Prolonged Cold Snap Impact South Florida Human And Environment

Introduction

Most of Florida consists of a low, 400 mile long peninsula, part of the nation's southeastern coastal plain which runs from Texas to Virginia. Although the highest elevation in Florida is only 345 feet above sea level, there is considerable local relief along its border with Alabama and southwestern Georgia, as well as along the spine of the peninsula. Within these two hill regions there are many places where, within a square mile, there is as much as a 150 to 200 feet difference between the highest and lowest elevation. The surface of most of the State is covered by infertile sand or loam, often with a hardpan layer beneath which restricts water absorption. The surface sands and barns rest upon a thick layer of soluble limestone that has been greatly eroded. Within much of the State, numerous limestone features such as sinkholes, underground rivers, and large volume springs may be found. In volume of discharge, Florida has some of the nation's largest springs. Also, within its limestone foundation are found several large aquifers, the most important of which is the Floridan, said to contain as much water as the entire Great Lakes system. Unfortunately, the water in the aquifer becomes saline under the southern half of the peninsula and is of little economic value.

Most of the State lies within the extreme southern portion of the Northern Hemisphere's humid subtropical climate zone, noted for its long hot and humid summers and mild and wet winters. The southernmost portion of the State is generally designated as belonging to the tropical savanna region, a climate that it shares with most of the Caribbean islands. Sometimes also called the wet and dry tropics, tropical savanna precipitation is highly concentrated in the warmer months. The chief factors that govern Florida's climate are latitude, land and water distribution, prevailing winds, storms, pressure systems and ocean currents. Although no place in Florida is far from sea level, during the winter altitude can be a significant local factor in affecting temperature. Early grove owners quickly learned that the citrus trees they planted in depressions were much more susceptible to freezes than those planted on higher ground.

Mean temperatures during Florida's coldest month (January) range from the lower 50s in the north to the upper 60s in the south. In the hottest month (usually July, but in places August) it is almost the same throughout the entire State, between 81 and 83 degrees Fahrenheit (° F). Every day of the year the sun reaches Florida at a higher angle than farther north, and consequently its power to heat is greater. For example, in New York City during January the rays of the sun reach a maximum angle during the day of about 26 degrees above the horizon, while in Miami the angle is about 40 degrees. The sun's rays at their highest, around June 21st, strike New York at about a 65° angle, while in Miami the sun is ...