11/18/2015ISOFS1 By Russell Vallimont Climate Modeling GEOG671 With Mace Bentley, PhD Foundations for Analyzing Climate Change in the 21 st Century

Outline What is climate? Looking at Earth’s Climate System Where solar output is constant Causes for variations in Earth’s Climate Why model Earth’s Climate System? What is required? Foundations for Analyzing Climate Change in the 21 st Century

16 January 2005 Lennart Bengtsson Celsius lecture 2005 Uppsala Unversity What is climate? There is a distinction between weather and climate Weather describes the conditions of the atmosphere at any given point in time As such, weather reflects aspects of the distribution of heat over short periods of time (1 to 14 days) Climate is a comprehensive statistical description the Earth’s warmth over a longer period of time Climate describes aspects of the distribution of heat through weather over designated periods of time ( years) In popular terms, climate is what one expects the weather to do based on the collected data over time and statistics, whereas weather is what one actually gets, and presents as the data of a given point in time

Looking at Earth’s Climate System Incoming Solar Energy (A) = Outgoing Reflected Energy (B) + Energy retained by Weather Conditions & Activities (C) Climate is one of Earth’s Systems which transforms energy from Solar Radiance into heat which in turn causes the Atmosphere to exhibit weather conditions.

Looking at Earth Climate Systems: A Average incoming UV Solar Radiation 100%=342 W/m^2 Average incoming UV Solar Radiation 100%=342 W/m^2 UV Reflected back to space 20% = 70 W/m^2 by Cloud Cover UV Reflected back to space 20% = 70 W/m^2 by Cloud Cover UV Absorbed by the Atmosphere 20% = 70 W/m^2 UV Absorbed by the Atmosphere 20% = 70 W/m^2 Total Outgoing as UV Reflected 30% = 102 W/m^2 Total Outgoing as UV Reflected 30% = 102 W/m^2 UV Reflected back to space 6% = 20 W/m^2 by Atmosphere & Particulates UV Reflected back to space 6% = 20 W/m^2 by Atmosphere & Particulates Outgoing UV = 102 Retained Heat =240 Total Incoming UV = 342 Outgoing UV = 102 Retained Heat =240 Total Incoming UV = UV Absorbed by Earth’s Land & Water Surface 50% = 170 W/m^2 UV Absorbed by Earth’s Land & Water Surface 50% = 170 W/m^2 This yields 254 K (= -19 Celesius = -3 Fahrenheit) UV Reflected Back to space by Surface 4%=12 W/m^2 UV Reflected Back to space by Surface 4%=12 W/m^2 Incoming Radiant Energy

11/18/2015ISOFS6 Solar Rays Change States of Energy in biogeochemical activity ATMOSPHERE Ozone Cycle Greenhouse Action HYDROSPHERE Hydrologic Cycle BIOSPHERE Photosynthesis LITHOSPHERE Photochemical Transformations Drives Biogeochemical Cycles

29% of original UV energy (=70 W/m^2) is Retained in the Atmosphere 29% of original UV energy (=70 W/m^2) is Retained in the Atmosphere Looking at Earth Climate Systems: B Total Outgoing IR Radiation 70%=240 W/m^2 Total Outgoing IR Radiation 70%=240 W/m^2 This yields 288 K (= +14 Celesius = +54 Fahrenheit) UV absorbed by the Clouds 3% = 7 W/m^2 UV absorbed by the Clouds 3% = 7 W/m^2 UV Absorbed by Earth’s Surface to heat energy & radiated as Infra Red Rays back to the Atmosphere 51% of UV = 170 W/m^2 UV Absorbed by Earth’s Surface to heat energy & radiated as Infra Red Rays back to the Atmosphere 51% of UV = 170 W/m^2 UV absorbed by the Stratosphere 16% = 46 W/m^2 UV absorbed by the Stratosphere 16% = 46 W/m^2 Released directly from Earth’s Surface 6% = 14 W/m^2 Released directly from Earth’s Surface 6% = 14 W/m^2 65% of original UV energy (=156 W/m^2) is Released to the Atmosphere 65% of original UV energy (=156 W/m^2) is Released to the Atmosphere Reflected UV 30% =102 W/m^2 Reflected UV 30% =102 W/m^2 90%=203 W/m^2 of Atmospheric Heat is Recycled back to the Earth 90%=203 W/m^2 of Atmospheric Heat is Recycled back to the Earth = + Total UV Retained 70%=240 W/m^2 Total UV Retained 70%=240 W/m^2 Incoming UV 100%=342 W/m^2 Incoming UV 100%=342 W/m^2 UV absorbed by conduction & convection movements 7%= 17 W/m^2 UV absorbed by conduction & convection movements 7%= 17 W/m^2 All heat is eventually Released to Space as IR Radiation Atmosphere=226 W/m^2 Outgoing Radiated Energy

Earth’s Energy Budget Energy Budget Summary:

What Causes Variations in Local Climate? Static Components— where climate factors are held constant relative to climate activity measured Latitude Altitude Location relative to water & topographic features Dynamic Components— where climate factors are changed relative to climate activities measured Solar Output Earth’s Orbital Atmosphere Hydrosphere Biosphere Lithosphere Here, changes in Earth-Solar dynamics take longer than units of time in climate measure Here, changes in Solar Output, Earth’s Orbit, the Atmosphere, Hydrosphere, Biosphere & Lithosphere take less than units of time in climate measure

Climate Systems

11/18/2015ISOFS11 Why Model Earth’s Climate System? Scientific Curiosity How did Earth’s climate evolve? Why does Earth look the way it does? How does the climate system change? Social Responsibility What are we doing to Earth’s climate? What are the implications for our future?

11/18/2015ISOFS12 What is Required to Model Earth’s Climate? Appropriate questions Systems Approach – Factoring in static components – Coupled with dynamic components Diversity of Scientific Expertise Reliable Data Computational Tools Testing against direct & accurate observation

References The University Corporation for Atmospheric Research Window to the Universe UNEP, International Panel on Climate Change