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© 2004Wendell S. Brown 21 September 2004
Revised SYLLABUS Fall 2004 (1 November 2004)
INTRODUCTORY PHYSICAL OCEANOGRAPHY
Courses and Instructors MAR 555: Introductory Physical Oceanography
Wendell Brown – [email protected] Miles Sundermeyer – [email protected]
ECOS 650: Physical Oceanography BernardGardner - [email protected]
PHYS 550: Fundamentals of Physical Oceanography COURSE STRUCTURE
• Lectures Tuesday and Thursday 1530 –1645 .....................WSB & BG Class Notes accessed via http://www.smast.umassd.edu/MAR555/ • Recitation Monday 1600 –1715 ......................................................MS Problem Sets accessed via http://www.smast.umassd.edu/MAR555/ 30%
(generally assigned Tuesday – due following Tuesday)
• Classroom Discussion Participation 10%
• Examinations 2 Term @ 15% each and 1 Final @ 30% 60% EXPECTATIONS OF STUDENTS TAKING THE COURSE FOR CREDIT
• Attendance at lectures and recitations • Submission of all assigned homework • Participation in class and particularly recitation discussions
PRIMARY INTRODUCTORY PO REFERENCES
• Knauss, J.A. Introduction to Physical Oceanography, Prentice-Hall, Englewood Cliffs, N.J., 1978.
• Pickard, L. and W.J. Emery. Descriptive Physical Oceanography, Pergamon Press, N.Y., 1978.
• Pond, S. and G. L. Pickard. Introductory Dynamics Oceanography, Pergamon Press, N.Y., 1978.
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OTHER INTRODUCTORY PO REFERENCES • Tolmazin, D. Elements of Dynamic Oceanography, Allen & Unwin, Boston,
1985.
• Von Arx, W.S. An Introduction to Physical Oceanography, Addison-Wesley Pub. Co., Reading, MA, 1974
GENERAL INTRODUCTORY OCEANOGRAPHY REFERENCES • Anikouchine W.A. and R.W. Sternberg. The World Ocean, Prentice Hall, Inc.,
Englewood Cliffs, N.J., 1973. • Duxbury, A. C. and A. Duxbury. The World’s Oceans, Addison-Wesley Pub. Co.,
Reading MA, 1984. • Gross, M.G. Oceanography – A View of the Earth, Prentice-Hall, Inc., Englewood
Cliffs, N.J., 1990. • Neshyba, S. Oceanography – Perspectives on a Fluid Earth, John Wiley & Sons,
N.Y., 1987. • Thurman, H.V. Introductory Oceanography, Charles E. Merrill Pub. Co.,
Columbus, Ohio, 1975.
LECTURE TOPICS LECTURER Week 1 Tues Sep 7 Introduction ..........................................................................................BG & WSB Thurs Sep 9 The Oceans: One Component of the Earth System – (Chapter 1)........................BG Planetary Heat Engine Week 2 Mon Sep 13 RECITATION ........................................................................................................ MS Sep 14 & 16 Heat Balance of the Earth/Ocean System............................................................. WSB Atmosphere Ocean Interaction – (Chapter 2) ...................................................... WSB Week 3 Mon Sep 20 RECITATION ........................................................................................................ MS Sep 21 & 23 Seawater Density – (Chapter 3)..................................................................................BG Seawater Temperature and Salinity ...........................................................................BG Sound Velocity Week 4 Mon Sep 27 RECITATION ........................................................................................................ MS Sep 28 & 30 Water Mass Analysis – (Chapter 4)...........................................................................BG Thermohaline Circulation .................................................................... BG Deep Ocean Circulation Week 5 Mon Oct 4 RECITATION Tues Oct 5 EXAMINATION ............................................................................................................... Thurs Oct 7 Elements of Dynamical Oceanography – (Chapter 5A)..................................... WSB Week 6 Mon Oct 11 NO RECITATION ...................................................................... COLUMBUS DAY
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Oct 12 & 14 Mass Conservation .................................................................................................. WSB Pressure Gradient & Coriolis Forces ..................................................................... WSB Week 7 Mon Oct 18 RECITATION ........................................................................................................ MS Oct 19 & 21 Force Balances (Chapter 5B).............................................................................. WSB Week 8 Mon Oct 25 RECITATION ........................................................................................................ MS Oct 26 & 28 Geostrophic Flow ..................................................................................................... WSB Method of Dynamic Sections ................................................................................. WSB Week 9 Mon Nov 1 RECITATION ........................................................................................................ MS Tues Nov 2 Inertial, Ekman and Vorticity .................................................................................WSB Thur Nov 4 Wind Driven Circulation – (Chapter 6) ................................................................WSB Week 10 Mon Nov 8 RECITATION ........................................................................................................ MS Tues Nov 9 Gulf Stream & General Ocean Circulation .............................................................BG Thurs Nov 11 NO CLASSES .............................................................................VETERANS DAY Week 11 Mon Nov 15 RECITATION ........................................................................................................ MS Tues Nov 16 Tropical Ocean Circulation & Climate Change.......................................................BG Thur Nov 18 EXAMINATION ............................................................................................................... Week 12 Mon Nov 22 RECITATION ........................................................................................................ MS