Global and Regional Climate Interaction: The Caspian Sea Experience

246 Pages·1994·7.472 MB·English

by  Sergei N. Rodionov (auth.)

GLOBAL AND REGIONAL CLIMATE INTERACTION:
THE CASPIAN SEA EXPERIENCE
Water Science and Technology Library
VOLUME 11
Series Editor:
V. P. Singh, Louisiana State University,
Baton Rouge, US.A.
Editorial Advisory Board:
S. Chandra, Roorkee (UP.), India
J. C. van Dam, Delft, The Netherlands
M. Fiorentino, Potenza, Italy
W. H. Hager, ZUrich, Switzerland
N. Harrnancioglu, Izmir, Turkey
V. V. N. Murty, Bangkok, Thailand
J. Nemec, GenthodiGeneva, Switzerland
A. R. Rao, West Lafayette, Ind., U.S.A.
Shan Xu Wang, Wuhan, Hubei, P.R. China
The titles published in this series are listed at the end of this volume.
GLOBAL AND REGIONAL
CLIMATE INTERACTION:
THE CASPIAN SEA
EXPERIENCE
by
SERGEI N. RODIONOV
National Center for Atmospheric Research (NCAR),
Boulder, Colorado, U.S.A.
SPRINGER SCIENCE+BUSINESS MEDIA, B.V.
A C.I.P. Catalogue record for this book is available from the Library of Congress.
ISBN 978-94-010-4468-4 ISBN 978-94-011-1074-7 (eBook)
DOI 10.1007/978-94-011-1074-7
Printed on acid-free paper
AII Rights Reserved
© 1994 Springer Science+Business Media Dordrecht
Originally published by Kluwer Academic Publishers in 1994
Softcover reprint ofthe hardcover lst edition 1994
No part of the material protected by this copyright notice may be reproduced or
utilized in any form or by any means, electronic or mechanical,
including photocopying, recording or by any information storage and
retrieval system, without written permission from the copyright owner.
CONTENTS
Acknawiedgments ............................................ vii
Chapter 1 Introduction...................................... 1
Chapter 2 Seasonal and Longer-Term Changes of aimatic
Characteristics in the Caspian Sea Basin ............... 11
2.1 General climate characteristics. . . . . . . . . . . . . . . . . .. 14
2.2 Long-term changes in the seasonal cycle " . . . . . . . . . . 20
2.3 Interannual and longer-term changes .............. 30
2.4 Temporal changes in the frequency structure ........ 48
Chapter 3 The Caspian Sea and aimatic Processes
in the Northern Hemisphere ......................... 58
3.1 Teleconnections ............................... 59
3.2 Atmospheric circulation patterns during a rise
and decline in the CSL . . . . . . . . . . . . . . . . . . . . . . . . 68
3.3 The role of the North Atlantic .................... 78
3.4 The extraordinary rise in the CSL after 1977 ......... 88
3.5 Climate and CSL changes during the past millennium . 99
Chapter 4 Forecasting the Caspian Sea Level . . . . . . . . . . . . . . . . . . . . 112
4.1 Causes of the CSL fluctuations .................. 113
4.2 Comparative analysis of 'climatological' methods .... 121
4.3 Instability of correlation relationships ............. 130
4.4 An approach based on probabilistic logic .......... 139
4.5 Experimental results .......................... 145
Chapter 5 Caspian Sea Level and Anticipated Global Warming ..... 154
5.1 Global climate modelling ....................... 156
5.2 Paleoclimate analogues ........................ 164
5.3 Climate of the 1980s and early 1990s .............. 180
Concluding Remarks ........................................ 196
Appendix Fortran-Program for Constructing a Linkage Tree ......... 201
References ................................................ 207
Index .................................................... 235
v
ACKNOWLEDGMENTS
A significant part of this work was carried out when I was with the State
Oceanographic Institute (SOl), Moscow, Russia, and I greatly appreciate helpful
discussions with my colleagues Valerii Sinitsyn, Maya S. Potaichuk and Raisa
Nikonova, as well as their assistance in obtaining information and data
processing. I am especially indebted to Rozalia V. Nikolaeva (Institut of Water
Problems, Moscow, Russia) for her helpful advise and valuable information on
the Caspian Sea. Many constructive comments on earlier Russian version of the
manuscript were received from Sergei S. Lappo (SOl), Larisa Lunyakova and Igor
Getman (both with the Russian Hydrometeorological Center, Moscow). I also
deeply appreciate the critical reviews from Esfir Ya. Runkova, Eugeniya
Semenyuk and Mikhail Bardin (all with the Institute for Global Change and
Ecology, Moscow). Special thanks go to Maria Krenz (Environmental and
Societal Impact Group - ESIG, National Center for Atmospheric Research,
Boulder, CO., retired) for her tireless efforts to make the manuscript readable in
English. I acknowledge with great appreciation Richard W. Katz and Mary
Downton (both with the ESIG/NCAR) for their valuable critical comments made
in the course of reading a complete English draft of the manuscript. Also, I want
to express my sincere appreciation to Steven L. Rhodes; his careful editing and
suggestions improved the manuscript significantly. The help with various
portion of the manuscript given by Jerry R. Broad (RGB Exploration Corp.),
David Smith, Melonie Mason (both ESIG/NCAR) and Thomas E. Croley, Jr.
