CONTENTS

Introduction

p1

References

p7

Chapter1.The Seasonal Changes of Tropical Cloud Distribution as Revealed from 5-day Mean Outgoing Longwave Radiation

p12

Summary

p13

1-I.Introduction

p13

1-II.Data and analysis procedures

p14

1-III.Seasonal change of the OLR fields

p14

1-IV.Conclusions

p26

Acknowledgements

p27

References

p27

Japanese summary

p30

Chapter2.The Seasonal Changes of Low Level Wind Fields in the Global Tropics

p31

Abstract

p32

2-I.Introduction

p32

2-II.Data and analysis procedures

p33

2-III.Seasonal changes of the wind fields

p33

2-IV.Seasonal divisions of the global tropics

p37

2-V.Discussion

p48

2-VI.Conclusion

p51

Acknowledgments

p52

References

p52

Notes

p54

Japanese summary

p56

Chapter3.Seasonal Changes of 500mb Height and 300mb Temperature Fields Associated with Abrupt Seasonal Changes in the Tropics

p57

Summary

p57

3-1.Introduction

p58

3-2.Data and analysis procedures

p60

3-3.Changes of 500mb height and 300mb temperature fields between the two consecutive natural seasons

p61

3-4.Conclusion

p69

Acknowledgments

p70

References

p71

Japanese summary

p75

Figures and a table

p76

Concluding remarks

p99

Acknowledgments

p104