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NATS 101: Class Notes |
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11. Mon. Feb. 10 |
21. Wed.
Mar. 5 22. Fri. Mar. 7 23. Mon. Mar. 10 |
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Turn off your cell phone! Syllabus handed out and key points reviewed; course web site (under construction at www.ltrr.arizona.edu/nats101) explored; Daily readings from Mackenzie textbook are listed in syllabus, but additional readings will be announced and made available through course web site; 2 questions on first quiz will come from list of questions at end of syllabus. Class roll was obtained by passing around lists where students indicated their presence Mention of some of the class content (examples of great concern with cooling temperatures in the 1970s; the graph of changing atmospheric CO2 concentration since 1958 that some have called the most important graph of the 20th Century; the graph of changing CO2 concentration over the last 12000 years) Global Change IQ quiz given in last 10 minutes to get some idea of prior global change knowledge of students coming in to class. (no grades will be assigned) Note: 15 student volunteers are needed to be group activity group leaders (eligible for 5 points extra credit)- send e-mail with your interest to sleavitt@ltrr.arizona.edu Note: Everyone should send Li Cheng (lcheng@ltrr.arizona.edu) a message indicating what e-mail account you would like us to use for the course listserve forum (deadline 5pm Jan. 29) This is a course requirement. |
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Fri. Jan. 17, 2003 | |||||
Hand-out (atom size [diameter, mass], moles, speed of light, conversions, etc) Intro to grand story of epic proportions (sort of like Star Wars, Bible,
etc) known as The Cast of characters Characteristics of matter Isotopes of a given element have same number of protons,
but different numbers of neutrons |
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Wed. Jan. 22, 2003 | |||||
Handout of Laws of Thermodynamics
and Terrestrial and continental productivity animation over 3 years from satellite composites in “Colors of Life” web link (http://www.gsfc.nasa.gov/gsfc/earth/environ/carbon/carbon.htm) Student Conservations Association information (www.theSCA.org) internship opportunities Finish questions on worksheet handed out last time (conversions, scientific notation) Back to epic story in Periodic Table of Elements: Only 2 elements, H & He, were formed in “Big Bang” 15 billion years ago when all matter in universe was contained at a point (“singularity”). Only H and He formed because universe was rapidly expanding (cooling) and there were progressively fewer interactions between atoms, neither of which was favorable to formation of heavier elements. Thus, the carbon (C) atoms in your hair and Gold (Au) and silver (Ag) atoms in your teeth did NOT form during the Big Bang. Elements from
lithium (Li) to iron (Fe) produced in the interior of normal
stars by “fusion” processes, i.e., lighter elements being combined to
manufacture heavier elements. For
example, in our Sun, fusion takes place converting 4 hydrogen atoms to
one helium atom; the mass of the helium atom is less than the 4 hydrogens,
so the difference in mass is what was converted to energy that contributes
to the internal heat of the Sun (E=mc2).
The energy from such nuclear reactions (involving nuclei of atoms)
>> energy from chemical reactions (involving electrons of atoms). |
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Fri. Jan. 24, 2003 | |||||
Periodic Table (cont’d) Observations of the Cosmos that fit Big Bang formation of 2 elements in Periodic Table: 1. High cosmic abundance of H and He; abundance generally declines with increasing atomic number but there is also a peak at Fe (iron) 2. Galaxies moving away from us at high speeds; the more distant the faster they are moving away (Hubble telescope deep-space images; Doppler effect and shift to lower frequency and longer wavelength electromagnetic radiation as source moves away from observer; distinct absorption lines of light wavelengths by sodium atoms lead to observation of "red shift") Eye-popping, jaw-dropping, awesome demonstration of the Big Bang, in full special effects mode with Dolby® Surround-sound®, and 3-D glasses The fusion taking place in the Sun and other stars represents a tremendous energy source, and research has been directed at trying to promote controlled fusion reactions on Earth as a limitless source of energy (The world already has many fission reactors in which large radioactive elements such as uranium, decay and release energy) Elements up to Iron can be produced by fusion because energy is released; Elements beyond (heavier than) iron cannot be produced by fusion, but can be produced by high fluxes of neutrons, such as occur when stars explode (supernova). Our sun has all of the elements of the Periodic Table, therefore it must have formed from remnants of other stars that have gone through their full life-time of fusion reactions and explosive instabilities Laws of Thermodynamics First Law- Energy cannot be created or destroyed, but it can be converted from one form to another (examples of energy- heat, like, kinetic energy, electrical energy, potential energy of petroleum, food and gravity) Second Law-
