Atmospheric Dynamics Mission. the Phase-A Studies Were All Completed in June 1999
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ESA SP-1233 (4) July 1999 Reports for Mission Selection THE FOUR CANDIDATE EARTH EXPLORER CORE MISSIONS Atmospheric Dynamics Mission ESA SP-1233 (4) – The Four Candidate Earth Explorer Core Missions – ATMOSPHERIC DYNAMICS _________________________________________________________________ Report prepared by: Earth Sciences Division Scientific Co-ordinator: Paul Ingmann Earth Observation Preparatory Programme Technical Co-ordinator: Joachim Fuchs Cover: Richard Francis & Carel Haakman Published by: ESA Publications Division c/o ESTEC, Noordwijk, The Netherlands Editor: Bruce Battrick Copyright: © 1999 European Space Agency ISBN 92-9092-528-0 Price: 70 DFl CONTENTS 1 INTRODUCTION................................................................................................................................5 2 BACKGROUND AND SCIENTIFIC JUSTIFICATION...............................................................9 2.1 GLOBAL WIND PROFILE MEASUREMENTS FOR CLIMATE AND NWP........................................9 2.2 THE NEED FOR ATMOSPHERIC WIND FIELDS FOR ATMOSPHERIC ANALYSES .........................10 2.3 POTENTIAL IMPROVEMENT OF NWP BY ENHANCED WIND OBSERVATIONS ...........................14 2.4 THE NEED FOR ATMOSPHERIC WIND FIELDS FOR CLIMATE STUDIES......................................22 2.5 FUTURE STUDIES AND PERSPECTIVES AIMING AT IMPROVING THE WIND FIELD KNOWLEDGE IN THE POST-2000 TIME FRAME ................................................................................................31 2.6 CONCLUSIONS ON NWP AND CLIMATE STUDIES ......................................................................33 3 RESEARCH OBJECTIVES .............................................................................................................35 3.1 MISSION OBJECTIVES .................................................................................................................35 3.2 NUMERICAL WEATHER PREDICTION .........................................................................................36 3.3 CLIMATE.....................................................................................................................................37 3.4 ADDITIONAL OBSERVATIONS ....................................................................................................39 4 OBSERVATIONAL REQUIREMENTS ........................................................................................41 4.1 INTRODUCTION...........................................................................................................................41 4.2 METEOROLOGICAL ANALYSIS ...................................................................................................42 4.3 COVERAGE REQUIREMENTS.......................................................................................................46 4.4 QUALITY OF OBSERVATIONS .....................................................................................................48 4.5 RELIABILITY AND DATA AVAILABILITY....................................................................................52 4.6 CONCLUSION ..............................................................................................................................53 5 MISSION ELEMENTS .....................................................................................................................57 5.1 INTRODUCTION...........................................................................................................................57 5.2 INSTRUMENTS AND DATA ..........................................................................................................57 5.3 ATMOSPHERIC ANALYSES AND NWP FORECASTS ...................................................................61 6 SYSTEM CONCEPT.........................................................................................................................63 6.1 FROM MISSION TO SYSTEM REQUIREMENTS.............................................................................63 6.2 MISSION DESIGN AND OPERATIONS ..........................................................................................66 6.3 THE ALADIN INSTRUMENT ......................................................................................................73 6.4 THE SATELLITE...........................................................................................................................95 6.5 THE LAUNCHER........................................................................................................................113 6.6 THE GROUND SEGMENT...........................................................................................................115 7 DATA PROCESSING AND VALIDATION................................................................................121 7.1 INTRODUCTION.........................................................................................................................121 7.2 SPECTRA AND DOPPLER FREQUENCIES ...................................................................................123 7.3 QUALITY CONTROL..................................................................................................................124 7.4 IMPORTANCE OF CLOUDS.........................................................................................................126 7.5 DISTRIBUTION AND ARCHIVING...............................................................................................127 7.6 GEOPHYSICAL PROCESSING CENTRE.......................................................................................127 7.7 CONCLUSIONS...........................................................................................................................129 3 8 MISSION PERFORMANCE..........................................................................................................131 8.1 INTRODUCTION.........................................................................................................................131 8.2 PERFORMANCE IN CLEAR AIR..................................................................................................133 8.3 THE IMPACT OF CLOUDS ..........................................................................................................134 8.4 USEFULNESS FOR NWP............................................................................................................137 8.5 USEFULNESS FOR CLIMATE STUDIES.......................................................................................138 8.6 OTHER ELEMENTS PROVIDED BY THE ADM ...........................................................................140 8.7 CONCLUSIONS...........................................................................................................................141 9 PROGRAMMATICS.......................................................................................................................143 9.1 DEVELOPMENT APPROACH ......................................................................................................143 9.2 HERITAGE, CRITICAL AREAS AND RISKS ................................................................................145 9.3 RELATED MISSIONS, INTERNATIONAL CO-OPERATION POSSIBILITIES AND TIMELINESS ......147 9.4 ENHANCEMENT OF CAPABILITIES AND APPLICATIONS POTENTIAL........................................148 REFERENCES ...........................................................................................................................................149 GLOSSARY ................................................................................................................................................153 ACKNOWLEDGEMENTS.......................................................................................................................157 ‘Hurricane force winds raged across Britain on Christmas Eve and yesterday leaving five people dead, five French fishermen feared drowned in the Irish Sea, thousands of people without power and scores of roads blocked by fallen trees and masonry. As the emergency services battled to cope, a fresh wave of storms with winds gusting up to 70 mph swept across London and much of southern England last night.’ (from ‘The Times’, 26 December 1997) 1 Introduction The ‘ESA Living Planet Programme’ (ESA, 1998) describes the plans for the Agency's new strategy for Earth Observation in the post 2000 time frame. It marks a new era for European Earth Observation based on smaller more focused missions and a programme that is user driven, covering the whole spectrum of interests ranging from scientific research-driven Earth Explorer missions through to application-driven 5 Earth Watch missions. The user community is therefore now able to look forward to a programme of more frequent but very specific missions directed at the fundamental problems of Earth system sciences. Out of the nine Earth Explorer core missions identified in ESA SP-1196 (1-9), four core missions were selected for Phase-A studies, which began in June 1998, namely: the Land-Surface Processes and Interactions Mission; the Earth Radiation Mission; the Gravity Field and Steady-State Ocean Circulation Mission; and the Atmospheric Dynamics Mission. The Phase-A studies were all completed in June 1999. This ‘Report for Mission Selection’ for the Atmospheric Dynamics Core Mission (ADM) was prepared by a Core Mission Drafting Team consisting of four members of the ADM Advisory Group (ADMAG); E. Källén, J. Pailleux, A. Stoffelen and M. Vaughan. They were supported by the other members of the ADMAG, namely