Search

Your search keyword '"Imada, Yukiko"' showing total 172 results
Start Over Author "Imada, Yukiko"
172 results on '"Imada, Yukiko"'

1. Mechanisms of tropical Pacific decadal variability

Author

Capotondi, Antonietta, McGregor, Shayne, McPhaden, Michael J., Cravatte, Sophie, Holbrook, Neil J., Imada, Yukiko, Sanchez, Sara C., Sprintall, Janet, Stuecker, Malte F., Ummenhofer, Caroline C., Zeller, Mathias, Farneti, Riccardo, Graffino, Giorgio, Hu, Shijian, Karnauskas, Kristopher B., Kosaka, Yu, Kucharski, Fred, Mayer, Michael, Qiu, Bo, Santoso, Agus, Taschetto, Andréa S., Wang, Fan, Zhang, Xuebin, Holmes, Ryan M., Luo, Jing-Jia, Maher, Nicola, Martinez-Villalobos, Cristian, Meehl, Gerald A., Naha, Rajashree, Schneider, Niklas, Stevenson, Samantha, Sullivan, Arnold, van Rensch, Peter, and Xu, Tongtong

Published
2023
Full Text
View/download PDF

3. EXPLAINING EXTREME EVENTS OF 2016 : From A Climate Perspective

Author

Herring, Stephanie C., Christidi, Nikolaos, Hoell, Andrew, Kossin, James P., Schreck, Carl J., Stott, Peter A., Webb, Robert S., Werner, Francisco E., Knutson, Thomas R., Kam, Jonghun, Zeng, Fanrong, Wittenberg, Andrew T., Brainard, Russell E., Oliver, Thomas, McPhaden, Michael J., Cohen, Anne, Venegas, Robert o, Heenan, Adel, Vargas-Ángel, Bernardo, Rotjan, Randi, Mangubhai, Sangeeta, Flint, Elizabeth, Hunter, Susan A., Oliver, Eric C. J., Perkins-Kirkpatrick, Sarah E., Holbrook, Neil J., Bindoff, Nathaniel L., Tett, Simon F. B., Falk, Alexander, Rogers, Megan, Spuler, Fiona, Turner, Calum, Wainwright, Joshua, Dimdore-Miles, Oscar, Knight, Sam, Freychet, Nicolas, Mineter, Michael J., Lehmann, Caroline E. R., Martins, Eduardo S. P. R., Coelho, Caio A. S., Haarsma, Rein, Otto, Friederike E. L., King, Andrew D., van Oldenborgh, Geert Jan, Kew, Sarah, Philip, Sjoukje, Vasconcelos, Francisco C., Cullen, Heidi, Jézéquel, Aglaé, Yiou, Pascal, Radanovics, Sabine, Vautard, Robert, Sippel, Sebastian, El-Madany, Tarek S., Migliavacca, Mirco, Mahecha, Miguel D., Carrara, Arnaud, Flach, Milan, Kaminski, Thomas, Otto, Friederike E. L., Thonicke, Kirsten, Vossbeck, Michael, Reichstein, Markus, Yuan, Xing, Wang, Linying, Wood, Eric F., Funk, Chris, Davenport, Frank, Harrison, Laura, Magadzire, Tamuka, Galu, Gideon, Artan, Guleid A., Shukla, Shraddhanand, Korecha, Diriba, Indeje, Matayo, Pomposi, Catherine, Macharia, Denis, Husak, Gregory, Nsadisa, Faka Dieudonne, Imada, Yukiko, Shiogama, Hideo, Takahashi, Chiharu, Watanabe, Masahiro, Mori, Masato, Kamae, Youichi, Maeda, Shuhei, Sun, Qiaohong, Miao, Chiyuan, Zhou, Chunlüe, Wang, Kaicun, Qi, Dan, Yuan, Xing, Wang, Shanshan, Hu, Zeng-Zhen, Qian, Cheng, Wang, Jun, Dong, Siyan, Yin, Hong, Burke, Claire, Ciavarella, Andrew, Dong, Buwen, Freychet, Nicolas, Lott, Fraser C., Tett, Simon F. B., Sun, Ying, Hu, Ting, Zhang, Xuebin, Wan, Hui, Stott, Peter, Lu, Chunhui, Christidis, Nikolaos, Manomaiphiboon, Kasemsan, Ciavarella, Andrew, Stott, Peter A., Hope, Pandora, Lim, Eun-Pa, Hendon, Harry, Wang, Guomin, Lewis, Sophie C., Mallela, Jennie, Grose, Michael R., Black, Mitchell, Risbey, James S., Uhe, Peter, Hope, Pandora K., Haustein, Karsten, Mitchell, Dann, Stott, Peter A., Christidis, Nikos, Herring, Stephanie C., Hoell, Andrew, Kossin, James P., and Schreck, Carl J.

