Global Hyrdological Cycle

Global Hyrdological Cycle - ISP 217 ISP 217 Global...

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Unformatted text preview: ISP 217 ISP 217 Global Hydrologic Cycle and Global Energy Dr. Peacor 1 GREAT LAKES Invasive Spiny Water Flea: Bythotrephes 2 Hydrologic Cycle Hydrologic Cycle Circulation and conservation of the earth’s water: Crucial to our lives and the earth’s ecosystems 3 Hydrologic Cycle Hydrologic Cycle Basic Overview Water vapor condenses to form clouds which result in precipitation when the conditions are suitable. Precipitation falls to the surface and infiltrates the soil or flows to the ocean as runoff. Surface water (e.g., lakes, streams, oceans, etc.), evaporates, returning moisture to the atmosphere, while plants return water to the atmosphere by transpiration. 4 Today’s Lecture: Two extreme options for your participation in class today: Option 1: So it rains, big deal. ISP 217. Hope class ends early and the class exercise is not too hard. Option 2: Cool. I always wondered what was up with rain. Why doesn’t the water just eventually stay settle to the ocean and stay there? Why does the water keep moving around? Rain and water movement drive agriculture, recreation and so many things that affect my life. In fact, without the hydrological cycle, I wouldn’t exist. This might be interesting…. 5 Hydrologic Cycle has many processes -Condensation -Precipitation -Infiltration -Runoff -Evaporation -Evapotranspiration -Atmospheric Advection 6 Condensation is the process of water changing from a vapor to a liquid. Water vapor in the air rises mostly by convection. This means that warm, humid air will rise, while cooler air will flow downward. As the warmer air rises, the water vapor will lose energy, causing its temperature to drop. The water vapor then has a change of state into liquid or ice. Formation of clouds 7 Condensation Condensation Condensation Condensation 8 Condensation Condensation 9 Condensation Condensation Cold soda can “sweats” Water vapor from air is hitting the cold surface and condensing 10 Precipitation Precipitation Precipitation is water being released from clouds as rain, sleet, snow, or hail. Precipitation begins after water vapor, which has condensed in the atmosphere, becomes too heavy to remain in atmospheric air currents and falls. 11 Precipitation over ground: Global Hydrologic Cycle Global Hydrologic Cycle Precipitation 3 From: Boktin and Keller 12 Global Hydrologic Cycle Precipitation 3 Precipitation over water (sea) From: Boktin and Keller 13 Evaporation occurs when radiant energy from the sun heats water, causing the water molecules to become so active that some of them rise into the atmosphere as vapor. Evapotranspiration is water evaporating from the ground and transpiration by plants. Evapotranspiration is also a way water vapor re­enters the atmosphere. 14 Evaporation & Evaporation & Evapotranspiration 15 Global Hydrologic Cycle Global Hydrologic Cycle Evaporation 3 Evaporation over water (sea) From: Boktin and Keller 16 Global Hydrologic Cycle Evapotranspiration Evapotranspiration over land 3 From: Boktin and Keller 17 Global Hydrologic Cycle Global Hydrologic Cycle Up and down 3 3 3 361,000 3 (361,000 + 62,000) – (324,000 + 99,000) = 0 From: Boktin and Keller 18 Global Hydrologic Cycle Global Hydrologic Cycle 3 3 3 ??? 361,000 3 From: Boktin and Keller 19 Infiltration Infiltration A portion of the precipitation that reaches the Earth's surface seeps into the ground through the process called infiltration. The more openings in the surface (cracks, pores, joints), the more infiltration occurs. 20 Run Off Run Off Precipitation that reaches the surface of the Earth but does not infiltrate the soil is called runoff. Runoff can also come from melted snow and ice. When the soil is saturated, rainfall can no longer enter it. Runoff will eventually drain into creeks, streams, and rivers, adding a large amount of water to the flow. 21 22 Global Hydrologic Cycle Infiltration and runoff 3 Infiltration and runoff *This is 8.5% of total rainfall over land + sea. 23 From: Boktin and Keller Atmospheric advection Atmospheric advection Water in atmosphere (clouds) is transported by wind from over sea to over land, and over land to over sea. 24 Global Hydrologic Cycle Advection 3 3 Atmospheric advection 3 Infiltration and runoff From: Boktin and Keller 25 Global Hydrologic Cycle Global Hydrologic Cycle 3 3 3 Rates, Flows 361,000 3 From: Boktin and Keller 26 Global Hydrologic Cycle Global Hydrologic Cycle 3 3 3 Rates, Flows 361,000 3 Question: But what about absolute AMOUNTS? What % of the earth’s water is held in different areas? 27 Rates and amounts (reservoirs) Rates and amounts (reservoirs) Atmosphere 13,000 km3 Precipitation 99,000 km3/year Evapotranspiration 62,000 km3/year Evaporation 361,000 km3/year Precipitation 324,000 km3/year Land 33,600,000 km3 Oceans 1,350,000,000 km3 Runoff/Groundwater 37,000 km3/year 28 Amount of water on earth: 326,000,000,000,000,000,000 gallons or “326 million trillion gallons” Metric: 1,260,000,000,000,000,000,000 liters. 