Middle and High School … from a Montessori Point of View
Video by Tobais Friedrich out of the University of Hawaii. It’s based on a recent paper that suggests that the large fluctuations in climate over the last 120,000 years opened and closed green corridors that allowed multiple pulses of migration out of Africa.
He has some other excellent earth science scientific visualizations.
Ed Hawkins posted this extremely useful visualization of month-by-month, global temperature changes since 1850.
Monthly climatic data from the Eads Bridge, from 1893 to the 1960’s. It’s a comma separated file (.csv) that can be imported into pretty much any spreadsheet program.
The last three columns are mean (MMNT), minimum (MNMT), and maximum (MXMT) monthly temperature data, which are good candidates for analysis by pre-calculus students who are studying sinusoidal functions. For an extra challenge, students can also try analyzing the total monthly precipitation patterns (TPCP). The precipitation pattern is not nearly as nice a sinusoidal function as the temperature.
Students should try to deconstruct the curve into component functions to see the annual cycles and any longer term patterns. This type of work would also be a precursor the the mathematics of Fourier analysis.
This data comes from the National Climatic Data Center (NCDC) website.
The National Snow and Ice Data Center has some interesting data-sets available, including a number of measures of the extent of Arctic sea-ice showing how fast it has been melting.
The Easy-to-use Data Products page has a lot of real data that middle and high school students can use for projects.
This summer’s arctic ice cap is the smallest since we’ve started watching it from space in the 1970’s, and the summer isn’t over yet.
Over the last few years, the rate at which the ice is melting is accelerating, probably due to the ice-albedo feedback. Albedo refers to how reflective a surface is; the average of the Earth is about 31%, while snow and ice has an albedo closer to 90%.
When the albedo is high, a lot of sunlight is reflected back into space, but when it’s lowered, such as when the sea-ice melts, the surface absorbs a lot more sunlight, which heats it up. Of course, more heat melts more ice which further decreases the albedo which causes more warming which melts more ice …. And you can see the problem.
The ice albedo feedback takes a small change (melting ice) and accelerates it. That’s a positive feedback, although the effects are usually not what you want, because they take the system (the Earth’s climate in this case) away from it’s current equilibrium. This is not to say that there are no benefits; the Northwest Passage will open up eventually, if it has not already.
↬ ClimateCentral.org ᔥ the NSIDC
Joel Cayford has posted a nice image showing the composition of the atmosphere over time — since the formation of the Earth.
Note that, although the Earth is 4.5 billion years old, and life has been around for over 4 billion years, there has only been oxygen in the atmosphere for about 2 billion years.
Oxygen is an extremely reactive gas, which is why we use it when we “burn” carbohydrates for energy. But it also means that any free oxygen added to the atmosphere would easily react with rocks, water, and other gasses in the atmosphere, so would not be available in the quantities needed for air breathing organisms until it slowly accumulated.
Also, you need a lot of oxygen in the atmosphere to produce enough ozone to form the ozone layer that protects life at the surface from high-energy, cancer-inducing, ultra-violet radiation from the Sun.
NOAA provides real-time (at least in the last 6 hours) images of the tropical Atlantic, which will often show the Inter-Tropical Convergence Zone (ITCZ) quite nicely.
They show images captured using visible light:
As well as infra-red:
HINT.FM has an amazing animation of winds over the U.S.. A major part of the awesomeness is that it’s updated hourly from the National Weather Service’s weather database, which has an awful lot of excellent data available.