These Proceedings were edited byIOI-Japan and Institute for Ocean Policy, SOF in cooperation.Proceedings ofDialogue between the Ocean and the Freshwater Communities;Forests, Rivers, Oceans and the Skies水はめぐる、森・川・海・空・・・Institute for Ocean Policy, Ship & Ocean Foundation (SOF)Kaiyo Senpaku Bldg.,1-15-16 Toranomon, Minato-Ku, Tokyo 105-0001 JapanPhone: +81-3-3502-1828Facsimile: +81-3-3502-2033E-mail: info@sof.or.jpURL: https://www.spf.org//english/index.htmlCopyrightShip & Ocean Foundation, 2003All rights reserved.No part of this publication may be used or reproduced in any manner whatever withoutwritten permissionexcept in the case of brief quotations embodied in critical articles and reviews.ISBN 4-88404-111-9Cover illustration: courtesy of Dietfinde BailetDesign: Daisuke Omi, IntercomFOREWORD“It is the nature of the oceans that pushes science and technology into the foreground.Without marine science and technology we would be blatantly unable to explore, exploit,manage, a conserve marine resources or to navigate safely or to protect our coasts. And it isthe nature of the marine environment that forces us to recognize that this science must beinterdisciplinary, integrating physical, chemical, biological, and social sciences, and that itmust be international, to cover the global dimension of the ocean and its interaction with theland and the atmosphere.”The Oceanic CircleElisabeth Mann BorgeseForests, Rivers, Oceans, and the Skies - Water goes round and round on our planet, in acycle regulated largely by the oceans. We have organized a session to promote a meaningfulexchange of opinions among those involved in water affairs at the 3rd World Water Forum,in the hope of facilitating the integrated management of both our fresh and ocean waterresources. Through in-depth discussions, we hope to create an effective model for anintegrated management approach to the water cycle.The session “Dialogue between the Ocean and the Freshwater Communities” was held inKyoto on March 17, 2003, as part of The 3rd World Water Forum held in Kyoto, Shiga, andOsaka in Japan from March 16 - 23, 2003, attended by more than 24,000 participants fromover 150 countries to share wisdom for better water management. The 1st and 2nd Forawere held in Morocco and the Netherlands respectively, and the 4th will be held in Mexicoin March, 2006.International Ocean InstituteInstitute for Ocean Policy, SOFCONTENTSEXECUTIVE SUMMARY (Eng/Jap) Dr. Gunnar Kullenberg and Mr. Hiroshi TerashimaINTRODUCTION Mr. Hiroshi Terashima, Dr. Gunnar KullenbergSUMMARIES of PRESENTATIONSEl Nino/ENSO PredictionDr. Kenneth DavidsonThe Role of the Indian Ocean in Climate Forecasting with a ParticularEmphasis on Summer Conditions in East AsiaProf. Toshio YamagataChanges in Terrestrial Material Transport, from the Mountains to the OceanProf. Michael CollinsThe Inseparable Relationship between Marine and Terrestrial Ecosystems through WaterProf. Yoshihisa ShirayamaThe Woods, the Darling of the Sea (Jap/Eng)Mr. Shigeatsu HatakeyamaSouthwest Monsoon: Provider of Water to South AsiaDr. Satish R. ShetyeThe Ocean Model of Comprehensive Management and EducationDr. Gunnar Kullenberg and Dr. Robin SouthFreshwater Input to the Arctic Ocean and its Links to Climate: A Case for ThoughtDr. Vladimir RyabininROUND TABLE DISCUSSIONCo-chaired by Dr. Gunnar Kullenberg and Mr. Hiroshi TerashimaCommentators: Prof. Kazuo Matsushita, Prof. Biliana Cicin-Sain,Prof. R. Rajagopalan, Dr. Satoquo Seino, Dr. Asami NakanishiCONCLUSION (Eng/Jap)APPENDIX 1 Report to “Roundtable on Water and Forest” (Jap/Eng)Dr. Asami NakanishiAPPENDIX 2 Biwako Declaration for Action on Water and Forests (Eng/Jap)APPENDIX 3 Yoshino River ExcursionSPEAKER0010090140180350380410490610770850981041091131151EXECUTIVE SUMMARYBy Gunnar Kullenberg and Hiroshi Terashima1. The initiationThe International Ocean Institute Operational Centre in Japan, IOI-Japan, in agreement withIOI Headquarters, first proposed this session in order to draw attention to the role of theocean in the hydrological cycle and freshwater availability and its management. TheIOI-Japan then worked closely with the secretariat of the Third World Water Forum to makethe meeting an official WWF3 session. The Institute for Ocean Policy, SOF, acted asCo-Organizer for the session, in line with the policy of the Global Forum on Oceans, Coasts,and Islands, which was formed at the WSSD in Johannesburg. The session also benefitedfrom the cooperation of the World Meteorological Organization and the IntergovernmentalOceanographic Commission of UNESCO.The co-sponsors IOI and SOF also agreed that the session would include some examples ofthe local Japanese community, efforts to address the linkages between land-uses and coastalocean-uses. Several leading Japanese experts were also invited to be present at the session,as speakers or commentators.The Session was widely advertised. The session profile and programme were circulated toconveners of other sessions, with several personal letters expressing interest in cooperationand inviting representatives from their sessions to attend the dialogue session. Informationabout the session was also provided to the Global Forum on Oceans, Coasts and SmallIslands.2. The SessionThe Session was part of the major theme “Water, Nature and the Environment” organized inKyoto, 17-18 March, with in all 19 different sessions.The Session was opened by the co-chairs, Mr. Hiroshi Terashima of SOF and Dr. G.Kullenberg of IOI, who explained the background and aim of the Session and introduced thespeakers.2Dr. K. Davidson of WMO highlighted the role of the ENSO phenomenon in relation toclimate variability, flooding and drought, freshwater availability and the possibilities offorecasting. He showed the regional and inter-regional influences and impacts of El-Nino,in particular with reference to flooding and drought.Professor T. Yamagata highlighted the role of the ocean-atmosphere-land interactions,focusing on the Indian Ocean – Western Pacific. He illustrated the importance of feedbacksand interactions between regional phenomena: El-Nino, monsoon, ocean circulation andfreshwater input.Professor M. Collins showed how freshwater management actions and land-uses, such asriver dams, diversions, irrigations, agricultural practices, and deforestations influenced theinflow of freshwater and terrestrial material to the ocean, focusing on the Mediterranean Sea.He demonstrated some basin-wide consequences with respect to coastal erosion, watercirculation and changes in salinity distributions.This was further demonstrated by Professor Y. Shirayama, who focused on the importance ofthe input from land carried by rivers to the coastal zone, of major and minor nutrients andother suspended and dissolved materials. He showed how these materials influence thebiological productivity, diversity