Published
2018

8. Global Historical Reanalysis with a 60-km AGCM and Surface Pressure Observations: OCADA

Author

ISHII, Masayoshi, primary, KAMAHORI, Hirotaka, additional, KUBOTA, Hisayuki, additional, ZAIKI, Masumi, additional, MIZUTA, Ryo, additional, KAWASE, Hiroaki, additional, NOSAKA, Masaya, additional, YOSHIMURA, Hiromasa, additional, OSHIMA, Naga, additional, SHINDO, Eiki, additional, KOYAMA, Hiroshi, additional, MORI, Masato, additional, HIRAHARA, Shoji, additional, IMADA, Yukiko, additional, YOSHIDA, Kohei, additional, NOZAWA, Toru, additional, TAKEMI, Tetsuya, additional, MAKI, Takashi, additional, and NISHIMURA, Akio, additional

Published
2024
Full Text
View/download PDF

9. Attributing Historical Changes in Probabilities of Record-Breaking Daily Temperature and Precipitation Extreme Events

Author

Shiogama, Hideo, Imada, Yukiko, Mori, Masato, Mizuta, Ryo, Stone, Dáithí, Yoshida, Kohei, Arakawa, Osamu, Ikeda, Mikiko, Takahashi, Chiharu, Arai, Miki, Ishii, Masayoshi, Watanabe, Masahiro, and Kimoto, Masahide

Subjects
Oceanography, Meteorology & Atmospheric Sciences
Abstract

We describe two unprecedented large (100-member), longterm (61-year) ensembles based on MRI-AGCM3.2, which were driven by historical and non-warming climate forcing. These ensembles comprise the "Database for Policy Decision making for Future climate change (d4PDF)". We compare these ensembles to large ensembles based on another climate model, as well as to observed data, to investigate the influence of anthropogenic activities on historical changes in the numbers of record-breaking events, including: the annual coldest daily minimum temperature (TNn), the annual warmest daily maximum temperature (TXx) and the annual most intense daily precipitation event (Rx1day). These two climate model ensembles indicate that human activity has already had statistically significant impacts on the number of record-breaking extreme events worldwide mainly in the Northern Hemisphere land. Specifically, human activities have altered the likelihood that a wider area globally would suffer record-breaking TNn, TXx and Rx1day events than that observed over the 2001- 2010 period by a factor of at least 0.6, 5.4 and 1.3, respectively. However, we also find that the estimated spatial patterns and amplitudes of anthropogenic impacts on the probabilities of record-breaking events are sensitive to the climate model and/or natural-world boundary conditions used in the attribution studies.

Published
2016

10. Initialization shock in the ocean circulation reduces skill in decadal predictions of the North Atlantic subpolar gyre

Author

Polkova, Iuliia, primary, Swingedouw, Didier, additional, Hermanson, Leon, additional, Köhl, Armin, additional, Stammer, Detlef, additional, Smith, Doug, additional, Kröger, Jürgen, additional, Bethke, Ingo, additional, Yang, Xiaosong, additional, Zhang, Liping, additional, Nicolì, Dario, additional, Athanasiadis, Panos J., additional, Karami, Mehdi Pasha, additional, Pankatz, Klaus, additional, Pohlmann, Holger, additional, Wu, Bo, additional, Bilbao, Roberto, additional, Ortega, Pablo, additional, Yang, Shuting, additional, Sospedra-Alfonso, Reinel, additional, Merryfield, William, additional, Kataoka, Takahito, additional, Tatebe, Hiroaki, additional, Imada, Yukiko, additional, Ishii, Masayoshi, additional, and Matear, Richard J., additional

