How Weather and Climate Work

American Thinker: There are three big drivers of weather for any place on Earth: the latitude, the local environment, and solar system cycles.

The biggest weather factor is latitude – are you in the torrid, temperate, or frigid zone?  These climatic zones are defined by the intensity of heat delivered to Earth’s surface by the sun.

In the Torrid Zone, the sun is always high in the sky.  It is generally hot, often moist, with low atmospheric pressure, muggy conditions, and abundant rain and storms, some severe.  Places close to the Equator get two summers per year (just one long summer) and very little winter.  Farther from the equator, there are two seasons: “The Wet” and “The Dry.”  The Torrid Zone produces many equatorial rainforests and also contains some deserts.  Most people dream of vacations or retirement in the warm zone.

The Temperate Zone is cooler, with more distinct seasons and sometimes severe droughts and floods.  The granaries of the world lie within it.  But the belt of sub-tropical high-pressure zones also produces most of the world’s great deserts.

The Frigid Zone has low humidity and high atmospheric pressure, with just two seasons (one cool, with a sun that never sets, followed by a long, cold, dark, sunless winter).  Only a few foolish people long for expansion of the frigid zone.

The second weather-maker is the local environment – geography, topography, winds, ocean currents, and human activity.

Oceans dominate Earth’s surface and its weather.  How near is the ocean, with its moist, changeable atmosphere and ocean currents?  These can be warm, cold, or variable.  Seaside places have fewer extremes of temperature, and highlands are generally cooler than lowlands.  Lands on the ocean side of mountains have more precipitation and forest vegetation, while those behind the hills lie in rain shadows and have more grasslands and deserts.

Winds generally create or define weather.  The rotation of the Earth generates semi-permanent trade winds, which have an easterly component on the surface in both hemispheres.  These are modified by convectional cells of rising and falling air created by differences in solar heating of Earth’s surface by the Sun.  Winds, ocean currents, and ocean over-turnings combine to create longer-term weather-makers such as El Niño.  Contour maps of air pressure (isobars) are one of the most useful tools for short-term weather forecasting, and they can have daily or seasonal predictability.

Intense human activity also affects local weather.  Mega-cities and urban sprawl generate and concentrate heat, producing their own artificial heat islands.  People, houses, buses, trains, cars, trucks, airplanes, factories, motors, generators, stoves, heaters, coolers, concrete, bitumen, and landfill all generate, absorb, reflect, exhaust or radiate heat.  As many temperature recording stations are located in or near such islands of man-made heat, this has distorted calculations of “global temperature.”

The third weather-maker relates to cycles in the solar system.  read more