The Most Important Natural Resource By Nolan Doesken Colorado State Climatologist and Senior Research Associate, Colorado State University Dept. of Atmospheric Sciences
Nolan Doesken pauses near the 120-year-old weather station on the university’s Fort Collins campus.
Essentials Climate is never stable or stationary. It varies. The world’s winds and ocean currents are in constant motion, maintaining balance. Climate is the result of laws of physics applied to an amazing combination of land, sea and air. Climate begins with the sun, which provides the energy to drive the global climate system. Sunlight passing through the atmosphere warms the earth and then heats the adjacent air, making our planet livable. The air warms most quickly over dry ground. Over water or moist vegetation, more of the solar energy is used to evaporate and transpire water. The rotation of the earth on its tilted axis and its continuous journey around the sun means that solar energy is distributed across the entire globe. Tropical regions get more sunlight. Polar regions get less. As the sun’s angle changes with the seasons, the distribution of solar energy constantly changes. In the mid latitudes, high latitudes and polar regions, these seasonal changes in sunlight are very large. In Colorado, energy from the sun reaching the ground is three times greater in summer than in winter. Differences in sunlight produce temperature variations. As temperature gradients develop, winds begin to blow. The earth’s rotation causes the winds to circulate in waves and large swirls that vary in strength and location according to the season. The winds strive constantly to maintain balance, moving energy away from the tropics and towards the poles while carrying water vapor from oceans to continents and from moist to dry regions. Periodic storms may deliver much-needed water in the form of rain or snow. The changing seasons add a rhythm to the winds, to the temperature, to the rain and snow and to our lives.
Colorado Foundation for Water Education
Published on Nov 20, 2013