Oceans and the Global Oceans and the Global Environment: SummaryEnvironment: Summary

Oceans and the Global Environment: Lecture 1

taking physics and chemistry outdoors

Peter Rhines1 Eric Lindahl2

Bob Koon2, Julie Wright3

Discovery Seminar 25 Aug-18 Sept 2008 University of Washington

www.ocean.washington.edu/courses/has221a-08

1Prof. of Oceanography and Atmospheric Sciences; UW Honors Program2GFD Lab, School of Oceanography3M.S. in Biological Oceanography, UW

course goalscourse goals

learn about the oceans of Earth, and their importance to learn about the oceans of Earth, and their importance to plants, animals plants, animals including humansincluding humans

improve our relationship with the natural world…’Nature’improve our relationship with the natural world…’Nature’

experimentexperiment

calculatecalculate

build ‘tools’ for your future (whether as a scientist or just build ‘tools’ for your future (whether as a scientist or just a person)a person)

consider ‘deep’ environmentalism…the growing consider ‘deep’ environmentalism…the growing understanding of understanding of interdependence within Nature, interdependence within Nature, which has roots in philosphy and art which has roots in philosphy and art as well as science, as well as science, and implications to medicine, business, law, and implications to medicine, business, law, international relations, global povery as well as to human-international relations, global povery as well as to human-centered centered technologies.technologies.

1.1. keep a journal dailykeep a journal daily (In two forms: in a roughly 8 (In two forms: in a roughly 8 ½ x 11” bound notebook…UW Bookstore and as a ½ x 11” bound notebook…UW Bookstore and as a Googe Document shared with the instructors online)Googe Document shared with the instructors online)classclass lecture lecture notes notes lab experimentlab experiment notes and results; sketches notes and results; sketches

(diagrams), graphs, explanations (diagrams), graphs, explanations problem solvingproblem solving notes and results notes and results readingreading: most interesting ideas; least interesting : most interesting ideas; least interesting

content content short short essaysessays which will be assigned; start your essay which will be assigned; start your essay

the day it is assigned and let it ‘grow’ in your the day it is assigned and let it ‘grow’ in your notebook. When it begins to look complete put it notebook. When it begins to look complete put it into your Google document; label it as a draft into your Google document; label it as a draft until you are happy with it (some of these will be until you are happy with it (some of these will be quick-turnaround, due the next day). (~typically quick-turnaround, due the next day). (~typically 2 to 3 page essays)2 to 3 page essays)

As an aid to journal-keeping we will suggest some As an aid to journal-keeping we will suggest some questions about the reading, lectures and in-class questions about the reading, lectures and in-class science problems which you can discuss in your science problems which you can discuss in your journal.journal.

Lec 1 the layered worldLec 1 the layered world

the Gulf Stream this morning…seen by NOAA infrared the Gulf Stream this morning…seen by NOAA infrared satellite sensors. We average for a week to get rid of satellite sensors. We average for a week to get rid of

cloudsclouds

http://fermi.jhuapl.edu/avhrr/gs/

104.5104.500 angle formed by angle formed by hydrogen- oxygen-hydrogen- oxygen-hydrogen tetrahedon; hydrogen tetrahedon;

covalent bond within the covalent bond within the water molecule yet water molecule yet ‘hydrogen bond’ ‘hydrogen bond’ between moleculesbetween molecules

Let’s remove Greenland’s ice Let’s remove Greenland’s ice (only temporarily)(only temporarily)

Topography of the sea floor, constructed from satellite radar Topography of the sea floor, constructed from satellite radar altimetry and direct acoustic ‘soundings’ from ships (altimetry and direct acoustic ‘soundings’ from ships (Smith & Smith &

Sandwell)Sandwell)

from Seagar, Introduction to Ocean Science, 2007

dissolved oxygen (in micro mols per kg of seawater), dissolved oxygen (in micro mols per kg of seawater), 15015000W (purple = large, yellow=small)W (purple = large, yellow=small)

image:AGU 2003

the northern Atlantic Ocean…with its seafloortopography and the ice-mountain of Greenland(note vertical exaggeration of the picture! Greenlandis about 3 km tall and 2000 km long…it lies between600 N and 830 N, which is ¼ of the way from North Pole to Equator

Erika Dan temperature section from Labrador to Greenland to Erika Dan temperature section from Labrador to Greenland to Ireland, 60NIreland, 60N

(red= warm, blue = cold)(red= warm, blue = cold)Worthington and Wright, 1962Worthington and Wright, 1962

surface

4 km deep

buoyant continents float like icebergs on top of denser buoyant continents float like icebergs on top of denser mantle mantle

question 1.1: how different is it to swim in Hawaii and to question 1.1: how different is it to swim in Hawaii and to swim in Kansas?swim in Kansas?

