Images
September 28, 2010 - Cloud patterns over the eastern United States
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A pinwheel-like pattern of high pressure clouds stretches across the eastern United States at 3:05 PM Eastern Daylight Time (19:05 UTC)on September 23, 2010. At that time the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard the Aqua satellite passed overhead and captured this true-color image. The high pressure weather system that brought fair weather and relatively clear skies to the United States also created this atmospheric art.
The circular pattern to the clouds—stretching from Ohio to Florida and from Arkansas to the Atlantic Coast—was caused by the flow of air around a sprawling high-pressure ridge centered in western Virginia, North Carolina, and eastern Tennessee. In meteorology, high pressure ridges form where air is sinking from high altitudes toward Earth's surface. The descending air flows out from the center in clockwise spirals in the northern hemisphere and counter-clockwise in the southern hemisphere.
The relatively low-level cumulus clouds (below 15,000 feet) shown in this image are likely the product of moisture near ground level being cooked by the Sun and convected into the lower atmosphere. Because the winds at that level are pretty strong, the clouds aligned parallel to the direction of wind flow, in “streets” curving along with the flow of the high-pressure system.
“To have convective clouds in such a strong flow is a bit unusual in the summer or even early fall,” said NASA atmospheric researcher Tom Arnold, “since winds at that level tend to be weaker in the summer months. It's a sight more common to large cold air outbreaks in the winter over the warm Gulf Stream waters.”
The heavier cloud cover to the north and west of this circular pattern was likely a response to a low-pressure system and to jet stream dynamics. The flow around the western side of the high and eastern edge of the low drew abundant moisture from the Gulf of Mexico.
Image Facts
Satellite:
Aqua
Date Acquired: 9/23/2010
Resolutions:
1km ( B), 500m ( B), 250m ( B)
Bands Used: 1,4,3
Image Credit:
Jeff Schmaltz, MODIS Land Rapid Response Team, NASA GSFC
A pinwheel-like pattern of high pressure clouds stretches across the eastern United States at 3:05 PM Eastern Daylight Time (19:05 UTC)on September 23, 2010. At that time the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard the Aqua satellite passed overhead and captured this true-color image. The high pressure weather system that brought fair weather and relatively clear skies to the United States also created this atmospheric art.
The circular pattern to the clouds—stretching from Ohio to Florida and from Arkansas to the Atlantic Coast—was caused by the flow of air around a sprawling high-pressure ridge centered in western Virginia, North Carolina, and eastern Tennessee. In meteorology, high pressure ridges form where air is sinking from high altitudes toward Earth's surface. The descending air flows out from the center in clockwise spirals in the northern hemisphere and counter-clockwise in the southern hemisphere.
The relatively low-level cumulus clouds (below 15,000 feet) shown in this image are likely the product of moisture near ground level being cooked by the Sun and convected into the lower atmosphere. Because the winds at that level are pretty strong, the clouds aligned parallel to the direction of wind flow, in “streets” curving along with the flow of the high-pressure system.
“To have convective clouds in such a strong flow is a bit unusual in the summer or even early fall,” said NASA atmospheric researcher Tom Arnold, “since winds at that level tend to be weaker in the summer months. It's a sight more common to large cold air outbreaks in the winter over the warm Gulf Stream waters.”
The heavier cloud cover to the north and west of this circular pattern was likely a response to a low-pressure system and to jet stream dynamics. The flow around the western side of the high and eastern edge of the low drew abundant moisture from the Gulf of Mexico.
Image Facts
Satellite:
Aqua
Date Acquired: 9/23/2010
Resolutions:
1km ( B), 500m ( B), 250m ( B)
Bands Used: 1,4,3
Image Credit:
Jeff Schmaltz, MODIS Land Rapid Response Team, NASA GSFC