29 Flows (rates) versus amounts (reservoirs): There is a lot of movement of water back and forth from the atmosphere to the sea, but the actual amount held in each is very unequal, with a relatively very small amount in the atmosphere at any given point in time. 30 Human Impact on Global Hydrologic Cycle Example: Humans have large impact on hydrological cycle Deforestation for agriculture and development Decreased infiltration, increased run off Increased flooding Great destruction and thousands of deaths. So, is flooding a “natural disaster” if humans were largely responsible? 31 Global Hydrologic Cycle Global Hydrologic Cycle Ground Water Component Closer Look From: Boktin and Keller 32 Groundwater Groundwater Aquifer = Porous layer of soil which becomes saturated with water. 33 Groundwater Groundwater Aquifer Types 1. Unconfined Aquifer = Aquifer which has water entering it from land above it. Top layer of saturated soil is called Water Table. Unsaturated soil above Water Table is called Vadose Zone. Water is not under pressure 34 Groundwater Groundwater Aquifer Types 1. Unconfined Aquifer 2. Confined Aquifer = Aquifer that is bounded on top and below by impervious rock or soil (an Aquiclude). Soil is saturated and under pressure. 35 An aquitard is a zone within the earth that restricts the flow of groundwater from one aquifer to another. Aquitards are comprised of layers of either clay or non­porous rock. 36 Aquifer Types From Enger and Smith, 2002 37 Ground Water Extraction Ground Water Extraction 38 Ground Water Extraction Ground Water Extraction Aquifer (water porous layer) no longer supports the rock 39 Mexico City is sinking a few inches each year! This causes historic buildings cracking and other problems. Cause: depletion of water in aquifer due to lake drainage and city use. 40 Aquifer Depletion Aquifer Depletion Global Problem Ogallala Aquifer in central U.S. Recharge is 10% of annual withdrawal! Structure of porous material is changing, limiting the potential for recharging permanently. Could affect future of America’s breadbasket 41 ew N su t ec bj Earth’s Energy Supply Earth’s Energy Supply Earth Receives Energy In Form Of Solar Radiation Solar Radiation Has Wide Wavelength Spectrum Human Eye Is Sensitive To Only Visible Portion Of Electromagnetic Spectrum 42 Sun’s Energy Sun’s Energy Thermal energy received from the sun is transferred throughout the world via wind and water currents The three different types of energy that drive weather: • radiation (from the sun) • thermal (heating of water and air) • mechanical (wind and water currents) 43 The radiation that we receive from the sun is transferred from radiant energy into thermal (heat) energy and then to mechanical energy (wind and water currents). 44 Electromagnetic Spectrum Electromagnetic Spectrum The electromagnetic spectrum is a continuum of all electromagnetic waves arranged according to frequency and wavelength. 45 Electromagnetic Spectrum Electromagnetic Spectrum Why do our electromagnetic radiation sensors perceive electromagnetic energy in the wavelength range of 400nm to 700nm? (400x10-9 m to 700x10-9m) (0.0000004 m to 0.0000007 m) 46 Electromagnetic Spectrum Electromagnetic Spectrum 50% of All Solar Radiation 1 nm = 10-9 m From: Cunningham, Cunningham and Saigo, 2003. 1 µm = 10-6 m 1 mm = 10-3 m 47 Electromagnetic Spectrum Electromagnetic Spectrum UV light: Most Blocked By Ozone & O2 1 nm = 10-9 m From: Cunningham, Cunningham and Saigo, 2003. 48 UV radiation UV radiation Harmful and Helpful effects Essential role in formation of Vitamin D by the skin Sunburn on human skin and cataracts in our eyes. Can cause damage at the molecular level to the fundamental building block of life— deoxyribonucleic acid (DNA). 49 Electromagnetic Spectrum Electromagnetic Spectrum Infrared light: 1 nm = 10-9 m From: Cunningham, Cunningham and Saigo, 2003. 50 Electromagnetic Spectrum Electromagnetic Spectrum Heat produces infrared radiation (IR). We can’t see it, but there are IR detectors: 51 Infrared Vision Infrared Vision “Heat vision” Rattlesnakes and other pit vipers use infrared sensory organs to detect and hunt warm­blooded prey. These infrared "eyes" are cuplike structures that can “see” infrared radiation, which is emanated by warm objects. 52 Electromagnetic Spectrum Electromagnetic Spectrum Water Starts Absorbing Energy At 12-15 µm, in IR range. 53 Why Does IR Warm Water? Why Does IR Warm Water? 12 IR µm O H H Incoming IR radiation makes the atoms within H20 molecules vibrate more. In this way, water adsorbs IR radiation and heats up. 54 Electromagnetic Spectrum Electromagnetic Spectrum Water Absorbs EMR From a really wide spectrum: 12 µm to over 1,000,000 µm Therefore Water (or Water Vapor) Can Absorb Lots of Energy 55 ...
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This note was uploaded on 03/23/2010 for the course ISP 217 taught by Professor Peacor during the Spring '08 term at Michigan State University.

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