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Don Paul: New satellites offer more than just a pretty picture

The new GOES-16 satellite, now known as GOES-East, and the even newer GOES-17 are offering data and imagery of a spectacular nature. Even those only casually interested in weather are finding these images stunning. They are posted frequently on social media from many sources, including NOAA, NASA, the University of Wisconsin and even individuals like me retweeting these products, which are often accompanied by useful text explanations.

Like the other GOES satellites, GOES-16 is geostationary, facing Earth from a fixed altitude of about 22,000 miles and 72.5-degree west location so that an entire hemisphere can be captured in the images with continuity. Focused areas of severe weather can be zoomed tightly and subject to rapid image scans taken every minute.

The datasets produced by this newest generation of GOES satellites are enormous in size, complexity and usefulness. The phrase “quantum leap forward” applies to these satellites by every measure. As NOAA notes, “ABI views the Earth with 16 spectral bands (compared to five on previous GOES) and provides three times more spectral information, four times the spatial resolution, and more than five times faster coverage than the current system (previous generation GOES).”

Let’s go through the toolbox. The Geostationary Lightning Mapper, at right, gives real-time imagery of cloud-to-cloud and cloud-to-ground lightning strikes. Increased lightning activity is often a marker for intensification of thunderstorms and supercell thunderstorms. Current ground-based lightning detection does not include cloud-to cloud-activity. Of course, this lightning mapping information is readily available to local National Weather Service offices and the Storm Prediction Center.

And here is archived lightning mapping from last month's Hurricane Florence last month. Storm intensification was often accompanied by increased lightning:

Sensors include dual sun-facing instruments that detect increased X-ray and solar flare activity, which can impact communications and parts of the energy grid on earth. These sensors will afford greater lead time warning of impending solar storm arrivals, and improved abilities to take precautionary steps to prevent large-scale blackouts, as well as advise of increased radiation hazards to International Space Station astronauts. This information will be flowing into such clearinghouse centers as the NOAA Space Weather Prediction Center in Boulder.

[PDF: GOES-R Series Space Weather Instruments]

There is also is improved instrumented ability to monitor the earth’s magnetic field. NOAA: “The Magnetometer provides measurements of the space environment magnetic field that controls charged particle dynamics in the outer region of the magnetosphere. These particles can be dangerous to spacecraft and human spaceflight. The geomagnetic field measurements provide alerts and warnings to satellite operators and power utilities.”

On television, viewers see two basic types of satellite imagery: visible (daylight) and infrared/IR (24 hour, good for night hours). The resolution and detail of this imagery is hugely improved over previous satellite generations, but there are 16 channels of imagery (two visible, four near IR, and 10 IR) produced by GOES-16. These enable meteorologists to discern between smoke, ice, dust, volcanic ash and water vapor. They may not mean a lot to the on-air weathercast, but they have become vital in the forecasting process:

For much of the summer until September, Saharan dust being blown across the tropical Atlantic helped to suppress this year’s hurricane season. The dust filters solar input and heating, and is generally associated with dry, continental air, which discourages the development of tropical waves and cyclones. The high-resolution imagery of this dust was very useful to tropical meteorologists:

Finally, there is the super-high resolution 30-second imagery available from this generation of satellites during severe weather events. This product shows the evolving storm structures and intensity trends in virtual real time.

NWS Doppler radar takes six minutes for a full set of scans to be completed because the radar is sampling so many layers of the atmosphere per each complete storm examination. Those Doppler products are irreplaceable, but the speed and detail of GOES rapid scan imagery, used in concert with its lightning mapping adds so much to the available information on severe convective cells.

Additional recent good news comes from breakthroughs in the ability to incorporate all this additional satellite imagery into our numerical weather models. A great deal of research has been ongoing at Pennsylvania State University. It is believed this inclusion of data will bring important improvements in the ability to model and predict the development of tornadic supercells.

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