question 1.2: Archimedes, according to legend, question 1.2: Archimedes, according to legend, determined the king’s crown was gold, by knowing the determined the king’s crown was gold, by knowing the density of gold. However the crown had a very elaborate density of gold. However the crown had a very elaborate shape, so he did not know its volume. “Aha” he said and shape, so he did not know its volume. “Aha” he said and fetched a basin of water. How did he use the water to fetched a basin of water. How did he use the water to learn the density of the metal in the crown?learn the density of the metal in the crown?

question 1.3: how many barbers are there in New York question 1.3: how many barbers are there in New York citycity

Lec 2 the gyre circulations Lec 2 the gyre circulations (great(great

and small)and small)

And.. the result is this circulation of the upper few hundred meters of the And.. the result is this circulation of the upper few hundred meters of the oceans, more or less in the direction of the winds: ‘gyres’ that look like the oceans, more or less in the direction of the winds: ‘gyres’ that look like the wind yet are concentrated on the western sides of the oceans in currents like wind yet are concentrated on the western sides of the oceans in currents like the Gulf Stream and Kuroshio (‘Black Current’) off Japan. This is the the Gulf Stream and Kuroshio (‘Black Current’) off Japan. This is the pressure field (simply related to the average height of the sea surface, by the pressure field (simply related to the average height of the sea surface, by the hydrostatic pressure rule). Think of these as flow lines, with the currents hydrostatic pressure rule). Think of these as flow lines, with the currents forming clockwiseforming clockwisegyres in the northern subtropics, and anti-clockwise gyres at high northern gyres in the northern subtropics, and anti-clockwise gyres at high northern latitude. The sense reverseslatitude. The sense reversesin the southern hemisphere, since the Earth’s rotation takes the opposite in the southern hemisphere, since the Earth’s rotation takes the opposite sense ‘down-under’.sense ‘down-under’.

Because the flow between to adjacent flow lines involves the same volume of fluid flow, thespeed of the currents is greater where the lines bunch together. The Gulf Stream and Kuroshioare ‘boundary currents’, very rapid (~ 2 to 4 knots…nautical miles per hour) as a result

the Southern Ocean connects the Atlantic, Pacific and the Southern Ocean connects the Atlantic, Pacific and Indian oceans, and the Antarctic Circumpolar Current Indian oceans, and the Antarctic Circumpolar Current circles round Antarctica in response to the very strong circles round Antarctica in response to the very strong

westerly (‘eastward’) windswesterly (‘eastward’) winds

Since 1992 it has been possible to see this circulation from space, using radar Since 1992 it has been possible to see this circulation from space, using radar altimeters on the Topex/Poseidon and JASON satellites of NASA and the European altimeters on the Topex/Poseidon and JASON satellites of NASA and the European Space Agency. This a view of the global distribution of sea surface height. The gyres of Space Agency. This a view of the global distribution of sea surface height. The gyres of circulation are not so clear because this instrument shows only the time-varying part of circulation are not so clear because this instrument shows only the time-varying part of the pressure field. NASA is working to determine the background ‘mean circulation’ the pressure field. NASA is working to determine the background ‘mean circulation’ missing here, using a remarkable technology of the GRACE satellite mission.missing here, using a remarkable technology of the GRACE satellite mission. What you do see are thousands of swirling eddies which propagate slowly westward What you do see are thousands of swirling eddies which propagate slowly westward and sometimes originate inand sometimes originate inthe intensest currents…the Gulf Stream, Kuroshio, and Antarctic Circumpolar Currentthe intensest currents…the Gulf Stream, Kuroshio, and Antarctic Circumpolar Currentfigure from Dudley Chelton, Oregon State Univ.

two dynamical ideas: pressure (weight of fluid two dynamical ideas: pressure (weight of fluid overhead, per square meter) and angular overhead, per square meter) and angular

momentum…figure skatersmomentum…figure skaters

The layers of ocean are not horizontal: so they The layers of ocean are not horizontal: so they must be moving. The forces acting on them are must be moving. The forces acting on them are few: gravity and the stress of the wind overhead. few: gravity and the stress of the wind overhead. Pressure variations within the ocean act toPressure variations within the ocean act to

redistribute these external forces (like people redistribute these external forces (like people elbowing one another in a crowd). So, how elbowing one another in a crowd). So, how would you expect the pressure and velocity of the would you expect the pressure and velocity of the ocean to be related?ocean to be related?

ocean

atmosphere

higher pressurelower pressure

?