(Great Lakes Environment Research Laboratory, NOAA, Ann Arbor, MI) is
likewise acknowledged. With particular pleasure I thank Michael H. Glantz
(ESIG/NCAR) for his support of the work leading to this book and his
encouragement to publish it.
vii
CHAPTER 1
INTRODUCTION
The Caspian Sea is the world's largest inland body of water both in area
and volume. Its drainage area is approximately 3.5 million square kilometers,
extending 2500 km in length, 35°N to 600N, and on average 1000 km wide, 400E
to 600E (Fig. 1). Located in a large continental depression about 27 m below sea
level and with no surface outlets, the Caspian Sea is particularly sensitive to
climatic variations. As with other closed-basin lakes, its level depends on the
balance between precipitation and evaporation, which is directly linked to
atmospheric circulation. Because of its large area and volume of water, the
Caspian Sea effectively. filters climatic noise, and as such may serve as a good
indicator of climatic changes through observed changes in its water level.
Recently, the Caspian Sea has come under increased attention from
physical and social scientists owing to its unique natural characteristics as well
as the' very important role it plays in the ecoriomil:!s of such countries as
Azerbaijan" Russia, Kazakhstan, Turkmenistan and Iran. Dissolution of the
Soviet Union and creation of new independent states resulted in difficult
negotiations to divide the wealth of the Caspian Sea and to establish new
economic zones. According to one assessment (Ratkovich, 1988), the Caspian Sea
basin accounted for about one-third of the total economic output, one-fifth of the
agricultural production, and one-third of the hydroelectric production of the
former Soviet Union. Maritime and river transport are also well developed: the
Volga River and its tributaries alone carry about 70% of the total cargo turnover
of internal water routes of the European territory of the country. The Caspian
Sea is linked by inland waterways with the Black Sea, the Sea of Azov, the White
Sea, and the Baltic Sea.
The Caspian Sea is very important for fishing, notably sturgeon, which
produces the famous black caviar. The Caspian is the only water body in the
world that has a large stock of sturgeon, yielding in recent years about 90% of
the world's catch. On average, it yields about 30% of the total catch of fish in
the interior waters of the former Soviet Union (Ivanov, 1989).
The Caspian Sea basin is also rich in oil. The Caucasian oil fields extend
into the sea, and there is considerable offshore production in Azerbaijan, off
Apsheron Peninsula. On the northeastern coast of the Caspian Sea, around
Astrakhan (Russia), Atyrau (former Guryev) and Tengiz (Kazakhstan), a
powerful oil and gas mining and processing industry has been growing in the
1
2 Chapter 1
o
200 400 600 800 km
I I I I I
I I
o
200 400 600
Fig. 1 The Caspian Sea basin.
Introduction 3
past few years (Sagers, 1993). Several agreements with Western oil companies,
such as Chevron, Mobil, British Petroleum and others, have been signed to
develop a number of fields in the Caspian Sea (Wall Street Journal, June 10, 1993).
The major ongoing development is the giant Tengiz field, which is one of the five
largest oil fields in the world. The Tengiz field is estimated to contain more than
3.3 billion tons of oil, of which about 1 billion tons is commercially extractable.
Output is expected to increase in stages as de-sulfurization and production
capacity is completed, from the current 3.6 million tons to 12 million tons
annually, and at peak output, to 36 million tons per year (750000 barrels per
day) in 2010 (Sagers, 1993). The oil and gas resources of the Caspian are so
immense that it is often likened to the Persian Gulf.