Published
2023
Full Text
View/download PDF

13. EXPLAINING EXTREME EVENTS OF 2017 : From A Climate Perspective

Author

Herring, Stephanie C., Christidis, Nikolaos, Hoell, Andrew, Hoerling, Marty, Stott, Peter A., Owen, Rebecca, Vano, Julie A., Dettinger, Michael D., Cifelli, Rob, Curtis, David, Dufour, Alexis, Miller, Kathleen, Olsen, J. Rolf, Wilson, Anna M., Nerem, R. S., Fasullo, J., Hoell, Andrew, Perlwitz, Judith, Dewes, Candida, Wolter, Klaus, Rangwala, Imtiaz, Quan, Xiao-Wei, Eischeid, Jon, Wang, Hailan, Schubert, Siegfried D., Koster, Randal D., Chang, Yehui, Christidis, Nikolaos, Betts, Richard A., Stott, Peter A., de Abreu, Rafael C., Cunningham, Christopher, Rudorff, Conrado M., Rudorff, Natalia, Abatan, Abayomi A., Dong, Buwen, Lott, Fraser C., Tett, Simon F. B., Sparrow, Sarah N., Navarro, Juan C. Acosta, Ortega, Pablo, García-Serrano, Javier, Guemas, Virginie, Tourigny, Etienne, Cruz-García, Rubén, Massonnet, François, Doblas-Reyes, Francisco J., Kew, Sarah F., Philip, Sjoukje Y., van Oldenborgh, Geert Jan, Otto, Friederike E. L., Vautard, Robert, van der Schrier, Gerard, Funk, Chris, Hoell, Andrew, Nicholson, Sharon, Korecha, Diriba, Galu, Gideon, Artan, Guleid, Teshome, Fetene, Hailermariam, Kinfe, Segele, Zewdu, Harrison, Laura, Tadege, Abebe, Atheru, Zachary, Pomposi, Catherine, Pedreros, Diego, Rimi, Ruksana H., Haustein, Karsten, Barbour, Emily J., Allen, Myles R., Takahashi, Chiharu, Shiogama, Hideo, Imada, Yukiko, Kosaka, Yu, Mori, Masato, Arai, Miki, Kamae, Youichi, Watanabe, Masahiro, Min, Seung-Ki, Kim, Yeon-Hee, Park, In-Hong, Lee, Donghyun, Sparrow, Sarah, Wallom, David, Stone, Dáithí, Sun, Ying, Dong, Siyan, Zhang, Xuebin, Stott, Peter, Hu, Ting, Wang, Shanshan, Yuan, Xing, Wu, Renguang, Chen, Yang, Chen, Wei, Su, Qin, Luo, Feifei, Sparrow, Sarah, Tian, Fangxing, Dong, Buwen, Tett, Simon F. B., Lott, Fraser C., Wallom, David, Zhou, Chunlüe, Wang, Kaicun, Qi, Dan, Tan, Jianguo, Perkins-Kirkpatrick, S. E., King, A. D., Cougnon, E. A., Grose, M. R., Oliver, E. C. J., Holbrook, N. J., Lewis, S. C., Pourasghar, F., Hope, Pandora, Black, Mitchell T., Lim, Eun-Pa, Dowdy, Andrew, Wang, Guomin, Pepler, Acacia S., and Fawcett, Robert J. B.

Published
2019

15. chapter 19: THE HEAVY RAIN EVENT OF JULY 2018 IN JAPAN ENHANCED BY HISTORICAL WARMING: The unprecedented precipitation total in Japan during the heavy rain event of July 2018 was increased by approximately 1% due to recent rapid warming around Japan

Author

Kawase, Hiroaki, Imada, Yukiko, Tsuguti, Hiroshige, Nakaegawa, Toshiyuki, Seino, Naoko, Murata, Akihiko, and Takayabu, Izuru

Subjects
Precipitation (Meteorology) -- Environmental aspects, Global warming -- Environmental aspects, Business, Earth sciences
Abstract

Extremely heavy precipitation occurred from central to western Japan in July 2018, which was named the 'heavy rain event of July 2018' by the Japan Meteorological Agency (JMA). The JMA [...]

