ 0.4hPa ߢ޽ࠆ‫ࠠࠬࡦࠕࠫࡦ࡜ࠣ࡜ࡒ࠮ޕ‬lines), and for MRI/JMA GCM hindcast (thin solid lines)࡯ࡓࠍ↪޿ߡ᳓ᐔ⒖ᵹߪ⸘▚ߐࠇߡ޿ࠆ‫ޕ‬ᚑጀ࿤ᓴⅣstarting from 5 and 6 Dec 2001 (a), and 12 and 13 Dec

ߩ⴫⃻ߦ㊀ⷐߥ㧘᡼኿㧘㊀ജᵄᛶ᛫㧘᡼኿ߦኻߔࠆࠛ

2001 (b). The dotted lines in (a) denote run S and run F.

ࠕࡠ࠱࡞ߩ⋥ធലᨐ߽⴫⃻ߐࠇߡ޿ࠆ‫ࡦ࠱ࠝޕ‬Ớᐲߪ㧘⚿ᨐ
ೋᦼ୯ߦኻߔࠆ㍈ᢅᕈ੍ႎታ㛎ߩᦼ㑆ߪ㧘᳇୥୯ࠍᏪ⁁ᐔဋߒߡਈ߃ࠄࠇࠆ‫ޕ‬ᶏ㕙᳓᷷ (SST) ߪ㧘᦬ᐔဋߒߚ᳇୥୯ߦೋᦼᤨೞߦ߅
ߌࠆ᳇୥୯߆ࠄߩ SST ஍Ꮕࠍ࿕ቯߒߡਈ߃ࠆ‫࡞࠺ࡕޕ‬ߦ㑐ߔࠆߐࠄߦ⹦ߒ޿ᖱႎߪ㧘Mizuta et al. (2006) ࠍෳᾖߩߎߣ‫ޕ‬߹ߕ㧘M05 ߢ␜ߐࠇߚ SSW ߩࠝࡦ࠮࠶࠻ᦼߦ੍᷹
ߩೋᦼ୯ߦኻߔࠆ㍈ᢅᕈ߇㜞ߊߥࠆߎߣ߇ GCM ታ㛎৻ᣇ㧘੍ႎታ㛎ߩೋᦼ୯ߪ M05 ߢ૶↪ߒߚ߽ߩߣหߢౣ⃻ߢ߈ࠆߎߣࠍ␜ߔ‫ޕ‬Fig. 1 ߩᄥታ✢ߪ㧘10hPa㧘ߓߢ޽ࠆ‫ߜࠊߥߔޕ‬㧘ೋᦼᤨೞߩ⸃ᨆ୯ߦ᳇⽎ᐡ⃻ᬺർ✲ 80 ᐲߦ߅ߌࠆ᷹ⷰߐࠇߚᏪ⁁ᐔဋ᷷ᐲ (T) ߢ޽৻ࡩ᦬ࠕࡦࠨࡦࡉ࡞੍ႎߩೋᦼ៨േࠍട߃ࠆߎߣߦࠃ

ࠆ‫ޕ‬SSW ߩ⊒↢ߦ઻޿㧘2001 ᐕ 12 ᦬ 28 ᣣߦ᷷ᐲߪࠅਈ߃ߚ‫ޕ‬2001/2002 ᐕߩ౻ቄߦߪ㧘᳇⽎ᐡ৻ࡩ᦬ࠕᦨ㜞ߦߥࠆ‫ ߩߎޕ‬SSW ߪ Fig. 2a ߢ␜ߐࠇߚࠃ߁ߦ㧘ࡦࠨࡦࡉ࡞੍ႎߪᲤㅳ᳓ᦐᣣߣᧁᦐᣣߩ 2 ࿁㧘៨േࠍ

ᵄᢙ 1 ߩᖺᤊᵄߩჇ᏷ߦࠃߞߡ↢ߓߡ޿ࠆ‫ ߩߎޕ‬Fig.

ട߃ߥ޿ೋᦼ୯ߣ㧘12 ୘ߩೋᦼ៨േࠍ฽߻ೋᦼ୯ࠍ↪

2a ߪ㧘12 ᦬ 27 ᣣ߆ࠄ 29 ᣣ߹ߢߢ 3 ᣣᐔဋߒߚ 10hPa޿ߡታᣉߐࠇߚ‫ߩߎޕ‬ೋᦼ៨േߪ㧘ࡉ࡝࡯࠺ࠖࡦࠣ╬࿶㕙㜞ᐲ႐ࠍ␜ߒߡ޿ࠆ‫৻ޕ‬ᣇ㧘Fig. 1 ߩ⚦ታ✢ߪ㧘

(Breeding of Growing Mode; BGM) ᴺ (Toth and Kalnayೋᦼᣣࠍ 12 ᦬ 5 ᣣ㧘6 ᣣ (Fig. 1a)㧘 12 ᦬ 12 ᣣ㧘131993) ࠍ↪޿ߡ↢ᚑߐࠇߡ޿ࠆ‫ޕ‬ೋᦼ៨േߪ㧘ർ✲ 20

ᣣ(Fig. 1b) ߣߔࠆ᳇⽎ᐡࠕࡦࠨࡦࡉ࡞੍ႎߩೋᦼ୯ࠍ

ᐲએർߩో᳇࿶㕙ߢਈ߃ࠄࠇ㧘500hPa ߢߩ㜞ᐲ႐ᄌേ↪޿ߡ MRI/JMA-GCM ࠍ 30 ᣣ㑆ᤨ㑆Ⓧಽߒߚ⚿ᨐࠍߩੑਸ਼ᐔဋᩮߩᄢ߈ߐ߇‫ޔ‬᳇୥୯ߩ 14.5%ߦߥࠆࠃ߁␜ߒߡ޿ࠆ‫ޕ‬12 ᦬ 5 ᣣߣ 6 ᣣࠍೋᦼ୯ߣߔࠆታ㛎⚿ᨐߦ៨േߩᝄ᏷߇ਈ߃ࠄࠇߡ޿ࠆ‫੍ޕ‬ႎታ㛎⚿ᨐߩᬌ⸽ߢߪ㧘޿ߊߟ߆ߩࡔࡦࡃ࡯߇߁߹ߊ SSW ߩ⊒↢ࠍౣߦߪ㧘᳇⽎ᐡో⃿ቴⷰ⸃ᨆ (GANAL) ࠍ↪޿ߚ‫ޕ‬ឭଏ⃻ߒߡ޿ࠆ‫৻ޕ‬ᣇ㧘12 ᦬ 12 ᣣ㧘13 ᣣࠍೋᦼ୯ߣߔࠆ

