July's Extreme Heat

Vegetation anomalies in North America (July 2011)

Throughout July 2011, the United States experienced extraordinarily high temperatures and many states in the Southwest felt the effects of drought conditions. The impact of this drought on vegetation growth can be seen in the photo above. The image, from the NASA Earth Observatory, displays vegetation anomalies across North America in July. To learn about the national weather pattern that caused such extreme conditions, visit this NOAA page. The progression of the heatwave can be seen in these two NOAA Environmental Visualization Laboratory animations that show how conditions changed throughout the second half of the month:

• High Dew Point Makes Heatwave Miserable
• Heat Wave Sweeps Across The U.S.

The Conveyor Belt

In honor of Discovery Channel's Shark Week, the CRE Blog is featuring ocean-related content  this week.

This image, from NASA, shows temperature values in the Gulf Stream.

The Gulf Stream is a warm ocean current that influences the climate on both sides of the Atlantic Ocean. By transporting warm water from Florida, up the United States' eastern seaboard, and across the Atlantic to Europe, this current creates warmer climates than otherwise would be possible from Bermuda to Northern Europe. Click here for maps of current sea surface temperatures in the Gulf Stream.

The Great Ocean Conveyor Belt

The Gulf Stream is one part a Global Conveyor Belt, known as Thermohaline Circulation, in the oceans that moves warm and cold water throughout the Earth's oceans. It is driven by density. Cold, dense water in the polar regions sinks, flows toward the equator, and rises back toward the surface. Warm water originating in the equatorial regions, on the other hand, is less dense and flows across the surface of the oceans toward the polar regions. These currents have a vital impact on the entire global climate. Click the animation above to see it in action!