Published
2020
Full Text
View/download PDF

16. The Climate-System Historical Forecast Project : Providing Open Access to Seasonal Forecast Ensembles from Centers around the Globe

Author

Tompkins, Adrian M., De Zárate, María Inés Ortiz, Saurral, Ramiro I., Vera, Carolina, Saulo, Celeste, Merryfield, William J., Sigmond, Michael, Lee, Woo-Sung, Baehr, Johanna, Braun, Alain, Butler, Amy, Déqué, Michel, Doblas-Reyes, Francisco J., Gordon, Margaret, Scaife, Adam A., Imada, Yukiko, Ishii, Masayoshi, Ose, Tomoaki, Kirtman, Ben, Kumar, Arun, Müller, Wolfgang A., Pirani, Anna, Stockdale, Tim, Rixen, Michel, and Yasuda, Tamaki

Published
2017

17. THE EFFECTS OF NATURAL VARIABILITY AND CLIMATE CHANGE ON THE RECORD LOW SUNSHINE OVER JAPAN DURING AUGUST 2017

Author

Takahashi, Chiharu, Shiogama, Hideo, Imada, Yukiko, Kosaka, Yu, Mori, Masato, Arai, Miki, Kamae, Youichi, and Watanabe, Masahiro

Subjects
Global temperature changes -- Analysis, Business, Earth sciences
Abstract

The record low sunshine over Japan during August 20/7 was mainly attributed to a blocking high and Pacific-Japan pattern. Anthropogenic warming and decaying El Nino contributed to an increase in [...]

Published
2019
Full Text
View/download PDF

20. OVER 5,000 YEARS OF ENSEMBLE FUTURE CLIMATE SIMULATIONS BY 60-KM GLOBAL AND 20-KM REGIONAL ATMOSPHERIC MODELS

Author

Mizuta, Ryo, Murata, Akihiko, Ishii, Masayoshi, Shiogama, Hideo, Hibino, Kenshi, Mori, Nobuhito, Arakawa, Osamu, Imada, Yukiko, Yoshida, Kohei, Aoyagi, Toshinori, Kawase, Hiroaki, Mori, Masato, Okada, Yasuko, Shimura, Tomoya, Nagatomo, Toshiharu, Ikeda, Mikiko, Endo, Hirokazu, Nosaka, Masaya, Arai, Miki, Takahashi, Chiharu, Tanaka, Kenji, Takemi, Tetsuya, Tachikawa, Yasuto, Temur, Khujanazarov, Kamae, Youichi, Watanabe, Masahiro, Sasaki, Hidetaka, Kitoh, Akio, Takayabu, Izuru, Nakakita, Eiichi, and Kimoto, Masahide

Published
2017

24. Regional Characteristics of Attribution Risk on the Record-High-Temperature Event of 2022 Rainy Season in Japan.

Author

Ito, Rui, Imada, Yukiko, and Kawase, Hiroaki

Subjects
*SEASONS, *HIGH temperatures, *CLIMATE change, *TOPOGRAPHY
Abstract

The attribution of 2022's high temperatures in Japan to human-induced climate change exhibits significant regional variability, with FARs of 0.33–1, influenced by large-scale wind changes and regional topography. [ABSTRACT FROM AUTHOR]

Published
2023
Full Text
View/download PDF

25. 19. CLIMATE CHANGE INCREASED THE LIKELIHOOD OF THE 2016 HEAT EXTREMES IN ASIA

Author

Imada, Yukiko, Shiogama, Hideo, Takahashi, Chiharu, Watanabe, Masahiro, Mori, Masato, Kamae, Youichi, and Maeda, Shuhei

Subjects
Southeast Asia -- Natural history, Climate change -- Environmental aspects, Hot weather -- Causes of -- Measurement, Business, Earth sciences
Abstract

The 2016 extreme warmth across Asia would not have been possible without climate change. The 2015/16 El Nino also contributed to regional warm extremes over Southeast Asia and the Maritime [...]

