Satellite Imagery Interpretation

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The SKY

• • • • Biggest lab in the world.

Available to everyone.

We view from below.

Satellite views from above.

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Why Are Satellites Important?

• • • Monitor atmosphere, land surface, and oceans at multiple scales using a single instrument.

Consistent global, high-resolution coverage over oceans, rugged terrain, and sparsely populated regions.

Another observed data set in forecasters toolbox to help solve meteorology and hydrology problems.

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Satellite Types

• • Geostationary:  Same position near equator – same rotation speed as earth.

 Constant height – 36000 km (22,400 mi).

 Resolution - 1 km visible to 4-8 km IR and H 2 O channels.

Polar Orbiting:  Every orbit passes over the poles.

 Height around 850 km  Scan earth in 2600 km wide swaths  View same location twice at equator; overlaps toward converging longitudes at poles.

 Resolution – 250 m (4 times more detail than GOES).

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Geostationary Satellite View

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Geostationary Satellite Global Coverages

(1) GOES East (12) – 75W (2) GOES West (10) – 135W (3) MTSAT (Japan) – 135E (4) METEOSAT 5 – Indian Ocean (5) METEOSAT 8 – Europe - 0°

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Geostationary Satellite View

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Polar Orbit Viewing Earth

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Satellite Radiometers

• • • • • Measure radiation of different wavelengths in discrete intervals Intervals are called windows, channels or spectral bands GOES measures five spectral bands; one visible and four IR Use mirrors to scan a region Transmit digital data to earth for processing 10

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GOES Satellite Basics

• 5-channel Imager:  Visible (0.69 μm): Distinguish thick from thin clouds, identify snow, fog, smoke  Near-IR (3.9 μm): Distinguish water and ice clouds and cloud particle size  Water Vapor (6.7 μm): Upper-level wind patterns, atmosphere water content, specific moisture plumes  IR Window (10.7 μm): Temperature of cloud tops and ground surface  CO 2 Absorption (13.2 μm): Cloud heights • 19-channel Sounder:  Provides hourly 10-km data to distinguish vertical temp and moisture structure in the atmosphere 13

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Albedo

• Fraction of total radiation reflected by an object (surface).

• Varies according to:  Cloud cover  Particles in air  Angle of sun’s rays  Types of surface 15

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NIGHT 3.9

:

m DAY Transparent Reflected Solar Radiation

HIGH CLOUDS - ANVIL CIRRUS (ice) 10.7

m

m COLD 3.9

m

m relatively warm

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Thunderstorms

• Can see all scales of motion.

• Large complexes down to developing cumulus.

• Clouds outline moisture – shallow or deep.

• Identify boundaries.

• Causing severe signatures.

• Linear and clusters.

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Three biggest tornadoes in Kiowa county. 2 nd formed just east of Greensburg and quickly grew to 2 mi in width!

At least 2 smaller "satellite“ tornadoes with the 1 st tornado

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that formed S of Greensburg.

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Frances Jeanne

Florida’s Furiously Full Calendar!

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Aug. Charlie Ivan Jeanne 27

Courtesy: Palm Beach Post Steve Leach 28

Blowing Dust

• • Hazard to visibility and breathing.

Reveal wind patterns.

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Blowing Saharan Dust observed from SeaWifs: February 26, 2000

F R O N T D U S T MODIS Visible from Terra for 3-3-2004 moderate resolution imaging Spectroradiometer

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Florida Fires

• • • • Drought provided conditions.

Several fires grew out of control.

Several plumes caused Interstates to close.

A close-up Ch2 (3.9 μm) shows “hotspots” from numerous fires.

Band 2 2032z Image combined with 1302z-2032z Visible Loop 34

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Summary

• • • • • Satellite imagery is the “real world”, not model “fantasy” world.

We see all atmospheric scales of motion in a single image.

Satellite imagery interpretation is an art.

The imagery can help explain weather events.

We cannot start too soon (in school) educating people in identifying features in the imagery.

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Satellite Links

Local Visible Loops: http://www.rap.ucar.edu/weather/satellite/ Geostationary Satellite Server: http://www.goes.noaa.gov/ RAMSDIS online: http://www.cira.colostate.edu/RAMM/Rmsdsol/main.html

NASA Global Hydrology and Climate Center: http://wwwghcc.msfc.nasa.gov/GOES/ Space, Science and Engineering Center, U of Wisconsin, Madison: http://www.ssec.wisc.edu/data/ GOES Status: http://www.oso.noaa.gov/goesstatus/ POES Status: http://www.oso.noaa.gov/poesstatus/ Sam Beckman web site: http://home.earthlink.net/~weateach/wxforecast.htm

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