No energy transformation is 100% efficient or Energy can be converted from
one form to another but in all conversions there is formation of some
‘low quality’, ‘non-usable’ heat or Heat cannot be completely
converted to work or Universe runs down as energy is dispersed to low-quality
heat energy or All systems tend to become
random (or dispersed) on their own. Entropy
is a measure of randomness, or dispersion or disorder |
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Mon. Jan. 27, 2003 | |||||
The quiz Wed will be given in the first 20 minutes (maybe 25 minutes) of class, with lecture to follow
in remainder of period. There
is sample quiz on web page. Origin
of Solar System |
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Wed. Jan. 29, 2003 | |||||
Wed. Jan. 29 Quiz 1 from about 12:02 to 12:20 after class took randomly
assigned seats. Law of Universal Gravitation- example of gravitational force exerted by nearest star (other than Sun) on you at birth vs. the gravitational force exerted by the doctor who delivered you. Structure of the Earth |
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Fri. Jan. 31, 2003 | |||||
Presentation
about the Student Conservation Association intern program by Dan Pascucci,
which finished with a rousing song designed to help us remember www.theSCA.org |
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Mon.Feb.3, 2003 | |||||
Quiz 1 handed back and answers given and discussed (+1 grade adjustment added to raw score) Make-up opportunities for GA #1- Students asked to provide availability for BOTH 1-2 Wed and 9-10 Friday for POSSIBLE make-up. Send your availability by e-mail to sleavitt@ltrr.arizona.edu Structure of the Earth Differences
in chemistry among layers (for example low SiO2 in mantle and higher in
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Wed.. Feb. 5, 2003 | |||||
Reminder
of GA1 make-ups today 1-2pm and Friday 9-10am (room 104 W. Stadium) Major
natural global change events in the first 4.50 billion years of Earth
history- |
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Fri. Feb. 7, 2003 | |||||
Demonstration
of the relationship of temperature, pressure and volume for gases, known
as the |
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Mon. Feb. 10, 2003 | |||||
A handout
involving energy and electromagnetic radiation. |
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Wed. Feb. 12, 2003 | |||||
Reminder to bring in 2-3 pages about your country’s water
resources to Friday’s GA2. |
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Fri. Feb. 14, 2003 | |||||
Group Activity 2- water resources around the world
and in Tucson Graded and unclaimed quizzes and writing exercise were handed back in GA packets |
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Feb. 17, 2003 | |||||
Sample quiz 2 is now on course web page (answers will be sent to listserve
and posted on web |
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Wed. Feb. 19, 2003 | |||||
Reminder of GA2 make-ups Friday at 9am (room 104 W. Stadium,
water issues research responsibility=KENYA) and 1pm (room 330 Space Sciences,
research responsibility= DOMINICAN REPUBLIC; also, everyone should bring
drinking water sample) Quiz 2 (20-25 minutes) Water cycle Handout of Properties of water Strong covalent bonds between hydrogen and oxygen "Polar" water molecule (which has a "positive" side and "negative" side) promotes cohesion, adhesion, capillary rise (water pulls itself upward in small tubes because of cohesion and adhesion), and surface tension Latent heat- 600 cal heat required to evaporate 1 g water (major mechanism of heat transfer from Earth's surface to atmosphere) Specific heat- 1cal of heat energy will raise temperature of 1 g of water 1C. Most other substances, eg ,metals, sand, have lower specific heat A measure of the amount of material dissolved in water is TDS (total dissolved solids)- it ranges from 0 parts per million (pure distilled water) to Tucson water (300-700 ppm), to ocean water (35,000 ppm also called 35ppt), to Dead Sea (200,000 ppm) Results of water analysis of all groups (conductivity ranged from 60 [Sam's Club] to 720 [Scottsdale]. All samples (about 5) from Coronado Dorm were fairly close in pH and conductivity indicating good reproducibility of results. pH was between 6 to 8 for all samples (pH=7 neutral, pH<7 acidic, pH>7 alkaline), and water from terrains with carbonate rocks (limestone, caliche) expected to have pH 7-8. With respect to conductivity, high values (high concentrations of dissolved salts) or low values (low concentrations of dissolved salts), this alone may not determine water quality. The specific dissolved ions could be more important to health issues. |
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Fri. Feb. 21, 2003 | |||||
Hand back quiz 2 and other unclaimed work; Quiz 2 answers