and ecosystem balance in the shelf seas. He showedthrough examples the consequences of changes in the input due to freshwater managementand other actions on land.Mr. S. Hatakeyama brought in practical experiences of these interactions by highlightingproduction variations in coastal areas focusing on Japanese oyster cultivation. Hedemonstrated from vast practical experiences the importance of maintaining a balance in thenatural ecosystem on land. He particularly stressed the role of forests. The devastatingimpacts of deforestation were again pointed out. The great importance of maintaining andalso managing the forests, from the mountains to the coast, was shown, so as to have ahealthy coastal zone.Dr. S. R. Shetye explained how the Indian Ocean South West monsoon phenomenon occurs.He stressed the positive and negative impacts on the land and the coastal areas, focusing onthe Bay of Bengal. He highlighted the role of freshwater input to the Bay of Bengal for thegeneration of air-sea interactions and atmospheric conditions there with resulting cycloneactivities. The very large importance of the monsoon for freshwater conditions on the IndianSub-Continent was shown. He elucidated the problems of forecasting the monsoon, in that3many non-linear, but yet not yet fully understood processes are involved. Successfulforecasting so far has been based on statistical modeling. Dr. Shetye stressed the importanceof education and public awareness with respect to both uses of freshwater and preparednessfor shortages, as well as other natural hazards, e.g. flooding, storm surges, cyclones.Dr. Kullenberg, finally, first highlighted some aspects of the paper by Dr. V. Ryabinin (ofWMO) on the role of the freshwater balance of the Arctic Basin with respect to oceancirculation and climate variations. Then he went on to present the ocean model forcomprehensive management and governance, referring to the Common Heritage of Mankindprinciples of Ambassador Arvid Pardo and further elucidated by Professor Mann Borgese.He reflected that these principles could be applied to freshwater resources together with themodel of comprehensive management as laid down in UNCLOS and UNCED 92agreements, which would also be in harmony with the WSSD partnership approach. In thiscontext he also brought out the importance of education, public awareness enhancement andparticipation. He referred to the work of the IOI and introduced the concept of the IOIVirtual University as a comprehensive educational mechanism.The presentations were followed by brief comments from an invited panel. These commentsall re-emphasized the importance of enhancing dialogue, the need for a comprehensiveapproach, governance and policy, public awareness, participation and education. It wasagreed that freshwater and ocean water should be regarded as a common heritage ofhumankind. The need for much more interaction between user sectors, possibly based onthe community co-management approach, as well as the use of Integrated Coastal AreaManagement was emphasized. It was suggested that ICAM could perhaps be expanded toinclude EEZ regions, although caution was expressed that this may be too large for theon-going programmes. It was also noted that the freshwater community had come a longway in organizing itself through the Water Council and the Water Forum, addressing thecentral, global issue of freshwater. The ocean community can benefit from learning thisthrough a dialogue with the freshwater community.The importance of research was brought up, stressing the need for an integrated approachalso in this context. However, the practical experiences brought out by Mr. Hatakeyamawere considered very important, and research activities should try to establish linkages withpractical experiences and applications. Such practical experiences should be used ineducation, awareness creating, and dialogue efforts, showing the social and economicimportance of linkages between ocean, coasts and land uses, with related practices andtraditional knowledge. The need for a comprehensive water law, both internationally and4nationally was brought out. This would support comprehensive governance, and could belinked to both community-based local action and a global cooperative approach.The need for management of forests was stressed, also noting that economic factors can playa negative role in this context, exemplified by some cases in Japan. This again highlights theneed for social responsibility and effective governance and government mechanisms at alllevels.Subsequently an open discussion followed. Several points were raised from the floor. Theinterest and need for dialogue was certainly confirmed. It was noted that the EuropeanUnion had recently published the Water Framework Directives. These constitute an exampleof an attempt towards a comprehensive legal approach. The Global International WaterAssessment (GIWA) was also referred to as an effort to integrate. The audience stressed andconcurred with the importance of education and use of practical experiences, bringing outthe importance of an enhanced dialogue.Dr. Kullenberg then summarized the main conclusions which could be drawn from thepresentations and discussions during the session, and thanked all the speakers, commentators,participants, co-sponsors, the Forum Secretariat, local organizers and interpreters.3. The follow-upThe World Water Forum is a recurring event, and the Secretariat had emphasized that thesessions should endeavor to identify an action plan which might be implemented as afollow-up in order to maintain the various efforts which had been initiated. The Secretariathad also stressed that one should seek to obtain commitments towards implementation, andaim at reporting progress to the next World Water Forum.Accordingly, during the consultations and preparations for the Session we had consideredpossible follow-up actions. These had also been indicated in the pre-session report requestedby the Forum Secretariat in January-February 2003. During the Session itself the elementsof a follow-up were highlighted. The presentations, comments and discussions were allsupportive of a follow-up action plan. The Chair summarized the possible follow-up actionsin the form of an inter-sessional action plan as given in the conclusions.Session ChairGunnar KullenbergHiroshi Terashima5要旨 （和訳）グンナ・クーレンバーグ、寺島紘士1. 準備段階水循環および淡水の確保と管理に関する海洋の役割の重要性に注目し、国際海洋研究所(IOI‐本部マルタ共和国)の日本におけるオペレーショナル･センターであるIOI ジャパンは、IOI本部の同意を得て当分科会の開催を企画した。第３回水フォーラム事務局はIOI ジャパンとの打合せを通じて、当セッションを第３回世界水フォーラム(WWF3)の公式な分科会とした。シップ・アンド・オーシャン財団(SOF)海洋政策研究所は、ヨハネスブルグでの「持続可能な開発に関する世界首脳会議(WSSD)」を契機に設立されたグローバルフォーラム「海洋、沿岸、島嶼に関する世界会議」の趣旨に基づき当分科会を共同開催することとした。当分科会は、また、ユネスコ政府間海洋学委員会(IOC)ならびに世界気象機関(WMO)の協力も得た。共催者となったIOI とSOF 海洋政策研究所は、陸地利用と沿岸海域利用の連続性を示す日本国内の事例を分科会に取り入れるとともに、国内外の優秀な専門家をスピーカーあるいはコメンテーターとして招聘することとした。当分科会は広く告知された。