What is surface reflectivity?
Surface reflectivity, often called albedo, is the measure of how much solar radiation a surface reflects back into space compared to what it absorbs. It is expressed as a value between 0 and 1, or as a percentage. Light-colored surfaces like sea ice and snow have high reflectivity, bouncing up to 90% of sunlight away and keeping regions cool. Conversely, dark surfaces like oceans and asphalt have low reflectivity, absorbing most energy and converting it into heat.
What is temperature?
Temperature is a quantitative measure of the average kinetic energy of the particles within a substance. At the microscopic level, atoms and molecules are constantly in motion; the faster they vibrate, rotate, or collide, the higher the temperature of the object. It dictates the direction of spontaneous heat flow, which always moves from an object of higher temperature to one of lower temperature. Temperature is commonly measured using scales like Celsius, Fahrenheit, or Kelvin.
What is thermal energy?
Thermal energy is the total internal kinetic energy of all the atoms and molecules within a substance, resulting from their random motions and vibrations. Unlike temperature, which measures the average kinetic energy, thermal energy depends on both the speed of the particles and the total mass of the object. The more mass or speed a substance possesses, the more thermal energy it contains. This energy naturally transfers between systems as heat.
What is the specific heat capacity of a substance?
Specific heat capacity is the amount of thermal energy required to raise the temperature of one gram of a substance by one degree Celsius (or one Kelvin). It measures how well a material resists changing its temperature when it absorbs or loses heat. Water has an unusually high specific heat capacity, meaning it absorbs a lot of energy before getting hot, whereas metals have low capacities and heat up rapidly
What is differential heating and cooling?
Differential heating and cooling is the process by which different materials on Earth absorb, retain, and release thermal energy at unequal rates when exposed to the same amount of solar radiation. This phenomenon is primarily driven by variations in specific heat capacity, surface reflectivity, and material structure. A classic example is the contrast between land and water: solid land heats up and cools down rapidly, while fluid oceans change temperature much more slowly and steadily.
What is density?
Density is a fundamental physical property that measures how much mass is contained within a given volume of a substance. It is calculated using the formula:
Density = mass/volume
Essentially, it describes how tightly packed the atoms or molecules are within an object. Substances with high density have closely packed particles and feel heavy for their size, while low-density substances have loosely arranged particles and are lighter.
What is evaporation?
Evaporation is the process by which a liquid changes into a gas or vapor before reaching its boiling point. It occurs when individual molecules at the liquid's surface gain enough kinetic thermal energy from their surroundings to overcome the attractive forces holding them together. As these fast-moving, high-energy molecules escape into the air, the average energy of the remaining liquid decreases, which produces a distinct cooling effect on the surface left behind.
What is air pressure?
Air pressure, also called atmospheric pressure, is the force exerted on a surface by the weight of the air molecules above it in the atmosphere. Though air seems weightless, gravity pulls its molecules toward Earth, creating a dense layer of pressure at sea level. Air pressure changes constantly with altitude and temperature. It is a driving force behind global weather, as air naturally moves from areas of high pressure to low pressure, creating wind.
How are air density and temperature related?
Air density and temperature are inversely related: as air temperature increases, its density decreases. When air is heated, its molecules gain kinetic energy and move faster, colliding and spreading farther apart. This thermal expansion means fewer molecules occupy the same amount of space, making the warm air lighter. Conversely, when air cools, molecules slow down and pack tightly together, increasing density. This relationship drives atmospheric buoyancy, causing warm, less-dense air to rise and cold, dense air to sink.
Your challenge is to investigate how different Earth materials absorb and retain heat energy. Using laboratory tools, you will model a microclimate to discover the physics behind why land and water heat up at completely different rates and the implications of this on the local weather.