ߐࠇߚ GANAL ߩ᳓ᐔ⸃௝ᐲߪ㧘᳓ᐔᩰሶ㑆㓒ߪ✲ᐲታ㛎⚿ᨐߢߪ㧘M05 ߢ␜ߐࠇߚࠃ߁ߦ㧘ోߡߩࡔࡦࡃ⚻ᐲᩰሶߢ 1.25 ᐲ㧘㋦⋥࡟ࡌ࡞ߪ 1000hPa ߆ࠄ 0.4hPa

࡯߇ SSW ࠍ੍᷹ߔࠆߎߣߦᚑഞߒߡ޿ࠆߎߣ߇ಽ߆߹ߢߩ 23 ጀߢ޽ࠆ‫ޕ‬ࠆ‫ޕ‬ૉߒ㧘MRI/JMA GCM ࠍ↪޿ߚ⚿ᨐߪ㧘᷹ⷰ୯߿᳇⽎ᐡ৻ࡩ᦬੍ႎ⚿ᨐߦᲧߴߡ㧘੍᷹ߐࠇߚᭂၞᚑጀ࿤᷷ᐲ߇ో⥸⊛ߦ㜞߼ߦߥߞߡ޿ࠆ (Fig. 1b)‫৻ޕ‬ᣇ㧘
M05 ߣห᭽ߦ㧘SSW ߩᦨ⋓ᦼ߅޿ߡ㧘12 ᦬ 5 ᣣߣ 6－ 428 －ᣣࠍೋᦼ୯ߣߔࠆࡔࡦࡃ࡯㑆ߩ߫ࠄߟ߈ (ࠬࡊ࡟࠶ኻᾖ⊛ߦ㧘⸃ᨆ୯ߣ run S ߢߪ㧘߆ߥࠅᒝ޿⷏㘑߇ർ࠼) ߪ㧘12 ᦬ 12 ᣣߣ 13 ᣣࠍೋᦼ୯ߣߔࠆࡔࡦࡃ࡯㑆✲ 80 ᐲઃㄭߩኻᵹ࿤਄ጀߦሽ࿷ߒ㧘ߘߩධ஥ߩ⷏㘑ߪߩ߫ࠄߟ߈ࠃࠅ߽ᄢᄌᄢ߈ߊߥߞߡ޿ࠆ‫߆ߣߎߩߎޕ‬ᒙߊߥߞߡ޿ࠆ‫ޕ‬ߎߩ㜞✲ᐲߦ߅ߌࠆ U ߩ㆑޿ߪ㧘Fig.

ࠄ㧘MRI/JMA-GCM ࠍ↪޿ߚ੍ႎታ㛎⚿ᨐ߆ࠄ߽㧘ߎ

3 ߦ⷗ࠄࠇࠆࠃ߁ߦ㧘ർᄢ⷏ᵗ㗔ၞߦ߅ߌࠆࡉࡠ࠶ࠠ

ߩ SSW ߩࠝࡦ࠮࠶࠻ᦼߦ SSW ੍᷹ߩೋᦼ୯ߦኻߔࠆࡦࠣߩᜬ⛯․ᕈߩ㆑޿ߦ↱᧪ߔࠆ߽ߩߢ޽ࠆ‫ߚ߹ޕ‬㧘㍈ᢅᕈ߇ᭂ߼ߡᄢ߈ߊߥࠆߎߣࠍ⏕⹺ߔࠆߎߣ߇ߢ߈ߎࠇࠄߩ㆑޿ߪ㧘M05 ߩ᳇⽎ᐡ৻ࡩ᦬੍ႎ⚿ᨐࠍ↪޿ߚ‫ޕ‬ߚ⸃ᨆߦ߅޿ߡ߽ห᭽ߦሽ࿷ߔࠆ‫৻ޕ‬ᣇ㧘ᚑጀ࿤਄ጀ

৻ᣇ㧘Fig. 2 ߆ࠄ߽㧘12 ᦬ 5 ᣣߣ 6 ᣣࠍೋᦼ୯ߣߔ

ߦ⌕⋡ߔࠆߣ㧘⸃ᨆ୯߿ run S ߩ U ߪ run F ߦᲧߴ߆ࠆࡔࡦࡃ࡯㑆ߩࠬࡊ࡟࠶࠼߇ᄢ߈ߊߥࠆߎߣࠍ⹺⼂ߔߥࠅᒝ޿‫ߦࠄߐޕ‬㧘⷏㘑ߩゲߪ run F ߦᲧߴᭂ஥ߦࠪ

ࠆߎߣ߇ߢ߈ࠆ‫ޕ‬Fig. 2b ߪ㧘ోߡߩࡔࡦࡃ࡯ߩਛߢ㧘ࡈ࠻ߒߡ޿ࠆ‫ޕ‬Fig. 4 ߦߪ㧘ᵄᢙ 1 ߩવ᠞ᣇะߣᵴേ

12 ᦬ 28 ᣣߩർ✲ 80 ᐲ㧘10hPa ߦ߅ߌࠆ T ߩ੍᷹୯ᐲ߽㧘E-P flux ࡌࠢ࠻࡞ߦࠃߞߡ␜ߐࠇߡ޿ࠆ‫⸃ޕ‬ᨆ߇ᦨᄢߢ޽ߞߚࡔࡦࡃ࡯ (run S) ߩ㧘12 ᦬ 27 ᣣ߆ࠄ୯ߦᲧߴ㧘run S ߿ run F ߪࠃࠅᄢ߈ߥᵄᵴേᐲࠍ␜

29 ᣣߢߩ 3 ᣣᐔဋ 10hPa 㜞ᐲ႐੍᷹୯ࠍ␜ߔ‫৻ޕ‬ᣇ㧘ߒߡ޿ࠆ߇㧘run S ߢߪኻᵹ࿤ߩർ✲ 60 ᐲઃㄭߢ㧘ᵄ

Fig. 2c ߪ㧘 ർ✲ 80 ᐲ㧘10hPa ߦ߅ߌࠆ T ߩ੍᷹୯߇

ᢙ 1 ߩᭂะ߈਄ะ߈ߩવ᠞߇㧘run F ߦᲧߴ᣿⍎ߢ޽ᦨዊߢ޽ߞߚࡔࡦࡃ࡯ (run F) ߩ੍᷹୯ߢ޽ࠆ‫ߩߎޕ‬ࠆ‫ߪߣߎߩߎޕ‬㧘ᵄᢙ 1 ᚑಽߩኻᵹ࿤ߦ߅ߌࠆ↢ᚑ߇࿑߆ࠄ㧘run S ߢߪ㧘ᵄᢙ 1 ᚑಽ߇᷹ⷰ୯ (Fig. 2a) ߣSSW ߩ੍᷹ߦߣߞߡ㊀ⷐߢ޽ࠆߎߣࠍ␜ໂߒߡ޿ࠆ‫ޕ‬ห᭽ߦᄢ߈ߊჇ᏷ߒߡ޿ࠆߎߣ߇᣿ࠄ߆ߢ޽ࠆ‫ޕ‬ૉߒ㧘᷹ⷰߣᲧߴ㧘ߘߩ૏⋧ߪ߿߿⷏ߦᄌ૏ߒߡ޿ࠆ‫৻ޕ‬ᣇ㧘࿁Ꮻಽᨆ

