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In the Northern Hemisphere, deciduous trees are beginning to come out of their dormant season and unfurl their leaves. Soon, the greys and browns that characterize America’s broadleaf forests during winter will be replaced the by the greens of spring and summer. Over the last four decades, there has been a global trend in the [...]

Over the past 250 years, the amount of carbon dioxide (CO2) in the atmosphere has risen from 280 parts per million to almost 400. Plants use sunlight to convert this atmospheric carbon into the sugars and starches that make up their tissues. As the amount of carbon in the atmosphere changes, plant growth patterns change [...]

Changes in the amount of carbon dioxide (CO2) in the air have been shown to affect plant growth rates, the amount and quality of fruit plants produce and how much water a plant releases through evaporation. A study conducted between 1996 and 2001 in the western Great Plains (parts of Colorado and Wyoming) grew several [...]

The temperature/pressure difference between the equatorial regions and the poles is at its maximum during the winter months. The energy this difference generates is thought to power the “storm tracks,” or the bands in the mid-latitudes where east to west traveling storms (cyclonic high and low pressure systems) are most common. The storm track over [...]

Snow is both a product of the weather and a weather maker. It has long been recognized that snow exhibits a cooling effect on local and regional scales. Snow reflects more sunlight than bare ground, meaning that it absorbs less energy. More snow cover also means soils stay moist for longer following the spring melting [...]

Carbon is a critical element in the Earth system. Carbon molecules are constantly moving from different states and from reservoir to reservoir. One reservoir is the terrestrial biosphere (the life systems that exist on land), which holds carbon primarily in the form of plant matter and soil. The atmosphere holds carbon in the form of [...]

At any given time, there is about 22 million tons of dust suspended in the atmosphere around us. Dust has important effects on Earth’s climate. It absorbs and scatters incoming radiation, affecting how much sunlight reaches the Earth’s surface and how much is reflected back into space. How much sunlight reaches the Earth’s surface helps [...]

Even if the sun’s energy suddenly stopped, Earth would still give off heat for a while. This is because while much of the sun’s energy is reflected back into space, much of the energy that does reach the Earth is “stored” by the atmosphere, the oceans and the land. These bodies gradually release accumulated solar [...]

While commonly considered two separate lakes, Lakes Michigan and Huron are actually hydrologically one body of water – they are connected at the Straits of Mackinaw and rise and fall in unison. Since 1980, Lake Michigan-Huron has been warming and annually averaged surface temperatures are now 3.6 degrees Fahrenheit warmer than they were in the [...]

When put in 2000 US dollars, freezing rain (ice storm) events in America caused an estimated 16.3 billion dollars in total losses between 1949 and 2000 due to downed power lines, downed trees, agricultural losses, transportation accidents and medical costs from injuries due to slippery conditions. Freezing rain events are most frequent in the Northeast, [...]

In the Southern Ocean around Antarctica, strong winds accompany strong ocean currents that move carbon from the ocean surface to the depths and from the depths to the surface. This ocean is considered to be a “Carbon dioxide (CO2) sink,” or a component of Earth’s climate that takes in more atmospheric CO2 as carbon concentrations [...]

Air temperatures are fickle – they fluctuate significantly from day to day, from season to season and from year to year. The temperature of a water body fluctuates as well, but is much more constant than the surrounding air temperature. Water has a higher heat capacity than air, which means it takes far more energy [...]

Temperature records suggest that the Earth’s surface temperatures warmed during the early part of the 20th century, cooled from the period 1940-1970 and have since been warming. While Arctic temperature trends have corresponded to this general warming and cooling pattern, it has followed these trends more severely. During the warming period from 1910-1940, the Arctic [...]

Much attention has been given to the decline of sea ice over the North Pole, which fell to a September minimum of 1.6 million square miles in 2007, about 40 percent below normal levels. On the other side of the world, the sea ice that extends from Antarctica’s continental ice sheets out over the ocean [...]

Near the center of Antarctica in the polar vortex, strong westerly winds that blow in a circle around the continent during winter trap an envelope of air near the South Pole, prohibiting this air from mixing with warmer air masses closer to the equator. The extreme cold in the vortex causes clouds to form in [...]

Once water is evaporated from the ocean or a moist land surface, it may spend days traveling through the air. Complicated systems of winds at different levels of the atmosphere can transport moisture (as well as other gases and dust) from the point of origin to remote locations thousands of miles away. While about 30 [...]

December is East Coast Winter Storm (ECWS) season. These storms are powered by warm water that flows from the Gulf Stream. The Gulf Stream current flows along the Eastern Seaboard past Florida and the Carolinas before reaching Cape Hatteras, where the warm water heads out into the Atlantic. ECWS’s travel northward along the coast causing [...]

Winter storm season is here. Storms will be blowing in from the Pacific, bringing rainfall to lower elevations and snow to the mountains. This year, the eastern tropical Pacific is in an El Niño phase, meaning that its waters are warmer than average. When the eastern Pacific is in an El Niño phase, the northwestern [...]

Winter storm season is here. Storms will be blowing in from the Pacific, bringing rainfall to lower elevations and snow to the mountains. This year, the eastern tropical Pacific is in an El Niño phase, meaning that its waters are warmer than average. When the eastern Pacific is in an El Niño phase, the southern [...]

Winter storm season is here. Storms will be blowing in from the Pacific, bringing rainfall to lower elevations and snow to the mountains. This year, the eastern tropical Pacific is in an El Niño phase, meaning that its waters are warmer than normal. When the eastern Pacific is in an El Niño phase, the southwest [...]