The peculiar laws of Newtonian physics, when applied to a rotating The peculiar laws of Newtonian physics, when applied to a rotating planet, say that a body tends to move perpendicular to the force exerted planet, say that a body tends to move perpendicular to the force exerted on it….not exactly but largely so. Here we have a ring of air (or water) on it….not exactly but largely so. Here we have a ring of air (or water) centered on the North Pole. A northward force moves it toward the Pole. centered on the North Pole. A northward force moves it toward the Pole. The angular momentum, H, of the ring is conserved: the product of The angular momentum, H, of the ring is conserved: the product of distance from the rotation axis, and total east-west velocity. ‘Total distance from the rotation axis, and total east-west velocity. ‘Total velocity’ means the sum of the wind speed relative to the Earth, call it u, velocity’ means the sum of the wind speed relative to the Earth, call it u, plus the Earth’s eastward velocity, plus the Earth’s eastward velocity, Ωr. Ωr. So So H = ru + ΩrH = ru + Ωr22 does not change, as r changes: as r does not change, as r changes: as r decreases,decreases,u increases, corresponding to an acceleration of the eastward winds. u increases, corresponding to an acceleration of the eastward winds. This can be calledThis can be calledthe ‘figure-skater effect.’the ‘figure-skater effect.’ The Earth spins at a rate Ω

meaning that the length of the day is 2π/Ω. So Ω = 2 π/24 hours or 7.27 x 10-5 sec-1 Ω is called the angular velocity

The Greenland waters reaching out over the Labrador Sea also carry strong primary productivity with them…as seen in SeaWIFS ocean color (May 2004). We have been working in this region with roboticSeagliders, and have identified the physical circulation that enables the dominant plankton bloom of spring, seen here from the SeaWiFS satellite (again, yellow to red is high biological activity, blues are low activity).

2005 days 91-120

Lec 3 the conveyor belt Lec 3 the conveyor belt circulationscirculations

Benjamin Thompson (Count Rumford) 1753-1814:Benjamin Thompson (Count Rumford) 1753-1814:American colonist in Concord (Rumford) New American colonist in Concord (Rumford) New

Hampshire; allied himself with the British as the Hampshire; allied himself with the British as the Revolutionary War approached, escaped to England and Revolutionary War approached, escaped to England and then Germany: yet he later endowed a professorship at then Germany: yet he later endowed a professorship at

Harvard.Harvard.

http://www.rumford.com/Rumford.html

Convection in fluids:

P

When we add Earth’s rotation to this heat convection, the ‘figure skater effect’ reorganizes the horizontal circulation.

Basically, the ‘conveyor belt circulations’now drive strong horizontal currents andlots of spinning, swirling eddies and strong,concentrated ‘jet streams’

This true both in the atmosphere and oceanwhich have remarkable similarities

The ‘weather’ of the ocean (that is, the100 km wide eddies) coexists with theglobal general circulation (the ‘conveyor’) just as the weather of the atmosphere coexistswith its general circulation (the easterly andWesterly winds and the atmospheric conveyor belt circulation which tranportsheat from warm latitudes toward the poles

Convection without Earth’s rotation

When the Earth’s rotation comes into play, this pattern When the Earth’s rotation comes into play, this pattern of convection currents is deflected at right angles into of convection currents is deflected at right angles into

‘east-west’ currents. The east-west flow breaks into ‘east-west’ currents. The east-west flow breaks into complex, swirling eddies which we call ‘weather’.complex, swirling eddies which we call ‘weather’.

Still images from the video of convection with Earth’s rotation…simulated in a bowl with Still images from the video of convection with Earth’s rotation…simulated in a bowl with an ice-filled cylinder in the middle. The ‘Arctic’ at the center cools the fluid, but rather an ice-filled cylinder in the middle. The ‘Arctic’ at the center cools the fluid, but rather

than just flowing in a simple convection pattern as in the previous slides, Earth’s than just flowing in a simple convection pattern as in the previous slides, Earth’s rotation and the figure-skater effect give the flow strong east-west acceleration. We see rotation and the figure-skater effect give the flow strong east-west acceleration. We see

round eddies and jet streams snaking around them. These structures do the work of round eddies and jet streams snaking around them. These structures do the work of carrying heat from the warm latitudes to the cold latitudes. There are actually 2 jet carrying heat from the warm latitudes to the cold latitudes. There are actually 2 jet

streams: fluid sinks at the cold ‘northern’ wall and moves south. The angular streams: fluid sinks at the cold ‘northern’ wall and moves south. The angular momentum principle says that this fluid will develop a westward flow (turning to its momentum principle says that this fluid will develop a westward flow (turning to its