他の分科会の主催者たちに対し、分科会概要とプログラムを配布して協力を要請、他の分科会の代表者たちには手紙を送り、討議への参加を呼びかけた。当分科会開催の情報は、WSSD グローバルフォーラム「海洋、沿岸、島嶼に関する世界会議」のメンバーにも伝えられた。2. 分科会当分科会は、WWF3 のテーマのひとつである「水と自然･環境」(3 月17～18 日京都で開催)に参加した19 の分科会の１つとして開かれた。初めに、共同議長である寺島紘士SOF 海洋政策研究所所長とグンナ・クーレンバーグIOI 前事務局長によって開会の辞が述べられた。両氏は当分科会の背景と目的について述べた後、スピーカーを紹介した。ケネス・デビッドソン博士は、 エルニーニョ南方振動(ENSO)現象の役割を気候変動、洪水、旱魃、淡水の確保、予測の可能性などに関連づけて論じた。特に洪水と旱魃を例に、エルニーニョの国際地域内および国際地域間の影響を提示した。6山形俊男教授は、特にインド洋－西太平洋に焦点をあてて海洋、大気、陸地間の相互作用の役割について論じた。エルニーニョ、モンスーン、海洋の循環、淡水の流入など地域に見られる様々な現象間のフィードバックおよび相互作用の重要性を示した。マイケル・コリンズ教授は、地中海を例にとり、河川における堰、分水路、灌漑、 農業慣行、森林伐採などの淡水管理活動や土地利用が、海洋に対する淡水や陸上物質の流入にいかなる影響を及ぼしてきたかを示した。沿岸の侵食、水の循環、塩分の分布の変化等に関し、流域全体に及ぼす結果を例証した。この点について、白山義久教授がさらに論証した。白山教授は、河川が沿岸域に運ぶ陸からの流入物および栄養塩、微量元素など、浮遊あるいは溶解している物質の重要性を強調し、これらの物質が大陸棚の生物生産力、生物多様性、生態系のバランスに与える影響を示した。また、淡水管理や他の陸上における活動による流入物の変化が与える影響を例示した。畠山重篤氏は、日本の牡蠣養殖に焦点をあて、沿岸域における生産の変動に注目することで、相互作用に関する実践経験を紹介した。畠山氏は、豊富な実践経験に基づき、陸上における自然の生態系のバランスを維持することの重要性を例証し、特に森林の役割を強調した。森林伐採の破壊的な影響を指摘し、健全な沿岸域を保つためには、山から沿岸に亘って森林を維持・管理することが非常に重要であることを提示した。S.R.シェティエ博士は、インド洋南西モンスーンがどのように発生するかを説明、特にベンガル湾に焦点をあて、モンスーンが陸上と沿岸域に及ぼすプラスとマイナスの影響について論じた。ベンガル湾への淡水の流入が、大気と海の相互作用を引き起こし、サイクロン活動をもたらす大気の状況を形成するのに果たす役割を強調した。インド亜大陸の淡水供給にとって、モンスーンが極めて重要であることも示した。シェティエ博士は、まだ十分に解明されていない多くの非線形プロセスを含むモンスーン予測の問題点を明らかにした。これまでに成功してきた予測は、統計モデルに基づいたものであった。シェティエ博士は、淡水の利用や淡水の不足対策および洪水、高潮、サイクロンなどの自然災害に関して、教育および一般の認識向上が重要であることを強調した。最後に、グンナ・クーレンバーグ博士が、まず、海洋循環および気候変動に関する北極海の淡水バランスの役割についてのウラジミール・リャビニン博士(WMO)の論文から、一部を紹介した。続いてアービド・パルド大使によって提唱され、エリザベス・マン・ボルゲーゼ教授によって明確にされた「人類の共同財産」原則を引用し、海洋の総合的管理とガバナンスのための海洋モデルを提案した。クーレンバーグ博士は、この原則が国連海洋法条約(UNCLOS)および1992 年国連環境開発会議(UNCED 92)など数々の合意で策定された統合的管理モデルとともに、淡水資源管理にも適用できるとの考えを示した。これはWSSD のパート7ナーシップ･アプローチとも一致する。これらの点を踏まえ、クーレンバーグ博士も、教育および一般の人々の認識向上と参加の重要性を指摘した。また国際海洋研究所(IOI)の活動に触れ、包括的な教育システムとしてのIOI バーチャル･ユニバーシティーの考え方を紹介した。以上の発表に続き、パネリストが簡潔にコメントを述べた。コメントはいずれも対話の向上、統合的アプローチの必要性、政策とガバナンス、一般の人々の認識と参加、教育の重要性を改めて強調するものであった。また、淡水と海水が人類の共同財産と見なされるべきであるという点でも意見が一致した。地域社会に根ざした共同管理的アプローチや統合的沿岸域管理(ICAM)を利用して、ユーザー・セクター同士の相互活動をさらに活発化する必要があることも強調された。さらに、現行のプログラムにとっては遠大すぎるとされながらも、ICAM を排他的経済水域(EEZ)にまで拡大する可能性も示唆された。淡水コミュニティーが長い道程を経て、水会議や水フォーラムを通じて自らを組織化し、世界的な重要課題である淡水問題に取り組むに至ったという点も確認された。海洋コミュニティーは淡水コミュニティーとの対話を通じ、これを学び役立てることができる。研究の重要性も取り上げられ、ここでも統合的アプローチの必要性を強調した。一方で、畠山氏が発表されたような実践的経験も非常に重要であり、研究活動は実践的経験と応用との橋渡しを試みるべきである。このような実践的経験は、教育、認識の喚起、対話などの取り組みにおいて用いられるべきである。その中では、慣行や伝統的知識を伴う海洋、沿岸、陸上の利用の連携が社会的、経済的に重要であることを示すことが大切である。国際・国内ともに、水に関する包括的な法整備が必要であることも取り上げた。これは総合的なガバナンスを支え、地域社会に根ざした地元での活動と地球規模的な協力体制の双方に連動するものとなる。森林管理の必要性が強調され、日本の事例から経済的要因がマイナスの役割を果たす場合があることも指摘した。社会的責任とあらゆるレベルにおける効果的なガバナンスとガバナンス・システムの必要性を再度浮き彫りにした。引き続き、公開討論が行われ、客席からも多くの意見が出された。対話への関心とその必要性が確実に感じられた。EU が最近「水枠組み条例」を出したことを指摘した。これは、包括的な法的アプローチへ向けての一つの試みである。地球国際水アセスメント(GIWA)もまた、統合への努力の例として取り上げた。聴衆は、教育および実践的経験の利用が重要であることに同意し、対話の推進の重要性を指摘した。その後クーレンバーグ博士が、それまでの発表および分科会中の討議から得られた主な結論を要約し、すべてのスピーカー、コメンテーター、参加者、共催者、フォーラム事務局、現8地のオーガナイザー、通訳に謝意を表した。3. フォローアップ世界水フォーラムは、繰り返し行われるイベントであり、事務局は、各分科会に対し、着手された様々な取り組みを継続するために、フォローアップとして実施可能な行動計画を各分科会で策定するよう強調していている。また、事務局は、実施に向けた公約に合意し、次回の世界水フォーラムに進捗状況を報告することを目指すべきであるとしている。このため、我々は当分科会の開催に向けた準備期間中に、フォローアップ・アクションについても検討した。これらは2003 年1～2 月に同事務局の要請で作成した分科会事前報告書にも示されている。分科会においても、フォローアップの要素が強調された。発表、コメント、討議はすべてフォローアップの行動計画を支持するものであった。議長は、可能なフォローアップ活動を「結論」に記したような行動計画の形でまとめた。分科会議長グンナ・クーレンバーグ寺島紘士9INTRODUCTIONBy Hiroshi TerashimaExecutive Director, Institute for Ocean Policy, SOFDistinguished participants, dear colleagues, ladies and gentlemen.I am Hiroshi Terashima, Executive Director of the Institute for Ocean Policy, SOF, and amprivileged to serve as the co-chair of today’s session. Welcome to a ‘Dialogue between theOcean and Freshwater Communities’. We are happy to have so many representatives fromboth communities in attendance today. Thank you for coming.The Global Forum for Oceans, Coasts, and Islands was established by public and privateparticipants at last year’s World Summit for Sustainable Development in order to promotethe exchange of information, discussion, and cooperation regarding the important oceanissues raised in UNCLOS, Agenda 21, and the WSSD Plan of Implementation. We decidedat that time that in order to make our voice heard on ocean issues we should activelyparticipate in global and regional conferences where these problems are being discussed.Believing the 3rd World Water Forum an ideal opportunity to do this, IOI (InternationalOcean Institute), Ship & Ocean Foundation, IOC of UNESCO, and World MeteorologicalOrganization sought to highlight the ocean/freshwater interface by holding today’s session.Under the general theme of ‘The Water Cycle: Forests, Rivers, Oceans, and the Skies’, wewill hear presentations and hold discussions on such topics as:- The effects of El Nino, monsoons, and other ocean-based weather phenomena onland-based rainfall patterns and water use plans,- The effects of land-based water management on the oceans,- The roles of education and public awareness in integrated management.In order to make today’s session a meaningful one, we would appreciate your cooperationand active participation.I would now like to introduce today’s other co-chairman and the driving force behindtoday’s session, Dr. Gunnar Kullenberg of IOI. Dr. Kullenberg, you have the floor.1 0INTRODUCTIONBy Gunnar KullenbergSenior Executive Director, International Ocean Institute (IOI)It is well accepted that water is a necessary part of all life on Earth. Water is also theworking substance of the global heat engine. The Ocean is the most important andlargest source of water vapour which is also the most important greenhouse gas. Theevaporation over the Ocean is larger than the precipitation there by 10%, while theevapo-transpiration over land is less than precipitation there by 60%. The globalfreshwater balance is very sensitive: small changes of it can trigger large changes in theocean and regional seas circulation and the heat transport. The Ocean provides on anaverage an annual input of about 40.103 Km3 freshwater to the land, equal to the averageannual river runoff. Can we forecast when and where the input of freshwater from theocean via the atmosphere is coming over the land? If we can, we could be prepared forwater harvesting, adjustments of agriculture, impacts on transportation, health problemsand flooding, protection of the security of people and resources. The answer is that wecan do some such forecasting with acceptable uncertainties. This is possible by acombination of ocean observations, data transmission in near-real time, computermodeling with data assimilation.Examples are provided by the El-Nino Southern Oscillation (ENSO) and the monsoonphenomena. These are parts of the global climate system, recurrent processes which canbe forecasted to some extent. The forecasting can be, and is being, used in relation toplanning, adjusting and managing many essential activities on land, even though