307 Flashcards Preview

Mod3 > 307 > Flashcards

Flashcards in 307 Deck (27)
Loading flashcards...

2 means of using precision grid lines to provide accurate reference on a satellite image

-Lines depicting geographical and geopolitical boundaries
-lines of lat and long
--usually to within 4km of actual position
--POES is less accurate because of fast relative motion.


examples of of geography affects satellite imagery

-Sloping terrain-orographic lift
-land/water interface - sea breazes, air mass modification
-Valley effects- valley fog, inversions, snow on ground


5 characteristics of cloud pattern recognition on SAT imagery



Ways to 'proof', or integrate data

-surface reports
--pilot reports
-Upper air soundings
-surface and upper air analysis


Shadow length determination
-VIS or NIR only

-Solar elevation
-Height separation between layers
Small sepration will cast narrow shadows
large separation will cast pronounces shadows


2 factors of texture on VIS

-Shape of cloud structure
-Degree of lighting


3 factors of tone (brightness)

-Height of sun
-Sensor reviewing anglr
-Albedo of surface


Factors that affect the tone of grey on any SAT image

-Cloud composition
-Thickness of cloud
-Resolution of sensor
-Enhancement of curve


High cloud on SAT

-Size - mesoscale to synoptic, dependent on extent of physical processes
-shape - defined by generating physical processes
---often elongated streaks
---ill defined, whispy, fibrous
-shadow, may cast moderate shadow on lower layers
-Texture/tone - VIS fibrous, whispy, thin white.
-IR minimal texture
- grey to white. dependent on thickness



Size-larger than mesoscale, dependent on physical processes
-Shape - edges well defined
-mountains may induce gravity wave patterns
-Shadow- may cast shadow on lower deck
-texture and tones - VIS, AS smooth, no texture, grey to white. -AC minimal texture
-IR little texture, grey to white ~temp


Low Level Cloud on SAT, ST FG

-Size- generally a local phenomena
-Shape- defined by terrain,sharp edges associated with topo features
-Shadow -Cast NO shadow
-Texture and Tone - smooth, little or no texture,VIS may show whisps over water, IR will not distinguish different surfaces of like temp, inversions appear dark


Low Level Cloud on SAT, SC

-Size- mesoscale or larger
-Shape - Defined by physical process, terrain and topo can influence shape, edges not sharp
-Shadow- little to none
-Texture and tone - VIS - fairly smooth, lumpiness depends on stability, roughness and underlying surfaces and boundary conditions, white to grey.
IR - usually smooth, minimal texture, grey.


Low Level Cloud on SAT, CU, TCU

-Size - individual clouds are mesoscale or less
Shape - circular shapes that can be organized into lines or streaks, sharp edges. influenced by processes and terrain.
-Shadow -May cast shadow on lower decks, depending on vertical extent
-Texture and tone- VIS - very lumpy globular, bright white
- IR - moderate texture


Low Level Cloud on SAT, CB

-Size individual clouds are mesoscale
-Shape -circular, sharp except anvil top,blown downstream if upper winds are significant, edges are sharp
-Shadow - May cast strong shadow on lower decks
-Texture and tone -VIS -very lumpy, globular, bright white.
IR - Strong texture, bright white


Areas of stability on SAT

-Smooth texture
-uniform, extensive coverage
-uniform temps


Areas of instability on SAT

-Brighter responses
-Globular, anvils
-Strong contours (enhanced IR)


Pattern recognition

-Comma looking returns are occluding systems


Techniques to recognize the centre of a low on SAT

-Pattern recognition
-Dynamic support deduction,-usually found under the strongest positive vorticity advection
-ground truthing with surface obs
-Warm front will be on the southern part of the CS or continuous middle cloud


Techniques to recognize the jetstream Axis

-CI baroclinic leafs from to the south of an anticyclonic jet.
-Maximum wind axis coincides with the dry air intrusion
-In the absence of high cloud, separates various low clouds
-combo of any or all of above


Areas of turbulence on SAT

-Strong surface wind - SC, CU. BL
-Convection -CU,TCU,CB ACC
-Stationary waves- rotor clouds, acsl, band clouds,
-Windshear - Transverse cloud banding, CI leafsm commas.
Deformation zones - band and comma cloud


Appearance of deformation zone is controlled by

-relative atmospheric flow
-strength of convergence
-the available moisture


On VIS 3 factors that lower reflectivity

-Sun angle falls below 45 degrees
-aging snow cover will have lower albedo
rain o snow will have a lower albedo


Black Stratus

-Strong inversion will show stratus as darker than the underlying ground


Sun Glint

-GOES - s of 23.5 N only
POES- ~on relative position of satellite and sun, may appear as a band
-Smooth surface - concentrated and very white
-rough surface - large, diffuse, not as white


2 requirements for Streamers

-A large body of water
-A source of cold air moving over that body of water
---temp differential of 13c
---fetch equal to or greater than 150 km
---Wind shear of 30 degrees or less below 10000 ft


Orographic cloud on SAT

Size- mesoscale
-Shape- parallel bands uniformly spaced
-Shadow - not prominent
-Texture/tone - VIS - banded, grey, white
IR -a little texture in band, grey to whire


Hurricanes on SAT

-Size - Synoptic
-Shape - Spiral bands
-Shadow - on the leading edge with isolated cells
tone/texture - spiral texture, white.