46 2 123 138 2016 2013 1, 2 * 1, 3 Stable isotopes in precipitation across Japan during an intensive observation period throughout 2013 Kimpei ICHIYANAGI 1, 2 * and Masahiro TANOUE 1, 3 Abstract To elucidate the spatial distribution and seasonal variability of stable isotopes in precipitation across Japan, the Isotope Mapping Working Group of the Japanese Association of Hydrological Sciences conducted precipitation sampling during an intensive observation period throughout 2013 IOP2013. More than 2000 precipitation samples were collected at 56 stations, and their stable water isotopes δ 18 O, δd were measured at Kumamoto University. The time-series of δ 18 O and d-excess of precipitation showed rapid and significant seasonal variability, affected by precipitation type i.e., the winter monsoon and Nangan-Low and by the amount of rainfall during the Baiu rainy season. The monthly mean δ 18 O and d-excess of IOP2013 were averaged in each of six regions across Japan and compared with previous studies, although the sampling periods varied. The seasonal variability of the monthly δ 18 O anomaly from the annual mean was not coincident, indicating the deviation depended on the sampling period. Conversely, the seasonal variability of the monthly d-excess was coincident, even though the absolute values were averaged. Based on the results of short-term sampling at each station, the temperature effect was found north to 35 N and also the precipitation amount effect was mostly found south to 37 N. Further observational data will be required to increase the spatial resolution for better understanding of the spatiotemporal variability of stable isotopes in precipitation across Japan. Key words: stable isotopes in precipitation, across Japan, short-term sampling, spatial distribution, seasonal variability δd, δ 18 O 1 Isotope Mapping Working Group, Japanese Association of Hydrological Sciences 2 Faculty of Advanced Science and Technology, Kumamoto University 3 School of Engineering, The University of Tokyo kimpei@sci.kumamoto-u.ac.jp 123
1 2013 48 d-excess δ 18 O d-excess 10 15 IMWG 60 2013 IOP2013 IMWG 2013; 2014 IOP2013 Ichiyanagi and Tanoue 2016 δ 18 O Tanoue et al. 2016 IMWG IOP2013 2013 IOP2013 10 IMWG 2013 NPO 56 2,000 11 Web Delta- 124