thedecision making has to be made under conditions of uncertainty, as in most othersocio-economic cases.The ENSO phenomenon occurs with an average return of 4 years; it can be 1-2 or even8-10 years apart. There has over the last decades been a growing interest in thephenomenon due to its large impacts in the Pacific rim countries, and throughteleconnections also in other parts of the world. Relations between El-Nino and changesin freshwater resources have been demonstrated for instance in South America, whereforecasting of the El-Nino is used in many countries; in Australia, parts of Africa, Japanand South-East Asia.11The Indian Ocean Southwest monsoon is an annual (seasonal) regular process occurringduring the months May/June to September, over the northern Indian Ocean, and the Bayof Bengal in particular. The monsoon brings rain to the Indian Sub-continent. It is themajor source of freshwater supply for India and other parts of the region. A normalmonsoon is essential for most actions on land: water availability; agriculture; energy;transport. A failed monsoon implies a major drought year: about 20 such have occurredover the past 100 years. Improved forecasting of the monsoon will have enormouspositive social and economic consequences.The freshwater management on land can have major impacts not only on the coastal zones,and shelf seas, through alteration of the freshwater and related dissolved and suspendedterrestrial material inputs, but also for ocean basin-wide conditions. Examples areprovided by the Black Sea, the Mediterranean Sea, the Arctic Basin, the Bay of Bengal.The changes in freshwater input and balance can generate changes in the air-seainteraction which can have very substantial consequences for the ocean circulation and theclimatic conditions.All the examples alluded to here are highlighted further during the session. They alldemonstrate the need for an integrated or comprehensive approach in the management anddecision making.The Ocean also provides for a model on how to achieve the integration andcomprehensive approach, including governance in the broad sense and sustainabledevelopment. The model is specified through the third United Nations Convention onthe Law of the Sea and results of the United Nations Conference on Environment andDevelopment 1992 and the associated on-going processes. However, the impetus behindthe international legal instrument comes from Ambassador Arvid Pardo of Malta who inthe end of the 1960’s elaborated two basic ideas:“all aspects of ocean space are inter-related and should be treated as a whole,”and“the resources of the deep sea-bed constitute the common heritage of mankind”,this is to be governed and managed for the benefit of all by a suitable internationalmechanism. This should not at all be misunderstood or misinterpreted as a“tragedy of the commons.”1 2Arvid Pardo gave the concept for dimensions:• Economic: the Common Heritage has to be developed;• Ethical: the Common Heritage has to be managed on behalf of mankind as a whole,with special considerations for the needs of the poor;• Environmental: the Common Heritage has to be conserved to be shared with futuregenerations, which are also part of mankind;• Peace and security: the Common Heritage has to be reserved exclusively for peacefulpurposes, so as to benefit mankind as a whole.The comprehensive approach cannot be achieved without a concerted and sustained effortto enhance dialogues across society; increase the exchange of information, the educationand the public awareness and participation. The current trends of increasing differencesbetween developed and developing, between North and South, must be reversed. Localand traditional knowledge, culture and policies can play a large role, but need to becoupled to regional and global scales as in the oceanic circle model. These aspects werealso brought out in the session.The session stimulated discussion across sectors on subjects such as: a model which canbe used to achieve comprehensive global management of water; examples on how to useforecasting, modeling, and observations to enhance water management, and preparednessfor water shortages as well as flooding and related natural disasters; cooperation betweensectors with respect to consequences of freshwater management actions on land, for coastsand ocean-basins, with enhanced dialogue and awareness; education needs, ethical andattitude changes, public awareness requirements, and ways to achieve these.1 3SUMMARIES of PRESENTATIONS1 4El Nino/ENSO PredictionKenneth DavidsonWorld Meteological Organization (WMO)（Notes on the Presentation by Kenneth Davidson）El Nino and La Nina are extremes of climate variability. Some basic facts about El Ninoand La Nina signals are major departure of normal climate patterns, with a recurringpattern, no two events being identical (Fig.1). We are currently in a moderate El Nino. Thepredictions are getting better and better. This particular one was forecast about fourmonths in advance. We actually gave countries the very good warning that this wascoming, for only the second time in history. We were able to assist countries inunderstanding what the impacts may be by the El Nino. It is generally detected aroundMay to June, in the years that it occurs. This particular time, it was forecast in Februaryand we actually found the signal and declared an El Nino in late May. It is just one of theextremes of climate variability and it associates with heavy rains and in some areas thereare severe dry conditions.El Nino is basically the departure from normal sea surface temperatures in the PacificOcean. This (Fig.2) is 1997-98 El Nino you can see the strength of it, and go all the wayback to 1982-83 El Nino. So what is its influence over the Pacific, or the other wayaround, what is the influence of Pacific over the El Nino. This is the normal conditions(Fig. 3). I think this is a very interesting slide because as you know we have generally anEasterly wind flow here which is depicted here. Let me orient you first. The SouthAmerican Coast is to the right. This is Central America and over here is Australia (Fig.2).This is going through the depth of Ocean (Fig.3). In normal conditions, December throughFebruary, we have convective activity over in the far west Pacific Area, which wouldcreate this kind of air flow pattern, you can see very little convective activity here off thecoast of South America (Fig.3 middle). We have a normal thermocline with shallow warmwater off the coast. Then March to May, a little bit more convective activity so that youcan see this circulation of the air patterns here. Slightly more warm temperatures just tothe North of the area that we are talking about Central America.Now an El Nino, once it starts, gets much more convective activity, much more warmwater here (Fig.3 left). Notice the