discussed; In-class writing exercise next Wednesday Pattern of latitude precipitation- highest at equator, and secondary peaks at about 45-55° latitude; minima at about 30° latitude and 90° latitude More Properties of water Attempted demo of capillary rise effect with tubes of different size openings. As water cools density increases to 4°C (39°F), and with further cooling density decreases- this contributes to lakes that freeze from the top down in the winter (rather from the bottom up) Water can dissolve many different types of substance such as salts (like table salt), polar compounds (like carbohydrates and proteins), and non-polar substance (like CO2 and O2) More salts and polar compounds can be dissolved in water at higher temperature, but non-polar gases are less soluble in water at higher temperatures. Water chemistry- differences in cation and anion concentrations in rainfall, rivers and sea water (that have progressively higher TDS). Some observations: 1. In rainfall, Na+ and Cl- tend to be high near coasts but lower inland (from oceans) 2. Ca++ and HCO3- tend to dominate in rivers even though they do not dominate rainfall (as water percolates through soil and rocks, Ca++ is being weathered and added to water, and very high CO2 in soils [from respiration] dissolves in the percolating water to produce high HCO3-. That percolating water eventually ends up in rivers with all the extra dissolved ions) 3. Na+ and Cl- dominate ocean because they are constantly added to oceans from the rivers, but there are few mechanisms to remove them Oceans Surface currents- driven by wind; flow in semicircular patterns known as "gyres"; high pressure drives air circulation that drives gyres; direction of circulation is different in the North and South hemispheres; California Current, Gulf Stream |
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Mon. Feb. 24, 2003 | |||||
Reminder of in-class writing exercise Wednesday In preparation for the group activity on Friday, 1. think about how much beef you eat per week 2. read the summary about "Beef nutrients work as hard as you do" at the following web site: http://www.teachfree.com/dsp/dsp_locationContent.cfm?locationId=1343 3. also read the summary about feeding the US population on the following web site: http://www.news.cornell.edu/science/Aug97/livestock.hrs.html 4.bring calculator Gulf Stream and mild climate of British Isles and Scandinavia (compared to more extreme climate of Virginia to Massachusetts where first European settlers arrived) "Upwelling" of nutrient-rich deep water along S. American coast and nutrients to support food webs El Niño and currents in S. Pacific El Niño tends to recur in irregularly from 2-7 years, and strength varies among events. It is related to atmospheric and ocean circulation in the tropical Pacific Ocean (see diagrams in textbook and http://www.pmel.noaa.gov/tao/elnino/nino-home.html) Evidence for El Niño events Thick, warm water pooled on east side of Pacific Reduced upwelling off S. American coast and fishing crash Higher sea level in east Pacific than west SOI (Southern Oscillation Index) negative (the atmospheric pressure at Darwin is greater than Australia) Westerly winds (west to east winds) in Pacific near equator High precipitation in Ecuador/Peru; Low precipitation in Australia/Indonesia During La Niña events conditions are opposite of those listed above. "ENSO" (El Niño/Southern Oscillation)- during El Niño events, there is increased precipitation along Peru and Ecuador, but there is reduced precipitation in Amazon, so it is ripe for fires just like the rainforests in Indonesia during El Niños (the opposite occurs during La Niñas The 1982-83 and 1997-98 events were the "El Niño's of the Century" "Teleconnections" are the influence of El Niño outside of the confines of the Pacific Ocean Basin; these include statistical correlations of El Niño with climate of diverse locales such as climate effects in the US Southeast and Northeast, eastern S. America (including the Amazon Basin), India, and Africa. In addition to El Niño, there is evidence of other cycles on longer scales that may influence Pacific climate and teleconnect elsewhere, including PDO (Pacific Decadal Oscillation) Fire and southwestern US climate (http://www.ispe.arizona.edu/climas/learn/fire/index.html) Tree rings record fire events with scars, so dates and extent of fires can be reconstructed. |
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Wed. Feb. 26, 2003 | |||||
Second in-class writing exercise, last 25 minutes on El Niño
and southwestern fire (link in Feb. 24 classnotes; instructions for preparation for GA3 appeared in Feb. 24 classnotes El Niño teleconnection to US Southwest results in cooler & wetter winter/spring conditions, which are not favorable to forest fires because fuels are moist and do not dry out rapidly Deep ocean currents ("thermohaline circulation", "oceanic conveyor belt") Requires dense water to start cycle by sinking Dense water achieved by (1) cooling or (2) increase in salinity through (2a) evaporation or (2b) freezing Densest water forms in Arctic and Antarctic areas of ocean, where there are cold temperatures and salinity greater than 35permil (35 parts per thousand=the average of ocean water) The excess salinity in N. Atlantic contributes to sinking of dense water that then moves as a deep current through the S. Atlantic Ocean, Indian Ocean and Pacific Ocean before rising and returning as a warm-water surface current back to the N. Atlantic (to replace water that has sunk to the deep currents) Thermohaline circulation transports heat and salinity (salt) as nature tries to even out these imbalances around the world ocean. |
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Fri. Feb. 28, 2003 | |||||
Group Activity 3- Beef consumption and production. All unclaimed, graded work was returned in folders for students present to pick up, including GA2. |