Table 1 Summary of the IOP2013, location, period and number of samples at each station. Northern Japan/Sea of Japan side NJS, northern Japan/Pacific Ocean side NPC, eastern Japan/Sea of Japan side EJS, eastern Japan/Pacific Ocean side EPC, western Japan/Sea of Japan side WJS, and western Japan/Pacific Ocean side WPC Sampling sites Prefecture Region Latitude Longitude Altitude a.m.s.l. Sampling period Number of samples Furano Hokkaido NJS 43 13 52.0 142 35 13.0 400 2012/12/25 2013/12/31 58 Aomori Aomori NJS 40 49 11.4 140 45 37.5 5 2013/01/01 2014/01/01 73 Akita-kita Akita NJS 39 48 7.1 140 2 41.3 20 2012/12/18 2014/01/07 92 Akita Akita NJS 39 43 33.3 140 8 4.2 10 2013/01/26 2014/01/03 30 Yamagata Yamagata NJS 38 12 140 18 130 2013/01/03 2014/01/01 65 Mamurogawa Yamagata NJS 38 56 140 15 180 2012/11/17 2014/01/08 18 Rokkasyo Aomori NPC 40 57 55.4 141 21 38.0 30 2012/12/28 2013/12/27 12 Morioka Iwate NPC 39 46 4.2 141 7 56.6 193 2012/12/27 2014/01/06 67 Sendai Miyagi NPC 38 16 9.0 140 52 14.0 50 2012/12/28 2013/12/31 37 Fukui Fukui EJS 36 3 49.0 136 13 6.0 10 2012/12/29 2014/01/04 34 Imizu Toyama EJS 36 42 29 137 5 47 20 2013/01/09 2014/01/04 74 Nonoichi Ishikawa EJS 36 30 136 36 40 2012/12/29 2014/01/04 79 Utsunomiya Tochigi EPC 36 33 0.3 139 54 47.3 115 2013/01/01 2014/01/07 29 Kiryu Gunma EPC 36 24 20 139 19 50 140 2013/01/01 2014/01/01 11 Isesaki Gunma EPC 36 15 55.0 139 12 6.0 50 2012/12/17 2014/01/06 49 Chiba Chiba EPC 35 37 22.8 140 6 15.5 20 2012/12/27 2013/12/31 37 Ichinomiya Chiba EPC 35 22 32 140 22 10 5 2012/12/30 2013/12/06 10 Funabasi Chiba EPC 35 43 6.0 140 1 43.0 30 2013/01/21 2013/12/27 21 Chichibu Saitama EPC 35 56 21.5 138 51 12.0 800 2013/01/14 2014/01/06 38 Arakawa Tokyo EPC 35 43 57.0 139 45 54.0 20 2012/12/28 2014/01/09 116 Meguro Tokyo EPC 35 39 45 139 40 38 40 2012/12/22 2014/01/01 34 Miyake Tokyo EPC 34 4 0 139 29 5 50 2013/01/11 2013/06/07 11 Yokohama Kanagawa EPC 35 28 10.0 139 35 33.0 60 2012/12/21 2014/01/10 36 Minamiizu Shizuoka EPC 34 38 56 138 51 11 30 2012/12/26 2014/01/06 48 Shizuoka Shizuoka EPC 34 58 32.0 138 22 57.9 30 2013/01/24 2014/01/03 12 Seto Aichi EPC 35 12 137 10 304 2012/12/27 2014/01/06 41 Kakamigahara Gihu EPC 35 24 12.0 136 52 0.0 40 2013/01/01 2014/01/01 13 Hikone Shiga EPC 35 15 32.0 136 12 59.0 90 2013/01/01 2014/01/01 48 Matsue Shimane WJS 35 29 59.9 133 5 7.5 10 2013/01/01 2014/01/02 17 Hofu Yamaguchi WJS 34 2 51.0 131 34 15.1 5 2012/12/25 2013/12/31 33 Yamaguchi Yamaguchi WJS 34 8 52.0 131 28 4.0 20 2012/12/26 2014/01/10 36 Hagi Yamaguchi WJS 34 24 46.0 131 23 7.0 5 2012/12/26 2014/01/04 29 Saga Saga WJS 33 15 26.3 130 19 9.0 5 2012/12/30 2013/12/21 34 Nagasaki Nagasaki WJS 32 47 10.1 129 51 53.3 20 2013/01/04 2014/01/06 32 Kumamoto Kumamoto WJS 32 48 48.0 130 43 45.0 30 2012/12/31 2014/01/10 57 Kuju Oita WPC 33 1 9 131 17 45 550 2012/12/16 2014/01/01 13 Kyoto Kyoto WPC 35 4 21,72 135 45 52.2 140 2012/12/29 2014/01/06 33 Uji Kyoto WPC 34 54 22.4 135 48 15.4 25 2012/12/26 2013/07/31 24 Nara Nara WPC 34 40 29.1 135 50 30.0 115 