right). right). Conversely, the fluid rising in the warm latitudes flows north to complete the circuit, but Conversely, the fluid rising in the warm latitudes flows north to complete the circuit, but is deflected into an eastward jet stream, very intense. These complex ‘weather’ patterns is deflected into an eastward jet stream, very intense. These complex ‘weather’ patterns

do the necessary work of the atmospheric ‘heat engine’, moving heat poleward and do the necessary work of the atmospheric ‘heat engine’, moving heat poleward and converting thermal energy into kinetic energy of motion. The ocean has similar converting thermal energy into kinetic energy of motion. The ocean has similar instabilities and eddies and jet streams, only they are 10 times smaller in width.instabilities and eddies and jet streams, only they are 10 times smaller in width.

Southern hemisphere and northern hemisphere circulations: weather introduces new time-scales into Southern hemisphere and northern hemisphere circulations: weather introduces new time-scales into high latitude life. Left is south polar view, right is north polar view. There are natural cycles over 10 high latitude life. Left is south polar view, right is north polar view. There are natural cycles over 10 years and longer, as well as global warming related change in weather patterns, temperature and years and longer, as well as global warming related change in weather patterns, temperature and rainfall. The jet streams are seen at the 300 HPa level (where just a few contours are selected to rainfall. The jet streams are seen at the 300 HPa level (where just a few contours are selected to highlight the jets). There is a highlight the jets). There is a strongstrong symbiosis between the synoptic highs and lows at the surface, symbiosis between the synoptic highs and lows at the surface, the jet, and the smoother, faster stratospheric polar vortex above. Note the much more zonal nature the jet, and the smoother, faster stratospheric polar vortex above. Note the much more zonal nature of the SH flow. One glitch: colors in the NH are SLP while colors in SH are 850 HPa of the SH flow. One glitch: colors in the NH are SLP while colors in SH are 850 HPa temperature….sorry for this confusion!temperature….sorry for this confusion!(dynamic height at 1000 Hpa (colors: blue = low pressure cyclones, red=high pressure anticyclones), (dynamic height at 1000 Hpa (colors: blue = low pressure cyclones, red=high pressure anticyclones), 300 Hpa, 30 Hpa 1993 (NH), 1996 (SH) winters, 100 days each300 Hpa, 30 Hpa 1993 (NH), 1996 (SH) winters, 100 days each

southern hemispherenorthern hemisphere

UW-GFD lab hemisphere

Model of the oceanic conveyor belt circulation, driven by Model of the oceanic conveyor belt circulation, driven by sources of deep water entering in the far north: sources of deep water entering in the far north: Caitlin Caitlin

Whelan, summer undergraduate fellow, GFD lab UW 2007Whelan, summer undergraduate fellow, GFD lab UW 2007

fluid is pumpedinto the modelocean in the farnorth, and flowssouth along thewestern boundariesof each ocean basin,then recirculates inbig gyres near the seafloor. This peculiarcirculation occurs because of the ‘stiffening’of the fluid by its planetary angular momentumvertical walls (simulating continents)

smethie CFCssmethie CFCs

mid-depth

deeper

deepest~ 3800m

Lec 4Lec 4 Flux or ‘transport’ defined for a flowing system Flux or ‘transport’ defined for a flowing system

with a reservoir:with a reservoir: = concentration C x velocity U x area A= concentration C x velocity U x area A

F = C A U e.g. kg phosphate/mF = C A U e.g. kg phosphate/m33 x m x m2 2 x m/secx m/sec= kg phosphate per second= kg phosphate per second

Residence time (for a steadily flowing system) Residence time (for a steadily flowing system)

= mass of system/flux: T= mass of system/flux: Tresidenceresidence = mass/F = mass/F

(can be expressed as reservoir volume/Flux of (can be expressed as reservoir volume/Flux of volume)volume)

Lec 5 WaterLec 5 Water

Lec 5-08Lec 5-08

water, ice, snow and their future under water, ice, snow and their future under global warmingglobal warming

Peter RhinesPeter RhinesOceanography and Atmospheric Sciences,Oceanography and Atmospheric Sciences,

UW Honors Program UW Honors Program University of WashingtonUniversity of Washington

image: Petermann Glacier, NW image: Petermann Glacier, NW Greenland Konrad SteffenGreenland Konrad Steffen Univ of Western Australia, 2x05

liquid water is a sort of ‘super molecule’ in which liquid water is a sort of ‘super molecule’ in which hydrogen bonds between molecules are fully 1/3 as hydrogen bonds between molecules are fully 1/3 as strong as the interior bonds of each molecule….and strong as the interior bonds of each molecule….and

hence we have lifehence we have life

water evaporates from the Great Lakes when cold north winds blow over them. It soon condenses back into water, as cloud droplets which then rain or snow out…The lake water has become cloud, and then the cloud piles up as deep snow, downwind of the lakes. This is called ‘lake-effect snow’.