Nov 23 Surface Waves – (Chapter 7)..................................................................................... BG Thur Nov 25 NO CLASSES ........................................................THANKSGIVING HOLIDAY Week 13 Mon Nov 29 RECITATION ........................................................................................................ MS Tues Nov 30 Wave Energy .........................................................................................................BG Thur Dec 2 Ocean tides .........................................................................................................BG Week 14 Mon Dec 6 RECITATION ........................................................................................................ MS Dec 7 & 9 Wind-Driven Coastal Circulation ..............................................................................BG Estuarine Dynamics – (Chapter 8) .............................................................................BG Week 15 Mon Dec 13 RECITATION ........................................................................................................ MS Tues Dec 14 Massachusetts Bay Circulation...................................................................................BG Thurs Dec 16 REVIEW ..........................................................................................WSB & BG TBD FINAL EXAMINATION
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CLASS NOTES
Introductory Physical Oceanography
MAR 555
ECOS 650 PHYS 550
1November 2004
Instructors Wendell S. Brown & Miles Sundermeyer
School for Marine Science and Technology University of Massachusetts Dartmouth
Bernard Gardner
ECOS University of Massachusetts Boston
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TABLE OF CONTENTS
References........................................................................................... 4
Forward ............................................................................................. 5
Chapter 1: Geophysical Perspective (20 October 2004)
Geophysical Issues .................................................................................................... 1 Heat Budget of the Earth System............................................................................. 7 Heat Budget of the Oceans........................................................................................16 Problems ......................................................................................................................22
Chapter 2: Atmospheric Circulation and Air/Sea Interaction (20 October 2004)
Planetary Winds.......................................................................................................... 3 Atmosphere/Land Interaction................................................................................... 7 Atmosphere/Ocean Interaction................................................................................. 8
Chapter 3: Physical properties of Seawater (23 September 2004)
Salinity Determination............................................................................................... 1 Sea Water Density ..................................................................................................... 2 Compressibility Effects ............................................................................................ 3 Water Column Stability ............................................................................................ 7 Temperature and Salinity Diagrams ....................................................................... 8 Surface Density Distributions .................................................................................. 9 Horizontal and Vertical Temperature Distributions ............................................ 10 Seasonal Temperature Distributions........................................................................ 11 Surface Salinity Distributions .................................................................................. 13 Vertical Profiles of Salinity .................................................................................... 14 Vertical Distribution of Density ............................................................................. 15 Sound Transmission in the Sea................................................................................. 17 Terminology Appendix.............................................................................................. 24 Problems ...................................................................................................................... 26 Chapter 4: Thermohaline Circulation (20 September 2004)
Introduction ................................................................................................................. 1 Thermohaline Circulation.......................................................................................... 3 T/S property Distribution .......................................................................................... 4 Elements of Water Mass Analysis .......................................................................... 5 Example of Water Mass Analysis: Wust’s Core Technique ............................... 7 Water Mass Formation Processes ........................................................................... 8 Thermohaline Circulation: Antarctica .................................................................... 16 Water Masses: Antarctic ........................................................................................... 20 Water Masses: Subantarctic ..................................................................................... 21 Water Masses: South Atlantic; Equatorial Atlantic; North Atlantic ................. 22 Water Masses: World’s Oceans .............................................................................. 20 Deep Thermohaline Flow ......................................................................................... 25
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Chapter 5: Elements of Dynamical Oceanography
