ECCB 303 Exam 1

Define biogeochemistry

the scientific study of interactions between the biology & chemistry of the earth system

Moist Soil (Stomata open)

Transpiration is controlled by roughness, mixing, temperature and VPD

Dry soil

transpiration controlled by stomata

Controls over Evapotranspiration: Forest

1. High roughness

2. high interception

3. high evaporation

Controls over Evapotranspiration: Grassland

1. low roughness

2. low interception

3. Low evaporation

P as in precipitation determines

the quantity of outputs

E as in evapotranspiration determines

the partitioning of Green vs Blue water

R as in runoff determines

the runoff to surface or deep groundwater (blue water)

Drought adapted plants wilting points

-3 to -8 MPa

Cavitation

Breakage of water column under pressure

MPa

unit for potential

Vapor Pressure Deficit (VPD)

Difference between actual vapor pressure and the pressure of saturated air at same temp

If Y_T= 0 then

pure water is under no pressure at soil surface

Soil Water Holding Capacity

Total Volume of water a soil can hold in pore spaces and on particle surfaces

Field Capacity

Quantity of retained water in soil after gravity has drained it

Water moves from ____ to ____ potential

High to Low (more negative)

Water Potential formula

Y_T=Yp ₊ Y_o+ Ym where:

Y_T= total water potential

Y_p= Pressure potential (gravity & physiological processes)

Y_o= osmotic potential (substances dissolved in water)

Y_m= Matrix Potential (adsorption of water to surfaces)

Hydrostatic Pressure (transpiration)

Tension/sucking moves water from soil to roots to leaves to atmosphere

Soil Size Classes

Defines soil texture

1. Clay < 0.002 mm

2. Silt= 0.002-0.05 mm

3. sand=0.05- 2 mm

What is soil water?

water that is stored in thin films on soil particles

Within Water Budgets the proportion of precipitation that reaches the soil will decrease with

1. Increase leaf area

2. Increase canopy density

3. Increase bark texture

Grasslands vs Forests: Whose soil will receive more water?

Grasslands

Storage in the Rnet Formula

energy stored chemically through photosynthesis (small fraction of Rnet, less than 5%) or as a temperature increases

What is turbulence within this class?

Air mixing

Evaporation will ____ temp

cool

Condensation will ___ temp

warms

What does Rnet do?

heats up land/water and is typically transferred out (balanced) of the system by non-radiative flux

Define Albedo

Reflectivity of surface

What is radiation budget?

Balance between incoming and outgoing radiation

Radiation Budget formula

NCT Radiation (Rnet)= (Kin-Kout) + (Lin-Lout)

K-in or K-out (Short wave)

the quantity of solar energy available to an ecosystem

L-in or L-out is the

Longwave

What does L-in or L-out depend on?

1. Object Temperature

2. Emissivity

3. Sky temperature

What does K-in or K-out depend on?

1. Where it is on Earth

2. Albedo

What does Water Vapor Feedback explain?

Why climate is sensitive to small changes in other Greenhouse Gases

What are Greenhouse Gases?

radiatively active gases

What are Climate Diagrams?

plots of monthly temperature and precipitation for a particular location

What do climate diagrams show? (list 5)

1. How climate varies throughout the year

2. Growing seasons

3. plant growth being limited by temp or precipitation

4. Key elements of fire season

5. Connecting diagrams throughout the world

What are biomes are classified by?

Dominant vegetation

What are some similar selective forces within biomes?

Convergent evolution

Ecosystems within a biome will:

Look and function similarly even if species are completely different

Define downwelling

Cold salty water sinking

In the Far North water does what?

Freezes; sea ice excludes salt

Where do surface currents carry warm water and what happens to the water?

To the North Poles where water cools, salinity increases, and density increases

Thermohaline Circulation

global pattern of surface and deep water currents (Fig 2.12)

Define Gyres

Wind + Coriolis effect + continents create circular surface currents between continents (normally will go counterclockwise)

How are oceans and climate connected?

Via currents that circulate water and heat

List five examples how oceans and climate are connected?

1. Unequal heating of oceans by the sun

2. Coriolis effect on flowing water

3. Wind pushing surface water

4. Topography of ocean basins

5. Downwelling of dense (cold/salty) water

Define Rain Shadow

A region with dry conditions found on the leeward side of a mountain range as a result of humid winds from the ocean, causing precipitation on the windward side

Define the Coriolis Effect

Deflection of an objects path as it moves along Earth’s surface

Which way does deflection go in the northern hemisphere?

right

Which way does deflection go in the southern hemisphere?

left

What does uneven heating cause?

