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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. [...]

During the warm seasons (spring through fall), the water in the Baltic Sea is stable and stratified. This means that the warmest and least dense water is on the surface, and as you dive deeper and deeper, layers of progressively colder, saltier, and denser water are encountered. During the decades of the 1970’s and 1980’s, [...]

Polar bears, Earth’s largest land predator, are most common on annual sea ice that sits over shallow seas. This ice provides the bears with a platform from which they can hunt for food. In Canada’s Western Hudson Bay region, which is at the southernmost extent of the polar bear’s range, winter and spring are the [...]

Climate variability in the mid- to high-latitudes of the Northern Hemisphere, or the area from about 35 degrees North to the poles, is largely controlled by two naturally occurring climate oscillations, the Pacific Decadal Oscillation (PDO) and the North Atlantic Oscillation (NAO). In 1977, both oscillations shifted from negative to positive phases, which resulted in [...]

The summer of 2003 was one of Europe’s warmest on record and maximum sea surface temperatures (SSTs) in the Mediterranean were well above average (by about 2.5 degrees Fahrenheit). These temperatures were the highest recorded between 1972 and 2004.  Also during this period, years when the maximum water temperature was above average were years when [...]

In the Pacific Northwest, Mountain Hemlocks grow at elevations between 3,600 and 7,500 feet. These shade tolerant trees grow underneath the faster growing but shorter-lived Douglas Firs, and gradually make their way to the top of the canopy over their 700 year life spans. At the region’s high elevations, some of the world’s most extensive [...]

The tropical Pacific basin is one of the planet’s warmest ocean regions, with surface water temperatures rarely falling below 83 degrees Fahrenheit. These perennially warm temperatures provide the fuel for tropical cyclone formation, and the strongest cyclones on record have formed here. Because these waters are already above the threshold for tropical cyclone formation, slight [...]

Convective available potential energy (CAPE) is a measure of how much energy is available for storm development (CAPE is measured by the number of joules present in a kilogram of air). Generally, the hotter and more humid conditions are, the more CAPE is present. A collection of atmospheric conditions, including some CAPE, are necessary for [...]

Eighty-three (83) percent of the moisture entering tropical Africa originates in the Indian Ocean. Over the last four decades of the 20th century, sea surface temperatures (SSTs) in the tropical Indian Ocean rose by nearly two degrees Fahrenheit, making these waters the warmest they have been in 120,000 years. As this has happened, rainfall over [...]

The Labrador Sea Water (LWS) is a stream of cold, fresh, and oxygen rich water that travels down the western Atlantic coast from the Labrador Sea, which is located between Greenland and Newfoundland, towards the Equator. This stream forms in the late fall/early winter after the seasonal accumulation of glacial melt water, which is less [...]

The Arctic Ocean is surrounded by a series of river drainage basins, which collectively occupy an area 1.5 times that of the ocean basin itself. No other ocean basin’s temperature and salinity levels are more dependent on what happens on the adjacent land surface. These temperature and salinity levels in turn influence the behavior of [...]

While land and sea surface temperature trends are the most common measures of climate change, changes in bottom temperatures, especially in shallow seas, can have major implications for marine species. Ocean species can generally adjust their ranges more easily than land species, as there are fewer geographic barriers in the ocean and many fish species [...]

The El Niño 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 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 [...]

The El Niño-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 Niña phases of the cycle, the [...]

Over the past century, measurements taken at geologically stable locations show that the global sea level rose by eight inches, with most of this rise happening over the second half of the 20th century. Measurements taken at most coastal locations, however, rarely correspond to this global value because near-shore environments are naturally dynamic. Storms, natural [...]

A common cotton disease in the southeast, hardlock, is caused by fungus and affected by temperature and humidity. The disease does better during years when humidity and rainfall levels are above average, especially during the months of July to September, when cotton plant flowers and bolls (pods containing 32 seeds from which the cotton fibers [...]

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 [...]

Ranging in size from barely visible to nearly 30 feet long, nematodes, or roundworms, are the most abundant animals on Earth. Because they comprise a substantial percentage of the animal life on the seafloor, changes in their abundance and diversity there can have major implications for ocean ecosystems. Between 1992 and 1994 in the deep [...]

Ocean currents transport heat from the Equator to the higher latitudes, as well as nutrient rich water from the depths of the ocean to the surface. The transport of cooler, nutrient rich water upward is a process known as upwelling. Upwelling feeds much of the life at the ocean’s surface, and 20 percent of the [...]