Cryosphere the frozen world is the cryosphere Green land ice caps Artic Ocean sea ice The cryosphere is unique because its spatial distribution is controlled by climate It can be frozen continuously while not actually being below freezing temperatures This can happen because even though sometime temps warm up it is never quite high enough to fully melt the ice thus the ice is always frozen Temperature refers to the amount of energy that is stored in a substance OR the kinetic molecular energy level of a substance 2 diff definitions The more energy there is the faster the molecules vibrate Ex a balloon being expanded because temp is raising and the molecules are vibrating faster INPUTS of energy are from Solar Radiation Inputs storage earth s temperature and OUTPUTS Longwave or Infrared Radiation Direct and Oblique the reason why it is hot in the tropics and cold in the poles Solar radiation is directly hitting the Tropics but hitting at an angle for the poles flashlight example 36 to 36 positive budget This is the tropics and the low midlatitudes So this means that they will continue to get hotter and hotter since that is what positive budget does This is actually not the case And at the Poles there is a negative budget so the temperature would be falling and falling continuous although this is not happening Why Because excess energy is getting distributed different ways to keep this from occurring Global warming Earth s Climate History Temperatures have been 8 deg C WARMER in the past Earth has gotten colder according to data 40 million BP before present we entered long term cooling phase A few of these phases have existed There has also been time in history where the earth has had a warming phase Quarternary 2 million BP Period temps dropped global temps got cold enough to develop huge continental ice sheets left substantial imprint on landscape represented substantial force Ice Age Cold temps lower than the present These cold perios are called glacial periods the period where glaciers form And the higher peaks on the graph are called the interglacial periods when the glaciers melt Here is a bit warmer phase Holocene Period 10 000 years ago There was an interglacial period within this What causes temperature fluctuations Change in inputs and outputs or movement of energy itself Inputs are NOT the answer The best theory today is called the Milankvitch Cycles Cycles of slow changes in the earth s orbit Milankovitch Cycles 1 Orbit shape is not circle it is elliptic or egg shaped When more circular there is less seasonality When it is more elliptical there is more seasonality which means more intense difference in temps etc between seasons 100 000 years is the length of the orbit 2 Axial Tilt more seasonality when tilt is larger And less seasonality when tilt is smaller Check on this 3 Direction of Axis All three of these together explain the change in the Quaternary Period Feedbacks are an impact as well This is why there can be a full on glacial period Glaciers Majority of ice 90 is locked up in Antarctica About 9 in Greenland Remaining 1 is found on high mountain elevations ice caps and scattered around the world How these form Must understand the Snow line the elevations at which snow can persist year round basis Measured by Meters So Gren land is 600 meters but most of Greenland is less than that making basically all of Greenland ice Positive feedbacks make snow get thicker and thicker remember positive feedback is the enforcement of what is already occurring so snow is being added and added getting it to be thicker Eventually icy granuals called Firn will form And the when that Firn is compacted it forms Glacial Ice Snow firn glacial ice How long does this take The cooler the area then it is dryer the longer it takes Seems counterintuitive a bit but this is the case Mass Balance accumulation Zone this zone is above the Snow Line Is persists on a year round basis and persists so now ice keeps forming Ablation Zone loss of material through the melting of ice 3 types of Budgets Positive the amount of ice forming is increasing than the amount melting So amount of storage is increasing Called Advancing Glacier so glacier is getting larger Negative Mass is decreasing storage getting smaller Glacier Retreating Balance the mass is constant stagnant glacier but even though not a getting smaller or larger there is still a lot of acticity occurring It is melting and new ice is forming constantly Glaciers have layers Glacial Movement The TOP is the Brittle Zone It is hard will crack under pressure The cracks are called cravaces Next is the Plastic Zone ice is flexible because of the weight of the Brittle Zone s brittle ice right above Molecules BEND and stretch here This bending and stretching is called internal deformation Meltwater act as lubricant and buoy up weight of ice making it easier for ice to slide on hill This sliding is called Basal Sliding Glaciers do a lot of work Glacial Erosion occurs 2 mechanisms of erosion Plucking glacier attached to bedrock and slides away while plucking out piece of rock with it Abrasion very parallel movement marks used to study flow of glaciers for research Alpine Landforms 1 Pre glacial 2 Glacial 3 Post glacial bowl shaped depression with little lakes after ice has melted these are Cirques Tarn and Paternaster are lakes here Arete rigid knife like feature or mountain after glacier passed very sharp Horns skeleton of the former mountain peak Sharp and jagged