2013/01/04 2014/01/06 44 Sakai Osaka WPC 34 32 6 135 27 54 10 2013/01/01 2014/02/01 21 Kushimoto Wakayama WPC 33 26 35 135 45 32 50 2012/12/27 2013/12/30 35 Shirahama Wakayama WPC 33 41 46 135 20 18 10 2012/12/23 2013/12/12 31 Takamatsu Kagawa WPC 34 20 35.2 134 2 16.5 10 2013/01/12 2014/11/31 23 Tokushima Tokushima WPC 34 4 0 134 29 20 10 2013/01/01 2013/12/27 30 Kochi Kochi WPC 33 32 133 29 30 2012/12/28 2014/01/06 16 Okayama Okayama WPC 34 41 21.9 133 55 37.1 7 2012/12/27 2014/01/06 18 Higashihiroshima Hiroshima WPC 34 23 56.4 132 42 39.9 220 2012/12/27 2013/08/01 14 Sera Hiroshima WPC 34 35 39 133 3 28 400 2012/12/28 2014/01/15 23 Miyazaki Miyazaki WPC 31 54 42.0 131 24 46.0 10 2013/01/02 2014/01/06 25 Gokase Miyazaki WPC 32 41 1 131 11 47 550 2012/12/25 2013/12/20 32 Kobayashi Miyazaki WPC 31 59 46.0 130 58 28.0 209 2013/01/01 2013/21/22 35 Kobayashi2 Miyazaki WPC 31 59 46.0 130 58 28.0 668 2013/01/01 2013/12/22 32 Miyakonojo Miyazaki WPC 31 44 45.2 131 3 58.0 149 2013/01/01 2014/01/01 12 Izumi Kagoshima WPC 32 5 26 130 21 10 15 2013/01/21 2013/12/21 31 Kagoshima Kagoshima WPC 31 37 23 130 31 27 15 2013/01/15 2013/07/31 14 Kinko Kagoshima WPC 31 14 56 130 47 31 20 2013/01/01 2014/01/01 40 125
V, Thermo Fisher Scientific δd δ 18 O δd 0.5 δ 18 O 0.05 Table 1 43 31 5 m 800 m 2013 6 1 6 3 3 1 Table 2 δ 18 O 13.1 9.2 9.3 8.7 9.5 8.6 10.7 6.6 8.1 6.7 9.3 5.1 δd δ 18 O d-excess 15 22 13 16 18 20 11 17 13 15 8 17 2013 δ 18 O, d-excess Fig. 1 δ 18 O d-excess 2013 1 14 15 δ 18 O 15 20 10 dexcess 20 4 10 d-excess 1986δ 18 O 10 d-excess 1986 d-excess d 10 40 20 d d 10 d 30 2 2013 d-excess d-excess d-excess 2 2013 δ 18 O dexcess 126
Table 2 Summary of the IOP2013, minimum, maximum and annual mean values of stable isotopes at each station. Sampling sites Region δd δ 18 O d-excess min. max. mean min. max. mean min. max. mean Furano NJS 126.88 26.86 84.64 17.45 5.30 12.49 3.14 30.57 15.29 Aomori NJS 120.20 1.70 62.91 17.35 1.48 10.21 2.04 43.05 18.73 Akita-kita NJS 158.20 0.79 59.19 21.48 2.86 9.53 4.32 41.92 17.02 Akita NJS 95.20 10.60 56.41 12.85 3.46 9.23 5.35 37.04 17.41 Yamagata NJS 171.80 8.70 82.34 24.38 2.57 13.14 0.71 39.13 22.81 Mamurogawa NJS 84.30 39.10 57.23 11.97 6.75 9.88 5.68 36.26 21.78 Rokkasyo NPC 71.70 28.74 52.68 10.81 4.43 8.69 6.72 31.35 16.80 Morioka NPC 125.93 1.65 54.65 19.13 0.71 8.70 4.02 31.64 14.99 Sendai NPC 156.90 2.60 60.75 21.80 2.54 9.32 5.14 42.24 13.78 Fukui EJS 113.20 4.30 48.80 14.58 3.17 8.60 3.48 36.28 19.98 Imizu EJS 154.10 7.80 55.34 21.22 2.02 9.50 1.03 38.56 20.66 Nonoichi EJS 141.10 2.10 33.74 18.93 2.94 9.08 3.04 37.40 18.73 Utsunomiya EPC 164.20 3.10 47.87 22.76 3.18 