difference of the depth of the warm water in Decemberthrough February verses the December through February in the normal conditions. And1 5then you can see the difference also March through May. You can see the much moreconvective activity coming all the way over to the West Coast of South America andCentral America (Fig. 3 left).We always talk about El Nino affects but there is a lot of effects of the opposite called LaNina as well (Fig.3 right, and Fig.4).So this is just another look at the same situation, this is the El Nino from September 1997(Fig.2), showing the great pool of warm water off South America. This is La Nina ofNovember 1988 (Fig. 4) and you can see the pool of cold water off South America. So themain predictor of El Nino for the climate centers around the world is both the surface andsub-surface water temperature. We now have the observing buoys all the way across thePacific Area to monitor this temperature and broadcast up to satellites. The data comeback down through a communication system to countries all over the world.So what are the warm episode affects of El Nino? In the Northern Hemisphere in summer,we have dry and warm conditions. Some windup North America, dry and cool conditionsdown all the way over Australia. Recall in this past summer and early fall, we had verydry conditions and the fires in Australia. I would say usually about 65% and 70%probability of these things happening during El Nino. When as I started off saying no twoEl Ninos are alike.During the cold episode La Nina, we have warm conditions over Australia, dry in themiddle of Pacific area, and cold and wet through the Southern portion of Central Americaand Northern South America.After 1997-98 El Nino, there was a proposal developed in the UN to create an El NinoResearch Center. Efforts were taken up by the Government of Equador, WMO and theISDR which is the International Strategy for Disaster Reduction.We have a series of regional climate outlook forums, this actually started during the 97-98El Nino. What we try to do is to get the countries together from various regions fromaround the world. We discussed the various global climate forecast. We tempt todownscale these based on meteorologists’ and climatologists’ knowledge andunderstandings on local and regional situations, so they can actually use it to better benefitgovernments. In many times we bring in various economic sectors sometimes it will beenergy sector, or agricultural sector to work with the climatologists in order to provide1 6better information to their governments. They are now a regular feature in Africa wherewe have four specific sub-regions we are working at; we have two activities in SouthAmerica, one in Northern South America, one in Central South America, and we have onein Central America as well and we have one going on in the Pacific Region.With the establishment of ISDR the work of the interagency task force on El Nino wastaken up and there is a specific working group called Climate Variability in Disasters.Through this working group we were producing annual climate statements that give thesummary of the climate for year, and we are also producing El Nino outlooks which wesynthesis for 9 active forecast centers, and they are issued through ISO and WMO. We dothis quarterly; we just did the last one in January, and we’ll be doing another one inMarch.In addition in 2003, finally after almost 4 years of work, we established The El NinoCenter. Its just getting started now. I hope this center can provide much more activitiesand not just research on El Nino. We’d like it to be a center that can help us establish databases, complete climate data bases and assist the countries in connecting with the variouseconomic sectors within their countries.Fig.11 7Fig.2Fig.3Fig.41 8The Role of the Indian Ocean in Climate Forecastingwith a Particular Emphasis on Summer Conditions in East AsiaToshio YamagataDepartment of Earth and Planetary Science, The University of TokyoABSTRACTThe Indian Ocean Dipole (IOD) is a natural ocean-atmosphere coupled mode that playsimportant roles in seasonal and interannual climate variations. In the present article, wedescribe the IOD event locked to a seasonal cycle and then discuss its close relation withthe Asian summer climate variations. In particular, we demonstrate that the extremelyhot and dry summer condition in 1994 was due to the positive IOD event.1 IntroductionIt is well known that the summer climate condition over East Asia is dominated byactivities of the East Asian summer monsoon system. Since the East Asian summermonsoon system is one subsystem of the Asian Monsoon (Wang and Fan, 1999), itinteracts with another subsystem, the Indian summer monsoon, via variations of theTibetan high and the Asian jet (Rodwell and Hoskins, 1996; Enomoto et al., 2002).Inspired by the anomalous summer conditions in East Asia during 1994 (e.g. Behera et al.,1999; Vinayachandran et al., 1999), Saji et al. (1999) discovered the existence of aneast-west SST dipole in the tropical Indian. They showed that this dipole is coupled tozonal wind anomalies in the central Indian Ocean, suggesting the Bjerknes-type of air-seainteraction as in the tropical Pacific. The term Indian Ocean Dipole (IOD) wasintroduced to denote this basin-wide ocean-atmosphere coupled mode in the Indian Ocean.The positive IOD event is characterized by the strong positive Sea Surface TemperatureAnomalies (SSTA) in the tropical western Indian Ocean (50oE-70oE, 10oS-10oN, denotedas Box A) and the negative SSTA in the southeastern Indian Ocean (90oE- 110oE, 10oSEq.,denoted as Box B). Thus the Indian Ocean Dipole Mode Index (IODMI) is definedas the zonal difference of SST anomaly of Box A (western pole) from that of Box B(eastern pole).1 9After introducing the IODMI, Saji et al.(1999) identified six major positive IOD eventsduring the period of 1958 -1999. The composite pictures of those six events (1961,1967, 1972, 1982, 1994, and 1997) demonstrated that the air-sea coupled IOD eventevolves during boreal spring, matures in fall and decays in winter (cf. Figs 2 and 3 in Sajiet al., 1999). The dipole pattern related to IOD is identified in heat content/sea levelanomalies (Rao et al., 2002a), OLR anomalies (Behera et al., 1999, 2002; Yamagata et al.,2002; Saji and Yamagata, 2002a) and sea level pressure anomalies (Behera and Yamagata,2002). We show all those indices in Fig.1. Several other authors also discussed thisIndian Ocean coupled phenomenon (Webster et al., 1999, Murtugudde et al., 2000, Iizukaet al., 2000; Vinayachandran et al., 2002; Feng et al., 2002; Ashok et al., 2002; Gualdi etal., 2002) using observed data and/or model simulations.We believe that the IOD has raised a new possibility to make a real advance in thepredictability of seasonal and interannual climate variations originating