A. (20 October 2004) Introduction ................................................................................................................. 1 Forms of Energy ....................................................................................................... 9 Application of Newton’s Laws to the Ocean ........................................................13 Conservation of Mass ................................................................................................14 Conservation of Momentum ....................................................................................17 Pressure Gradient Force ............................................................................................20 Gravitational Force and Hydrostatic Balance ........................................................22 Model Ocean Pressure Fields ...................................................................................24 Friction Forces.............................................................................................................27 Pseudo Forces ..............................................................................................................29 Coriolis Force ..............................................................................................................31 Problems ......................................................................................................................38 B. (1 November 2004) Geostrophic Balance .................................................................................................47 Geostrophic Frontal Flow: Margules Equation .....................................................52 Geostrophic Flow: Continuously Stratified Ocean ...............................................54 Computation of Geostrophic Velocities .................................................................56 Method of Dynamic Sections ..................................................................................58 Inertial Motion: A Case of Accelerated Circular Flow .......................................72 Cyclostrophic Motion: Another Case of Accelerated Circular Flow.................76 Meander Flow: Still Another Case of Accelerated Circular Flow .....................77 Friction Effects ...........................................................................................................80 Wind Stress on Sea Surface .....................................................................................84 Ekman Flow.................................................................................................................87 Vorticity .......................................................................................................................90 Problems ......................................................................................................................97 Chapter 6: Ocean Circulation (29 September 2004)
Introduction to Wind-Driven Circulation ............................................................... 1 Ekman Layer Role in Ocean Dynamics – via Mass Conservation..................... 4 Ekman Layer Role in Ocean Dynamics – via Vorticity Conservation.............. 9 Antarctic Circumpolar Current.................................................................................17 Wind-Driven Circulation in the Tropics .................................................................19 Theories of Thermohaline Circulation ....................................................................24 Chapter 7: Waves and Tides Surface Gravity Wave Model................................................................................... 2 Wave Energy ............................................................................................................... 16 History of a Wind-Driven Wave.............................................................................. 22 Standing Waves and Reflections.............................................................................. 29 Seiches .......................................................................................................................... 32 Appendix: Long Wave dynamics............................................................................. 33 Tides.............................................................................................................................. 38 Equillibrium Tides ...................................................................................................... 41 Harmonic Analysis of Tides ..................................................................................... 55 Other Ocean Waves: Internal Waves ...................................................................... 58 Planetary Waves ......................................................................................................... 62 Problems ...................................................................................................................... 67
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Chapter 8: Estuaries Salt Wedge Estuaries.................................................................................................. 1 Partially Mixed Estuaries .......................................................................................... 3 Well-Mixed Estuaries................................................................................................. Mixing and Transport of Biogeochemical Constiutents ...................................... 13 Problems ..................................................................................................................... 20 Appendix A: Physics Review
Appendix B: Water Mass Analysis
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References (Bold = Suggested References)
Anikouchine, W.A., and R.W. Sternberg, The World Ocean, Prentice Hall, Inc.,
Englewood Cliffs, N.J., 1973.
Anthes, R.A. Meteorology, Macmillan Publishing Co., N.Y., 1992.
Baggeroer, A., and W. Munk. “The Herd Island Feasibility Test,” Physics Today, September 1992.