run F ߢߪ㧘ᭂ᷵ߪଐὼߣߒߡᒝ޿⁁ᘒࠍ଻ߞߡ߅ࠅ㧘

Fig. 3 ߢߺࠄࠇߚർ᧲ᄢ⷏ᵗၞߢߩࡉࡠ࠶ࠠࡦࠣ㜞ᭂၞߩ᷷ᐲ߽ૐ޿߹߹ߢ޽ࠆ‫ߦ߁ࠃߩߎޕ‬㧘SSW ߩ੍᳇࿶ߩᒻᚑߣ㧘ߘࠇߦᒁ߈⛯ߊ SSW ߩ⊒↢ߣߩ㑐ଥ᷹ߩ㎛ߪᵄᢙ 1 ᚑಽߩჇ᏷ߢ޽ࠆߎߣ߇ಽ߆ࠆ‫ޕ‬M05

ߪ㧘M05 ߣห᭽ߦ㧘12 ᦬ 5 ᣣߣ 6 ᣣࠍೋᦼ୯ߣߔࠆో

ߢ߽⸥ߐࠇߚࠃ߁ߦ㧘12 ᦬ 5 ᣣ㧘6 ᣣࠍೋᦼᣣߣߔࠆ26 ࡔࡦࡃ࡯ߩ GCM ੍ႎታ㛎⚿ᨐࠍ↪޿ߚ 500hPa 㜞ࡔࡦࡃ࡯㑆ߢ㧘ᵄᢙ 1 ߩᵄᵴേᐲߩ㋦⋥વ᠞ࠍ⴫⃻ߔ࿶㕙㜞ᐲߦኻߔࠆ࿁Ꮻಽᨆ߆ࠄ߽⏕⹺ߔࠆߎߣ߇ߢ߈

ࠆ E-P flux ߩ㋦⋥ᚑಽߩᄢ߈ߐ߇㧘 㜞✲ᐲߩᚑጀ࿤ਅ

ࠆ‫ޕ‬Fig. 5 ߪ㧘᣹᷷ࡇ࡯ࠢᦼߦኻᔕߔࠆ 12 ᦬ 28 ᣣߩጀߢ 12 ᦬ 13 ᣣ㗃ߦᄢ߈ߊߥࠆ‫߼ߚߩߎޕ‬㧘12 ᦬ 13 ᣣ

10hPa㧘ർ✲ 80 ᐲߩ T ੍᷹୯ߩࠕࡦࠨࡦࡉ࡞ᐔဋ߆ࠄ

ઃㄭࠍ SSW ߩࠝࡦ࠮࠶࠻ᦼߣ⠨߃ࠆ‫ޕ‬ߩ஍Ꮕߦ࿁Ꮻߐߖߚ㧘12 ᦬ 12 ᣣ߆ࠄ 14 ᣣߩ 3 ᣣ㑆ߢᰴߦ㧘SSW ߩ↢ᚑߦᔅⷐߥ೨㚟⃻⽎ࠍᝒ߃ࠆߚ߼㧘ᐔဋߒߚ 500hPa ╬࿶㕙㜞ᐲ႐੍᷹୯ߩ஍Ꮕߢ㧘 T ஍ࠝࡦ࠮࠶࠻ᦼߦ߅ߌࠆ run S ߣ run F ߩᝄ⥰޿ߩ㆑޿ࠍ

Ꮕ߇ +1 ᮡḰ஍Ꮕߣߥࠆߣ߈ߦኻᔕߔࠆ 500hPa ╬࿶㕙⷗Ყߴࠆ‫ޕ‬Fig. 3 ߪ㧘ߎߩࠝࡦ࠮࠶࠻ᦼߩ 3 ᣣ㑆ߢᐔ㜞ᐲ႐஍Ꮕࠍ␜ߔ‫ޕ‬ਔ⠪ߩ⋧㑐ଥᢙߩ᦭ᗧᕈࠍ㧘⥄↱ဋߒߚ 500hPa ╬࿶㕙㜞ᐲ႐ࠍ␜ߔ‫⸃ޕ‬ᨆ୯߿ run S ߢᐲ 24 ߩ t-ᬌቯߦࠃߞߡ⷗Ⓧ߽ߞߚ⚿ᨐࠍ㒶ᓇߢ␜ߔ‫ޕ‬ߪ㧘⊒㆐ߒߚࡉࡠ࠶ࠠࡦࠣ㜞᳇࿶ߦ઻޿㧘ർ᧲ᄢ⷏ᵗߎߩ⥄↱ᐲߪ㧘26 ୘ߩࠕࡦࠨࡦࡉ࡞ࡔࡦࡃ࡯߇੕޿ߦ

ၞߢ㧘ࠫࠚ࠶࠻᳇ᵹ߇߆ߥࠅ㜞✲ᐲߦࠪࡈ࠻ߒߡ޿ࠆ‫ޕ‬⁛┙ߢ޽ࠆߣ઒ቯߒߡ⷗Ⓧ߽ߞߚ‫ߩߎޕ‬࿑߆ࠄ㧘ർ᧲ߒ߆ߒ run F ߢߪ㧘ࡉࡠ࠶ࠠࡦࠣ㜞᳇࿶ߪ߆ߥࠅᒙߊ㧘ᄢ⷏ᵗ਄ߩࡉࡠ࠶ࠠࡦࠣߦ઻߁ᱜߩ㜞ᐲ႐஍Ꮕߪ㧘ߘߎߩߚ߼ᄢ⷏ᵗၞߩࠫࠚ࠶࠻᳇ᵹߪ㧘ߘߩ᳇୥ቇ⊛ߥ

ߩ 2 ㅳ㑆ᓟߩ SSW ߩ⊒↢ߣ᦭ᗧߦ㑐ㅪߒߡ޿ࠆߎߣ૏⟎ߢ޽ࠆർ✲ 60 ᐲઃㄭߦሽ࿷ߔࠆ‫ࡦࠠ࠶ࡠࡉߩߎޕ‬߇ಽ߆ࠆ‫ߪࠇߎޕ‬㧘run S ߣ run F ߦኻߔࠆ೨ㅀߒߚ⸃

