1. Section 3 Remote sensing of global change Climate change Global Change Instructor: Dr. Cheng-Chien LiuCheng-Chien Liu Department of Earth Sciences National Cheng Kung University Office: Building of Earth Sciences, room 30206 Voice: +886-6-2757575 ext. 65422 E-mail: ccliu88@mail.ncku.edu.tw Office hours: Monday 14:00 – 17:00, Wednesday 9:00 – 12:00 URL: http://mail.ncku.edu.tw./~ccliu88/http://mail.ncku.edu.tw./~ccliu88/ Last updated: 12 May 2005

2. Factors affecting climate change  Climate change  interaction of Hydrosphere Lithosphere Atmosphere  Thermometer of climate system Biosphere  Factors affecting climate change Internal factors  climate change  feedback from the atmosphere External factors  climate change  no feedback from the atmosphere

3. Internal factors  Constituents of atmosphere Greenhouse gasses Aerosol  Change of landform Dessert Rainforest  Ocean Short-term: El Niño Long-term: circulation of temperature and salinity

4. Internal factors  Cloud High altitude Low altitude  Atmospheric dynamics Butterfly effect

5. External factors  Sun-Earth connection Revolution  variation of eccentricity: 0.000483~0.018~0.061, T  10 5 yr Earth Rotation, Precession and Nutation  Precession: T  22,000 yr  Nutation: 22 0 ~23.5 0 ~24.5 0, T  40,000 yr http://earthobservatory.nasa.gov/Library/Giants/Milankovitch/Images/ milankovitch_precess_high.mov http://earthobservatory.nasa.gov/Library/Giants/Milankovitch/Images/ milankovitch_precess_high.mov Milankovitch cycle  the Earth's inclination and orbit relative to the Sun http://svs.gsfc.nasa.gov/vis/a000000/a000000/a000075/a000075.mpg http://svs.gsfc.nasa.gov/vis/a000000/a000000/a000075/a000075.mpg  axis tilt  the seasonal contrast  so that winters are warmer and summers are colder  ice leftover from previous year  albedo  positive feedback  iceage

6. Fig. 1 Fig. 1 Sun-Earth connection. Source: image adopted from The Amosphere by Lutgens and Tarbuck, © 1998 by Prentice- Hall, Inc

7. External factors (cont.)  Sunspot A closer look of sunspot  http://svs.gsfc.nasa.gov/vis/a000000/a002600/a002656/facula e.mpg http://svs.gsfc.nasa.gov/vis/a000000/a002600/a002656/facula e.mpg Under the sunspot  http://svs.gsfc.nasa.gov/vis/a000000/a002700/a002713/Sunsp ots.mpg http://svs.gsfc.nasa.gov/vis/a000000/a002700/a002713/Sunsp ots.mpg Periodicity of Sun spot  Fig. 7.2.2 Number of sunspot  climate change ?

8. External factors (cont.)  Plate movement Sea-land distribution  uneven rate of heating  seasonal wind Sea-land distribution  ocean circulation  e.g. disconnection of the South America and Antarctic  Antarctic circulation  warm current is cut  T 

9. External factors (cont.)  Eruption of volcano Large aerosol  Absorption of long-wave radiation  warming effect  All fall down on the ground after several months Small aerosol  Scatter solar radiation  cooling effect  May stay in the stratosphere for a couple of years

10. Fig. 7.3.2 Fig. 2 Variations of the number of sunspot in the past three hundred years. Source: http://140.115.123.30/gis/globalc/fig/07-03.gifhttp://140.115.123.30/gis/globalc/fig/07-03.gif

11. Simulation of climate change  Manipulation and analysis of virtual weather systems constructed in cyberspace Virtual rain and electric storms – New Tools for Understanding Seasonal Climate VariationsVirtual rain and electric storms – New Tools for Understanding Seasonal Climate Variations Qualify and quantify the relationship between all factors that effect climate change  need researches! Validate the model based on real observations  satellite data is an ideal source Assimilate observations to achieve a better accuracy  optimizations of parameters that cannot be measured Stability of model prediction under normal conditions

12. Questions  What is the role that human plays in climate change?