Published
2018
Full Text
View/download PDF

30. 北半球夏季のダブルジェットの力学変動

Author

NAOE, Hiroaki, ENOMOTO, Takeshi, and IMADA, Yukiko

Subjects
夏の環状モード, Astrophysics::High Energy Astrophysical Phenomena, 519.9, summer northern annular mode, double jets, Physics::Atmospheric and Oceanic Physics, Physics::Geophysics, ダブルジェット
Abstract

This study investigates the dynamical variability of the double-jet structure in the Northern Hemisphere summer months of June and July. The summer northern annular mode (NAM), which is the leading mode of the empirical orthogonal function analysis in the extratropical troposphere for each month, is used for this analysis. The strong positive NAM is characterized as the double jets with the subtropical jet located at around 40°N and the polar front jet (the eddy drive jet) at 60°–70°N; the strong negative NAM is characterized as the single jet with the dominant subtropical jet at around 40°N. The vertical profile of momentum budget at 60°–85°N in the strong NAM months has peaks of the EP flux convergence and the poleward absolute vorticity advection at 300 hPa. The difference of zonal wind between the strong positive and negative NAM is estimated at around 5 m s⁻¹.

Published
2021

33. WMO Global Annual to Decadal Climate Update A Prediction for 2021-25

Author

Hermanson, Leon, Smith, Doug, Seabrook, Melissa, Bilbao, Roberto, Doblas-Reyes, Francisco, Tourigny, Etienne, Lapin, Vladimir, Kharin, Viatcheslav V., Merryfield, William J., Sospedra-Alfonso, Reinel, Athanasiadis, Panos, Nicoli, Dario, Gualdi, Silvio, Dunstone, Nick, Eade, Rosie, Scaife, Adam, Collier, Mark, O'Kane, Terence, Kitsios, Vassili, Sandery, Paul, Pankatz, Klaus, Frueh, Barbara, Pohlmann, Holger, Mueller, Wolfgang, Kataoka, Takahito, Tatebe, Hiroaki, Ishii, Masayoshi, Imada, Yukiko, Kruschke, Tim, Koenigk, Torben, Karami, Pasha, Yang, Shuting, Tian, Tian, Zhang, Liping, Delworth, Tom, Yang, Xiaosong, Zeng, Fanrong, Wang, Yiguo, Counillon, Francois, Keenlyside, Noel, Bethke, Ingo, Lean, Judith, Luterbacher, Juerg, Kolli, Rupa Kumar, Kumar, Arun, Hermanson, Leon, Smith, Doug, Seabrook, Melissa, Bilbao, Roberto, Doblas-Reyes, Francisco, Tourigny, Etienne, Lapin, Vladimir, Kharin, Viatcheslav V., Merryfield, William J., Sospedra-Alfonso, Reinel, Athanasiadis, Panos, Nicoli, Dario, Gualdi, Silvio, Dunstone, Nick, Eade, Rosie, Scaife, Adam, Collier, Mark, O'Kane, Terence, Kitsios, Vassili, Sandery, Paul, Pankatz, Klaus, Frueh, Barbara, Pohlmann, Holger, Mueller, Wolfgang, Kataoka, Takahito, Tatebe, Hiroaki, Ishii, Masayoshi, Imada, Yukiko, Kruschke, Tim, Koenigk, Torben, Karami, Pasha, Yang, Shuting, Tian, Tian, Zhang, Liping, Delworth, Tom, Yang, Xiaosong, Zeng, Fanrong, Wang, Yiguo, Counillon, Francois, Keenlyside, Noel, Bethke, Ingo, Lean, Judith, Luterbacher, Juerg, Kolli, Rupa Kumar, and Kumar, Arun