Exploitation of these resources, however, which has always been
characterized by a low level of environmental protection, significantly threatens
marine life and the recreational potential of the sea (Kasimov and Velikhanov,
1992). The entire ecosystem of the Caspian is characterized by severe degrada
tion. Russia's once-great sturgeon populations are in danger of extinction. In the
past decade alone, sturgeon yields have decreased by a factor of 29, whereas for
the other regular species the factor is 46 (Golub, 1992).
Among numerous problems faced in the Caspian Sea, one of the most
important is fluctuations in its water level. These fluctuations are so significant
that they affect almost all of the economy of the region. A considerable amount
of effort has been devoted to explain and predict changes in the Caspian Sea
level (CSL). Nevertheless, the problem is still unsolved and remains a challenge
to scientists.
Awareness of the costly impacts of CSL changes grew dramatically in the
1930s when an abrupt drop of the CSL occurred. The climate of the 1930s was
exceptionally dry in the basin and runoff to the sea was extremely low. Over a
period of 7 years, from 1933 to 1940, the CSL decreased by 1.7 m (from -26.1 m
to -27.8 mr and the sea-surface area shrank by 23000 km2 (from 403000 km2 to
380000 km2).
This drop in the water level had disastrous economic consequences.
Maritime transport suffered extensively, particularly in the Northern Caspian,
due to increasingly shallow waters. Approach channels became shallow,
landings and docks were left dry, newly emerged shoals and reefs presented
hazards for navigation. Some ports, such as Astara in Azerbaijan, were no
longer in operation. In the principal ports of the Caspian Sea - Baku, Makhach
kala, Krasnovodsk - and on their seaward approaches, navigation was
maintained only as a result of constant dredging of ship channels. Additional
dredging was required to keep the navigation between the Volga River and the
Caspian Sea. As a consequence of the retreating sea, the Volga-Caspian Channel
<Hereafter, CSL elevations are expressed relative to the zero point of the Kronshtadt
water level gauge located in the Baltic Sea.
4 Chapter 1
became 20 kIn longer. Once a sea channel, it had become virtually a land canal.
Many arms of the Volga delta that had been used earlier by the fishing fleets
were no longer navigable.
Agriculture also suffered, especially in the Volga delta and along the coast
of the Northern Caspian. Arms and canals dried up in the Volga delta,
hampering irrigation. Many orchards·were abandoned, the area of valuable reed
growths was reduced, and livestock farms experienced a water shortage. It was
necessary to build expensive pasture-watering systems and other irrigation
facilities. Some populated places were resettled.
Decreased runoff from the Volga River, particularly during spring flood,
considerably impacted the fisheries, significantly worsening spawning conditions
for many species. Many spawning and feeding grounds in the Northern Caspian
and the Volga and Ural deltas laid dry. These areas used to yield about 80% of
the total Caspian fish catch. Due to decreased runoff, the entire hydrochemical
regime of the Northern Caspian was changed. Salinity increased up to 10.4 parts
per million (7-8 parts per million is considered to be optimal for fish). The
Caspian ecosystem reacted quickly and very adversely to these changes. As a
result, catches of most commercially important species were reduced by about
one half.
This exceptional drop in the CSL and its disastrous economic consequenc
es stimulated a scientific study of this phenomena, as evidenced by the large
number of publications subsequently devoted to the subject. Numerous scientific
conferences were held in the 1950s and early 1960s on CSL problems, and the
first engineering projects for saving the sea were developed.
It seemed then that researchers were on the verge of finding the reason
for the CSL changes and that prediction methods were almost at hand. Thus,
Girs (1957) explored the principal types of atmospheric circulation in the
Atlantic/European sector of the Northern Hemisphere (see section 2.2 for details)
and found that changes in the frequency of these circulation types could explain
even minor CSL variations. He emphasized that CSL variations were even in
better agreement with these circulation frequency changes than they were with
the variability of winter precipitation in the Volga basin. Belinsky and Kalinin
(1946) found that there was a close relationship between the CSL and the index
of atmospheric circulation in the vicinity of the Azores high, based on which the
USSR Hydrometeorological Center began issuing regular forecasts of the CSL
changes 5 years in advance. Great hopes were also attached to the relationship
that was found with solar activity, which was considered to be almost determin
istic (Eigenson, 1957). It was also anticipated that CSL forecasts would soon be
easier because anthropogenic influences, which could be easily accounted for,
would be a dominating forcing beginning in the 1960s. According to Apollov
(1957), the contribution of human activity to CSL variability would amount to
75% by 1965, while that of climate would be as little as 25%.