A Study of Surface Heath on The Earth's Atmosphere

The Earth's Atmospheric and Surface Heat: What a Treat! Worth a Tweet?

The purpose of the lab is to discover, compare, and analyze various factors of Earth's temperature, including but not limited to: the latitude (directly proportional to the amount of direct sunlight striking Earth's surface), proximity to the ocean (coastal or inland areas), the color and/or chemical makeup of the surface (reflective/absorptive properties), and whether the surface is water or sand (oceans or continents). This was achieved by doing several experiments testing each of these components of Earth's temperature.

Hypothesis:

If two different substances from two different locations are chosen randomly, then it is extremely likely that their temperatures will be different, due to a multitude of factors, including juxtaposition to the ocean, amount of direct sunlight (latitude), whether on ocean or land (heating or cooling), and albedo of heat off certain surfaces.

Materials:

• An abundance of sand (of similar temperatures, but some light, and some dark, with the vast majority being light sand)
• A profusion of water (of similar temperatures)
• 5 heat sources (4 lamps and 1 Hot Plate)
• 11 thermometers
• A spherical object (for thermometers to be stuck into)
• 4 small, open-topped containers of equal volume, mass, and heat conductivity (ideally bowls or some sort of aluminum pans)
• 1 ringstand and 1 ringstand base
• 1 clamp for the ringstand
• 1 test tube rack
• 2 plugs of modeling clay
• 5 flat, temperate surfaces on which to conduct the experiment
• 5 timers or stopwatches
• 5 calculators
• 5 pencils and 5 pieces of paper

Procedure:

There were five parts to the lab, each experiment performed by a small group of students, who gathered the materials, put on all necessary safety gear (namely heat-protective gloves), and performed the experiment, recording dutifully detailed results and drawing intelligent conclusions.

In the first experiment, students placed a spherical object meant to represent the Earth, and put it in front of a lamp, sticking thermometers in at each pole and at the equator. Those students tested the characteristic of latitude, otherwise known as the amount of direct sunlight, and determined that this characteristic is one of the defining ones of a location's temperature, and by extension, climate. In the second experiment, students heated two test tubes, one filled with water and another with sand, recording the rate at which each cooled. Those students tested the characteristic of the ability of a surface to retain heat, otherwise known as absorptive properties, and determined that water, with its high specific heat, retains more heat than water, making its temperature much harder to change, unlike land, represented by the sand. In the third experiment, students filled two pans, one with water and one with sand, recording the rate at which each heated. Those students tested the characteristic of, similarly to the previous experiment, the ability of a surface to change temperature, directly related to the water's high specific heat. In the fourth experiment, students filled two pans, one with dry, unsaturated sand, and the other with wet, saturated sand, recording the rate at which each heated. Those students tested the characteristic of the effect to the rate of heating of by areas' proximity to the oceans, and it was found that the inland areas heated much faster than the coastal areas, once again because of water's high specific heat. In the fifth, and final, experiment, students filled two pans, one with lights sand, and one with dark sand, recording the rate at which each heated. Those students tested the characteristic of the reflective properties of surfaces in reference to how much heat they absorb, and found that areas with a high tendency to reflect light, such as ice and snow, heat at a much slower rate than a surface with a high tendency to absorb light, such as asphalt.

Discussion:

There are many factors that affect the temperature of a planet. Percentage of heat reflected away from the planet (albedo), extent of the effect of the Greenhouse Effect on that particular planet (insulation;), amount of direct sunlight (taking into account orbital eccentricity), amount of radiation given by conduction/effectiveness or amount of ozone, thickness of the planet's atmosphere, of lack thereof (if there is no atmosphere, then there is nothing to stop all heat from striking the surface, and leaving just as fast, like the Moon, which receives a third more heat than the Earth during the day, but loses it all during the night, while the Earth, through the Greenhouse Effect, maintains a significant portion of the heat it receives), the efficiency of the winds circulating heat, and the moderation of temperature extremes (both based upon the thickness of the atmosphere), are all crucial factors to a planet's temperature. Earth's temperature, after all of these facets, looking at the big picture, is called the Goldilocks Effect, no too hot, like Venus, and not too cold, like Mars.

Using the infrared map, the hottest temperatures are on the equator (0 degrees latitude), as this is the place on Earth that receives the most direct sunlight (the equator constitutes a slight bulge in the Earth). The coldest temperatures are in the middle of the South Pole, Antarctica. Both poles are very cold, because they receive much less radiation from the sun than the rest of the Earth, and additionally the bright white surface of the ice reflects much of the sunlight that does reach the polar regions. However, the South Pole/Antarctica is colder than the North Pole because the South Pole's thick ice sheet raises it over a mile and a half above sea level, and below that, a continent. Altitude affects temperature, making the surrounding areas colder (the reason that mountains have snow and are extremely cold). Also, the Arctic Ocean around and in the North Pole traps heat from the atmosphere on the summer, heating it in the winter. This logical conclusion is supported by the first experiment in the lab (Latitude-North Pole to Bogota), which found that latitude does affect temperature, and more specifically that the equators had the highest temperature, and that the poles had the lowest, with the South Pole having an incremental difference in a lesser temperature.

