1 Degree C Per Meter Ocean Water example essay topic

- The pump found in the tropical oceans is responsible for the movement of air and the surface ocean over most of the globe. The energy source that drives this pump is solar radiation from the sun. - The second pump is the deep ocean circulation which is also driven by the sun. - The third pump is the heating of the earth's interior by radioactive decay and radiation of heat causes plate tectonics and continents to move. This long term pump has ceased in Mars.

- The winds and ocean currents redistribute the energy received from the Sun- Air moves from high pressure areas to low pressure areas horizontally due to horizontal differences in pressure. - As a parcel of air warms up it becomes more buoyant and the air rises. Warmer air has less density. - Pressure differences among air masses are typically related to the distribution of surface temperatures- The radiation reaching the Earth is spread over larger and larger areas as we move from the equator to the poles. You get more light per unit area at the equator than at high latitudes. - The incoming solar radiation varies with latitude and seasons, whereas the outgoing terrestrial radiation depends on the temperature at the surface and atmosphere.

- Primary causes for temperature distribution on earth are because it's warmer at the equator and colder at higher latitudes. - The solar radiation absorbed at the surface varies with cloud cover and atmospheric absorption. - Heated air rises at the equator causing air to move towards the equator. This converging air makes up the inter tropical convergence zone. - Rising air cools which causes it to loose its water in the form of rain. - Areas of rising air cause low pressures.

- The warmer stratosphere acts as a barrier to the rising warm air causing it to spread out and diverge. As the air diverges it becomes more and more cooler and it sinks at 30 degrees N / S of the equator (Hadley Cell) - Most of the earth's deserts are located at about 30 degrees N / S of the equator. Descending air causes an area of high pressure at this 30 degrees N / S- Hadley Cell: the convergence occurring in the tropics and divergence some 30 degrees N / S of it is called the Hadley Cell. - The Hadley Cell and the ITCZ are not continuous around the globe.

- The equator ward-moving cold air meets the warm air moving poleward from the subtropics producing a zone of steep temperature gradients called the polar front zone at approximately 60 degrees N / S latitude. - Cold air sinks at the poles producing high pressures- Because we have high and low pressure area, we would expect winds to blow out of the high pressure zones at the poles and 30 degrees N / S towards the low pressure zones at the equator and at about 60 degrees N / S. - The east-west movements of surface winds are the result of the Coriolis Effect. - The coriolis effect is a result from forces acting on an object moving on a rotating body- There is no coriolis effect at the equator. - In the Northern Hemisphere, moving objects go to the right and in the Southern Hemisphere moving objects go to the left. - The distribution of surface winds is a combination of heating, pressure gradients, and Coriolis Effect. - meteorologists refer to winds in terms of the direction from which they blow- in mid latitudes (35-55 degrees N / S) you will find westerly winds as a result of air moving towards 60 degrees N / S and coriolis effect- in high latitudes you will find easterly winds- at the tropics (25-5 degrees N / S) you will find easterly winds called the northeast and southeast trade winds as a result of low pressure and coriolis effect- At the equator you will find light winds that change direction frequently.

These winds are referred to as doldrums. - Winds around high pressures in the northern hemisphere flow clockwise aka anti-cyclonic flow. - Winds around high pressures in the Southern Hemisphere flow counter-clockwise aka cyclonic flow- Winds around low pressures in the northern hemisphere blow counter-clockwise aka cyclonic flow- Winds around low pressures in the southern hemisphere blow clockwise aka anti-cyclonic flow- Upper level flow in the atmosphere generally is poleward- The height of the troposphere is greater at the equator (where it is warmer) than at the poles. This creates a pressure gradient force moving air from the equator poleward- The pressure gradient force is balanced by the Coriolis Effect such that the air actually flows at right angles to the pressure gradient.