ࠣߪ㧘੍ႎታ㛎ߩೋᦼᤨೞߦߪߔߢߦ⊒㆐Ბ㓏ߦ޽ߞᨆ⚿ᨐߣ⍦⋫ߒߥ޿‫ޕ‬Fig. 5a ߦߪ㧘M05 ߢ⷗ࠄࠇߥ߆ߚߚ߼㧘ߎߩ㆑޿ߪࡉࡠ࠶ࠠࡦࠣߩᜬ⛯ᕈߩ㆑޿ߦࠃߞߚ᦭ᗧߥ㜞ᐲ႐஍Ꮕ߇ሽ࿷ߔࠆ߇㧘Fig. 5 ߢ⷗ࠄࠇࠅ↢ߓߡ޿ࠆߣ⠨߃ࠄࠇࠆ‫․ߩࠄࠇߎޕ‬ᓽߪ㧘M05 ߩࠆᄢ⷏ᵗ਄ߩᱜߩ㜞ᐲ႐஍Ꮕߪ㧘M05 ߩ Fig. 3a ߢ␜ߐ⚿ᨐߣ౒ㅢߒߡ޿ࠆ‫ޕ‬ࠇߚ߽ߩߣ߶߷หߓ࿾ℂ⊛૏⟎ߦ޽ࠆ‫ߪߣߎߩߎޕ‬㧘ߎߩࠝࡦ࠮࠶࠻ᦼߢ 3 ᣣᐔဋߒߚᏪ⁁ᐔဋ᧲⷏㘑(U) ߩሶඦ㕙ಽᏓࠍ Fig. 4 ߦ␜ߔ‫ޕ‬Fig. 4a ߇⸃ᨆ୯㧘

SSW ߩᚑ࿃ߣߒߡࡉࡠ࠶ࠠࡦࠣ߇㊀ⷐߥᓎഀࠍᨐߚ
ߒߡ޿ࠆߎߣࠍ␜ໂߒߡ޿ࠆ‫ޕ‬

Fig. 4b ߇ run S㧘Fig. 4c ߇ run F ߢ޽ࠆ‫ޕ‬ᖺᤊᵄߩ↢ᚑห᭽ߩ࿁Ꮻಽᨆࠍ 12 ᦬ 12 ᣣ߆ࠄ 14 ᣣߩ 3 ᣣ㑆ߢᐔ߿વ᠞ߪ U ߩಽᏓߦᓇ㗀ߐࠇࠆߚ߼㧘U ߩಽᏓߪ SSW

ဋߒߚ U ߦߟ޿ߡ߽ⴕߞߚ (Fig. 6)‫ߩߎޕ‬࿑߆ࠄ㧘ᱜࠍ߁߹ߊ੍᷹ߔࠆߚ߼ߦ㊀ⷐߥⷐ࿃ߩ৻ߟߢ޽ࠆߣ⠨ߩ㜞ᐲ႐஍Ꮕߦ઻߁ർ✲ 60 ᐲઃㄭߩኻᵹ࿤਄ጀߩ U߃ࠄࠇࠆ‫ߩߎޕ‬࿑߆ࠄ㧘⸃ᨆ୯߿ run S ߣ㧘run F ߣߩ஍Ꮕ߽㧘SSW ߩ⊒↢ߣ᦭ᗧߦ㑐ଥߒߡ޿ࠆߎߣ߇ಽ߆㑆ߦߪ᣿⍎ߥ㆑޿߇ኻᵹ࿤㜞✲ᐲၞߢ⷗ߡขࠇࠆ‫ߔޕ‬ࠆ‫ߚ߹ߪߣߎߩߎޕ‬㧘M05 ߢ߽⏕⹺ߐࠇߡ޿ࠆ‫߆ߒޕ‬ߥࠊߜ㧘run F ߢߪኻᵹ࿤਄ጀߩർ✲ 80 ᐲઃㄭߦᒙ޿

ߒߥ߇ࠄ㧘M05 ߩ Fig. 4a ߣߪ⇣ߥࠅ㧘Fig. 6a ߦ߅ߌࠆ᧲㘑㧘ർ✲ 60 ᐲઃㄭߦᒝ޿⷏㘑߇ሽ࿷ߔࠆ‫ߪߣࠇߘޕ‬੝ᾲᏪ㗔ၞߦ߅ߌࠆ U ஍Ꮕߪ᦭ᗧߢ޽ࠆ߇㧘ᭂၞߦ－ 429 －

Fig. 2 3-day mean 10-hPa height field (m) during 27-29 Dec 2001 for the analysis (a), run S (b), and run F (c).

Contourinterval is 200 m.

Fig. 3 3-day mean 500-hPa height field (m) during 12-14 Dec 2001 for the analysis (a), run S (b), and run F(c). Contour interval is 100 m.

Fig. 4 Latitude-height cross sections of U (m/s) averaged over 12-14 Dec for the analysis (a), run S (b), and run F (c). The
vectors show 3-day mean WN1 E-P flux (kg/s2) above 700 hPa. E-P flux is scaled by the reciprocal square root of the pressure. The magnitude of the reference vectors at 1000 hPa is shown in the lower right corner.

－ 430 －Fig. 5 (a) Regressed anomaly of the predicted 3-day mean 500-hPa height (m) during 12-14 Dec upon the predicted 10-hPa Tat 80N on Dec 28 using all ensemble forecasts starting from 5 and 6 Dec by MRI-JMA GCM. The light (heavy) shades indicate regions where the statistical significance of the anomaly exceeds 95 (99) %. Contour interval is 20 m. (b) Ensemble average of the predicted 3-day mean 500-hPa height (m).

Fig. 6 As in Fig. 5, but for the predicted 3-day mean U (m/s) and WN 1 E-P flux (kg/s2) during 12-14 Dec. The vectors in (a)show the regressed WN 1 E-P flux anomalies of which vertical or meridional component is significant at 90% level above
700 hPa. Their magnitude is multiplied by 10. E-P flux is scaled by the reciprocal square root of the pressure. The magnitudeof the reference vectors at 1000 hPa is shown in the lower right corner.

߅ߌࠆߘࠇߪ᦭ᗧߢߪߥ޿‫ޕ‬Fig. 6a ߆ࠄ㧘Fig. 4 ߢ␜ൻ߇ SSW ߩ⊒↢ߣ✕ኒߦ㑐ㅪߒߡ޿ࠆߎߣ߇ಽ߆ࠆ‫ޕ‬ߐࠇߚࠃ߁ߦ㧘SSW ߩ⊒↢ߣ᦭ᗧߦ㑐ㅪߒߡ㧘ᚑጀ࿤ߎߩ㑐ଥߪ㧘M05 ߢ߽⏕⹺ߐࠇߡ޿ߚ߇㧘ߘߩ⛔⸘⊛਄ጀߩ⷏㘑߇ᭂၞߦࠪࡈ࠻ߔࠆߎߣ߇ಽ߆ࠆ‫ޕ‬᦭ᗧᕈߪ M05 ࠃࠅ߽ᄢ߈޿‫৻ޕ‬ᣇ㧘Fig. 6b ߆ࠄ㧘ࠕࡦ