Duxbury, A.C. and A. Duxbury, The World’s Oceans, Addison-Wesley Pub. Co., Reading, MA, 1984.
Gross, M.G., Oceanography – A View of the Earth, Prentice-Hall, Inc., Englewood Cliffs, N.J., 1990.
Knauss, J.A., Introduction to Physical Oceanography, Prentice-Hall, Englewood Cliffs, N.J., 1978.
Neshyba, S., Oceanography – Perspectives on a Fluid Earth, John Wiley & Sons, N.Y., 1987.
Neumann, G. and W. J. Pierson, Principles of Physical Ocean ography, Prentice-Hall, Englewood Cliffs, N.J., 1966.
Open Ocean Course Team, Ocean Circulation, Pergamon Press, N.Y., N.Y., 1989.
Pickard, L. and W.J. Emery. Descriptive Physical Oceanography, Pergamon Press, N.Y.,1978.
Pond, S. and G. L. Pickard. Introductory Dynamics Oceanography, Pergamon Press, N.Y.,1978.
Thurman, H.V. Introductory Oceanography, Charles E. Merrill Pub. Co., Columbus, Ohio,1975.
Tolmazin, D. Elements of Dynamic Oceanography, Allen & Unwin, Boston, 1985.
Von Arx, W.S., An Introduction to Physical Oceanography, Addison-Wesley Pub. Co., Reading, MA, 1974.
Vonder Haar, T. H.and A. H. Oort, New estimates of annual poleward energy transport by Northern Hemisphere oceans, J. Physical Oceanography, 3, 169-172, 1973..
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Forward
Physical Oceanography in America W.S. Brown editor
[Editor of an essay by Harold L. Burstyn (The William Paterson College of New Jersey and U.S. Geological Survey, Reston) and Susan B. Schlee (Marine Biological
Laboratory, Woods Hole)] Benjamin Franklin, the first postmaster general of the American colonies (circa 1740),
tried to explain the longer westward sailing times of the England to New York mail ships.
He collaborated with expert sailor (and cousin) Timothy Folger in attributing the delay
to a “strong, adverse, warm current” near the New England coast. To avoid (find) the
current on the England to American (American to England) trips, he instructed the ship’s
captains to measure sea surface temperature regularly. Thus began the first scientific
examination of the "Gulf Stream" in 1775 (Figure 1).
Figure 1. Benjamin Franklin’s map of the Gulf Steam based on his compilation of the sea surface temperatures.
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Alexander Bache , the great grandson of B. Franklin and first Superintendent of the U.S.
Coast Survey, committed the government to systematic study of the Gulf Stream and
coastal currents and sea level, committed the government to systematic study of the Gulf
Stream and coastal currents and sea level in the first half of the 19th century.
Matthew Fontaine Maury, a U.S. naval officer and first Superintendent of the U.S.
Naval Observatory, organized information from ships logs from all around the world in
an effort to infer the first global description of winds and currents.
This work inspired the curiosity of those who wanted to understand the physical basis of
the currents in the ocean. However, the Civil War and changing political priorities
undermined the American effort in physical oceanography and caused a decline during
the latter half of the 19th century.
By the turn of the century, a group of Scandinavian explorers, headlined by arctic
explorer Fritjof Nansen, began making systematic ocean measurements (Figure 2).
Nansen’s observations and prestige prompted meteorologists, namely Vilhelm Bjerknes
– a theoretical physicist- and Norwegian Bjorn Helland-Hansen, F. Nansen and V.W.
Ekman to apply the principles of physical meteorology to the understanding the ocean
circulation.
In April 1912, the Titanic struck an iceberg and sank in the North Atlantic with great loss
of life (Figure 3) . The prominence of the people who died traveling on “an unsinkable
ship – the largest ever built prompted the Americans and Europeans to respond. Thus the
International Ice Patrol was established in 1913.
The mission of the Patrol, operated by the United States Coast Guard, was to keep track
of the hundreds of icebergs that endangered shipping in the sea lanes of the North
Atlantic in the spring of each year. The problem was that direct observations of the ice
were hampered by the fog. Thus the Coast Guard officers soon became convinced that
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they needed to employ modern scientific techniques for calculating ocean currents
indirectly through the measurement of water properties.