This is referred to as the geostrophic wind. - Geostrophic flow occurs when the winds move along the lines of equal pressure (isobars). This flow will occur to the right of the pressure gradient in the N / S hemispheres due to Coriolis Effect. In other words there will be westerly components to the flow in both hemispheres. - The seasons are controlled by earth obliquity and earth's orbit around the sun. The hemisphere that is tilted towards the sun experiences summer white it is winter for the hemisphere tilted away from the sun.

- Seasonal effects changes the latitudes of maximum heating from 23 degrees N to 0 to 23 degrees S, which in turn affects pressure gradients and winds- When the Sun is directly overhead the equator you will experience the equinoxes. When the sun is overhead 23.5 degrees N the northern hemisphere will experience summer and longer days. It is likewise for southern hemisphere- The largest N / S temperature gradients occur in the winters of the N / S hemispheres. This is due to the fact that because the sun shines continuously for 6 months at each pole compensates for the fact that the poles do not receive as much solar energy per unit area as do the tropics. This reduced temperature gradient weakens the strength of the atmospheric circulation. Furthermore, because the sun is directly overhead somewhere away from the equator, the maximum solar energy is directed somewhere poleward.

- The ITCZ also moves northward and southward as a result of these seasonal shifts in insolation- The ocean absorbs more solar energy than does land at the same latitude because the Aledo of the ocean surface is considerably lower than the Aledo of most land surface- Thermal conductivity is the rate at which heat energy passes through a column of material that has a temperature gradient along the column of 1 K or 1 degree C per meter- Ocean water has high thermal conductivity so heat is transferred downward and to the atmosphere above by convection- Land has relatively low thermal conductivity so heat is not transferred downward, instead heat is transferred upward rapidly by convection- Heat capacity is the energy required to raise the temperature of a unit mass of a substance by 1 K or 1 C w / o changing its volume. In other words, heat capacity is a measure of how much energy must be added to an object to raise its temperature. - The heat capacity for water is 3-4 times greater then it is for land. Thus the input for a given amount of energy will raise land temperatures much more than it will raise sea surface temperatures.

