Hourly Forecast Detailed. 1  0am:The Santee, SC forecast for Apr 11 is 63 degrees and Clear. There is 74 percentage chance of rain and 4 mph winds from the South-Southeast. 2  3am:The Santee, SC forecast for Apr 11 is 55 degrees and Clear. There is 79 percentage chance of rain and 4 mph winds from the South.
Most Important Organism? Marine plants produce between 70 and 80 percent of the oxygen in the atmosphere.
I thought the average oxygen level was approximately 20.95 percent by volume? Both vary in space and time, but the variability of oxygen is much smaller than that of CO2. Your value for the oxygen concentration is close to the US Standard Atmosphere value of 20.9476%.