Lesson 307 Satellite Imagery Interpretation

Question 1

Why are geographical features important to satellite imagery?

Answer 1

Geographical features substantially influence the formation and dissipation of cloud, snowfall/rainfall and vegetation cover. Topography greatly influences the weather.

Question 2

Which image will sometimes display displaced geography?

Answer 2

On POES images due to the satellite moving very quickly.

Question 3

What are the five characteristics of cloud pattern?

SSSTT

Answer 3

Size of clouds or cloud groupings
Shape of clouds or cloud groupings
Shadow vertical structure (VIS and NIR only)
Texture of the surface
Tone or radiation flux (grey shade)

Question 4

Which satellite images will display a shadow?

Answer 4

VIS and NIR

Question 5

What factors will affect the tone of grey on all images?

TREC

Answer 5

Thickness of cloud
Resolution of sensor
Enhancement curve
Cloud composition (ice crystals vs. Water droplets)

Question 6

How can we determine between low clouds and water bodies using satellite imagery?

Answer 6

Compare IR and VIS imagery. Keep in mind the temperature of bodies of water. Gaps wide enough to be resolved by the sensor occurs frequently over water surfaces.

Question 7

Why may thin cirrus not be accurately displayed on IR imagery?

Answer 7

Cirrus clouds are partially transparent to IR radiation at 11 microns

Question 8

Which cloud casts the longest shadow?

Answer 8

Cumulonimbus

Question 9

Why are areas of instability easier to identify on satellite imagery?

Answer 9

Due to distinct,easily recognizable signatures.

Question 10

Which image is the best to identify the position of the jet stream?

Answer 10

Water vapour then IR and VIS.

Question 11

Name the five atmospheric processes that indicate the possibility of turbulence on satellite imagery.
SCSWD

Answer 11

Strong surface winds
Convection (CU,TCU,CB,ACC)
Stationary waves (Chinook) rotor cloud, ACSL, band clouds
Wind shear (jet stream) transverse banding, CI leaf, comma
Deformation zones - band and comma clouds

Question 12

As the air in the flow successively rises and falls, cloud successively forms and dissipates creating the characteristic __________ __________ which is usually indicative of moderate to severe turbulence.

Answer 12

Transverse banding

Question 13

How can we differentiate between ice/snow and clouds?

Answer 13

Ice generally has a mosaic pattern to it with some larger leads appearing black. The reflectivity of snow when the sun angle falls below 45 degrees,aging snow and rain on snow have lower albedo, snow on different types of terrain. Use animation to help identify.

Question 14

What is the main factor for the formation of stratus which is known as black stratus on IR imagery?

Answer 14

Strong radiation cooling during the night-time hours creates a well-defined boundary layer temperature inversion making the altitude of the stratus cloud tops several degrees warmer than the surrounding cloud free surface.

Question 15

What can visually differentiate between a tropical storm and a hurricane on satellite imagery?

Answer 15

The tropical storm lacks an eye at the centre.

Question 16

Which images better display smoke?

Answer 16

POES NIR and VIS and GOES VIS. The point source of the smoke will remain immobile and is indicative of the location of the fire.

Question 17

At least two ingredients are needed to form streamers, they are:

Answer 17

A large body of open water

A source of cold air moving over that open water

Question 18

What are some forms of data a briefer must integrate for proper and informed interpretation of cloud structures on satellite imagery?
SPURS

Answer 18

Surface reports
Pilot reports
Upper air soundings 
RADAR imagery
Surface and upper air analysis