This is because the amount of surface material that must be warm is greater in the ocean, and secondly there is differential absorption for both surfaces. Whereas, all the solar radiation falling on the land surface is reflected or absorbed right at the surface, some of the solar radiation falling on the ocean penetrates and is absorbed below surface- The sea breeze is a result of land surface heating up quickly during the day and cooling down quickly at night, and ocean surface heating up slowly during the day and cooling for minutely at night. - refers to the phenomenon of continents being warmer during the summer then ocean and oceans being warmer in the winter then the continents. the more continental the climate the more it is characterized by seasonal temperature extremes. - in the summer continents tend to have low pressures- in the winter, continents have high pressures which then lead to colder temperatures and descending air- the monsoon is a seasonal reversal in the surface winds- during the summers in South-East Asia, their is intense convection (rise) of air above the surface, this rising air is replaced by air moving in from the high-pressure region of the Indian ocean to the south. the moist air drawn from the Indian Ocean cools as it rises above the Himalayas. this rising air produces clouds and heavy rainfall. - During the winter in South-East Asia, land is very cold causing high atmospheric pressures; air descends from land to the ocean resulting in dry-cold winds from the NE. - there is much more continental land mass in the Northern Hemisphere than there is in the Southern Hemisphere which results in very little variability in the distribution of winds around the southern hemisphere compared to the northern hemisphere. - both water vapor and clouds are important because they play a dominant role in the global energy balance, they are a significant factor in determining the distribution of fresh water around the globe, and they are highly variable in time and space. - water vapor in the atmosphere equals 7% of the gas in the tropics and near 0% at the poles- Water Vapor is the most important greenhouse gas- the latent heat of vaporization refers to the energy needed to convert liquid water vapor (gas). the amount is 2260 kJ / kg at 100 degrees C. when this process is reversed and changed from gas to a liquid the same amount of energy is released. - the latent heat of vaporization is 6 times greater then latent heat of fusion- to change the temperature of liquid water from 0 degrees C to 100 degrees C you will require 419 kJ / kg- the latent heat of fusion refers to the amount of energy needed to convert ice into water. this amount is 335 kJ / kg at 0 degrees C. when the process is reversed the same amount of energy is released into the environment. - the distribution and movement of water in its various phases has important consequences for the transfer of energy and the global pattern of surface temperatures. - water is essential in weathering rocks and transporting chemicals / nutrients throughout the Earths system- 97% of the water on Earth is in the Oceans, 3% is on land (2/3rd in the form of glaciers-Antarctic ice sheet; which will raise sea level 60 m if it melts and groundwater is the second biggest land reservoir of water) and lastly the atmosphere which contains less then 0.001% of water on Earth- global hydrologic cycle: comprised of the water reservoirs and patterns of water storage and movement throughout the system- rainfall evaporates over land and evaporation creates rainfall over the oceans. this process causes a net transfer of water from land to oceans - precipitation occurs when atmospheric water vapor condenses to form small droplets of liquid water- warm air can hold 3 X the water vapor as cold air- relative humidity is the observed vapor pressure / vapor pressure at saturation- the water vapor pressure when evaporation and condensation are at a equilibrium is referred to as the saturation vapor pressure. - as temperature increases, the saturation vapor pressure increases. - clouds form when the air is at the saturation vapor pressure of water. evaporation add water vapor molecules to the air where they condense to form water droplet in clouds- in clean air we have no cloud condensation nuclei, and even though the relative humidity is 100% (supersaturated) you may have no cloud formation- most rainfall occurs with some sort of uplift or rising of air masses- convection occurs not only in the tropics but also where there is intense surface heating. although convection does not always produce rainfall it is the dominant rainfall-producing process over warm land masses in the summer- three processes of uplift are: large = scale uplift that occurs with the mixing of air masses of different densities, uplift due to convection (causes heavy precipitation in the polar front zone in the mid-latitudes and within the vicinity of the ITCZ), and lastly an uplift occurs when moving air masses encounter mountain ranges. - deserts are located in the vicinity of the descending arms of Hadley cells and on the leeward slopes of mountains Deserts also form where there is a lack of moisture supply due to cold ocean currents that reduce evaporation (desert of Baja California and Namib Desert of Africa). - Ocean circulation is ultimately driven by solar radiation- upwelling of deep subsurface water brings nearly all of the nutrients to the surface ocean for marine plant uptake (this is primary production) - sun warms the lower atmosphere where there are clouds and more gas, which causes vertical circulation. whereas, in the ocean the sun warms the surface (top few 100 meters) causing stratification. the warmer water at the surface of the oceans is less dense then the cooler water at the bottom of the ocean- winds resulting from air rising at the equator causes the Hadley cells to create areas of high and low pressures- water movement due to winds is usually confined to the top 50-100 meters of the ocean- the coriolis effect influences ocean currents just as it does winds. due to the coriolis effect the water is deflected to the right of the path of winds in the Northern Hemisphere and to the left of the path of winds in the Southern Hemisphere. - the effect of the coriolis is greater at the poles and less near the equator- water piles up (converges) in the middle of a gyre in the Northern Hemisphere caused by the Ekman transport. this convergence in the middle of the gyre causes higher sea levels, down welling, and low nutrient supply.