7.41 4.81 28.87 11.42 Kiryu EPC 170.43 15.65 60.03 22.90 3.68 9.49 11.65 20.76 15.90 Isesaki EPC 176.90 3.00 66.14 24.59 0.67 9.88 2.73 30.74 12.86 Chiba EPC 150.76 2.59 46.84 20.99 1.84 7.81 4.24 33.91 15.61 Ichinomiya EPC 69.80 12.80 40.33 11.13 4.28 7.06 8.78 24.74 16.16 Funabasi EPC 108.53 0.09 40.54 16.41 3.66 6.82 9.16 29.34 14.02 Chichibu EPC 203.31 26.02 72.44 27.88 4.20 10.68 2.04 30.18 12.99 Arakawa EPC 191.72 18.39 49.14 25.45 1.34 8.09 2.90 35.68 15.57 Meguro EPC 156.76 3.57 66.67 21.99 2.90 10.28 1.45 30.19 15.56 Miyake EPC 122.00 2.40 38.92 17.02 3.24 6.87 6.85 24.83 16.06 Yokohama EPC 156.00 5.80 45.97 21.84 1.26 7.70 6.38 30.36 15.63 Minamiizu EPC 148.38 3.13 38.66 19.69 2.21 6.62 4.58 32.29 14.28 Shizuoka EPC 85.10 11.10 46.51 12.72 3.23 7.38 7.26 25.05 12.50 Seto EPC 194.59 10.16 57.95 26.01 2.20 8.99 6.45 33.71 14.01 Kakamigahara EPC 104.93 9.88 53.84 15.18 3.08 8.41 8.63 38.52 13.48 Hikone EPC 137.60 6.20 55.36 19.76 2.22 9.08 1.81 37.51 17.24 Matsue WJS 96.25 22.50 48.37 13.65 3.56 8.03 2.95 28.29 15.86 Hofu WJS 95.80 8.10 49.13 13.25 1.56 7.92 1.32 31.98 14.22 Yamaguchi WJS 123.90 5.90 50.02 16.95 1.42 8.10 2.81 35.12 14.75 Hagi WJS 69.26 8.20 48.87 10.39 3.42 7.85 2.51 30.69 13.90 Saga WJS 107.10 4.00 46.42 14.84 0.29 7.54 3.77 33.44 13.88 Nagasaki WJS 100.70 6.00 38.97 14.22 0.29 6.76 0.76 42.67 15.07 Kumamoto WJS 119.32 15.55 45.42 15.82 1.03 7.30 0.61 32.12 12.95 Kuju WPC 84.00 29.40 56.02 12.49 5.38 8.67 9.93 24.46 13.35 Kyoto WPC 140.70 3.30 53.17 19.41 2.03 8.30 3.52 33.11 13.25 Uji WPC 170.40 7.30 46.61 22.59 2.30 7.66 6.79 29.34 14.71 Nara WPC 191.42 3.25 60.83 25.92 1.95 9.26 1.89 36.19 13.21 Sakai WPC 121.10 2.50 50.60 17.28 2.19 8.16 4.35 29.03 14.71 Kushimoto WPC 149.40 3.90 26.81 19.93 2.16 5.06 2.28 34.94 13.66 Shirahama WPC 158.90 1.60 48.80 20.39 2.25 7.59 0.22 31.17 11.95 Takamatsu WPC 113.00 2.60 59.49 16.22 0.10 9.04 8.78 35.11 12.82 Tokushima WPC 162.00 1.80 57.59 22.11 1.75 9.07 3.07 33.30 14.95 Kochi WPC 75.20 2.79 36.17 11.23 2.89 6.03 0.66 27.20 12.07 Okayama WPC 100.70 5.10 59.29 15.02 2.74 8.80 4.02 29.49 11.13 Higashihiroshima WPC 118.64 8.79 56.08 16.99 4.22 8.84 8.97 30.24 14.65 Sera WPC 143.70 12.30 40.89 20.04 3.46 6.69 5.39 30.98 12.59 Miyazaki WPC 87.60 12.40 45.77 12.12 0.80 7.45 6.08 31.78 13.81 Gokase WPC 124.90 13.00 52.94 17.36 1.58 8.33 0.35 34.08 13.74 Kobayashi WPC 98.08 14.05 49.93 13.90 1.52 7.31 0.39 30.03 8.52 Kobayashi2 WPC 93.93 2.05 44.28 13.42 2.54 7.46 5.45 32.15 15.36 Miyakonojo WPC 71.20 18.40 46.52 10.24 4.22 7.59 10.02 22.11 14.20 Izumi WPC 71.60 4.10 41.97 10.45 0.72 7.17 0.79 33.07 15.36 Kagoshima WPC 70.80 6.00 41.67 11.83 2.75 7.42 7.74 24.98 17.71 Kinko WPC 72.63 9.83 39.06 10.58 0.87 6.46 1.68 32.16 12.59 127