Figure 2. F. Nansen and the R.V. Fram stuck in the arctic ice.
During the early part of the 20th century, Scandinavia had become the world center for
physical oceanography. Scientists from Sweden, Norway and Denmark had developed
the methods for measuring temperature and salinity in the open ocean and using these
measurements to compute the direction and strength of open ocean current s. In
Scandinavia, the perceived decline of the North Sea fisheries led to intensive study, and
the scientists were quick to see that biological productivity had to depend on the physical
conditions of the marine environment. Thus they began to make measurements that
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received increasing support because of the participation of the noted Arctic explorer,
Fritjof Nansen. Nansen soon interested the most distinguished mathematical physicist in
Scandinavia, Vilhelm Bjerknes, in the problem of ocean currents, and Bjerknes' students
- J.W. Sanstrom and Bjorn Helland-Hansen worked out the techniques for calculating
currents from the temperature and salinity data which was now routinely collected. A
method existed by 1905 for the determination of currents indirectly.
Figure 3. On its maiden voyage in April 1912, the SS Titanic –“the unsinkable ship”- hit an iceberg in the
North Atlantic and sank.
Thus in 1924, a young Coast Guard officer Edward H. Smith, was sent to the
Geophysical Institute at Bergen, Norway, to work with Bjorn Helland-Hansen, the
developer of the formula for computing what we now call geostrophic ocean currents. It
is interesting that Smith had to leave the US, which had been on the forefront of physical
oceanography during the mid-1800s, and go to Scandinavia learn the most modern
physical oceanographic techniques in the early 1900s. How had the United States lost its
dominance of the study of ocean?
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American dominance of the science of physical oceanography in the first half of the 19th
century derived from the way in which the American economy developed. Before the
Civil War, US commerce was mainly the exchange of its vast natural resources for
finished goods. This type of commerce depended almost entirely upon water
transportation; river steamboats on the western rivers and sailing ships on the ocean. Thus
from 1815 to 1860 the American merchant marine quadrupled in size and North Atlantic
shipping routes became the world's busiest.
The importance of seaborne commerce meant that there was compelling need for safer
and faster sea travel. By 1850 three federal agencies had been founded to furnish what we
now call research and development service to maritime commerce. Further the employees
of these American agencies raised the science of physical oceanography to a dominant
position in world.
The first of these agencies was the civilian United States Coast Survey, founded in 1807
under the aegis of President Thomas Jefferson. Under its first director, the Swiss
immigrant F.R. Hassler, the Survey established high standards. However between 1818
to 1832, the Survey operations were suspended because of the financial after-effects of
the War of 1812 and a growing role of the navy employing the war's surplus naval
officers. After Hassler's death, Alexander Dallas Bache became superintendent of the
Coast Survey. Bache led the Survey through a period of rapid expansion, sending vessels
to sea to chart currents as well as surveying the land, and he found employment for a
number of American scientists. The Coast Survey under Bache became the principal
center of the American scientific community, in part because he developed alliances with
professors in the leading colleges and with scientists in Europe. Despite its rise to
prominence, the future of the Survey was not secure because of its competition with the
US Navy.
The US Navy’s role in supporting commerce was expressed through the establishment of
the Depot of Charts and Instruments in 1830. The initial reason for its establishment of
the Depot was to provide a shore billet for Lieutenant Charles Wilkes, who was
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organized and led the U.S. Navy Exploring Expedition - America's principal contribution
to the geographical reconnaissance of the ocean world. Unfortunately, few physical
oceanographic measurements were made during his four-year cruise. Around 1840, the
federal government built a world-class astronomical observatory; and relocated the Depot
there under the leadership of Lt. Matthew Fontaine Maury.
