GG101 Lecture 7: GG101 LESSON 7
LESSON 7
Daily Temperature Patterns
• - Lowest in the morning
• - Rises to a peak in the mid to late afternoon
• - Falls in the evening
What Controls Daily Cycle in Temperature?
• - Solar radiation strikes the surface where some is absorbed, and the remainder is
reflected
• - Surface is warmed and remits longwave radiation
• - The air above the surface is also absorbing radiation and emitting longwave radiation,
some of which is directed towards the surface
• - The net radiation of the surface reflects the balance of inputs (+SW and +LW) and
outputs (-SW and -LW)
• - A more complete treatment of the energy transfers at the surface would include heat
transfers through conduction and convection and evaporation
• - The ground surface will continue to warm as long as it is gaining energy
• - In the afternoon period, the ground could be gaining energy not just from solar
radiation but also longwave radiation
• - When the energy balance becomes negative the ground surface will be losing energy
and it will cool
• - In the evening, the surface cools as outgoing longwave radiation is emitted and energy
balance becomes more negative
• - Temperatures are lower on clear nights than overcast nights as there are no clouds
which can absorb the longwave radiation that is emitted from the surface
Controls on Temperature Specific Heat
Document Summary
Rises to a peak in the mid to late afternoon. Solar radiation strikes the surface where some is absorbed, and the remainder is reflected. Surface is warmed and remits longwave radiation. The air above the surface is also absorbing radiation and emitting longwave radiation, some of which is directed towards the surface. The net radiation of the surface reflects the balance of inputs (+sw and +lw) and outputs (-sw and -lw) A more complete treatment of the energy transfers at the surface would include heat transfers through conduction and convection and evaporation. The ground surface will continue to warm as long as it is gaining energy. In the afternoon period, the ground could be gaining energy not just from solar radiation but also longwave radiation. When the energy balance becomes negative the ground surface will be losing energy and it will cool. In the evening, the surface cools as outgoing longwave radiation is emitted and energy balance becomes more negative.
