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Winter Ecology. Why is it cold in winter?. We’re farther away from the sun? NO!! We’re tilted away from the sun? YES!!. Scranton, PA. Scranton, PA Weather Records. Types of Snow Crystals:. The most basic snow crystal is a hexagonal prism and can come in many shapes and sizes.
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Why is it cold in winter? • We’re farther away from the sun? NO!! • We’re tilted away from the sun? YES!!
Types of Snow Crystals: The most basic snow crystal is a hexagonal prism and can come in many shapes and sizes. The prism has 8 sides: 2 surfaces known as basal facets and 6 prism facets.
How does a dull hexagonal ice crystal make such beautiful and elaborate flakes? The intricate flakes come from the condition in which the ice crystals are formed.
Types of Snow Flakes Simple Prisms
Life History of a Snowstorm • Powder • Destructive metamorphism • Constructive metamorphism • Melt metamorphism
Constructive Metamorphism • Temperature gradient in snowpack…where is it warmer, top or bottom? • Ice sublimates, vapors moving up • Warmer top melts a little, joining grains as it refreezes • Lower sublimation continues, leaving depth hoar • Creates subnivean zone • Destabilizes snow pack…avalanche danger!
Northern Shrike Common Redpoll
What Do Organisms Do in Winter? • Die • Migrate • Hibernate • Stay and tough it out!
The Pro’s ? The Con’s DANGEROUS! (more than half never return) DANGEROUS!! (going to unknown area; hiding places, food sources, etc.) DANGEROUS!!! (already inhabited with competitors) Why Migrate?
Avoid Freezing Garter Snake hibernaculum in Canada