Thus for almost two decades thereafter, Maury and Bache were great rivals on the
scientific scene, both in the United States and abroad. This rivalry arose from the ir
differing views on the relative value of basic and applied sciences. Maury, first and
foremost a self-educated naval officer, perceived no difference between them. Bache,
who graduated West Point at the head of his class when only 19, stood for science as a
profession in its own right.
Bache and his friends collaborated in persuading the government to establish the Nautical
Almanac Office with a mission to serve shipping through its scientific research. Part of
the Navy, the Almanac Office was located by its founder, Navy Lieutenant Charles
Henry Davis, in Cambridge, Massachusetts. There it could make use of the Harvard
College Observatory (rather than Maury's National Observatory). Since its job could
never be finished, the Almanac Office was more secure than the Survey and thus was
able to build its staff of skilled scientists and mathematicians.
About this time, the Coast Survey under Bache inaugurated a highly sophisticated
investigation of the Gulf Stream, the most intense of the currents of the North Atlantic.
From 1844 to 1860 Coast Survey ships ran fourteen lines of temperature measurements
across the Gulf Stream between New Jersey and Florida, setting the pattern of research
on the world's most studied ocean current.
In the early years of the Depot, Maury led the pains-taking analysis of ships' logs, from
which he compiled charts that showed bathymetry (Figure 4), prevailing winds and
currents over the worlds' oceans. However, by 1849 he also wanted to direct research at
sea. Ironically the same appropriations bill (passed by a lame-duck Congress) that
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funded the establishment of the Almanac Office, also funded the construction of two
naval vessels that Maury wanted to do oceanography at sea. Maury’s ideas about the
physics of the ocean currents that his charts revealed were first published as part of the
Sailing Directions that accompanied his charts. Maury's theories were later collected into
one of the all- time best-sellers of science, his Physical Oceanography of the Sea (1855).
Although Maury’s ideas were generally rejected by those who understood best the
problems that he considered, they did motivate others with alternate ideas.
Figure 4. Bathymetry of the Atlantic compiled by Matthew Maury in 1859.
In particular they stimulated a self- taught schoolteacher, William Ferrel of Nashville,
Tennessee, to develop and advance his own. Thus began the career in dynamical
meteorology and physical oceanography of the leading American practitioner of both.
Ferrel's first paper, his pioneering "Essay of the Winds and Currents of the Ocean," was
published in Nashville in 1856. In it he presented for the first time anywhere the
principle that the earth's rotation accounts for the general circulation of the atmosphere
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and ocean. When this and other papers came to the attention of Bache and his circle,
Ferrel was invited to Cambridge to join the staff of the Nautical Almanac Office. There
he remained until 1867, when Bache's successor and close friend, the Harvard
mathematician Benjamin Pierce, took Ferrel to Washington and the Coast Survey.
Fifteen years later in 1886, Ferrel left the Coast Survey to close out his distinguished
career there for the Signal Service -predecessor of the Weather Bureau. During this long
and fruitful career, Ferrel worked on the theory of winds, ocean currents, and tides, and
in the process built one of the earliest tide-predicting machines. While Ferrel was
probably the world's most distinguished physical oceanographer of his day, he left no
successors. Thus the period of American dominance in physical oceanography ended.
What had happened to the structure erected by Bache, Maury, and their contemporaries
had erected? The Civil war was probably single most significant event that led to the
decline of American marine science in the late 1800s. The War removed the Virginian
Maury from the scene, and it drove Bache into war work so strenuous that he suffered a
stroke and died soon after Appomattox. After the war, America turned inward as the vast
interior was opened to exploitation by the spread of the railroad. The American merchant
marine and navy almost vanished from the ocean. Seaborne commerce gave way to
mining as the theme of the American quest for riches.
Whatever reputation the Coast Survey had around the turn of the twentieth century came
from the tidal work of Rollin A. Harris. Here, American physical oceanography
suffered directly from the low prestige of Federal science as of American theoretical
science generally. Harris' outstanding work ran counter to the theories of G.H. Darwin, a
professor at Cambridge University in England. As a result, Harris' efforts did not receive
the acclaim they deserved, and the Survey suffered with him.
