Hydrosphere test 2

True or false density effects temperature and salinity

True. thermocline (vertical pattern of temp) halocline(salinity) density difference is due to temperature

Surface circulation

(Direction of Ekman tranport -wind drag leads to surface currents -deeper currents offset due to Coriolis effect. -direction of wind in one direction, coriollis will have net effect. -lead to local upwelling zones -vertical mixing (Ekman spiral) whirl wind spirls (process of mixing in the surface)

Primary production in oceans

- ~1/2 of earth's total: 40X10^15 g C yr-1 primary productivity is the base of carbon fixation carbon and energy enter into food webs. about 1/2 of C fixation due to: -planktonic algae, bateria (cyanobateria)-->autotrophic fix carbon dioxide. incorporate into organic matter and initiate the process of food web generation. -Zones (where does this occur) --Open Ocean (80%) (not really including gyres) --Deposition Areas (atmospheric : dust and precipitation) deposition --Upwelling wind has created offshore current that allows deep water to fill void --Coastal/riverine inputs riverine discharge Carbon and be drawn down under some conditions, but it rarely found to be limited in highly buffered ocean -Limits to oceanic productivity: N,P,Si,Fe

Oceanic Removal Process

-Composition constant millions of year -Constant composition means ions must be removed -Key removal processes --Carbonate precipitation (Ca) -Pyrite formation (SO42-) -Silicate reonstruction (K) -Sediment flocculation (Na,Mg,K -Thermal vents (mid ocean ridges) (scrubs Mg, SO4). Magma pours of of deep sea flow. it is an engine that drives circulation of sea water. It draws in water and pumps out (super head)(high pressure) dissolves certain constituents and pumps out and recrystalize to effectively scrub out certain ions mg and so4

Which of the following is a major factor providing the driving force for global ocean circulation?

-Ice formation

Fresh water meets salt water (River inputs/coastal mixing)

-important for productivity and species -fresh and salt don't mix due to density. Salt water is more dense,but slowly with (currents,winds,tides,waves) help mixing of fresh and salt. processes are important for a variety of species to live -river entering into ocean (e.g. amazon) is important for re delivery of nutrients into the ocean

Vertical patterns of productivity of ocean -Conservative elements -Non-conservative elements

1. Conservative elements -concentration of individual and collective elements inc./dec. together -Not controlled by major chem/biol. reactions -only effected not required or effected by biological and chemical reactions, so inc. and dec. together. ex: evaportation happens (inc. or dec. together) not type of precipitation mechanism. wherever water goes, the constituents remain the same 2. Non-conservative -selective inc./dec. of individual elements -greatly affected by chem/biol. reactions things can react with them apart from conserved rxns, are effected for biological and chemical reactions. not going to be conserved in composition

1.Most of water is contained where? 2. what percent of freshwater is total amount of water? 3.

1.The oceans 2. 3%, only about .3% is contained in surface water (very important for ecosystem) ground water and ice caps (not much going on) not very dynamic, just tie uo

Ocean structure Epipelagic zone

Epipelagic (photic zone) where sunlight penetrates. important for photosynthetic, and microbial (pelagic means open and deep part of ocean) Mesopelagic: below 200m, light diminished (cant maintain photosynthesis) "twilight" region low light, but not completely dark. surface component is essentially epipelagic and mesopelgaic and deeply mixed. surface and deep dont really mix. littoral- photic zone contacts benthic surface (where photic intersect sediments) penetrates to the bottom. important for photosynthesis on bottom of ocean (extend to 200m or so)

Ocean composition

Oceans are not just evaportated river water composition is relatively constant compared to mixing

In the model of seasonal patterns of stratification of a freshwater body, which of the following is true?

There are likely more nutrients in the bottom water in August (end of summer) than in May (beginning of summer)

thermohaline cirulation

circulates water around globe those two processes give us circulation in the ocean

difference between surface (epipelagic and mesopelgaic) and deep ocean

difference because of density stratification (layers). the surface is lighter and deeper is higher in density (bottom). two layers. density similarity means your will be mixed. because of the difference in density, it is hard to mix.

Which of the following does not cause elevated ocean productivity?

evaportation

true or false Evidence for the fact that the chemical composition of the oceans was NOT derived from evaporating river water comes from an analysis of chloride content.

false

Residence time for bodies of water

long residence times:oceans (3200 years),glaciers,groundwater (shallow),groundwater (deep) intermediate: lakes short residence time seasonal snow cover, soil moisture, rivers, atmosphere

Redfield ration (1934)

open ocean most of the ocean is approaching near nutrient limiting so decomposition of biomass is very important Redfield ratio: C:N:Si:P (106:16:15:1) almost constant ratio. silica is important for diatoms in water. If there is a deviation of that ratio, it tells relative availability of one is changing or nutrient demand that is present in the biomass. nutrient of water and biota are so close. it is as if biota dervied from water and vice versa.

Productivity in freshwater ecosystems is most often limited by:

phosphorus

Ocean productivity

remember back to the wind patters. you get these hot spots of productivity extending due to transport of nutrients from continents to ocean. (nutrients, dust) extend long distance for continent upwelling of bottom water (higher in nutrients) upwelling occuring in Africa in North central and south africa where fisheries occur. wind pulls surface current away from shore

Ocean composition

salinity mainly made of NaCl and Sulfate Majority Chemical ions in ocean: 1.Chloride 2.Sodium 3.Sulfate 4.Magnesium

As you increase with ocean depth

temperature decreaces (halocine)increasing salinity

Ocean current

thermohaline circulation (ice formation) (driving force due to density (falling water at artic that pushes water down and recycle) and then flow back at surface

Vent scrubbing

to maintain the Mg/SO4 concentrations

true or false The Coriolis effect plays a major role in ocean productivity

true