in the tropics.Here we first describe that the IOD is a physical mode and then discuss itsteleconnections.Fig. 1. Normalized indices of IOD, based on the anomalies of SST (SSTDMI) , zonal wind (UDMI),TOPEX/POSEIDON sea level (SLDMI), OLR (OLRDMI) and sea level pressure (SLPDMI). Niño-3 indexfrom the eastern Pacific is shown for reference. SSTDMI is a difference between western (500E-700E,100S-100N) and eastern (900E-1200E, 100S-Eq) Indian Ocean. Similarly, SLPDMI is a difference between(960E-1000E, 130S-90S) and (520E-560E, 90S-50S) and OLRDMI is a difference between (700E-800E, 50S-50N)and (900E-1000E, 100S -Eq). The UDMI is obtained by taking area-average in the central equatorialregion (700E-900E, 50S-50N). SLDMI is the sea level anomalies from the eastern box of the SSTDMI.2 02 IOD as a natural coupled mode in the tropical Indian Ocean2.1 IOD’s appearance in the statistical analysesDespite the remarkable presence of IOD events, the dipole pattern appears as the seconddominant mode in the SST anomalies in conventional statistical analysis such as the EOFmethod. It is rare for climate dynamists to discuss the second mode of variability. Thisis why some felt difficulties in understanding the new concept of the IOD. The dominantEOF mode is a basin-wide SST monopole that has a high correlation (~0.85) with theNino-3 index, when the latter leads the former by 4 months. Thus, the dominant IndianOcean SST variability is caused by the external forcing related to ENSO. The waveletspectra of the SST anomalies in the eastern (100S-Eq., 900E-1100E) and western(100S-100N, 500E-700E) poles show different behavior because of the masking effect ofthe dominant EOF mode (Fig. 2). However, we recover a remarkable coherence in thevariability of the two boxes after removing the external ENSO effect (Fig 2 lower panels).This shows quite a contrast to other major oscillatory modes such as the SouthernOscillation and the north Atlantic Oscillation that appear as the first dominant modes; thestatistical dominance allows a negative correlation between the poles for those two modesin the raw data. Since IOD is the second mode in SST variability, we need to removethe dominant mode to detect its sea-saw statistically as demonstrated inFig. 2. Wavelet power spectrum (using the Morlet wavelet) of the SST anomalies (derived from GISST,Rayener et al. 1996) in eastern (left panels) and western (right panels) poles of the IOD. Upper twopanels show the spectrum for the whole data and lower two panels show the spectrum when ENSOeffect is removed from the data through a 4-month lagged regression of the Niño-3 index. Shaded isthe wavelet power at each period being normalized by the global wavelet spectrum and the thickblack contour is the 95% significance level.2 1Behera et al. (2002). This subtle aspect of the tropical Indian Ocean variability asdiscovered by Saji et al. (1999) was missed unfortunately in earlier studies (e.g.Hastenrath et al., 1993).2.2 IOD’s relation with ENSOThe IOD evolution is locked to seasons. Thus it is important to introduce the seasonalstratification in the statistical analysis (cf. Nicholls and Drosdowsky, 2000; Allan et al.,2001). During the peak season (September-November) of the IOD, the first twodominant EOF modes (for the Indian Ocean north of 150S) show the east-west dipolepatterns (figure not shown). Interestingly, the first EOF mode has a stronger correlation(~0.65) with the IOD as compared to its correlation with the Niño-3 (~ 0.58). The lattercorrelation corresponds to a similar correlation (~0.54) between IODMI and Niño-3during this season; one is apt to conclude that IOD events occur as a part of ENSO eventsbecause of this high correlation (Allan et al., 2001; Baquero-Bernal et al., 2002). Rather,we claim that it reflects the fact that one third of the positive IOD events co-occur with ElNiño events. The non-orthogonality of two time series does not necessarily mean thatthe two phenomena are always connected in a physical space.We note that the second EOF mode, which also shows a dipole, has a significantcorrelation coefficient with IODMI (~0.69) but an insignificant value with the Niño-3(~0.28). This difference in statistical correlation confirms the visual examination of theprincipal component that the second dipole mode is related to independent occurrences ofIOD in certain years such as 1961, 1967 and 1994 (figure not shown).Table. 1 Years of IOD events. Theasterisk denotes pure events, i.e.no El Niño (La Niña) during apositive (negative) IOD event.Years ofPositive IODYears ofNegative IOD1 1961* 1958*2 1963 1960*3 1967* 19644 1972 19705 1977* 1989*6 1982 1992*7 1994* 1996*8 1997 -2 2To investigate such a complex relation, Yamagata et al. (2002) have analyzed the Walkercirculation that may connect the Indian Ocean with the Pacific through the atmosphericbridge. As 30% of the positive IOD co-occur with El Niño, a simple correlationanalysis is misleading. Therefore, they used appropriate statistical tools like thecomposite technique and the partial correlation method to extract the distinct nature of theIOD. A positive (negative) IOD event is identified as a pure event when it is notaccompanied simultaneously by El Niño (La Niña) (see Table 1). The presence of theanomalous Walker cell operating only in the Indian Ocean is clearly seen in the pure IODcomposite (Fig. 3), thereby confirming the independent occurrence of the pure IOD. Toavoid misunderstanding, we repeat that this analysis does not exclude the possibility thatsome IODs may be physically linked with some ENSO events.3 IOD teleconnections in East AsiaThe societal benefit of the IOD can be appreciated by analyzing its impact on the globalclimate system. Several recent studies (Ashok et al., 2001; Li and Mu, 2001; Behera andYamagata 2002; Saji and Yamagata 2002b; Guan et al., 2002; Lareef et al., 2002) haveshown IOD influences on many parts of the globe such as India, Australia, East Africa,and East Asia. However, we here focus our attention only on East Asia because oflimitation of space.Fig.3: September through November IOD composite ((positive events-negative events)/2) of zonal massflux in the equatorial band (50N-50S) for pure IOD events (bottom). Contour interval is 4*109 kg s-1.2 3The activities of the East Asian summer monsoon have profound economical and societalimpacts on the East Asian countries. The anomalous changes in the summer monsooncirculation can lead to either abnormally hot (and dry) or cold (and humid) summer in thisregion. As mentioned in Introduction, East Asian countries suffered from therecord-breaking hot and dry summer climate in 1994. Park and Schubert (1997)examined the nature of this year using some assimilated data from 1985 through 1994.Their conclusion is that “the anomalous circulation is primarily the result of an orographicforcing