The Polar cell is likewise a simple system. Though cool and dry relative to equatorial air, air masses at the 60th parallel are still sufficiently warm and moist to undergo convection and drive a thermal loop. Air circulates within the troposphere, limited vertically by the tropopause at about 8 km.
Good sources of calcium. Good sources of calcium include: 1  milk, cheese and other dairy foods. 2  green leafy vegetables â such as broccoli, cabbage and okra, but not spinach. 3  soya beans.4  tofu. 5  soya drinks with added calcium. 6  nuts. 7  bread and anything made with fortified flour.8  fish where you eat the bones â such as sardines and pilchards.ood sources of calcium. Good sources of calcium include: 1  milk, cheese and other dairy foods. 2  green leafy vegetables â such as broccoli, cabbage and okra, but not spinach. 3  soya beans.
Dairy products are good sources of calcium. An 8-ounce glass of milk contains about 300 mg of calcium. Two slices of firm cheeses, such as American, Swiss, cheddar or mozzarella have about as much calcium as a glass of milk. Softer cheeses, like cottage cheese, most often contain 1/3 to 1/2 this amount of calcium per serving. Other calcium-rich foods are yogurt, salmon, tofu, almonds (100 mg in a 2-ounce serving), and beans. Also, many foods such as orange juice and soy milk come in calcium fortified forms. The average American daily diet contains about 200 mg of calcium in non-dairy food.