Sunday, September 17, 2017

Hurricane Genesis

Genesis: the origin or mode of formation. In the context of hurricanes, two of which devastated the Caribbean region and the US mainland in late summer 2017, we wonder about the sequence of events which results in a fully mature hurricane. The energy of a hurricane exceeds by 200 times the electrical generating capacity of the entire world according to US Department of Energy figures. What sorts of forces could generate such powerful storms?

Scientists have informed us of constant powerful forces operating in our worldwide weather system. Some are explained by familiar terms we may have learned in weather units in middle school, high school, or college. We have heard that evaporation of liquid water is a cooling process. This is illustrated by the fact that when our bodies perspire a large quantity of heat is removed from our body surface. When water vapor condenses back into liquid water, a large quantity of heat is returned to the air. These processes are more formally called latent heat of evaporation or latent heat of condensation. In terms of the scope of total energy flow on our planet, the quantities are unimaginable.

After receiving heat from radiation of the sun, heat energy spontaneously flows from warm to cold regions. Most Earth weather phenomena are driven by this flow. Warm regions and cold regions are characterized by different air pressure conditions. Generally, cold air is denser than warm air because atoms and molecules are packed together more closely. Movement of air spontaneously occurs from high pressure regions to low pressure regions. Weather events are powerful forces of heat movement and pressure equalization producing mighty environmental effects. Some of these effects cause serious inconvenience and pain albeit they are relatively infrequent. In perspective, Earth’s weather more frequently provides seasonal warmth for human enjoyment, growth of food crops and beautiful ornamental plant varieties for human enjoyment and even pleasant spring warming for family picnics or Little League baseball or autumn cooling for high school football or soccer matches. Our blog has more often characterized Earth as “a place to thrive” rather than “a place of brokenness and despair.”

Humanity is embedded in a wondrous collection of weather phenomena. Consider the term cyclogenesis. Two parts of the term are cyclone, a rotating low pressure area in which air spirals inward from high pressure toward low pressure, and genesis, meaning formation. Cyclogenesis explains the formation of tropical hurricanes in the Atlantic Ocean and the Caribbean and other storms in mid-latitudes. In other parts of the world hurricanes are known as typhoons or simply, cyclones. They form over warm water where there is much moisture in the air. An organized region of thunderstorms forms over the ocean and these regions are later called tropical waves. A tropical depression develops and the air begins to spin around the low pressure center at a speed above 39 mph. If the storm strengthens to 75 mph, it a Category 1 hurricane. Wind speeds sometimes increase to 157+ mph—a Category 5 hurricane.

On our spherical earth there exists a phenomenon called Coriolis effect. Large moving objects, including moving air, are deflected to the right in the northern hemisphere, away from an expected straight line path. Air rushing from high pressure to a low pressure center as in tropical depressions and hurricanes are deflected from their direction of travel owing to the different speeds of rotation on a spherical earth. This causes a counter-clockwise rotation of storms in the northern hemisphere (clockwise in the southern hemisphere), and forms a well-developed “eye.” Heavy rains, severe winds, and sometimes tornadoes are generated many miles from the hurricane’s eye.

The God of Creation is author of the orderliness of matter. In terms of Earth’s weather, this includes the predictable, uniform characteristics of air molecules—several quintillion of them in each cubic centimeter of volume. Latent heat, the tendency of energy to flow from warm to cold regions, the tendency of air to flow from high pressure to low pressure, the constant forces of gravity: We affirm, in concert with the scriptural statements such as “Through him all things were made; without him nothing was made that has been made” (John 1:3 NIV), that God originated the concepts of an orderly universe. The truth of God as Creator of all things seems discoverable intuitively.

Foundational principles of energy flow, pressure phenomena, and hundreds of constant characteristics of matter form the framework for understanding the genesis of hurricanes. With the passage of time humanity has discovered more information on knowing a hurricane is approaching and how to prepare for it. The two recent hurricanes produced relatively few fatalities. Beyond this some are not sufficiently aware of strategies for risk aversion and willing to act on the information. For example, many are unwilling to obey heroic building codes or locate their homes and businesses away from flood prone areas. Humans still have much to learn.    

God created a very good but not a perfect world according to the idealism of some people. Many religious people and skeptics question why God permits hurricanes and other natural disasters to occur. In a future post we will address these questions in more depth, but not as an effort to present final answers. Some questions may be unanswerable in human terms.