Fig. 6a ߦߪ㧘SSW ߩ⊒↢ߣ᦭ᗧߦ㑐ㅪߔࠆᵄᢙ 1 ߩࠨࡦࡉ࡞ᐔဋߒߚ WN1 ߩᵴേᐲߪᚑጀ࿤ਅㇱߢߪർ

E-P flux ஍Ꮕߩ࿁Ꮻ߇␜ߐࠇߡ޿ࠆ‫ޕ‬ኻᵹ࿤ߦ߅ߌࠆ✲ 60 ᐲઃㄭߢᄢ߈޿߇㧘SSW ߩ⊒↢ߣ᦭ᗧߦ㑐ㅪߔᭂะ߈વ᠞ߩଦㅴߣ㧘ኻᵹ࿤਄ጀߢߩ਄ะ߈વ᠞ߩᒝࠆߩߪർ✲ 70 ᐲઃㄭߢߩ਄ᣇવ᠞ߢ޽ࠆߎߣ߇ಽ߆－ 431 －Fig. 8 As in Fig.1, but for the MRI/JMA GCM hindcast
experiments starting from 13 Dec 2001 with initial conditions composed of the ensemble mean field (Fig. 6b) andFig. 7 As in Fig. 6a, but for the regressed U and E-P flux

the regression field (Fig. 6a) multiplied by a coefficient

vectors upon PC1 of the predicted 3-day mean U during

which is denoted on the lines. The analysis is shown by the12-14 Dec of the ensemble forecasts starting from 5 and 6

broken line, predictions with positive coefficients by thinDec.

solid (dotted) lines.

ࠆ‫ߚ߹ޕ‬㧘M05 ߢߪ᣿⍎ߦ⷗޿಴ߖߥ߆ߞߚ߇㧘Fig. 6a↱ࠍਈ߃ߡ޿ࠆߣ⠨߃ࠄࠇࠆ‫ޕ‬Fig. 7 ߩ⍫ශߢ␜ߐࠇ

߆ࠄኻᵹ࿤ߩർ✲ 70 ᐲઃㄭߦ߅ߌࠆᵄᢙ 1 ᚑಽߩ↢

ߚ PC1 ߦኻߔࠆᵄᢙ 1 ᚑಽߩ E-P flux ߩ࿁Ꮻ߽㧘ߎߩᚑߪ㧘⋥ធ⊛ߦ㧘ᚑጀ࿤ߦ߅ߌࠆ਄ᣇવ᠞ߩჇᄢߣ㑐ផ⺰ࠍᡰᜬߒߡ޿ࠆ‫ޕ‬Fig. 6a ߣห᭽ߦ㧘Fig. 7 ߢ߽㧘ଥߒߡ޿ࠆߎߣ߇ಽ߆ࠆ‫ߪߣߎߩߎޕ‬㧘ߎߩ SSW ߩർ✲ 60 ᐲઃㄭߢኻᵹ࿤߆ࠄᚑጀ࿤߳ߩ਄ᣇવ᠞߇᦭⊒↢ߦߪ㧘ࠝࡦ࠮࠶࠻ᦼ㑆ߦ߅ߌࠆᵄᢙ 1 ߩᵄᵴേᐲᗧߦᒝൻߐࠇߡ޿ࠆ‫ ߪࠇߎޕ‬SSW ࠍ⺃⿠ߔࠆߣ⠨߃

ߩવ᠞․ᕈߩᄌൻࠃࠅ߽㧘߻ߒࠈᵄᢙ 1 ߩ↢ᚑ⥄૕߇ࠄࠇࠆ‫ޕ‬㊀ⷐߢ޽ࠆߎߣࠍ␜ໂߒߡ޿ࠆ‫ޕ‬
Fig. 1a ߢ⷗ࠄࠇߚ㧘SSW ߩ੍᷹߇ೋᦼ୯ߦᒝ޿㍈ᢅ࿁Ꮻ࿑ࠍ↪޿ߚ੍ႎታ㛎ᕈࠍ␜ߔߣ޿߁ߎߣߪ㧘M05 ߣห᭽ߦ Fig. 7 ߆ࠄ߽⺑೨▵ߢ⛔⸘⊛ߦᓧࠄࠇߚ㧘SSW ߩ⊒↢ߣ㑐ㅪߔࠆ᣿ߔࠆߎߣ߇ߢ߈ࠆ‫ޕ‬Fig. 7 ߪ㧘SSW ࠝࡦ࠮࠶࠻ᦼߦ

Fig. 5a ߿ Fig. 6a ߩ࿁Ꮻࡄ࠲࡯ࡦߩ㊀ⷐᕈࠍ⏕⹺ߔࠆߚ߅ߌࠆࠕࡦࠨࡦࡉ࡞ࡔࡦࡃ࡯㑆ߩࠬࡊ࡟࠶࠼߇ᦨ߽ᄢ

߼ߦ㧘ೋᦼᣣࠍ 12 ᦬ 13 ᣣߣߒ㧘Fig. 5b ߿ Fig. 6b ߢਈ߈ߊߥࠆࡄ࠲࡯ࡦࠍ␜ߔߚ߼㧘12 ᦬ 5 ᣣߣ 6 ᣣࠍೋᦼ߃ࠄࠇࠆࠕࡦࠨࡦࡉ࡞ᐔဋ୯ߦ㧘࿁Ꮻࡄ࠲࡯ࡦߦ޽ࠆ୯ߣߔࠆోߡߩ੍᷹ታ㛎⚿ᨐࠍ↪޿ߡ㧘12 ᦬ 12 ᣣ߆

ଥᢙ D ࠍដߌߡട߃ߚ߽ߩࠍೋᦼ୯ߣߔࠆ৻ㅪߩ੍

ࠄ 14 ᣣߩ੍᷹ߐࠇߚ 3 ᣣᐔဋ U ߦኻߒߡਥᚑಽಽᨆႎታ㛎ࠍታᣉߒߚ‫࡞ࡉࡦࠨࡦࠕߩߎޕ‬ᐔဋ߿࿁Ꮻࡄ࠲

ࠍⴕ޿㧘ᓧࠄࠇߚ╙ 1 ਥᚑಽࠬࠦࠕ (PC1) ߦ࿁Ꮻߒߚ

࡯ࡦߪ㧘12 ᦬ 5 ᣣߣ 6 ᣣࠍೋᦼᣣߣߔࠆ GCM ੍ႎታU ஍Ꮕࠍ␜ߒߡ޿ࠆ‫ޕ‬ਥᚑಽಽᨆߪ 1000 ߆ࠄ 0.4hPa㧘㛎ߩ 12 ᦬ 12 ᣣ߆ࠄ 14 ᣣߩ 3 ᣣ㑆ߢᐔဋߒߚ੍᷹୯ࠍ

