Tag: meteorology

Maven makes first map of Mars’ high altitude winds

9:11 am

High altitude wind patterns on Mars

Scientists using the Martian orbiter Maven have produced the first global map of the high altitude wind circulation of Mars.

The measurements of winds that were recently mapped above Mars were found at an altitude range of about 140-240 kilometers (85-150 miles) above the planet’s surface.

The wind data has been gathered by the Neutral Gas and Ion Mass Spectrometer (NGIMS). NGIMS’ original purpose was to determine the structure and composition of the Martian atmosphere by measuring in it the amounts of ions (electrically charged particles) and gases. However, although it was not originally designed to do so, in April 2016, the MAVEN team began using NGIMS to observe horizontal winds. Pausing normal collection of data, scientists on Earth programmed the instrument to nod back and forth so that it could detect the direction of winds along its track.

By combining data from many tracks as MAVEN orbits Mars, scientists slowly built up a map of wind behavior. This led to a startling discovery: the wind patterns actually correlated with the Martian topography below.

They have found that even at this high altitude the winds shift around the high volcanoes of the Tharsis Bulge.

To my eye, the wind pattern seen in the image, taken from the video at the link, is remarkably similar to the global wind patterns found on Venus, forming a widening V-pattern moving from east to west. Though the two are vastly different, the similarity is quite intriguing.

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Do tornadoes form top-down or down-up?

10:13 am

The uncertainty of science: New data now suggests that tornadoes might form from the ground upward, not from the clouds downward, as previously and generally accepted believed.

Houser and a team of researchers from the University of Oklahoma happened to be monitoring the storm with a new type of mobile Doppler radar system that collected tornado wind speeds every 30 seconds. Afterwards, Anton Seimon, a geographer at Appalachian State University in Boone, North Carolina who had chased the El Reno storm, collected hundreds of still photos and videos of the epic twister from citizens and fellow storm chasers.

When Houser compared her radar data with images collected by Seimon, she noticed something odd. The images clearly showed a visible tornado at the ground several minutes before her radar picked it up. Puzzled, Houser went back through her radar data and analyzed the data taken at the ground. It is typically difficult to get good radar measurements at or near the ground, but Houser and her team had deployed their instrument on a slight rise and there were no obstructions between them and the tornado, so this time, they had data good enough to work with.

She found clear evidence of rotation at the ground before there was rotation at higher altitudes. Houser then examined other sets of tornado data and found that in many cases, tornado-strength rotation develops at or near the ground first, rather than starting in the cloud itself. In all four datasets she analyzed, none of the tornadoes formed following the classical “top-down” process.

What is really interesting about this research is that it shows that at least some tornadoes develop from the ground up, something no one predicted. The research also illustrates that the formation of tornadoes is very complicated and that we still do not understand it, in the slightest.

While the researchers here try to imply that this data also proves that all tornadoes must form from the ground up, they are wrong. The data shows that some appear to form from the bottom up, but this does not prove that others might do the opposite. We simply do not know enough yet.

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India wins contract to launch private weather satellites

8:39 am

The competition heats up: The first two satellites in the first private weather satellite constellation will be launched on India’s PSLV rocket.

With 12 satellites on orbit, PlanetiQ will collect approximately 34,000 “occultations” per day, evenly distributed around the globe with high-density sampling over both land and water. Each occultation is a vertical profile of atmospheric data with very high vertical resolution, comprised of measurements less than every 200 meters from the Earth’s surface up into the ionosphere. The data is similar to that collected by weather balloons, but more accurate, more frequent and on a global scale.

“The world today lacks sufficient data to feed into weather models, especially the detailed vertical data that is critical to storm prediction. That’s why we see inaccurate or ambiguous forecasts for storms like Hurricane Joaquin, which can put numerous lives at risk and cost businesses millions of dollars due to inadequate preparation or risk management measures,” McCormick said. “Capturing the detailed vertical structure of the atmosphere from pole to pole, especially over the currently under-sampled oceans, is the missing link to improving forecasts of high-impact weather.”

This project is a win-win for aerospace. Not only will this weather constellation help shift ownership of weather satellites from government to private ownership, the company’s decision to use India’s PSLV rocket increases the competition in the launch industry.

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The weather on an exoplanet: Cloudy and clear.

3:09 pm

The weather on an exoplanet: Cloudy and clear.

Astronomers using data from NASA’s Kepler and Spitzer space telescopes have created the first cloud map of a planet beyond our solar system, a sizzling, Jupiter-like world known as Kepler-7b. The planet is marked by high clouds in the west and clear skies in the east. Previous studies from Spitzer have resulted in temperature maps of planets orbiting other stars, but this is the first look at cloud structures on a distant world.

This result is cool, but no one should take it too seriously. They have detected evidence of that to the scientists “suggest” clouds, but no one really knows.

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