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Mon. Mar. 3, 2003 | |||||
Writing Exercise
introduced (handout); Topics
were assigned to each student (this info is on |
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Wed. Mar. 5, 2003 | |||||
Graded in-class writing exercise 2 was handed
back, and both parts of the exercise were discussed; if you can't read comments or if you have questions, see Prof. Leavitt. Sample quiz 3 is on web page; Quiz 3 is Friday at beginning of class Two primary groups of organisms- prokaryotes, eukaryotes Biosphere "biotic components"- trophic (nourishment) levels [1-primary producers=autotrophs; 2-primary consumers=herbivores(heterotrophs);3-secondary consumers=carnivores(also heterotrophs); 4-decomposers] Food chains and food webs: 90% loss of energy going from one trophic level to the next level above it Energy consequences of "eating low" on the food chain Biosphere "abiotic components"- climate, nutrients (eg, C,O,H,N,S), sunlight, water Examples of prose that illustrate how to put the best foot forward in selling something (restaurants, resorts, art exhibits) |
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Fri. Mar. 7, 2003 | |||||
Quiz 3 (ended about 12:20am); handout of biomass/productivity
and dry matter distribution in biomes YES, A LECTURE DID FOLLOW THE QUIZ; AS IT WILL FOLLOW ALL QUIZZES More writing: 1- For first assignment on March 26 (references part), make sure any web references (URL addresses) are given in sufficient detail that anyone can find the exact page that you accessed; also given the sometimes short shelf-lives of web addresses, in addition to title, author and web address, give the date you accessed the page; 2- examples of how poison is sold to hundreds of millions with positive imagery and a few choice persuasive words; 3- examples of writing to avoid using "there is" and "there are" Abiotic and biotic components comprise biosystems (ecosystems) Large, easily identified community units are known as "biomes"; interaction of biota and climate on a regional scale. Biomes around the world, such as grasslands (fig. 4.8; table 4.3) A closer look at abiotic factors of nutrients (eg, major nutrients C,O,H,N,S,P and minor nutrients K, Ca, Fe, Mg) and climate; world climate classification map (has biome elements) Distribution of dry organic matter in biomes (living=leaves,trunks/stems,roots + dead=litter, soil organic matter)- Contrast of grassland and tropical rainforest biomes that are similar in total organic matter, but differ in distribution (handout) Biomass is mass of living organisms (= phytomass + zoomass, which is approximately equal to phytomass alone) (mass/volume; mass/area) |
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Mon. Mar. 10, 2003 | |||||
Handed back quiz 3 and went over answers; also handed back GA3 and other unclaimed graded work; handout of global carbon cycle Study recommendation- sample quizzes, real quizzes, your lecture notes, my lecture synopses on course web page, readings, group activities; it will be through today’s lecture. There will be review session Tuesday, 4:15-5:30 in room 308 Space Sciences next to our classroom; It will be driven by the questions of those who come. Primary productivity is amount of plant matter produced [by photosynthesis] (per area per time) Gross Primary Productivity (GPP) is total production Net Primary Production (NPP) = GPP-respiration losses Biomass in oceans is about 0.5% of biomass on continents, but NPP in oceans is almost 1/2 of NPP on continents. Biomass is needed on continents to provide support to reach light, and therefore the continental biomass is dominated by structural components (CHO). Marine biomass does not need the structural components, tends to have a higher ratio of proteins to carbohydrates, and have much shorter life spans than terrestrial organisms Modern systems have great abundance of species (especially insects), but extinction rates seem to be high. There have been massive extinctions in the past, unrelated to human activity: Permian-Triassic extinction event the largest of the 6 major extinction in the Phanerozoic (last 600 million years); evidence from geological record suggesting the possibility it was driven by large volcanic eruptions (Siberian traps) or meteorite/comet impact. Evidence suggests loss of land plants and lots of sediments, and many "Bucky Balls" (fullerenes) containing inert gases whose isotopic composition suggests extraterrestrial origin. "Box Models" of biogeochemical cycles require defining the system and subsystems including the reservoirs (compartments, pools) and predicting and evaluating paths and fluxes between reservoirs. Carbon cycle cartoon diagram and box model, showing different reservoirs and primary forms of carbon [atmosphere= CO2, CO, CH4; hydrosphere= HCO3-, CO3-, dissolved CO2; biosphere= CH2O; lithosphere= limestone (CaCO3) and kerogen (oil, coal, and finely dispersed organic matter)] Terminology: reservoirs/compartments=places where element/compound resides; flux/flow/transfer=rate of movement between reservoirs Mean residence time (MRT)= reservoir size/flux in (or out) Turnover rate= flux in (or out)/reservoir size Sample calculation of MRT of carbon in atmospheric reservoir of global carbon cycle |
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More will be added.... |