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El Nino years correspond to higher temperatures and above average rainfall in the Southeastern U.S. If this increased rainfall comes in frequent and steady showers instead of a few strong storms, then conditions for mosquito breeding are ideal. Yellow Fever, which has been eliminated in the U.S. due to mosquito control efforts and a vaccine, [...]

The El Nino Southern Oscillation (ENSO) cycle, or the cyclical movement of heat in the tropical Pacific Ocean, affects the upper atmosphere over the Atlantic Ocean. This affects both the frequency of Atlantic tropical cyclone formation as well as the positioning of the region?s high and low pressure centers that steer the tropical cyclones. La [...]

The charismatic and colorful Wood Duck provides bird-watchers with a familiar and welcome sight. Hunters also value this bird, which is second only to the mallard in terms of numbers shot each year. Data shows that in parts of the Southeast, the duck is now breeding a full month earlier than it did in the [...]

The El Nino-Southern Oscillation (ENSO), or the cyclical movement of heat in the tropical Pacific Ocean, affects atmospheric phenomena throughout the world. Its effects are the most pronounced during the winter, when the temperature difference between the atmosphere and the oceans is the greatest. The cycle affects the strength and position of the Pacific Jet [...]

The AO is the oscillation of pressure difference between the middle and high latitudes in the Northern Hemisphere. Negative phases occur when there is relatively high pressure over the polar regions and low pressure over the mid-latitudes, with positive phases featuring the opposite characteristics. Since the 1970?s, the index has been predominately positive. Positive phases [...]

From the time of its discovery in the Gulf of Mexico in the 1940′s until about 1990, a single-celled marine parasite (Perkinsus marinus) was rarely spotted north of the Chesapeake Bay. Perkinsus marinus is best known for causing large-scale die-offs of the commercially important Eastern Oyster (Crassostrea virginica). Since 1992, however, outbreaks of the parasite [...]

The Atlantic Multidecadal Oscillation (AMO) is a 65-year cycle during which sea-surface temperatures in the North Atlantic alternate between warm (positive) and cool (negative) phases. The effects of this Oscillation are felt around the World. For example, warm (positive) sea-surface temperatures in the North Atlantic generally correspond to drier and warmer conditions in the Western [...]

Tree Swallows are medium-sized birds with white underbellies and iridescent blue-green capes that run from their heads to their wing tips. They often live in flocks that can number hundreds of thousands of birds and just before sunset, these flocks will swarm around their roosting spots in great circles that resemble living tornadoes. In the [...]

When the Earth warms, as it has since the Little Ice Age ended in about 1850, waters expand and ice melts. These factors cause global sea levels to rise. Over the Twentieth Century, the Planet?s seas rose at an average rate of 0.8 inches per decade, and since 1993 this rise has accelerated to 1.3 [...]

Over the last century, the World’s sea level rose eight inches. Changes in coastlines have been particularly pronounced in Louisiana. Since 1900, over one million acres of the State’s coastal wetlands have been inundated and converted to open water, and the area of the State’s barrier islands has been reduced by one-third. Since the 1970s [...]

Seabirds, such as auks, gulls, petrels, terns, and gannets, have spent tens of millions of years adapting to life on the ocean. Some species, such as the Sooty Tern, can spend years at sea before returning to land. The success of these species is dependent on the success of their food sources (such as fish [...]

An air mass is a large body of air with relatively uniform temperature and humidity. These masses can be thousands of miles across and up to ten miles high. Air masses develop over what are known as source regions; air masses that develop in the winter over Canada, for instance, are cold and dry these [...]

In the Amazon Rainforest, woody climbing vines, also known as lianas, are increasing in dominance throughout the Amazon Rainforest at a rate of 1.7 to 4.6 percent a year. Lianas harm the trees that they attach to and use as ladders, and are considered parasites. Carbon Dioxide (CO2) levels have risen from 280 parts per [...]

The El Nino-Southern Oscillation (ENSO), or the cyclical movement of heat in the tropical Pacific Ocean, affects atmospheric phenomena throughout the world. The cycle affects the strength and position of the Pacific Jet Stream, an upper atmosphere wind current that flows from the Pacific over North America. During La Nina phases of the cycle, the [...]

The warming trend over the last thirty years in the Eastern U.S. has coincided with changes in the behavior of migratory birds. Depending on each individual specieslifestyle, birds that breed in the northern U.S. and southern Canada may either delay or advance the date at which they begin their journey south in the fall. Because [...]

Over the last 40 years in the eastern U.S., there has been an increase in the frequency during warm months of 30-day periods when there is no rain. These dry spells now occur about twice as often as they did in the 1960′s. Rainfall events push water through municipal sewer and storm water systems. During [...]

The amount of energy that the North Atlantic Basin accumulated over the last 50 years is equivalent to almost four trillion tons of TNT (1.610 1022 joules). This energy has not been distributed uniformly, as the tropical and subtropical regions of the North Atlantic have warmed the most, and the subpolar region has actually cooled. [...]

The Atlantic Multidecadal Oscillation (AMO), or the North Atlantic’s periodic shift (65-year period) from predominately warm to predominately cool regimes, controls much of the climatic variability in the Northern Hemisphere. During warm (positive) AMO phases, the Northern Hemisphere is generally warmer, by as much as a few degrees Fahrenheit when compared to the cool phases. [...]

A warmer atmosphere results in an amplification of the water cycle. Some areas of the world are net importers of rainfall (such as tropical rainforests), while some are net exporters (such as oceans around the tropics). The “amplification” of the cycle means that dry regions become drier, and wet regions become wetter. During the 20th [...]

Prior to European settlement, Longleaf Pine forests covered a 140 million square mile area that runs along the Atlantic and Gulf Coasts from Southern Virginia to Texas. Frequent, low-intensity fires, which traditionally happened every two to four years and would sweep across the forest floor like a broom without killing the Pine trees themselves, keeping [...]