1. Key components of the iron fertilization feedback include: More dust delivery
ID: 291263 • Letter: 1
Question
1.
Key components of the iron fertilization feedback include:
More dust delivery in cold climates
A larger equator-to-pole temperature gradient
Stronger biological pump leading to more carbon deposition in the deep ocean
All of the above
None of the above
2.
More algae growth leads to ____ low clouds, ____ warming and a _____ feedback during ice ages.
less; more; positive
more; less; positive
more; more; positive
more; less; negative
3.
Dansgaard-Oeschger events were rapid ______ events, identified in ice core data by more _______ ?18O values. (note: 'enriched' means higher or less negative, 'depleted' means lower or more negative)
cooling; depleted
warming; depleted
warming; enriched
cooling; enriched
4.
The Younger Dryas event (12,800 to 11,500 years ago) is thought to have been caused by a slowdown of the formation of the North Atlantic deep water. What is thought to have caused this slowdown?
Increases in sea ice formation
The melting of Antarctica
An abrupt influx of freshwater from a large glacial lake
Slowed upwelling in the Pacific
High precipitation rates
What does the ?18O data shown above from the Greenland NGRIP ice core tell us about Greenland air temperatures since 8000 years ago until today?
There has been a slow general cooling
There has been a slow general warming
6.
During the last interglacial (Eemian), CO2 was at 280 ppm but it was much warmer than today because of
increased ice sheet extent
orbital configurations leading to more solar radiation at 65 N
greenhouse gases being higher than today's concentrations
more ocean upwelling
AMore dust delivery in cold climates
BA larger equator-to-pole temperature gradient
CStronger biological pump leading to more carbon deposition in the deep ocean
DAll of the above
ENone of the above
33r -33.5 Greenland NGRIP -34 -34.5 9 35 35.5 36 -36.5 -37L 10,000 9,000 8,000 7,000 6,000 5,000 4,000 3,000 2,000 1,000 0 Years before presentExplanation / Answer
1. Iron fertilization feedback includes a high equator-pole temperature gradient, increased dust supply to oceans, strong carbon uptake, and deposition in oceans. So, option D. is correct.
2. Marine algae release dimethyl sulfide which acts as aerosols forming clouds. So, their growth leads to more low clouds, less warming which reverses the positive feedback loop and hence a negative feedback. The correct option is D.
3. Dansgaard-Oeschger events were rapid warming events, identified in ice core data by more depleted 18O values. Delta O18 values decrease with increasing temperature. So, option B. is correct.
4. An outburst from a glacial lake called Lake Agassiz in the geological North American continent caused the slowdown of North Atlantic conveyor belt by providing cold, freshwater. So, option C. is correct.
5. Since 8000 years, there has been a gradual warming as the delta O-18 values have fallen with time. The lighter isotope of oxygen becomes enriched in fossils as the temperature and precipitation increases. So, option B. is correct.
6. The Eemian Period was warmer because orbital forcings, particularly eccentricity and obliquity, greatly amplified the pattern of solar radiation falling on the Northern Hemisphere. So, option B. is correct.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.