Scientific Issues of AMY08 Atmosphere-Ocean-Land Interaction-Part I Guoxiong WU 3 September, 2007 Bali, Indonesia

1. Science Significance 2. Energy and water cycle 3. Land-air-sea interaction 4. Science Issues Outlines

Monsoon and the Year of Tropical Convection -WCRP JSC-XXVIII Guoxiong WU, Richard Lawford and Howard Cattle 27 March, 2007 Zanzibar

Monsoon- one of the central components of the climate system:  influence the global climate system  has distinct regional characteristics Monsoonal circulations dominate south and east Asia and are also significant in Africa and the Americas. 1. Science Significance

NDVI image for August 2000, from Pathfinder AVHRR EAM WAM Major monsoons systems of the world IM AUM SAMS NAMS NDVI surface vegetation AMY08

 Africa: AMMA ‘s focus on West African Monsoon (WAM) and its variability with an emphasis on daily- inter-annual timescales;  Asia-Australia : directed at understanding the processes responsible for the onset, evolution and termination of the monsoon  Americas : emphasizes the determination of the sources and limits of predictability of warm season precipitation. CLIVAR and GEWEX coordinate studies in the three primary monsoon regions

 Monsoons  Presentations were made by G. Wu (assisted by R. Lawford and H. Cattle), Yasunari and J. Shukla.  Main points of discussion are as follows: There is a large number of national and multi-national monsoon programmes and activities. The idea of holding an International Monsoon Year (as component of an International Monsoon Study ) created interest and the support of the JSC….…. It was recommended that a short term task team (one year) be appointed (Chairs B. Wang and J. Matsumoto) to develop a 5 year Implementation Plan, building on and integrating the existing plans for Year of Tropical Convection (YOTC) (joint with THORPEX), the Asian Monsoon Year and to ensure the monsoon data sets are exchanged and appropriately archived and that the appropriate modelling studies are pursued…. The consensus was that the crosscut should be deeply rooted in CLIVAR and GEWEX projects. CLIVAR and GEWEX should organise further pan WCRP workshops building on the progress of the first pan WCRP Monsoon Workshop. The JSC group responsible for further oversight of Monsoons is G. Wu (Chair), J. Slingo, T. Yasunari, C. Vera, L. A.. Ogallo and J. Shukla.

 Decision:  Endorse the WCRP crosscutting Monsoon Initiative. The JSC commented that the monsoon crosscut should include all the monsoon groups with a broader perspective, led by CLIVAR and GEWEX with participation of SPARC, CliC and WGNE and several activities outside WCRP (particularly THORPEX).  Request CLIVAR and GEWEX to agree on how it will be supervised and the development of an implementation plan. The proposals for and concepts of an Asian Monsoon Year and an International Year of Tropical Convection should be considered as components of an International Monsoon Study , a 5-year strategy of WCRP monsoon research, which would include issues related to the East African Monsoon, capacity building and application of observations and predictions in monsoon regions for societal benefit. GEWEX and CLIVAR to rationalise the number of monsoon committees.

“Asian Monsoon Year (AMY’08)”: The “Asian Monsoon Year (AMY08)” ( ) initiative is a coordinated observation and modeling effort on understanding the aerosol-cloud/radiation--hydrology cycle- circulation interaction and ocean-land- atmosphere interaction of the Asian monsoon system, and on improving monsoon prediction. 2. Energy and water cycle

 The “Asian Monsoon Year-2008” (AMY08) was proposed on the international workshop, “Impact of elevated aerosols on radiation-monsoon-water cycle interaction” in Xi’ning in August,  The initiative of International Monsoon Year (IMY) was then developed to cover other monsoon activities.  The two proposals have obtained strong supports from both many scientists and CLIVAR and GEWEX of WCRP.  It has been agreed that a series of conferences or workshops need to be organized to coordinate the ongoing activities and to plan the AMY08. China is honored to host the workshop in the spring of History:

Some Related International Projects AMY08  China – AIPO  India – STORM  India –CTCZ  India – CTCZ  Japan – JEPP/JAMSTEC  Japan –MAHASRI (GEWEX)  Japan – MAHASRI (GEWEX) Monsoon Asia Hydro-Atmosphere Scientific Research and Prediction Initiative Monsoon Asia Hydro-Atmosphere Scientific Research and Prediction Initiative  (WWRP) China – SCHeREX  (WWRP) SoWMEX  (WWRP) US-TiMREX  Joint Aerosol-Monsoon Experiment (JAMEX)  Monsoon Asia Integrated Regional Study (MAIRS)

Global mean Downward net Radiation Latent heat release Sensible heat release Longwave radiation Energy Budget at the surface

Water cycle over SCS May-Jun. (  E,  N ); 1.0  10 6 kg s -1. JUN PRCP MAY EVAP 98.6 PRCP JUNE EVAP PRCP 334.7

PRCP JULY EVAP PRCP AUG EVAP PRCP Water cycle over SCS Jul-Aug. (  E,  N ); 1.0  10 6 kg s -1.