The Sargasso Sea is an example of convergence in the middle of a gyre. low current speeds / light with variable winds made this place hard to explore with sailing ships. - Ekman's Spiral: the deeper below the surface, the further each layer of water is deflected to the right or left of the surface layer above it, producing a spiraling effect- ek man's spiral predicts that the surface ocean current will flow at 45 degrees to the surface wind path, this flow will be reversed at 100 meters below the surface (that is, the current at 100 m will flow in a direction opposite to the surface current), and it will also be considerably reduced in speed, observations show that the surface flow is to the right of the surface wind path, when the movements of all individual layers of water are added the net direction of transport within the water column is at a right angle (90) to the wind direction (aka ek mans transport) - Divergence occurs at the equator and 60 degrees N / S of the equator. divergence causes upwelling, lower sea levels, and large nutrient supply. it is an area of high productivity. - Geostrophic flow is the balance between pressure gradient force (high to low sea levels) and coriolis force. the geostrophic flow is clockwise in the NH and counter-clockwise in the SH. - the sinking of water is a process called down welling- the rising of cooler water to the surface to replace warm, divergent surface water is referred to as upwelling- western boundary currents (gulf stream) are narrow, fast and deep. (50-70 km wide, 1 km depth, speeds of 3-10 km / hr ) - eastern boundary currents are divergent, diffuse, shallow, and wider- differences in eastern and western boundary currents is caused by vorticity (angular rotation along the rotational axis of the Earth.) - the top 100 m of the ocean circulation is driven by winds- deep ocean circulation is driven by density or circulation- deep ocean circulation is aka circulation because it is driven by temperature and salinity- warm water is less dense then cold water- the salinity is greatest in the deep ocean because higher = more salt per volume = more density- the primary constituents of sea water are the ions: Cl, Na, sulfate (SO 4) magnesium (Mg), calcium (Ca), and potassium (K) - the salts in sea water are a result of weathering. they are primarily carried to the ocean by rivers. - salts are removed from the ocean by evaporite deposits, biological process (marine microorganisms use Ca and silicon to form there shells), and burial / interaction with hydrothermal vents. - the Mean Residence Time of salt in sea water is (supply = removal) - Salt in sea water causes the freezing point of sea water to be lower then pure water. (-1.9 degrees C) - density increases as salinity increases and temperature decreases- the surface zone is often referred to as the mixed layer because at this layer interaction takes place through evaporation, precipitation, exchanges of kinetic energy, radiative exchanges, and the exchange of heat. - zone: marked by the transition zone in which there is an rapid increase in density- halo cline: marks the rapid increase in salinity when it dominates rate of density- thermocline: marks the rapid decrease in temperature when it dominates density- bottom water constitutes the densest water produced in the ocean near the sea-ice margin in the polar oceans. - one of the major sites of bottom water formation is the Weddell Sea off Antarctica (Antarctic Bottom Water). Another major site is Labrador Sea in North Atlantic (North Atlantic Deep Water) - 50-100 million years ago deep ocean water was dense because of salt not because of temperature. there was a different circulation and different climate- the circulation time of the conveyor belt is 1000-2000 years from the north Atlantic to the north pacific- the deeper ocean is relatively rich in nutrients. the conveyor belt transfers these nutrients to the surface in areas of upwelling, primarily along the continental margins. consequently, the concentrations of marine life are the greatest in these areas. heat transfer in the atmosphere and the ocean are equal. however, the ocean is more effective in heat transfer at low latitudes (0-30 degrees) and the atmosphere is more effective in heat transfer at high latitudes ( 30 degrees N / S) - the energy that drives the circulation of the solid earth derives not from the Sun but from the interior of the Earth- where continents collide, huge mountain belts form, where oceanic blocks collide with each other or with continents deep-sea trenches and volcanoes form. these plate tectonic forces join with the surface processes of rock weathering and erosion to generate landscapes and recycle elements from solid earth reservoirs into soils, hydrosphere, and atmosphere.

