Last week, the East Coast of the United States got hit with the first snowstorm of Winter 2019. The powerful storm dropped about 7 inches in southeast New York (my back and arms are still sore), and up to 1.5 feet in areas of Rhode Island and Massachusetts.
Just a couple days before the storm, the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite captured this image of a wide arc of clouds stretching across the northern part of the nation.
“The arc is a cirrus cloud associated with the jet streak. There was just enough moisture and upward motion to create localized cirrus clouds on the poleward side of the jet stream,” explained Emily Berndt, a Short-term Prediction Research and Transition Center (SPoRT) scientist at NASA’s Marshall Space Flight Center.
Jet streaks, like jet streams, play a key role in weather prediction. Jet stream winds steer air masses and storms while jet streaks—pockets of extremely fast winds embedded within the jet stream—are associated with rising air and can triger clouds and precipitation.
According to NASA, When the image was acquired, air was circulating around the entrance of the jet streak near Nebraska. As air enters a jet streak, it generally speeds up. In this case, warmer air was rising to the south of the cloud band, and cooler air was sinking north of it.
“After the cirrus clouds formed, strong winds associated with the jet streak whisked them downstream, pulling them north and east,” noted SPoRT scientist Christopher Hain.
More on MODIS
The MODIS instrument provides high radiometric sensitivity (12 bit) in 36 spectral bands ranging in wavelength from 0.4 µm to 14.4 µm. The instrument’s Scan Mirror Assembly uses a continuously rotating double-sided scan mirror to scan ±55-degrees and is driven by a motor encoder built to operate at 100 percent duty cycle throughout the 6-year instrument design life. The optical system comprises a two-mirror off-axis afocal telescope, which directs energy to four refractive objective assemblies; one for each of the VIS, NIR, SWIR/MWIR and LWIR spectral regions.
A high-performance passive radiative cooler provides cooling to 83 K for the 20 infrared spectral bands on two HgCdTe Focal Plane Assemblies. Novel photodiode-silicon readout technology for the visible and near infrared provide quantum efficiency and low-noise readout with exceptional dynamic range. These MODIS instruments offer a look at terrestrial, atmospheric and ocean phenomenology for a wide community of users throughout the world.
Republished courtesy of Adam Voiland, NASA. Photo: NASA Earth Observatory image by Lauren Dauphin.