Heat Temperature and Layers of the Atmosphere Temperature

Heat, Temperature, and Layers of the Atmosphere

Temperature • Air molecules are moving all around us • Temperature = a measure of the average speed of those molecules • There are 3 temperature scales we use, but you only need to know 2 of them for this class • F = (1. 8)*(°C) + 32 • C = (5/9)*(°F – 32) – Measured using a thermometer – Always measured in shady conditions

Temperature Scales You Ought to Already Know • Fahrenheit – Water Freezes at 32°F – Water Boils at 212°F • Centigrade or Celsius – Water Freezes at 0°C – Water Boils at 100°C

Temperature Change w/Altitude Rising Expansion Cooling Sinking Compression Warming Intro to Meteorology

Difference Between Heat and Temperature • Heat = transfer of energy from 1 object to another…the transfer is measured by temperature • Air in an oven at 500°F has high temperature but little heat, but touch anything solid in the oven, and you’ll get burned. • Ever notice that food still gets cold, even on a hot summer day? • Why?

Heating the Atmosphere • The 3 mechanisms of heat transfer are conduction, convection, and radiation • Conduction: transfer of heat through contact • Convection: transfer of heat through circulation • Radiation: transfer of heat through air, or space

Radiation and our Atmosphere • When radiation from the Sun interacts with our atmosphere, there are 4 possible results. Energy either… – passes through – absorbed – scattered – Reflected

Earth’s Energy/Heat Budget Of the 100% of the Sun’s radiation which strikes our atmosphere 30 units reflected or scattered back to space Atmosphere absorbs 19 units A total of 64 units radiated back into space via the atmosphere 6 units radiate to space from Earth’s surface 15 units radiate from surface to atmosphere Evaporation transfers 23 units to atmosphere Earth’s surface absorbs 51 units Conduction and convection transfer 7 units to atmosphere

Reflection, Absorption, and Scattering • Reflection depends on surface albedo – Ice = High Albedo (next slide) • The surface absorbs solar radiation and re-emits it back into our atmosphere as heat. . but … • Greenhouse gases like CO 2 and H 2 O Vapor then absorb this heat and reemit some of it back into the atmosphere…trapping it

Global Albedo

Albedo = % energy reflected • Fresh snow: 75 – 95% • Old snow: 40 – 60% • Desert: 25 – 30% • Deciduous forest, grassland: 15 – 20% • Conifer forest: 5 – 15% • Camera light meters set to 18%

Water Vapor and Heat • Water and water vapor are excellent heat absorbers, absorbers which is why coastal locations are typically cooler than inland regions in the summer…it’s also why it feels warmer on a humid day than a dry one

The Effect of the Ocean on Annual Temperature

Structure of the Atmosphere • The atmosphere is divided into layers based on temperature…. draw this! • Troposphere – Where Weather Happens • Stratosphere – Ozone Layer • Mesosphere – Meso = middle part of the atmosphere • Thermosphere – where Auroras occur

Inversions • Normal = temperatures decrease with height • So, when temperatures increase with height, we say the atmosphere is inverted • Here in SM, our summers are dominated by an inversion