Despite this downturn in American interests, oceanographic research continued. A key
contributor was Alexander Agassiz, despite being a zoologist and geologist, helped to
link the 19th and 20th century periods of highly active American physical oceanography.
Agassiz sustained his efforts in marine science (mainly at Harvard) through the fortune
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that he built from the Michigan copper mines. This enabled him to make a series of
cruises on the steamer Blake for the Coast Survey beginning in 1877. The Coast Survey’s
Blake was later used by Lieutenant John E. Pillsbury for a systematic study of the Gulf
Stream with his newly invented current meter. From 1884 to 1890 the Survey's vessel
spent part of each year moored along six sections that crossed the Gulf Stream between
Cape Hatteras and the southern tip of Florida. Pillsbury published these measurements in
the Survey's 1890 annual report. Unfortunately, they made little impact at the time.
Alexander Agassiz was associated through much of his life with Harvard University,
though his income came from copper mining. As a result, he had a number of students
who learned from him the ways of the sea and used the library he collected at the
Museum of Comparative Zoology to learn about these new developments in Scandinavia.
One of these students was William E. Ritter, who left Harvard to become chairman of
the Department of Zoology at the University of California in Berkeley.
Each summer, Ritter studied organisms at the seaside from a portable tent that moved up
and down the California coast. Finally in about 1905, he settled north of San Diego at a
permanent site acquired through the generosity of E.W. Scripps and his sister and
founded the Scripps Institution for Biological Research. His Berkeley colleague Charles
A. Kofoid went to Europe on sabbatical in 1907-1908 and returned to Scripps with the
Scandinavian message that a study of the physical conditions, especially the currents, was
necessary for understanding the biology of the oceans. When Ritter came to La Jolla and
the Scripps Institution in 1911, he brought a graduate student in mathematics, G.F.
McEwen, who immediately began to introduce the new Scandinavian methods to
Scripps.
If McEwen was doing Scandinavian-style physical oceanography in the in California,
then why did Edward Smith of the Ice Patrol choose to go to Europe? While there are no
clear answers to this question, we have some suggestions. First, McEwen, like his
predecessor William Ferrel, was a shy and solitary man, whose efforts he could be
understood by few and these few remained working at Berkeley with other
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mathematicians rather than go to La Jolla. Second, it seems to be true that the most
successful theoreticians pursue problems that can be tested experimentally. The
problems of ocean currents were not very high on the lists of US mathematicians. This
was due in part to the lack of a dynamic leader like Bjerknes, Harold Sverdrup, Henry
Stommel, or Walter Munk to attract students and colleagues. Neither McEwen nor Ferrel
were able to establish groups to carry on the tradition in American physical
oceanography. Thirdly, the American workers of the time may not have been convinced
of the validity of the new Scandinavian techniques before they were decisively
demonstrated in 1924. In that year, the German physical oceanographer Georg Wust
compared the currents in the Florida Strait calculated from Pillsbury’s measured
temperature and salinity data. The general agreement between the measured and
estimated currents confirmed the soundness of the Scandinavian methods. Fourthly, his
advisor on oceanographic matters probably thought of Scripps Institution as a rival.
In any case, Edward Smith went to Scandinavia for his studies. His return marked a
rejuvenation of American physical oceanography. Shortly thereafter in 1930, the
Rockefeller Foundation played a crucial role in the establishment of Woods Hole
Oceanographic Institution, whose first director was Henry Bryant Bigelow. At the same
time the Foundation built a new building at Scripps Institution and at the behest of T.
Wayland Vaughan, Ritter's successor as director, the name was changed to Scripps
Institution of Oceanography.
Therefore, in spite of America's turning inward after the Civil War, in spite of the decline
in the scientific stature of the Coast Survey, in spite of the loss of American dominance in
physical oceanography, Alexander Agassiz and his students were able to link the two
periods of American preeminence in physical oceanography: that of the mid-nineteenth
century and that of today.