Light

These flashcards cover key concepts related to light, its absorption, and its role in marine primary productivity.

What percentage of incoming solar radiation is absorbed by the ocean surface?

51% of incoming solar radiation is absorbed by the ocean surface.

What is the relationship between the angle of incidence and reflectance?

The greater the angle of incidence, the greater the reflectance.

How does light intensity change with depth in the ocean?

Light intensity exponentially decreases with depth.

Which color of light penetrates deepest into the water?

Blue light penetrates deepest into the water.

What drives photosynthesis in the ocean?

Light drives photosynthesis, which is the primary productivity in marine ecosystems.

What is the compensation depth (Dc)?

The compensation depth is where the carbon fixed via photosynthesis equals the carbon lost through respiration.

What does the critical depth (Dcr) represent?

The critical depth is where photosynthesis throughout the water column equals respiration.

What environmental factors can influence light availability in the ocean?

Factors include diel variations, seasons, latitude, particle density and size, upwelling, tides, currents, and land run-off.

In which ocean zone is light present but not sufficient for photosynthesis?

In the mesopelagic zone (200-1000 m), light is present but not enough to support photosynthesis.

What happens below 1000 m in the ocean concerning light?

There is no light below 1000 m except that generated through bioluminescence.

What percentage of incoming solar radiation is absorbed by the ocean surface?

51\% of incoming solar radiation is absorbed by the ocean surface.

What is the relationship between the angle of incidence and reflectance?

The greater the angle of incidence, the greater the reflectance.

How does light intensity change with depth in the ocean?

Light intensity exponentially decreases with depth according to Beer's Law: Iz = I0 e^{-kz}.

Which color of light penetrates deepest into the water?

Blue light penetrates deepest into the water.

What drives photosynthesis in the ocean?

Light drives photosynthesis, which is the primary productivity in marine ecosystems.

What is the compensation depth (D_c)?

The compensation depth is where the carbon fixed via photosynthesis equals the carbon lost through respiration.

What does the critical depth (D_{cr}) represent?

The critical depth is where photosynthesis throughout the water column equals respiration.

What environmental factors can influence light availability in the ocean?

Factors include diel variations, seasons, latitude, particle density and size, upwelling, tides, currents, and land run-off.

In which ocean zone is light present but not sufficient for photosynthesis?

In the mesopelagic zone (200 to 1000 m), light is present but not enough to support photosynthesis.

What happens below 1000 m in the ocean concerning light?

There is no light below 1000 m (the aphotic zone) except that generated through bioluminescence.

What is the Light Attenuation Coefficient (k)?

k is a measure of how quickly light is absorbed or scattered as it travels through water.

What defines the Euphotic Zone?

The Euphotic Zone is the layer from the surface to the compensation depth (D_c), typically the top 200 m, where net primary production is positive.

Why is red light absorbed more rapidly than blue light in the ocean?

Red light has a longer wavelength and lower energy, which causes it to be absorbed by water molecules in the first few meters.

What is the impact of high turbidity on the photic zone?

High turbidity increases scattering and absorption, which decreases light penetration and makes the photic zone shallower.

What does the term Albedo refer to in marine science?

Albedo refers to the fraction of solar radiation that is reflected back from the ocean surface into the atmosphere.

How does the Disphotic Zone differ from the Euphotic Zone?

The Disphotic Zone (Mesopelagic) has enough light for vision but not enough for the rate of photosynthesis to exceed the rate of respiration.