| Home | Calendar | Course Outline | Announcements | Syllabus | Study Aids | Grades | Geog/Geol Dept | UWSP |

EARTH'S RADIATION & ENERGY BALANCE

A. INTRODUCTION

1. Energy

2. Calorie

---

B. FORMS OF ENERGY

1. Radiant Energy (electromagnetic radiation)

temperature of a substance affects:

• wavelength of radiation emitted

• intensity (amount) of radiation emitted

solar radiation and terrestrial radiation:

 

2. Heat (thermal) Energy

a. temperature and heat

b. specific heat and heat capacity

c. forms of heat energy

• sensible heat      

• latent heat

---

C. RADIATION BALANCE

1. Net radiation = total in - total out

2. Shortwave (solar) radiation  (K)    

incoming shortwave = (S+D) direct beam solar (S) diffuse (scattered) solar (D) outgoing shortwave reflected radiation = [a(S+D)] albedo: proportion of insolation reflected from a surface (a) insolation reflected by atmosphere & earth's surface albedo varies geographically & temporally

Maps of

Image source: NASA Visible Earth http://visibleearth.nasa.gov/view_rec.php?id=1683

net shortwave

• 

• absorbed radiation (direct & diffuse)

3. Longwave (terrestrial) radiation            

incoming longwave radiation emitted by atmosphere function of air temperature outgoing longwave radiation emitted by earth function of surface temperature net longwave earth's surface and atmosphere absorb longwave radiation

4. Radiation balance summary

net radiation = amount radiant energy available to do work

net radiation = total in - total out

---

D. ENERGY BALANCE

1. Energy always transferred from warmer to cooler substances

• energy gradient

• energy flux: rate of energy transfer through a given area of space

  • calories/cm²/min or watts/m²

2. Mechanisms:

• radiation

• conduction

• convection

• Q* = net radiation

• H = sensible heat flux  

• LE = latent heat flux  

• G = ground heat flux
  

---

E. SUMMARY

Temperature patterns affected by:

• spatial & temporal imbalances in radiation & energy fluxes

• type of work energy does (sensible or latent heat flux)

• heat capacity of earth's surface