Fig. 1 Time-series of precipitation amount, δ 18 O, and d-excess at each station. 128
Fig. 1 continued 129
Fig. 1 continued 130
Fig.1 continued 131
Fig. 2 The seasonal variability of the monthly δ 18 O anomaly from the annual mean averaged in each of six regions, compared with Tanoue et al. 2013 and IOP2013. δ 18 O δ 18 O d-excess 50 2013 IOP2013 IOP2013 6 δ 18 O d-excess Fig. 2 Fig. 3 2013 IOP2013 δ 18 O δ 18 O 6 δ 18 O δ 18 O 132
Fig. 3 Seasonal variability of the monthly d-excess averaged in each of six regions, compared with Tanoue et al. 2013 and IOP2013. δ 18 O IOP2013 IOP2013 3 5 2013 1 δ 18 O 2013 1 14 δ 18 O 1986 δ 18 O 2003 Suzuki and Endo 2001 δ 18 O d-excess IOP2013 2013 133
Table 3 Summary of the IOP2013, Local Meteorological Water Line LMWL, temperature effect, and precipitation amount effect at each station. Sampling sites Region LMWL Temperature effect Precipitation effect slope intercept r T C slope r P mm/yr slope r Furano NJS 7.32 8.09 0.95 5.6 0.20 0.64 1,404 0.037 0.28 Aomori NJS 6.80 14.46 0.87 2.1 0.10 0.30 1,694 0.006 0.09 Akita-kita NJS 7.85 21.65 0.92 7.3 0.04 0.13 2,416 0.011 0.15 Akita NJS 7.53 14.01 0.90 11.6 0.03 0.13 2,544 0.008 0.31 Yamagata NJS 7.50 16.68 0.96 6.2 0.17 0.40 1,313 0.089 0.51 Mamurogawa NJS 4.46 13.08 0.66 8.5 0.10 0.52 4,430 0.003 0.35 Rokkasyo NPC 5.15 5.87 0.81 9.2 0.07 0.34 1,494 0.009 0.37 Morioka NPC 7.27 9.99 0.97 9.5 0.14 0.35 1,626 0.004 0.03 Sendai NPC 7.50 12.17 0.98 12.4 0.32 0.62 1,123 0.007 0.06 Fukui EJS 8.46 22.81 0.90 14.3 0.05 0.17 2,683 0.015 0.38 Imizu EJS 7.93 18.83 0.94 13.5 0.01 0.02 3,162 0.036 0.46 Nonoichi EJS 8.16 20.08 0.93 13.9 0.01 0.03 3,180 0.029 0.40 Utsunomiya EPC 7.85 13.44 0.98 14.2 0.17 0.37 1,650 0.004 0.09 Kiryu EPC 7.88 14.33 1.00 14.9 0.34 0.55 719 0.004 0.05 Isesaki EPC 7.65 10.48 0.99 15.1 0.18 0.35 1,316 0.042 0.37 Chiba EPC 7.27 11.19 0.95 16.3 0.20 0.46 1,418 0.010 0.15 Ichinomiya EPC 7.28 11.49 0.95 17.0 0.15 0.53 965 0.008 0.20 Funabasi EPC 7.37 13.50 0.97 14.2 0.19 0.52 1,224 0.004 0.09 Chichibu EPC 7.55 9.03 0.99 13.0 0.21 0.45 1,510 0.004 0.03 Arakawa EPC 7.96 14.59 0.97 17.5 0.17 0.32 1,318 0.044 0.23 Meguro EPC 7.55 12.42 0.98 16.5 0.20 0.41 1,943 0.027 0.57 Miyake EPC 8.23 18.55 0.98 13.3 0.49 0.55 919 0.007 0.10 Yokohama EPC 7.63 13.65 0.97 16.0 0.19 0.40 1,712 0.006 0.12 Minamiizu EPC 8.14 16.07 0.97 17.2 0.10 0.22 1,970 0.005 0.07 Shizuoka EPC 7.95 13.81 0.96 16.9 0.11 0.32 2,099 0.005 0.18 Seto EPC 8.26 18.58 0.98 15.6 0.10 0.21 1,848 0.012 0.15 Kakamigahara EPC 8.06 17.60 0.95 11.7 0.04 0.13 1,997 0.000 0.01 