Published
2022
Full Text
View/download PDF

36. WMO Global Annual to Decadal Climate Update: A Prediction for 2021–25

Author

Hermanson, Leon, primary, Smith, Doug, additional, Seabrook, Melissa, additional, Bilbao, Roberto, additional, Doblas-Reyes, Francisco, additional, Tourigny, Etienne, additional, Lapin, Vladimir, additional, Kharin, Viatcheslav V., additional, Merryfield, William J., additional, Sospedra-Alfonso, Reinel, additional, Athanasiadis, Panos, additional, Nicoli, Dario, additional, Gualdi, Silvio, additional, Dunstone, Nick, additional, Eade, Rosie, additional, Scaife, Adam, additional, Collier, Mark, additional, O’Kane, Terence, additional, Kitsios, Vassili, additional, Sandery, Paul, additional, Pankatz, Klaus, additional, Früh, Barbara, additional, Pohlmann, Holger, additional, Müller, Wolfgang, additional, Kataoka, Takahito, additional, Tatebe, Hiroaki, additional, Ishii, Masayoshi, additional, Imada, Yukiko, additional, Kruschke, Tim, additional, Koenigk, Torben, additional, Karami, Mehdi Pasha, additional, Yang, Shuting, additional, Tian, Tian, additional, Zhang, Liping, additional, Delworth, Tom, additional, Yang, Xiaosong, additional, Zeng, Fanrong, additional, Wang, Yiguo, additional, Counillon, François, additional, Keenlyside, Noel, additional, Bethke, Ingo, additional, Lean, Judith, additional, Luterbacher, Jürg, additional, Kolli, Rupa Kumar, additional, and Kumar, Arun, additional

Published
2022
Full Text
View/download PDF

42. Additional file 1 of Anthropogenic climate change has changed frequency of past flood during 2010-2013

Author

Hirabayashi, Yukiko, Alifu, Haireti, Yamazaki, Dai, Imada, Yukiko, Shiogama, Hideo, and Kimura, Yuki

Abstract

Additional file 1: S1. Event attribution experiments. S2. Selection of historical flood events between 2010 and 2013. S3. Extreme distribution function. Table S1. Summary of selected flood events between 2010 and 2013. The effects of anthropogenic climate change on flood events (E, enhanced; S, suppressed; N/A, no significant effect) were judged as E (S) when both percentile of fraction of attribution (FAR50) scores between ALL and NAT_dtr (dtr) and those between ALL and NAT_CMIP5 (CMIP5) show the same signal. Fig. S1. Results of the evaluation of the fraction of attribution risk based on a bootstrap method. Fig. S2. Scatter plot of the annual maximum discharge derived from GRDC and global daily discharge reanalysis based on the 136 GRDC stations. Geographic location of the stations are shown in Fig. . Fig. S3. Correlation of annual max discharge derived from GRDC and global daily discharge reanalysis at 136 GRDC stations. Fig. S4. Comparisons of the annual maximum daily discharge derived from observations (GRDC), discharge reanalysis (S14FD), and ALL-LNG experiments. Fig. S5. The cumulative distribution function of annual maximum daily discharge for 22 events derived from observations (GRDC), discharge reanalysis (S14FD), and ALL-LNG experiments. Shade indicates maximum and minimum range among 650 ALL-LNG experiments. Fig. S6. The probability density function and cumulative distribution function of annual maximum daily discharge for 22 events derived from event attribution experiments (ALL, ALL-LNG, NAT-dtr, and NAT-CMIP5). The orange dot line indicates magnitude of 10-year flood in ALL-LNG experiment. Fig. S7. Difference of average annual precipitation between ALL and mean of NAT (NAT-dtr and NAT-cmip5) experiments for selected flood events (mm/day). Fig. S8. Same for Fig 3 but the difference between ALL and NAT-cmip5 (a) and ALL and NAT-dtr (b). Fig. S9. Difference of average annual temperature (K). Difference between ALL and NAT-cmip5 (a), ALL and NAT-dtr (b), and ALL and NAT (average of NAT-dtr and NAT-cmip5) (c) experiments. Average for 2010-2013 are shown. Fig. S10. Difference of mean annual 5th largest daily rainfall. Difference between ALL and NAT-cmip5 (a), ALL and NAT-dtr, and ALL and average of NAT-dtr and NAT-cmip5 experiments for 2010-2013 are shown.

