EPS SCI 15 Lecture 12 Review

The Biological Pump binds what (from CO2) into biomass (Soft-Tissue Pump) and what (Carbonate Pump)?

Carbon, carbinate shells

The Biological Pump exports where?

From the surface to the deep ocean

The Physical Pump dissolves what from the atmosphere?

CO2

Where does the Physical Pump transport to?

The deep ocean at places of deep water formation

(Physical Pump) In coastal upwellign regions, what is released from the ocean back to the atmosphere?

CO2 (atmospheric + recycled)

Reminerlaization is the process of:

Converting organic material back to inorganic substances (Co2 + nutrients), interchangeable with respiration

In the water column, organic carbon can be either remineralized within:

The surface ocean via the microbial loop (mostly DOC consumption) or it can be exported to the deep ocean as POC (marine snow, fecal pellets)

Why does the sinking particle flux decrease with water depth?

It decreases due to continuous remineralization during transport

What (like sinking particle flux) also decreases with depth?

Labile (easily disgestible) organic carbon

What creates Oxygen Minimum Zones (OMZ)?

In nutrient rich (productive) coastal upwelling regions, organic carbon degredation in the water can be so high that oxygen declines dramatically

How much organic carbon reaches the seafloor depends on:

The productivity at the surface and the water depth

What organisms feed on organic carbon at the seafloor?

1. Suspension feeders

2. deposit feeders

3. prokaryotes

Microbial biomass in sediments declines:

1. exponentially with water depths

2. linearly with POC flux

What is the benthic microbial organic carbon turnover?

Highest on the shelf, lowest in the deep sea (shelves only represent the minority of ocean seafloor)

What do bioturbation and bioirrigation be animals do?

It stimulates microbial organic matter degredation in sediments (think of the earth worm in soil as an anaolog)

What is bioirrigation (ventilation)?

Ventilation by animals

What is bioturbation?

Mixing by animals

When is CO2 returned to the atmosphere from the euphotic zone?

Within days

When is CO2 returned to the atmosphere from the deep sea?

Centuries (remember ocean conveyer)

What does deep water accumulate more and more of as it travels through the oceans?

Co2 that is released from recycling processes, which is why the oldest deep water (Pacific Ocean) carries the largest amount of CO2