Hikone EPC 7.46 17.80 0.92 11.7 0.05 0.15 1,403 0.039 0.33 Matsue WJS 7.38 11.07 0.94 13.2 0.10 0.34 2,526 0.004 0.12 Hofu WJS 7.89 15.26 0.95 16.3 0.06 0.16 1,817 0.022 0.40 Yamaguchi WJS 8.22 18.76 0.96 14.7 0.00 0.01 2,379 0.011 0.27 Hagi WJS 7.96 15.12 0.90 16.7 0.02 0.07 1,930 0.010 0.32 Saga WJS 7.45 11.64 0.96 17.1 0.01 0.01 2,048 0.015 0.35 Nagasaki WJS 7.80 15.78 0.92 17.9 0.05 0.12 1,929 0.016 0.27 Kumamoto WJS 8.67 17.37 0.98 19.8 0.06 0.13 1,631 0.033 0.28 Kuju WPC 7.76 13.14 0.97 13.9 0.02 0.05 1,156 0.006 0.14 Kyoto WPC 8.03 16.12 0.97 16.2 0.05 0.12 1,513 0.014 0.17 Uji WPC 8.22 16.92 0.98 12.0 0.09 0.18 715 0.017 0.13 Nara WPC 8.02 15.29 0.97 14.1 0.07 0.13 1,540 0.029 0.26 Sakai WPC 8.04 15.34 0.97 15.6 0.01 0.03 1,286 0.021 0.32 Kushimoto WPC 7.75 13.74 0.94 18.0 0.15 0.31 1,697 0.005 0.04 Shirahama WPC 8.83 18.99 0.97 17.4 0.02 0.04 1,676 0.014 0.31 Takamatsu WPC 7.17 8.81 0.94 15.6 0.02 0.06 1,608 0.015 0.45 Tokushima WPC 7.70 11.98 0.98 15.1 0.15 0.32 1,622 0.008 0.11 Kochi WPC 7.84 15.08 0.93 15.6 0.09 0.29 2,430 0.005 0.25 Okayama WPC 7.89 13.44 0.97 15.0 0.03 0.06 1,319 0.013 0.33 Higashihiroshima WPC 8.53 20.53 0.98 13.9 0.06 0.14 915 0.038 0.47 Sera WPC 8.09 19.38 0.97 8.3 0.10 0.20 1,732 0.002 0.05 Miyazaki WPC 8.76 21.27 0.98 17.2 0.07 0.19 2,421 0.013 0.37 Gokase WPC 7.56 12.06 0.97 14.8 0.07 0.17 2,384 0.012 0.31 Kobayashi WPC 8.29 13.94 0.96 16.6 0.07 0.18 1,983 0.013 0.28 Kobayashi2 WPC 8.36 20.37 0.96 16.6 0.03 0.09 1,892 0.008 0.16 Miyakonojo WPC 8.16 16.22 0.97 16.9 0.04 0.16 1,790 0.005 0.33 Izumi WPC 8.16 16.24 0.94 18.3 0.09 0.26 1,143 0.022 0.35 Kagoshima WPC 7.69 13.40 0.97 17.7 0.05 0.13 1,055 0.026 0.66 Kinko WPC 8.10 14.35 0.93 16.4 0.00 0.01 1,963 0.024 0.64 134
Fig. 4 Spatial distributions of a slope and b intercept of the Local Meteoric Water Line, the c temperature effect / C and d precipitation amount effect /100 mm of the δ 18 O based on the results of short-term sampling at each station. 2013 IOP2013 25 IOP2013 25 20 25 10 d-excess 1, 2 IOP2013 25 2013 20 IOP2013 10 2013 5 d-excess 3 IOP2013 δ 18 O Ichiyanagi and Tanoue 2016 135
Table 3 Fig. 4 7.1 8.8 8 22 3 18 6.8 0 2001 2011 Hasegawa et al. 2014 7.5 7.9 4.2 22.6 IOP2013 2013 Fig. 4 δ 18 O 35 0.1 0.2 / C δ 18 O 37 0.0015 0.0044 /mm Araguás-Araguás et al. 1998 GNIP GNIP IOP2013 Ichiyanagi and Tanoue 2016 IOP2013 δ 18 O 0.36 / C 0.0002 /mm IOP2013 δ 18 O d-excess 6 δ 18 O d-excess δ 18 O 35 37 1 IMWG IOP2013 1 2014 JSPS 24510256 16H05619 CREST 136
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2013 1, 2 * 1, 3 2013 IOP2013 56 δ 18 O d-excess 6 δ 18 O 2013 IOP2013 δ 18 O d-excess δ 18 O 35 37 2013 138