Slide 1

The reflective property of snow keeps earths climate in balance, against the futile, yet persistent, force of solar radiation. ___ What a beauty! Slide 2 How the sun affects earth! Earth rotates around the sun! The tilt of the earth gives more sun rays to the northern hemisphere in our summer, and to the southern Hemisphere in our winter! Slide 3 What are sun rays?! Solar Radiation (sunlight) To the point! The sun gives off (radiates) massive amounts of energy with difference wavelengths. We can see some of that energy, most we cannot, but all can warm up the atmosphere! Slide 4 Feel the Heat Energy is higher where there is more radiation. Because of the tilt of the earth, energy culmination fluctuates from the northern hemisphere to the southern hemisphere throughout the year. Slide 5 Energy Distribution So, warm temperatures move from the Tropic of Capricorn to the Tropic of Cancer, from January to August, as earths southern hemisphere begins to receive more radiation due to the tilt of the earth. Slide 6 Why does this matter? This trend in weather makes areas such as Australia and Sub-Saharan African the warmest places between January and April Between April and August, North Africa, Southern US, China, India, and the Arabian Peninsula have the highest temperatures. Between September and December, Warm temperatures return to Sub- Saharan Africa and Australia. Slide 7 Land Surface Temperature: August vs. January Slide 8 What do you call a water droplet that is too cool for school? SNOW! Snow has one of the highest reflectivity coefficients of the known materials, known as ALBEDO ALBEDO is measured from a perfectly black surface, which absorbs the most solar radiation, to a perfectly white surface, which reflects the most. -Asphalt has an ALBEDO of 0.04 - Snow has an ALBEDO of 0.90 SO! A lot of snow = a lot of REFLECTION So Why Dont We Fry??? Slide 9 SNOW! SNOW! SNOW! Snow cover is greatest in the Northern Hemisphere between December and February In the Southern Hemisphere, snow cover is greatest between June and August The Southern Hemisphere generally has a lower amount of snow cover than the northern hemisphere due to having less land mass EGH Facts. Dreadful! Slide 10 December, when Santa satisfies his addiction to snow. Because of the fluctuations in heat (transfer of thermal energy) throughout the year, between the north and the south, there is a difference in the snow cover between well, the north and the south. Snow Cover: August vs. January The North Wins Again! Maybe. One could argue that south is cheating. Antarctica -.- Slide 11 Tying the Knot So, what ties heat and snow cover together? Some might say, ALBEDO!, and they will be right. The reflective property of snow keeps earths climate in balance, against the futile, yet persistent, force of solar radiation. Us (2011) When the sun beams down on the Northern Hemisphere, snow accumulated in the north over the wintery months melts and helps to keep the northerners from heat exhaustion. Snow, then builds up in the south, further helping to divert suns radiation. Because of this, the average temperature of Earth stays relatively the same. !WATCH OUT -> GLOBAL WARMING! Slide 12 ALBEDO Hey! January: A lot of snow means that there will be a lot of reflection in the northern Hemisphere (dark blue) August: A lot of the snow has melted in the northern hemisphere, and now the south is nice and cool while we suffer extreme temperatures. Slide 13 Snow Cover Vs. Temperature Slide 14 All Together Now ALBEDO! jk Snow Cover Land Surface Temperature Reflected Short Wave Radiation Slide 15 BEEF JERKY CONCLUSION Areas with high land surface temperature have lower amounts of snow cover Snow cover can be compared to an enormous mirror, reflecting energy (short-wave radiation) from the sun. This regulates surface temperature. However, global warming leads to decreased snow cover. This leads to less energy being reflected and even greater temperatures. Prime example of positive feedback loop. Higher temperatures -> less snow -> even higher temperatures -> DOOM! Snow cover has been decreasing since the 1960s. Decreasing snow cover harms wildlife that rely on snow for food storage, insulation, or burrows. Knowing this is important, trust us! Slide 16 The End