Published
2021
Full Text
View/download PDF

47. Limiting global warming to 1.5 °C will lower increases in inequalities of four hazard indicators of climate change

Author

Shiogama, Hideo, primary, Hasegawa, Tomoko, additional, Fujimori, Shinichiro, additional, Murakami, Daisuke, additional, Takahashi, Kiyoshi, additional, Tanaka, Katsumasa, additional, Emori, Seita, additional, Kubota, Izumi, additional, Abe, Manabu, additional, Imada, Yukiko, additional, Watanabe, Masahiro, additional, Mitchell, Daniel, additional, Schaller, Nathalie, additional, Sillmann, Jana, additional, Fischer, Erich M, additional, Scinocca, John F, additional, Bethke, Ingo, additional, Lierhammer, Ludwig, additional, Takakura, Jun’ya, additional, Trautmann, Tim, additional, Döll, Petra, additional, Ostberg, Sebastian, additional, Müller Schmied, Hannes, additional, Saeed, Fahad, additional, and Schleussner, Carl-Friedrich, additional

Published
2019
Full Text
View/download PDF

49. Tropical rainfall predictions from multiple seasonal forecast systems

Author

Scaife, Adam A., Ferranti, Laura, Alves, Oscar, Athanasiadis, Panos, Baehr, Johanna, Dequé, Michel, Dippe, Tina, Dunstone, Nick, Fereday, David, Gudgel, Richard G., Greatbatch, Richard John, Hermanson, Leon, Imada, Yukiko, Jain, Shipra, Kumar, Arun, MacLachlan, Craig, Merryfield, William, Müller, Wolfgang A., Ren, Hong-Li, Smith, Doug, Takaya, Yuhei, Vecchi, Gabriel, Yang, Xiaosong, Scaife, Adam A., Ferranti, Laura, Alves, Oscar, Athanasiadis, Panos, Baehr, Johanna, Dequé, Michel, Dippe, Tina, Dunstone, Nick, Fereday, David, Gudgel, Richard G., Greatbatch, Richard John, Hermanson, Leon, Imada, Yukiko, Jain, Shipra, Kumar, Arun, MacLachlan, Craig, Merryfield, William, Müller, Wolfgang A., Ren, Hong-Li, Smith, Doug, Takaya, Yuhei, Vecchi, Gabriel, and Yang, Xiaosong

Abstract

We quantify seasonal prediction skill of tropical winter rainfall in 14 climate forecast systems. High levels of seasonal prediction skill exist for year‐to‐year rainfall variability in all tropical ocean basins. The tropical East Pacific is the most skilful region, with very high correlation scores, and the tropical West Pacific is also highly skilful. Predictions of tropical Atlantic and Indian Ocean rainfall show lower but statistically significant scores. We compare prediction skill (measured against observed variability) with model predictability (using single forecasts as surrogate observations). Model predictability matches prediction skill in some regions but it is generally greater, especially over the Indian Ocean. We also find significant inter‐basin connections in both observed and predicted rainfall. Teleconnections between basins due to El Niño–Southern Oscillation (ENSO) appear to be reproduced in multi‐model predictions and are responsible for much of the prediction skill. They also explain the relative magnitude of inter‐annual variability, the relative magnitude of predictable rainfall signals and the ranking of prediction skill across different basins. These seasonal tropical rainfall predictions exhibit a severe wet bias, often in excess of 20% of mean rainfall. However, we find little direct relationship between bias and prediction skill. Our results suggest that future prediction systems would be best improved through better model representation of inter‐basin rainfall connections as these are strongly related to prediction skill, particularly in the Indian and West Pacific regions. Finally, we show that predictions of tropical rainfall alone can generate highly skilful forecasts of the main modes of extratropical circulation via linear relationships that might provide a useful tool to interpret real‐time forecasts.

Published
2019
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results