Total Precipitation P= P o+ P i Recyc. Prec. Ratio R=P i /P Evaporation and rainfall Vq PoPo PiPi E

“Asian Monsoon Year (AMY’08)”: The “Asian Monsoon Year (AMY08)” ( ) initiative is a coordinated observation and modeling effort on understanding the aerosol-cloud/radiation--hydrology cycle- circulation interaction and ocean-land- atmosphere interaction of the Asian monsoon system, and on improving monsoon prediction. 3. Land-air-sea interaction

b LSC a D LSC D c Kd -1 LSCD Summertime quadruplet heating LOSECOD

Circulation exited by LOSECOD

AAEA PNAA b c d AAEA PNAA a Subtropical LOSECOD Heating and anticyclone

PSAm ASAf IAU b c d a PSAm ASAf IAU Subtropical LOSECOD Heating and anticyclone

Western Pacific Subtropical anticyclone Sub. High Rain

台风路径的合成差分布（暖年－冷年， 7 － 10 月） Western Pacific SSTa and Typhone tract

Ocean thermal state Transfer of watervaper evaporation 索马里急流 水 汽 水 汽 海 面 蒸 发 Indian Ocean

季风低压 D D 索马里急流 马斯克林高压 Monsoon=>ocean current=>SST -- QBO, MISO

图 5.24a

图 5.27a

 During northern summer, the oceanic TCZ migrates seasonally over Indian sub-continent  and leads to formation of a semi-permanent system known as monsoon trough (CTCZ) by second fortnight of July. The monsoon trough is controlled by two centers of lows Seasonal low At western end over Pakistan and adjoining area Transient disturbances Form over the Head Bay region and move across the trough.

frequency distribution of SAH center (NCEP/NCAR pentad mean) Modulation of the Tibetan Plateau

The composed 100hPa streamlines and vectors in Jul-Aug

the composed surface temperature anomalies

composed precipitation for Tibetan High in Jul-Aug (mm/5day)

Coupling of air-sea interaction between tropical Pacific and Indian Ocean

赤道太平洋 - 印度洋海气相互作用的耦合示意图 Affect: interannual variability and MISO=>Active and break of monsoon Indian Ocean Pacific Ocean upweling upwelling 太平洋 Warm water Atmos circulation

Our shortcomings in tropical convection severely limit the representation of key physics in weather & climate models Diurnal cycle - strongest “forced” signal in the climate system. Synoptic waves and easterly waves, including development & evolution of hurricanes and Tropical cyclones Madden-Julian Oscillation (MJO) and other large-scale convectively-coupled waves monsoon variability, including onset and break activity. Tropical mean state, including ITCZ and distributions of rainfall over oceans & continents Winter Kelvin Waves Rossby Waves MJOs Dominant Convectively-Coupled Tropical Waves Projected onto OLR Anomalies. Wheeler and Weickmann, 2001

SAM EAM AM WP Flow 台风源区 Three monsoon systems interact Typhoons invade The monsoon moisture flux The monsoon moisture flux

Persistent anomaly Sudden flood

4. Science Issues The regional perspective strengthening coordination of Asian-Australian monsoon research: The air-sea interaction over Indian Ocean and its impacts on Asian monsoon variability (MISO, seasonal and interannual);  The air-sea interaction over Indian Ocean and its impacts on Asian monsoon variability (MISO, seasonal and interannual);  Land-sea thermal contrast, diurnal cycle and CTCZ/OTCZ;  Modulation of the TP energy and water cycle on the air-sea interaction over N Indian Ocean;  Air-sea interaction over Western Pacific and its impacts on subtropical anticyclone;  The impacts on Asian monsoon of the air-sea coupling process between tropical Pacific and Indian Ocean;  Water cycle and its variation over the Asian monsoon areas