ർ✲ 20 ᐲએർߩ㗔ၞߢⴕ޿㧘㕙Ⓧࡈࠔࠢ࠲࡯ࠍട๧ߔ

↪޿ߡ㧘MRI/JMA-GCM ߩోߡߩ੍ႎᄌᢙߦߟ޿ߡ⸘ࠆߚ߼✲ᐲߩࠦࠨࠗࡦߩᐔᣇᩮߣ㧘ฦ᳇࿶㕙ߢߩኒᐲ▚ߒߚ‫ޕ‬ߎߎߢ D ߩ୯ߪ㧘-2.0 ߆ࠄ 4.0 ߩ▸࿐ߢ 0.5 Ფߦਈߩᐔᣇᩮࠍ஍Ꮕߦដߌߚ‫ ╙ޕ‬1 ਥᚑಽߪ㧘ࠕࡦࠨࡦࡉ
࡞ᐔဋߩ࿁ࠅߢߩ U ߩోಽᢔߩ 43%ࠍ⺑᣿ߔࠆ‫ޕ‬Fig.

߃ߚ‫࡞ࡉࡦࠨࡦࠕޕ‬ᐔဋ୯߆ࠄߩ੍ႎታ㛎ߪ D7 ߢ␜ߐࠇߚ U ஍Ꮕߩᄢ߈ߐߪኻᵹ࿤਄ጀߢᦨᄢߢ㧘⋧ᒰߔࠆ‫ߩߢ߹ࠇߎޕ‬࿁Ꮻಽᨆߩ⚿ᨐ߆ࠄ㧘ᱜߩ D ࠍ0ߦർ✲ 45 ᐲߣ 70 ᐲߦ▵᭴ㅧࠍᜬߜ㧘10hPa ߦ߹ߢ㆐ߔ

ೋᦼ୯ߣߒߡਈ߃ߚ႐วߦߪ SSW ߩ⊒↢ߔࠆ⏕₸߇ࠆ㗅࿶⊛ߥ᭴ㅧߢ․ᓽߠߌࠄࠇࠆ‫৻ޕ‬ᣇ㧘਄ጀᚑጀ࿤㜞ߊߥࠅ㧘⽶ߩ႐วߦߪૐߊߥࠆߎߣ߇੍ᦼߐࠇࠆ‫ޕ‬ߢߪ㧘ർ✲ 55 ᐲઃㄭߩ▵ࠍᜬߟ෺ᭂሶ᭴ㅧ߇ථ⿧ߒߡ

ߎߩ੍ႎታ㛎ߩ⚿ᨐࠍ Fig. 8 ߦ␜ߒߚ‫ߩߎޕ‬࿑ߪ㧘ർ޿ࠆ‫․ߩࠄࠇߎޕ‬ᓽߪ Fig. 6a ߢ␜ߐࠇߚ㧘SSW ߩ⊒✲ 80 ᐲ㧘10hPa ߦ߅ߌࠆ T ߩᤨ㑆ᄌേࠍ␜ߒߡ޿ࠆ‫ޕ‬↢ߣ㑐ㅪߔࠆ U ߩࡄ࠲࡯ࡦߣ⦟ߊ㘃ૃߒߡ޿ࠆ‫ޕ‬ᓥ✢ߩ਄ߦ⸥ߐࠇߚᢙሼ߇ D ߢ޽ࠆ‫ߩߎޕ‬࿑߆ࠄ㧘ᱜߢߞߡ㧘M05 ߣห᭽ߦ㧘ߎߩ㘃ૃᕈߪ㧘SSW ߩࠝࡦ࠮࠶

ᄢ߈ߥ D ࠍਈ߃ߚ႐วߦߪ 12 ᦬ 28 ᣣ㗃ߦታ㓙ߦ᣹᷷

࠻ᦼߦ SSW ߩ੍᷹߇ೋᦼ୯ߦᒝ޿㍈ᢅᕈࠍ␜ߒߚℂ߇⿠߈ࠆ௑ะߦ޽ࠅ㧘⽶ߢᄢ߈ߥ D ߩ႐วߦߪ᣹᷷߇－ 432 －ࠃࠅ߽㧘㓏Ბ㑐ᢙ⊛ߢ޽ࠆ‫੍ޕ‬ႎታ㛎ߢᓧࠄࠇߚ T ߪ㧘

D ߇ᱜ(⽶)ߩ୯ߦኻߒߡ㧘240 (210) K ઃㄭߦ㓸߹ߞߡ޿ࠆ‫ߚ߹ߪߣߎߩߎޕ‬㧘SSW ߇⊒↢ߔࠆߚ߼ߦᔅⷐߥ

D ߩ㑣୯߇ሽ࿷ߔࠆߎߣࠍ␜ໂߒߡ޿ࠆ‫ޕ‬ᓥߞߡ㧘
SSW ߩࠝࡦ࠮࠶࠻ᦼߢߪ㧘೨㚟⃻⽎ߦ઻߁஍Ꮕߩᄢ߈ߐߦኻߒߡ㧘ᚑጀ࿤ᓴⅣߪ㕖✢ဳ⊛ߦᔕ╵ߒߡ޿ࠆߣ޿߃ࠆ‫ޕ‬߹ߣ߼᳇⽎ᐡ 1 ࡩ᦬ࠕࡦࠨࡦࡉ࡞੍ႎߩฦࡔࡦࡃ࡯ߩೋᦼ
୯ࠍ↪޿ߡ MRI/JMA-GCM ߦࠃࠆ੍ႎታ㛎ࠍⴕ޿㧘
M05 ߢႎ๔ߐࠇߚ 2001 ᐕ 12 ᦬ߦ↢ߓߚᵄᢙ 1 ဳߩSSW ߩ੍᷹߇ೋᦼ୯ߦᒝߊଐሽߔࠆߎߣߦߟ޿ߡี๧ߒߚ‫੍ߩߎޕ‬ႎታ㛎ߢ߽ห᭽ߦ㧘SSW ߩࠝࡦ࠮࠶࠻ᦼߦ㧘ೋᦼ୯ߦኻߔࠆ㍈ᢅᕈ߇ᄢ߈ߊߥࠆߎߣࠍ⏕⹺ߒߚ‫ޕ‬
ߎߩ GCM ታ㛎ߩ⚿ᨐ㧘M05 ߢ␜ߐࠇߚߩߣห᭽ߥFig. 9 Relationship between 10-hPa T (K) at 80N on Dec

Ꮺ⁁㘑ߩ․ᓽ⊛ߥ஍Ꮕ႐ߪ㧘ߘࠇߦᒁ߈⛯޿ߡ↢ߕࠆ28 and the coefficient of 3-day mean U anomaly duringᚑጀ࿤ᭂၞߦ߅ߌࠆ᣹᷷ߣ᦭ᗧߦ㑐ㅪߒߡ޿ߚ‫ߩߎޕ‬

12-14 Dec.

