Quiz 4 Flashcards
Weather
Present conditions of the atmosphere over periods of up to 2 weeks
Climate
Average conditions of all environmental components (temp, rainfall, pressure, particle counts) over a time of usually 30 years
Low change (climate)
Proximity to oceans, altitude, proportion of land to water
Dynamic change (climate)
Ocean currents, density and type of vegetation coverage, changes in quantity of greenhouse gas
Climate change
rise in surface temps, drought, shift in ocean and wind currents
Global Warming
ongoing rise in mean surface temps across Earth
Prehistoric Climate Change caused by…
movement of continents, wobbles in Earth’s orbit, Volcanism, changes in solar energy output, asteroid impact, dinosaur gas
Previous climate changes
Snowball Earth (700 mya)
Cretaceous period (100 mya)
PETM (55 mya)
Pliocene (3 mya)
Glacial cycles
Driven by changes in Earth’s orbit, reinforced by greenhouse gases, positive feedback loop of more cooling
Last major ice age
Quaternary period (20,000 ya)
Present interglacial period
Holocene epoch
How are water temps measured?
ships in remote areas w/ drifting floats that measure, record and report to satellites directly
Proxy records
tree rings - more dense = cool season
Corals - skeletons made from extracts and precipitates of seawater
Clam shells - analyzed for chemical composition, oxygen isotopes present in the water
Pollen - preserved in lakes/bogs, changes in pollen shows changes in plants due to CC
Fossilized Vegetation and Insects - changes in type, distribution and coverage of vegetation
Milder changes = improved plant growth
Large changes = rapid loss, vegetation stress, desertification
Rock Hyrax Urine - stay in one place for generations, evident of climate events of last ice age
Ice Cores - Temp, ocean volume, gas comp., volcanic eruptions
Volcanic activity affecting climate change
Large eruptions cause ash to block incoming radiation, leading to worldwide temporary cooling
Temperature anomalies
Temperature change over time more important than absolute temp., show how temps have changed relative to common base period
Arctic Circle
Includes Article ocean, Greenland, Baffin Islands, Parts of Europe, Russia, Alaska, Canada, Iceland, Finland
Sea Ice
Different than icebergs, made of fast ice and drift ice
Sea Ice retreat
Less “old” ice-more vulnerable to melting, loss of sea ice doesn’t result in significant sea level rise
Loss of Ringed Seals
adapted to living on stable article sea ice, create breathing holes.
Warming causes loss of sea ice, collapse of lairs=exposure to predators
Loss of sea-ice Polar Bears
Malnutrition, lower cub survival, cannibalism
Loss of sea ice Walruses
use ice to rest between dives, triggered increase in trampling deaths, shifted depth of hunting areas
Glaciers
Perennial mass of ice which moves on land
Glacier movement
due to pressure of own weight, retreat caused by increase in temps, evaporation
Continental glaciers
massive, thick ice sheets found at poles, cover entire surface beneath them
Alpine glaciers
Form on mountain slopes, valleys, cap mountains when snow piles up, turns into glacial ice - US, Switzerland, Norway
CC indicator: smaller, less stable
Terminal moraine
Melting zone of alpine glaciers
Glacier, ice cap retreat impacts
- seasonal meltwater important for water supplies
- more freshwater entering North Atlantic- may slow conveyor, leading to regional cooling
Rain on Snow Events
Warmer temps-more rain than snow, alternating freeze/thaw cycles. Creates crust.
Precipitation changes-reindeer
- Rain on top of snow creates crust=must use more energy to find food
- breaking through ice during migrations
- increased insects-decreased fitness
- changes in plant composition
Permafrost
Occur in soil where max annual below freezing for 2 or more years in shallow coastal sea bed
Loss of Permafrost
Frozen soil-like rock disintegrates when ice is removed, thawing creates cavities/depressions, long-term water drains from surface of soil, leading to drier conditions, increase in landslides, rock falls, erosion
Drunken forests
Ice normally stabilizes ground, trees grow on thin layer of soil over permafrost, when permafrost removed, shallow root bed undermined
Animals affected by permafrost loss
Lemmings - collapse of foraging spaces
Birds/Mammals dependent on forests
Effect of permafrost loss on humans
Infrastructure - shifting soil
Ice roads-built seasonally but more stable when ground is frozen
Greening of Arctic earlier
Disrupts local populations because of change in composition of plant communities, peak vegetation coming earlier before calving season of caribou
Marginal ice zones
Where drifting pack ice meets open water, nutrients build up under ice in water, exposure to light =increased primary productivity
Primary consumers of Sea Ecosystems
Zooplankton - eats smaller particles, photo plankton, smaller zooplankton, detritus
Copepods
Krill, which whales feel on
Secondary Consumers of Sea Ecosystems
arctic cod, char, jellyfish
Some have antifreeze compounds in blood
Top Predators of Sea Ecosystems
Arctic whales - beluga, narwhal, polar bear, walrus, seabirds
Detritus
Old ice algae, dead organisms, fecal pellets, suspended in water gradually settles to sea floor - eaten by seals, walruses, gray whales, ducks
One of the largest migrations of any mammal annually
Gray whales migrate 10,000 mi to feed on crustaceans living on sea floor Coastal CA to Bering Sea
Ozone depletion
Hole grows each year-Largest in Sept.
- Might have dominant role in recent climate change in this area
- prevents outflow of cold air near south pole
Does loss of sea ice result in significant sea level rise?
No, they are typically made of drift ice and are not as dense as glaciers
T or F: The present warming we are seeing is higher than ever seen in the geologic record of the Earth’s history
False
If the global mean temp measurement for the year 2015 was 68 deg F, and the avg. global mean temperature measurement from the base period of 1950-1980 was 70 deg F, what would be the temperature anomaly for the year 2015.
-2 degrees F
The Article circle is located above what latitude
66 deg N
Of the ways to measure the temperature of the Earth, which has the longest record
Air temperature
T or F: The scientific study of climate change and the effects of CO2 emissions on the Earth began in the 1950s
False