Meehl et al. Geophysical Research Letters 2005

change in rainfall predicted for last 20 yrs of this century…stripes of dry and wetwhich are similar to the present dry and wet regions…everything gets more extreme!

the legendary Ogallala aquifer supports much of the the legendary Ogallala aquifer supports much of the agriculture in dry central US regions..yet is depleting rapidly agriculture in dry central US regions..yet is depleting rapidly

((1/5 the irrigated land in US, 40% of our cattle drank its water in 1970s1/5 the irrigated land in US, 40% of our cattle drank its water in 1970s) ) 40 to 100m below surface; water dates from last ice age40 to 100m below surface; water dates from last ice age

thickness 0 – 300m. Decline of 9% between 1950 and 2005 thickness 0 – 300m. Decline of 9% between 1950 and 2005 ((WikipediaWikipedia))

As China moves toward industrialization and a diet with As China moves toward industrialization and a diet with more meat, it begins to use much more water, grain and more meat, it begins to use much more water, grain and

other resources. The world grain harvest, once with a other resources. The world grain harvest, once with a big surplus, seems to be turning into a deficit state.big surplus, seems to be turning into a deficit state.

xxx gallons of water to raise 1 lb of beef:xxx = 5000 (environmentalist), or 435 (National Cattlemens Assoc.) www.beef.org

Lec 6 estuariesLec 6 estuaries

http://green.kingcounty.gov/WLR/Waterres/hydrology/GaugeMap.aspx

Segar, 2007text

lab model of the conveyor belt lab model of the conveyor belt circulation in an estuarycirculation in an estuary

open ocean river input

Parker MacCready, UW Oceanography

time

Haug et alNature 2006

Deep timeDeep timeshowing theshowing thecooling of thecooling of theEarth since theEarth since theend of the end of the Creaceous period Creaceous period (the dinosaur era).(the dinosaur era).There was little or noThere was little or nosnow or ice on Earthsnow or ice on Earththen. Abruptly, about 2.5then. Abruptly, about 2.5million years ago,million years ago,the curve startsthe curve startsoscillating wildly:oscillating wildly:the beginning of thethe beginning of theice ages ice ages

Vogelherd horse carved 32,000 years ago from mammoth tusk. This, Vogelherd horse carved 32,000 years ago from mammoth tusk. This, along with the cave paintings in France and Spain, represent the along with the cave paintings in France and Spain, represent the

earliest discovered art works of humans. This was the peak of the last earliest discovered art works of humans. This was the peak of the last ice age, when glacial ice must have been just north of the site of this ice age, when glacial ice must have been just north of the site of this

art. Development of human intelligence may have occurredart. Development of human intelligence may have occurredat times of extreme climate and climate change.at times of extreme climate and climate change.

What is our place among the millions of species on What is our place among the millions of species on Earth…the only known life of the Universe?Earth…the only known life of the Universe?

Top predator? Sentinal species? Fellow traveler on Top predator? Sentinal species? Fellow traveler on Spaceship Earth?Spaceship Earth?

Whaling by the Inupiat natives of Alaska’s north slope (image by Whaling by the Inupiat natives of Alaska’s north slope (image by Charles Wohlforth, author of Charles Wohlforth, author of The Whale and the Supercomputer. The Whale and the Supercomputer. These bowhead whales weight about 100,000 lbs and may live in These bowhead whales weight about 100,000 lbs and may live in

excess of 200 years. This says something about the stability of their excess of 200 years. This says something about the stability of their environment.environment.

destruction of forest catchments, aquifers and natural rivers, with their regional economies, commodification of water are acts of terrorism

an historian’sview: evolutionarystrategies of rats and sharks:do we adapt orremain intoxicatedby cheap energy?

of the 5 major reasonscivilizations succeed orfail, the environmentis central to 3 and involvedin all 5

how was theworld beforewe arrived? Howquickly will itrepair if we aregone?

can-do: solutions found by working through the profit system, investing in the environment as one values other capital; biomimicry, closed cycle industries, with zero net imprint on the biosphere, service-flow economies… Hawken, Lovins & Lovins, Natural Capitalism, Rocky Mountain Institute, Colorado www.natcap.org