Open circles are for ensemble experimentsኻᵹ࿤ߦ߅ߌࠆᏪ⁁㘑஍Ꮕߪ㧘M05 ߣห᭽ߦ㧘ᄢ⷏ᵗstarting from 5 and 6 Dec, crosses are for hindcast experi-ၞߦ߅ߌࠆᜬ⛯ᕈߩ㜞޿ࡉࡠ࠶ࠠࡦࠣ㜞᳇࿶ߦ઻߁߽ments from 13 Dec starting from the ensemble mean fieldߩߢ޽ࠅ㧘ߘࠇߪኻᵹ࿤߆ࠄᚑጀ࿤߳ߩᵄᢙ 1 ᚑಽߩ(Fig. 6b) added with the regression field (Fig. 6a) multi-਄ᣇવ᠞ࠍଦㅴߔࠆ‫৻ޕ‬ᣇ㧘SSW ߩࠝࡦ࠮࠶࠻ᦼߦᚑ

plied by the coefficient (value of the abscissa).

ጀ࿤Ꮺ⁁ᐔဋ㘑ߦ߽․ᓽ⊛ߥ஍Ꮕ߇ሽ࿷ߔࠆߎߣ߇␜ߐࠇߚ‫ߪࠇߎޕ‬㧘M05 ߢߪႎ๔ߐࠇߡ޿ߥ޿‫ߦࠄߐޕ‬M05 ߣᲧߴ㧘ᵄᢙ 1 ᚑಽߩബ⿠ߪࠃࠅ᣿⍎ߢ޽ߞߚ߇㧘ᛥ೙ߐࠇ ࠆ௑ ะߦ޽ࠆ ߎߣ ߇ಽ߆ࠆ ‫ߥ߁ࠃߩ ߎޕ‬ኻᵹ࿤Ꮺ⁁㘑஍Ꮕߩ⛔⸘⊛᦭ᗧᕈߪ߿߿ዊߐߊߥߞߚ‫ޕ‬

MRI/JMA-GCM ࠍ↪޿ߚ੍ႎታ㛎߆ࠄ㧘 SSW ߩ⊒↢ߎߩ㆑޿߆ࠄ㧘SSW ߩ⊒↢ߦߪ㧘ᵄᢙ 1 ߩવ᠞․ᕈߩ

ߦኻߔࠆ Fig. 5a ߿ Fig. 6a ߢ␜ߐࠇߚ࿁Ꮻࡄ࠲࡯ࡦߩᄌൻࠃࠅ߽㧘߻ߒࠈߘߩബ⿠ߘߩ߽ߩ߇㊀ⷐߢ޽ࠆߎ

㊀ⷐᕈࠍ␜ߔߎߣ߇ߢ߈ߚ‫ޕ‬ߣࠍ␜ໂߒߡ޿ࠆ‫ߚ߹ޕ‬㧘ߎߩᏪ⁁㘑஍Ꮕߩࡄ࠲࡯ࡦ

Fig. 9 ߢߪ㧘ߐࠄߦ㧘ർ✲ 80 ᐲ㧘10hPa ߦ߅ߌࠆ T ߣߪ㧘M05 ߣห᭽ߦ㧘SSW ߩࠝࡦ࠮࠶࠻ᦼߦ߅ߌࠆࠕࡦD ߣߩ㑐ଥࠍี๧ߔࠆߎߣ߇ߢ߈ࠆ‫ߩߎޕ‬࿑ߢ㧘ᮮゲߪ D 㧘❑ゲߪ T ߢ޽ࠆ‫ޕ‬12 ᦬ 13 ᣣࠍೋᦼᣣߣߔࠆ੍ႎታ㛎⚿ᨐߪ u ߢ㧘ೋᦼᣣ߇ 12 ᦬ 5 ᣣ㧘6 ᣣߩ
MRI/JMA-GCM ࠕࡦࠨࡦࡉ࡞੍ႎታ㛎⚿ᨐ߇ $ 㧘᷹ⷰ୯߇ x ߢ␜ߐࠇߡ޿ࠆ‫ߚ߹ޕ‬㧘ߎߩ࿑ߩ x-ゲߩ୯ߪ㧘ࠨࡦࡉ࡞ࡔࡦࡃ࡯ߩᏪ⁁㘑஍Ꮕߦ㑐ߔࠆ╙ 1 ਥᚑಽߣ߶߷৻⥌ߒߡ޿ߚ‫ޕ‬ᓥߞߡ㧘ࠝࡦ࠮࠶࠻ᦼߦ߅ߌߡSSW ߩ੍᷹߇ೋᦼ୯ߦᒝߊଐሽߔࠆߎߣߪ㧘ߎߩਔ⠪ߩࡄ࠲࡯ࡦߩ৻⥌߆ࠄ⺑᣿ߔࠆߎߣ߇ߢ߈ࠆ‫ޕ‬ߐࠄߦ࿁Ꮻಽᨆߩ⚿ᨐᓧࠄࠇߚ SSW ߩ⊒↢ߣ㑐ㅪ

Fig. 6a ߢ␜ߐࠇߚ U ߩ࿁Ꮻࡄ࠲࡯ࡦ b ߦ㧘U ߩ஍Ꮕ aߔࠆ஍Ꮕ႐ߩ㊀ⷐᕈࠍ⏕߆߼ࠆߚ߼ߦ㧘ࠍ኿ᓇߒߚ୯ࠍ␜ߒߡ޿ࠆ‫ߢߎߎޕ‬኿ᓇߪ<a, b>/<a,MRI/JMA-GCM ࠍ↪޿ߚ੍ႎታ㛎ࠍⴕߞߚ‫ߩߎޕ‬ታ㛎a>ߢቯ⟵ߒߚ‫ޕ‬ૉߒ㧘<a, b>ߪ㧘ർ✲ 20 ᐲએർ㧘1000hPaߢ↪޿ߚೋᦼ୯ߪ㧘⛔⸘⊛ߦᓧࠄࠇߚ࿁Ꮻࡄ࠲࡯ࡦߦ

߆ࠄ 0.4hPa ߩ㗔ၞߢቯ⟵ߐࠇࠆ a ߣ b ߣߩౝⓍࠍ⴫޽ࠆଥᢙࠍដߌߚ஍Ꮕ႐ࠍࠕࡦࠨࡦࡉ࡞ᐔဋߦട߃ࠆߔ‫ߩߎޕ‬ౝⓍߦߪ✲ᐲߩࠦࠨࠗࡦߦᲧ଀ߔࠆ㕙Ⓧࡈࠔߎߣߦࠃࠅ૞ᚑߒߚ‫⚿ߩߘޕ‬ᨐ㧘ᱜߩଥᢙࠍਈ߃ࠆߣ㧘ࠢ࠲࡯ࠍട๧ߒߡ޿ࠆ‫ߦࠄߐޕ‬㧘஍Ꮕߪ㧘12 ᦬ 12 ᣣታ㓙ߦᚑጀ࿤ߢߩ᣹᷷߇⊒↢ߔࠆߎߣ߇⏕߆߼ࠄࠇߚ‫ޕ‬