associated with zonal wind changes over Tibet”. However, we here show thatthe abnormal 1994 East Asian summer conditions are actually related to anocean-atmosphere coupled signal in the tropical Indian Ocean, which is now called IOD.Using the SST data (GISST2.3b) from 1979 through 1999 (Parker et al., 1995), wecalculated the SSTA for June-July-August (JJA) and its standard deviation (σ ) for threedifferent tropical regions and the IODMI (Table 2, lower line). The IOD event in 1994shows the variance that reached about 2.6σ , indicating a very strong positive IOD eventin the summer of 1994. We also note that the NINO3 region (5 oS-5 oN, 150 oW-90 oW)showed the weak negative SST anomaly during the same period despite the negativeSouthern Oscillation Index (cf. Behera and Yamagata, 2002).Regions IODMI Box A Box B NINO3SSTA 0.90 0.24 -0.65 -0.21σ 0.35 0.32 0.31 0.85Table 2: JJA mean SSTA (1994) and its standard deviation for different tropical regionsThe Indian summer monsoon is expected to be significantly influenced by the IOD.Using all Indian rainfall data derived from the in situ observations (Parthasarathy et al.,1995), we actually found that India received good monsoon rainfall duringJune-July-August of 1994; it amounts to 265mm per month, which is 19% above the meanclimatological value. This is consistent with our earlier study using both theobservational data and an atmospheric general circulation model (AGCM) which suggeststhat the well-known negative correlation between Indian summer monsoon rainfall and ElNiño can be interfered by the IOD during some decades (Ashok, et al., 2001).The Indian summer monsoon system interacts with the tropical Indian Ocean. The EastAsian summer monsoon interacts with the Indian summer monsoon via the troposphericjets, Tibetan high, and even the westerly jet stream at about 40oN in the upper troposphere2 4(e.g. Lau and Li, 1984; Liang and Wang, 1998; Wang and Fan, 1999; Wang et al, 2001;Enomoto et al, 2002; Lu et al, 2002). When the circulation over South Asia changesanomalously, it is reasonable to expect that the summer monsoon circulation over EastAsia will also change anomalously. We here show using the reanalysis data how theatmospheric circulation was influenced by the IOD during the summer in 1994.3.1 Anomalous circulation featuresUsing the NCEP/NCAR reanalysis data (Kalnay, et al., 1996) from 1979 through 2001and the CMAP precipitation data from 1979 through 1999 (Xie and Arkin, 1996), we haveplotted the circulation anomalies during the summer months (JJA) of 1994 (Figs. 4 and 5).Large positive air temperature anomalies are found over the northeastern and easternChina, Korea, and Japan in 1994 summer (Fig. 4a). Some positive anomalies are alsofound above the Kuroshio Extension in the Northwestern Pacific. The anomalies ofthickness between 200hPa and 850hPa isobaric surfaces are also positive (not shown),indicating the temperature of the air column is anomalously high. Those regions areassociated with the strong negative precipitation anomalies (Fig. 4b). The water vaporanomalously diverges from this region, leading to a severe drought condition. Theseresults agree well with those in Park and Schubert (1997). It is known that thisnortheastern part of Asia was covered during the summer of 1994 by an anomalousanticyclonic circulation in the lower troposphere. This anomalous circulation is found inthe upper troposphere over this region (Fig. 5a), showing its equivalent barotropicstructure. On the other hand, we find an anomalous cyclonic circulation elongatingwestward from the tropical western Pacific to the southern part of China (Fig. 4a); thiscirculation facilitates the surplus rainfall in this region (Fig. 4b). It prevents the moistmonsoonal southerly wind from blowing northward from the Bay of Bengal and the SouthChina Sea to the eastern part of China, Korea and Japan.The above anomalous cyclonic circulation along with the intensified monsoon trough overIndia appears to be linked directly with the tropical IOD event. As seen in Fig. 4b, thedistinctive 1994 IOD structure over the tropical Indian Ocean is manifested in rainfallanomalies and also in the velocity potential field (Fig. 5b). The water vapor convergesinto the western Indian Ocean (Fig. 4b), while it diverges in the southeastern Indian Ocean.An anomalous meridional circulation associated with the IOD connects the anomalousdecent branch over the southeastern Indian Ocean and the anomalous ascent branch atabout 20 oN, as simulated by Ashok et al., (2001). More precisely, the anomalousnorthwestward low-level winds from the eastern pole of IOD reaches the Peninsula of2 5India and then turns eastward (Fig. 4a). Since just the opposite winds are seen in theupper troposphere (Fig. 5a,b), the wind field in the tropics has a baroclinic structure.These results are in agreement with other results obtained from both data analysis andAGCM studies (Behera, et al., 1999; Ashok, et al., 2001; Guan et al., 2002).Fig.4. (a)The JJA mean anomalous air temperature at 2m above the earth surface (in oC) along withthe wind at 850hPa (in m⋅s-1) during 1994. (b) The anomalous precipitation (in mm⋅d-1) and theanomalous water vapor flux (in Kg⋅m-1⋅s-1) which is vertically integrated from the earth surface up to300hPa (shown with vectors).2 6Fig.5: (a) JJA mean anomalous vorticity (to be multiplied by 1×10-6 s-1) along with the rotational wind(m⋅s-1) at 150hPa in 1994. (b) JJA mean velocity potential along with the divergent wind (m⋅s-1) at150hPa in 1994. The contour interval is 4×10-5m2⋅s-1. (c) JJA mean zonal-vertical circulation averagedover (25°N-25°N). The contours denote the zonal component of the divergent wind with contourinterval of 0.2m⋅s-1.3.2 Teleconnection mechanismsThe precipitation over India and the southern part of China is enhanced during the positiveIOD event (Saji and Yamagata, 2002b). The northward branch of the meridionalcirculation excited by the eastern pole of the positive IOD leads to the anomalous updraftand the associated divergent flow in the upper troposphere over the Tibetan Plateau (Fig.5b). As discussed by Sardeshmukh and Hoskins (1988) using a simple model, weobserve the anticyclonic circulation at 150 hPa west of the vorticity source region, i.e., theTibetan Plateau (Fig. 5a). A cyclonic circulation is simultaneously generated east of thevorticity source region. A Rossby wave train is also excited, propagating northeastwardfrom the monsoon region.The IOD-induced divergent flow in the upper troposphere near India also progresseswestward and converges over Mediterranean/Sahara region (Fig. 5b). The zonal sectionaveraged between 25 °N and 35 °N at 150 hPa captures the vertical circulation (Fig. 5c);2 7the anomalous convection over India, which is induced by the IOD SSTA as explained, isamazingly linked to the