RalfLindau Climate Atlas of the Atlantic Ocean
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RalfLindau CLIMATE ATLAS of the ATLANTIC OCEAN Derived from the Comprehensive Ocean Atmosphere Data Set (COADS) With 428 Plates, 19 Figures and 2 Tables Springer
Dr. Ralf Lindau University of Kiel Department of Marine Sciences Dtistembrooker Weg 20 24105 Kiel Germany E-mail: rlindau@ifm.uni-kiel.de ISBN-13:978-3-642-64009-4 DOl: 10.1007/978-3-642-59526-4 e-isbn-13:978-3-642-59526-4 Library of Congress Catatloging-in-Publication Data Climate atlas of the Atlantic Ocean: derived from the Comprehensive Ocean Atmosphere Data Set (COADS) I RalfLindau. p. cm. Rev. ed. of: The Bunker climate atlas of the North Atlantic Ocean I Hans-Jorg Isemer, Lutz Hasse. c1985-1987. Includes bibliographical references. ISBN-13:978-3-642-64009-4 1. Atlantic Ocean-Climate-Charts, diagrams, etc. 2. Climatic changes-atlantic Ocean-Charts, diagrams, etc. 3. Ocean-atmosphere interaction-atlantic Ocean Maps. I. Isemer, Hans-Jorg. Bunker climate atlas of the North Atlantic Ocean. II. Title. This work is subject to copyright. All rights are reserved, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitations, broadcasting, reproduction on microfilm or in any other way, and storage in data banks. Duplication of this publication or parts thereof is permitted only under the provisions of the German Copyright Law of September 9, 1965, in its current version, and permission for use must always be obtained from Springer-Verlag. Violations are liable for prosecution under the German Copyright Law. Springer -Verlag Berlin Heidelberg New York a member of BertelsmannSpringer Science+Business Media GmbH Springer -Verlag Berlin Heidelberg 2001 Softcover reprint of the hardcover 1st edition 2001 The use of general descriptive names, registered names, trademarks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. Product liability: The publishers cannot guarantee the accuracy of any information about dosage and application contained in this book. In every individual case the user must check such information by consulting the relevant literature. Typesetting: Camera-ready by author Cover Design: design & production, Heidelberg Production: PRO EDIT GmbH, Heidelberg Printed on acid-free paper SPIN: 10643444 3213136Re-5 432 1 0
Acknowledgement I greatly appreciate the support and faith of Prof. Dr. Lutz Hasse. It were the productive discussions with him and Dr. Hans-Joerg Isemer which laid the foundations for this atlas.
Preface The presented climate atlas follows with regard to structure and volume the Bunker Climate Atlas of the North Atlantic Ocean published 1985 by H.-J. Isemer and L. Hasse, which has become a standard work for the climate study community. A new edition was appropriate, since during the last decade much progress was achieved in the correct interpretation of the wind speed reported by merchant ships. As the wind speed is an essential parameter for the fundamental air-sea interactions, namely the exchange of momentum and energy between ocean and atmosphere, considerable impact on resulting climate key parameters as Sverdrup transport or meridional heat transport could be expected. Furthermore, individual ship observations are nowadays available from COADS, the Comprehensive Ocean Atmosphere Data Set, and, due to the grown computer power, these data are processable in reasonable time. Thus, improving the calculations of air-sea fluxes, as performed by Isemer and Hasse, is no longer a complex and tricky venture, since flux parameterizations can be applied directly to the ship observations. Compared to the Bunker Altas we expanded the considered sea area and included also the South Atlantic. Considering the entire Atlantic Ocean reveals not only interesting features of the southern hemisphere but allows also a finer assessment of the resulting energy fluxes. Kie!, August 2000 RalfLindau
Contents 1 2 3 3.1 3.2 3.3 3.3.1 3.3.2 3.3.3 3.3.4 3.4 Introduction....... Data and Data Treatment Derivation of Air-Sea Fluxes by Parameterisations.. Net Shortwave Radiation... Net Longwave Radiation... Latent and Sensible Heat Fluxes. Exchange Coefficients..... Systematic Errors of Temperature Observations. Beaufort Equivalents...... Time Dependent Beaufort Scale. Wind Stress........... 4 Net Air-Sea Heat Flux and Meridional Heat Transport. 5 6 Concluding Remarks. References...... 1 1 2 2 5 5 6 6 7 9 10 12 16 17 Part I Observations...... 19 Time-Latitude Diagrams....... 21 Annual Cycles at Selected Locations 26 Observation Density... 47 Sea Surface Temperature...... 53 Air Temperature........... 73 Air minus Sea Surface Temperature. 80 Mixing Ratio............. 100 Relative Humidity.......... 120 Air minus Sea Surface Mixing Ratio. 127 Total Cloud Cover.... 134 Low Cloud Cover.... 149 Precipitation Frequency. 156 Sea Level Air Pressure.. 171 Scalar Wind Speed plus Resultant Wind Vector. 191 East Component of the Wind. 211 North Component of the Wind.......... 231 Magnitude of Resultant Wind plus Resultant Wind Vector.. 251 Direction of the Mean Wind Vector. 258 Directional Steadiness of the Wind. 264
X CONTENTS Divergence ofthe Wind. 271 Part II Air-Sea Interactions.. 279 Time-Latitude Diagrams. 281 Annual Cycles at Selected Locations 285 Net Shortwave Radiation 306 Net Longwave Radiation 321 Net Radiation.. 336 Latent Heat Flux.. 343 Evaporation.... 358 Sensible Heat Flux. 365 Total Net Air-Sea Heat Flux. 380 Wind Stress......... 395 East Component ot the Wind Stress. 410 North Component of the Wind Stress 425 Curl of Wind Stress.....440 Ekman Volume Transport. 455 Vertical Ekman Velocity.470 Sverdrup Transport.... 477 Streamfunction of Sverdrup Transport. 483