- Alfred Wegener is credited for the theory of plate tectonics. he was fascinated with the near perfect fit between the coastlines of Africa and South America and by correspondence among the geological features, fossils, and evidence of glaciers on these two separate continents. he believed that all the continents were once assembled into a supercontinent and he called this supercontinent Pangea "all Earth". Continental drift is the theory that all the continents begin to break apart 200 million years ago. however his theory was not accepted by other because he didn't understand mechanisms well nor the timing of drift movement- earthquakes create vibrations called seismic waves that ripple through earth's interior. two types of seismic waves are body waves and surface waves. body wave's travel through the earth's interior. surface waves travel only across the surface. - body waves are categorized in P waves or S waves. P waves aka primary waves result from compression of materials in Earth's interior, it travels as a series of compression and expansion. S waves aka secondary or shear waves are transmitted as displacements perpendicular to the overall direction of wave travel; S waves are not transmitted through liquid. - A seismograph detects seismic waves- seismic discontinuities define the core, mantle, and crust. - densities are quite high at the core. the inner core is solid and the outer core is molten and it is the source of Earth's magnetic field. the outer core can convect because a temperature gradient is established across it by heat loss from the solid, inner core. the core is dominated by Fe (iron) and small amounts of nickel. - the mantle extends from the moho to the fluid outer core. moho is the crust / mantle boundary. the mantle is uniform in structure and formed of silicate materials. it the largest by volume and it is made of Mg SiO 4 or olivine- Crust: the earth's upper most layer. it varies in thickness and composition (not homogeneous). continental crust underlies the continents and mainly composed of pink granite. the oceanic crust underlies the ocean basins and is mainly composed of black basalt. - the continental crust and oceanic crust are considered to be igneous rocks. igneous rocks are formed by the cooling and solidification of magma which is molten or liquid rock. if magma solidifies beneath Earth's surface it is called intrusive igneous rocks (granite). is magma solidifies at the surface it is called extrusive igneous rocks (basalt). - compaction and se mentation are processes that contribute to. is the conversing of loose sediments into thick, cohesive, layered deposits known as sedimentary rocks. sedimentary rocks formed from sand-size grains are called sandstones. sedimentary rocks may instead form chemically or biochemically. - metamorphic rocks are igneous or sedimentary rocks exposed under high temperatures and pressures. as long as their is no melting, the rocks are said to be metamorphosed. Ex: marble is metamorphosed limestone and slate is metamorphosed shale. - evidence for Earth's structure is that we see meteorites that are exactly like our core. irons meteorites represent the core. stony-irons meteorites represent the core / mantle boundary. chondrites or stone meteorites represent the mantle or crust. - mid ocean ridges are chains of sub sea volcanic mountains running down the centers of the ocean basins. a rift or narrow valley runs down the center of the ocean ridges. ridge axis is the middle of the rift. - sea floor spreading rates are 2 cm / yr in the Mid Atlantic and about 18 cm / yr from - the E. Pacific rise- spreading rates affects mean depth of ocean basins- continents drift because continents and segments of ocean floor are connected into plates that continuously move away from one another at mid ocean ridges- signatures are found around the spreading centers- life at mid oceanic ridges in based on chemosynthesis and not photosynthesis- sea water sulfate (SO 4) + hot rock - hydrogen sulfide (H 2 S). this H 2 S is given off in hydrothermal vents. hydrothermal vents are found by observing white clams on Black Lava- Bacteria are the base of the food chain which include huge crabs, clams, and tube warms- there are about 20 plates in the lithosphere. (oceanic and continental) - three types of plate boundaries: divergent, convergent, and transform- as a result of friction, there are alternating periods of stasis (stress build up) and periods of movement (when stress is released) both at plate boundaries and near the surface. after a period of stasis pent-up energy is released suddenly as the plates jump past each other, causing earthquakes. hence, the distribution of earthquakes at Earth's surface follows plate boundaries quite closely. - divergent boundaries are where plates are moving away from each other. divergent boundaries that occur on land represent sites of continental fragmentation, or rifting.

Ex: mid-Atlantic ridge- convergent margins are regions where two plates are forced together- oceanic / continental convergent plates - there is a subduction of oceanic plates (Peru trench and Andes Mountains) - Oceanic / Oceanic convergent plates - one oceanic plate subduct's and forms an island arc (Japan) - Continental / Continental convergent plate- mountain building (Himalayan Mountains) - Hot Spot: a big plate moving over the Pacific Plate (Hawaii) - transform faults: plates are slipping past each other (San Andreas Fault) - Heat driving plate tectonics form from radioactive decay and residual heat- radioactive decay (U, K, Th) in plate tectonics is 5 times less than when earth formed.