߆ࠄ 14 ᣣ߹ߢߩ 3 ᣣᐔဋ୯ߩࠕࡦࠨࡦࡉ࡞ᐔဋ႐ૉߒ㧘᣹᷷ߩᄢ߈ߐߪ㧘ਈ߃ࠆଥᢙߩᄢ߈ߐߦߪᲧ଀

(Fig. 6b) ߆ࠄߩᏅߢቯ⟵ߒߚ‫ߩߎޕ‬࿑߆ࠄ㧘ో૕⊛ߦߒߥ޿‫ࠈߒ߻ޕ‬㧘ᚑጀ࿤ᓴⅣߩᔕ╵ߪਈ߃ߚଥᢙߦ㑐ߪ㧘 D ߣ 12 ᦬ 28 ᣣߩ T ߣߩ㑆ߦᱜߩ⋧㑐߇޽ࠆߎߒߡ㓏Ბ㑐ᢙ⊛ߢ޽ࠅ㧘SSW ߇⊒↢ߔࠆߚ߼ߦߪ㧘ߎߣ߇ಽ߆ࠆ‫ߩߎޕ‬㑐ଥࠍ␜ߔ࿁Ꮻ⋥✢ߪ Fig. 9 ߩታ✢ߩଥᢙߩᄢ߈ߐߦ޽ࠆ㑣୯߇ሽ࿷ߔࠆߎߣࠍ␜ໂߒߡߢ␜ߐࠇߡ޿ࠆ‫ࠄ߇ߥߒ߆ߒޕ‬㧘ਔ⠪ߩ㑐ଥߪ✢ᒻ⊛޿ࠆ‫ޕ‬－ 433 －ߎߩࠃ߁ߥᚑጀ࿤ᓴⅣߩ㕖✢ဳ⊛ߥ․ᓽߪ㧘

events during the winter of 1979. Mon. Wea. Rev., Vol.

Yoden(1987)ߢ߽ႎ๔ߐࠇߡ޿ࠆ‫ޕ‬ᓐߪ㧘ᄢᄌ◲⇛ൻߐ

113, pp. 1015-1029.

ࠇߚᄢ᳇ࡕ࠺࡞ࠍ↪޿ߡ㧘޽ࠆࡄ࡜ࡔ࡯࠲ߩ▸࿐ߢߪ㧘

Miyakoda, K., Strickler, R. F. and Hembree, G. D. (1970):

ᚑጀ࿤ᓴⅣߦߪੑߟߩ቟ቯߥᵹࠇߩ⁁ᘒ߇ሽ࿷ߔࠆߎ

Numerical simulation of the breakdown of a polar-nightߣࠍ␜ߒߚ‫⷏ߪߟ৻ߩߘޕ‬㘑߇ᒝ޿ᭂ᷵ߩᒝ޿⁁ᘒߢ

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޽ࠅ㧘ઁᣇߪᄢᝄ᏷ߩᖺᤊⷙᮨᵄ߇ሽ࿷ߔࠆ SSW ߦ139-154.

ૃߚ⁁ᘒߢ޽ࠆ‫ߥ߁ࠃߩߎޕ‬㕖✢ဳࠪࠬ࠹ࡓߢߪ㧘޽Mizuta, R. and coauthors (2006): 20-km-mech global cli-ࠆ৻ߟߩ቟ቯߥᵹࠇߩ⁁ᘒ߆ࠄ㧘ઁᣇߩ⁁ᘒ߳ߩㆫ⒖߇↢ߓࠆߚ߼ߦߪ㧘ਔ⠪ߩ㑆ߦሽ࿷ߔࠆ‫ࡖࠪࡦ࠹ࡐޟ‬࡞㓚ო‫ߥ߁ࠃࠆࠇࠄ߃⿧ࠍޠ‬ೋᦼ៨േ߇ᔅⷐߣߥࠆ‫ޕ‬ߐࠄߦ㧘ㆫ⒖߇↢ߓ߿ߔߊߥࠆ‫ޟ‬ಽጘὐ‫ޠ‬ઃㄭߢߪ㧘૏⋧ⓨ㑆ߦ߅ߌࠆੑߟߩ቟ቯߥ⁁ᘒࠍ⚿߱ᣇะߦ゠㆏ߪ᜛߇ࠅ߿ߔߊߥࠆߚ߼㧘ೋᦼ៨േ߽ߘߩᣇะߦਈ߃ࠆߣ㧘ࠃࠅㆫ⒖߇↢ߓ߿ߔߊߥࠆߣ⠨߃ࠄࠇࠆ‫ߩߎޕ‬⎇ⓥߢᓧࠄࠇߚ SSW ߩ⊒↢ߣ㑐ㅪߔࠆ࿁Ꮻࡄ࠲࡯ࡦߪ㧘ߘߩᣇะࠍ␜ߒߡ޿ࠆน⢻ᕈ߇޽ࠆ‫ޕ‬ߎߎߢᓧࠄࠇߚ࿁Ꮻࡄ࠲࡯ࡦࠍ㧘ߐࠄߦ♽⛔⊛ߦ◲නൻߒߡ੍ႎታ㛎ࠍⴕ߁ߎߣߦࠃࠅ㧘SSW ߩ⊒↢ߦᦨ
߽㊀ⷐߥ೨㚟⃻⽎ࠍขࠅ಴ߖࠆน⢻ᕈ߇޽ࠆ‫ࠃߩߎޕ‬߁ߥታ㛎ߦࠃߞߡ㧘ኻᵹ࿤ࡉࡠ࠶ࠠࡦࠣߣ SSW ߣߩ

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during Sudden Warming Events

Hitoshi MUKOUGAWA, Toshihiko HIROOKA* and Yuhji KURODA***Department of Earth and Planetary Sciences, Kyushu University**Meteorological Research InstituteSynopsis
In order to examine dynamical predictability of the stratosphere-troposphere coupling during stratosphericsudden (SSW) warming events, we conduct a series of hindcast experiments using an atmospheric general circulation model (MRI/JMA-GCM) for a SSW occurring in December 2001. As a result, high sensitivity to the initial condition of the prediction for the SSW and the tropospheric precursory event are confirmed as in Mukougawa et al. (2005). It is also found that the response of the stratospheric circulation to the magnitude of the precursory anomaly is nonlinear.
Keywords: predictability, stratospheric sudden warming, blocking, ensemble forecast－ 435 －