anomalous decent in the Mediterranean/Sahara region, asdiscussed by Rodwell and Hoskins (1996) in a somewhat different context.To examine mechanisms behind the above circulation changes in more detail, we show inFig .6 the heat budget anomalies. Over the northern as well as the eastern part of China,the anomalous diabatic heating is dominant in the thermodynamic equation (Fig. 6c).Over Japan and Korea, the dynamic heating due to the anomalous descent of air isdominant, which cancels the anomalous negative horizontal advection of temperature.Around the Sea of Okhotsk, however, the anomalous positive horizontal advection oftemperature balances the dynamic cooling (Fig. 6b). These differences imply, from theviewpoint of the heat budget, that there are different mechanisms of the hot summer overland and sea. Furthermore, these results indicate that the strong positive SSTA aroundJapan in 1994 (not shown) is not the cause of the hot summer. Rather, it is the result ofthe hot and dry summer condition.Over India and the Bay of Bengal, the net anomalous diabatic heating is found (Fig. 6c),which is balanced by the negative anomalies of dynamic cooling due to the anomalousupward motion (Fig. 6b). On the other hand, the net diabatic cooling is found over theMediterranean Sea/Sahara region (Fig. 6c). The negative anomalies of the horizontaladvection of temperature are also found in this region (Fig. 6a). The anomalous dynamicheating due to the decent of air compensates both the diabatic and dynamic cooling.Based on this heat budget diagnosis along with the vertical circulation shown in Fig. 5c,the relationship between the IOD/Monsoon and the anomalous circulation changes overthe Mediterranean Sea/Sahara region can be established. The present view confirms themonsoon-desert mechanism put forward by Rodwell and Hoskins (1996); they suggestedthat the diabatic heating due to convective activities in the Indian region could induce ananticyclonic Rossby wave pattern that covers west Asia and northern part of Africa. Theadiabatic decent thus induced by the remote thermal forcing from the Asian summermonsoon may intensify the decent induced by radiative cooling over the MediterraneanSea/Sahara region.2 8Fig.6. JJA mean vertically integrated quantities for 1994. (a) The anomalous horizontal advection oftemperature, (b) the anomalous vertical advection of potential temperature, and (c) the anomalousdiabatic heating rate. All these quantities are vertically averaged over pressure from surface to 100hPa.The unit is oC⋅d-1.The IOD-induced dynamic warming due to the decent of the air over the MediterraneanSea/Sahara region and its vicinity must steadily perturb the mid-latitude westerly. Sincethe mid-latitude westerly acts as a Rossby wave-guide (Hoskins and Ambrizzi, 1993), thewave energy could propagate along the westerly eastward to East Asia, resulting in thesummer circulation variations around East Asia and the Western Pacific.2 9Fig.7. (a)The wave-activity flux T M (in m2⋅s-2) along with the 3-dimensional divergence T ∇ ⋅ M 3(to be multiplied by 1.0×10-6 m⋅s-2) at 200hPa. (b) The wave-activity flux ( , ) Tx Tz M M and the3-dimensional divergence in zonal-vertical section. The high frequency components in thetime-series have been removed by using a 5-day running mean. The wave-activity fluxes and theirdivergences in (b) have been averaged over (35oN-45oN). The vertical component of wave-activityflux Tz M is enlarged by 10 before plotting.This scenario can be examined by calculating the wave activity flux (WAF) (Plumb, 1986;Takaya and Nakamura, 2001). Fig. 7a clearly shows that the wave activity flux at200hPa are much larger along the Asian westerly jet than those over other regions. Thelongitude-height cross-section (Fig. 7b) shows that the anomalous wave energypropagates upward into the upper troposphere around the regions of the MediterraneanSea, the Caspian Sea, and the East Asia along the westerly jet stream. To the north ofthe Asian jet, the wave propagation is very weak; this suggests that the 1994 East Asiansummer climate is not directly related to variations in higher latitudes. The upwardpropagating wave energy in the eastern flank of the Tibetan Plateau suggests thatorographic forcing also plays an important role in 1994, as suggested by Park andSchubert (1997).3 04 SummaryUsing various ocean and atmosphere data, we have demonstrated that the IOD is a naturalocean-atmosphere coupled mode in the Indian Ocean. Although the IOD emergesstatistically as the second major mode in the SST anomalies, it shows up as a remarkableevent in some years and induces climate variations in many places of the world. Theyear of 1994 is such a case and the dramatic impact on summer conditions in East Asiaactually led authors to shed light on this important climate signal. We have discussedhere how the IOD event influences summer conditions in East Asia.The abnormally hot and dry summer in 1994 was associated with the anomalousanticyclonic circulation over Japan, Korea and the eastern and northeastern part of China.The anomalous cyclonic circulation over the southern part of China and the westernPacific weakened the monsoonal northward wind from the Bay of Bengal, the SouthChina Sea, and the tropical Western Pacific, preventing the subtropical East Asia fromreceiving the normal water vapor from the tropical regions. The anomalously hotsummer climate over East Asia is explained as a result of the anomalous dynamic heatingaround Japan, and diabatic heating over the northeastern and eastern part of China.The IOD induced the summer circulation changes over East Asia in 1994 are at least intwo ways. One is that a Rossby wave train is excited in the upper troposphere by theIOD-induced divergent flow in the upper troposphere over the Tibetan Plateau. Thewave train propagates northeastward from the southern part of China. Another is that theIOD-induced diabatic heating around India excites a long Rossby wave pattern to the westof the heating. Through the monsoon-desert mechanism proposed by Rodwell andHoskins (1996), the circulation changes over the Mediterranean Sea /Sahara region can belinked to the IOD/Monsoon variations. The westerly Asian jet acts as a waveguide foreastward propagating tropospheric disturbances to connect the circulation change aroundthe Mediterranean Sea with the anomalous circulation changes over East Asia. Thisprocess may contribute to strengthening the equivalent barotropic structure in East Asia assuggested by Enomoto et al.(2002).The study of teleconnections of IOD has just started. It is rather amazing that themonsoon-desert mechanism which plays a key role in understanding the hot and drysummer in East Asia was introduced by examining the summer of 1994 prior to thediscovery of IOD (cf. 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