All on locations on land at the same latitude do not necessarily have the same temperatures, shown by (on the infrared map) how western Mexico and Baja California have a higher temperature than the land just east of it, on the same latitude. Although the amount of direct sunlight received in directly proportional to the decrease in latitude, all land on the same latitude does not all have the same temperatures. This is revealed in the fourth and fifth experiments in the lab (Heating of Dry Sand vs. Heating of Wet Sand-Myrtle Beach, and Heating of Different Colored Sands-Kalahari Desert, respectively), which found that the wet sand (representing the coastal regions along the shore) heated much slower than the dry sand (representing the inland regions), once again because of the water's high specific heat. An example of this on the infrared map is northern Australia, where the inland areas had a higher temperature than the coastal areas. The experiments also found that light sand (representing surfaces such as snow that reflect much light) heats at a much slower rate than dark sand (representing all surfaces that do not reflect much light) because the light sand reflected the vast majority if the light while the dark sand absorbed the vast majority of the light, heating the dark sand. An example of this on the infrared map is how the poles (especially Antarctica, see the first paragraph of the discussion) are much, much colder than an area such as the Arabian Peninsula. Although the difference in latitude plays a major role, it does not account for the vast discrepancy in temperatures. This is due to the reflective properties, or lack thereof, of the surfaces of the aforementioned areas of land.

Using the infrared map, continents and oceans warm up and cool down differently. Continents both heat up faster (because their composition of minerals, metals, and such has a lower specific heat than the ocean water) and cool down faster (because the water retains the heat more, it takes more energy to both raise it one degree in temperature, and to decrease it one degree in temperature). Continents are both hotter in the summer and cooler in the winter than the oceans. For example, on the infrared map, the land in western Mexico and Baja California, North Africa and the Sahara, the Arabian Peninsula, India, and northern Australia is warmer than the surrounding oceans, as indicated by the colored key. This deduction was supported by the second and third experiments in the lab (Cooling of Water and Sand-Bahamas, and Heating of Water and Sand-Tahiti, respectively), which found that water, because of its high/low specific heats, it both heats, and cools, slower than the sand (the water accurately representing the oceans, and the sand representing the continents).

The experiments, as a whole, found that there are very many factors in a n area's temperature (as stated succinctly in the purpose, hypothesis, procedure, and earlier discussion section). Specifically, the statistic of rate of change for different substances under different conditions proved quite intriguing. For the first experiment, the rate of change was 25% for both the North and South Poles, and 133% for the equator, proving that latitude does affect Earth's temperature in the way that the farther away from the equator the colder it is, generally, because of the amount of direct sunlight. For the second experiment, rate of change was -2.92°F/12 minutes for the sand, and -2.33°F/12 minutes for the water, and in the third experiment 0.67°C /minute for the sand and 0.5°C/minute for the water, proving that continents and oceans heat up and cool down differently because of the water high specific heat, making it resistant to temperature change, much more so than land. For the fourth experiment, the rate of change was 0.98583333333°C/minute for the dry, unsaturated sand, and 0.375°C/minute for the wet, saturated sand, proving that coastal areas heat up at a slower rate than inland areas, once again because of water's high specific heat. For the fifth, and final, experiment, the rate of change was 2.4166°C/minute for the dark sand, and 0.5°C/minute for the light sand, proving that the reflective/absorptive properties of a surface also plays a major role in the quickness of the rate it heats.

There were many sources of error, but for the most part they were accounted for, and ideas were proposed to eliminate these irregularities in the data and the procedure of the experiment (see paragraph two in the conclusion for sources of error and suggested solutions). Some factors in determining the temperature of an area were proven to be more decisive than others (specifically amount of direct sunlight), but all were taken into the groups' final conclusions, and overall this lab really furthered the knowledge of the participating students on the subject at hand.

Conclusion:

The full purpose of the lab was achieved. All participants in the lab discovered, compared, and analyzed various factors of Earth's temperature, and furthered their knowledge of the Earth's atmosphere, climate, and overall comprehension of science as a whole. The hypothesis was accepted, because the factors, as previously predicted in the hypothesis, that affect a location's temperature (such as altitude), were proven to be true.

Some ways to possible make the lab more reliable would be precise measuring equipment (to accurately measure the distance to the lamps), automatic thermometer readings at specified times (to remove human error from the equations), a system of rock processing in the sand before the experiment (to take away unwanted weight that might disrupt the findings of the experiment), a way of accounting for weight and/or temperature of water and/or other materials for the lab before the start of the experiment (to maximize the amount of unaccounted for variables), and finally a way to measure the weight of the sand past one-tenth of a gram (the limit of the provided scales).

In this lab and its included experiments, the participants discovered, compared, and analyzed various factors of Earth's temperature, and furthered their knowledge of the Earth's atmosphere, climate, and overall comprehension of science as a whole.