It causes global patterns of atmospheric circulation (Fig: 5.6)

What does the Earth’s System consist of?

Atmosphere, Lithosphere, Hydrosphere, Biosphere

What does biogeochemistry focus on?

The cycles of crucial elements (C, H, N, O, P, S) that are needed for life

What are 3 common scales to define systems of study?

1. Global

2. Biome

3. Ecosystem

Define Global

considering the whole Earth System

Define Ecosystem

an interacting system that consists of living and nonliving objects as an integrated whole

defined by its structure and function

scale independent (from a petri dish to a rainforest) where it is defined by its research question.

Element Cycling

the movement/ transport and transformation of elements within and among ecosystems and global reservoirs

cycle between chemical forms, global reservoirs, ecosystems, and reservoirs within an ecosystem

specifically focus on CHNOPS.

Mass Balance & Energy Balance

a tool used to follow the movement and fate of materials and energy

focused on understanding where things are and where they are going

allows you to measure the integrated activity of a system without having to measure the properties and interactions of each of its parts

in a system materials that come in either stay in or leave so you can estimate the size of a single unknown flux by the difference between inputs and outputs.

Mass Balance Equation

Inputs= Outputs + Storage

Define storage

the gaining or losing at a rate

Steady State

an ecosystem where inputs=outputs

Storage=0

Sink

an ecosystem where inputs accumulate with storage

Positive storage

inputs > outputs

Source

an ecosystem where there is net loss of storage

Negative storage

inputs < outputs

Flux

the movement of energy or matter between pools

measured in units of matter over time.

Pools/ Stock/ Reservoirs

the storage space for energy or matter expressed as: mass, temperature, concentration

Solar Inputs

incoming energy from the sun

dictates the global energy balance

regulates the distribution of biomes on earth

drives the hydrological cycle and the organic carbon cycle

Uneven heating of Earth’s surfaces causes

1. Temp to decrease with latitude

2. Atmospheric convection currents

3. Climate variation

4. Location of biomes

What are atmospheric convection currents?

Circulations of air involving transfer of heat between the surface of Earth and the atmosphere

List 4 properties that influence atmosphere convection

1. Air density

2. Water vapor saturation point

3. Latent heat release

4. Adiabatic cooling and warming

Air density is determined by

atmospheric pressure, volume, and temperature

What is atmospheric pressure?

The weight of atmosphere at sea level (29.92 in of Hg; 14.7 Ibs/in²)

Define Water Vapor Saturation Point

maximum amount of water that air can hold at a given temperature, expressed as g H2O/m³ air (saturation point increases with temperature since air can hold more water when its warmer)

Define Latent Heat Release

Energy transfer due to condensation of water

What happens if water vapor exceeds saturation point (ex: humid air being cooled)?

Water vapor condenses into liquid water which releases energy and warms surrounding air

What happens if water vapor is below saturation point?

Liquid water evaporates into water vapor which requires energy and cools surrounding air

Heat of Vaporization of water

540 cal/g H2O (2,260 J/g H2O); requires a huge amount of energy

Define Adiabatic cooling and warming

the change in temperature due to changes in pressure and volume without loss or gain of heat

Define Heat

the average amount of kinetic energy

Define Inversion

High stability with temperature increasing with altitude (ex: the warm air stays longer because it is warmer than the cooling smoke)

Write out the Ideal Gas Equation and what each variable stands for

PV=mRT where

P= pressure

V= volume

m= mass

R= 8.314

T= temp

Energy balance

the energy of earth is balanced with ingoing and outgoing energy being equal but just in different forms

Incoming/Direct radiation

the energy emitted by the sun that is 343 watts/m^2.

Direct Radiation

reaches earth's surface

total the earth's surface absorbs 168 watts/m^2.

Atmosphere absorbtion of radiation

some light is absorbed by the atmosphere

the atmosphere is absorbing 72 watts/m^2.

Scattered radiation

other light is scattered by molecules

Outgoing radiation

radiation that earth is putting into space

Reflection of radiation

some incoming light is reflected by land, clouds, and the atmosphere back out into space

outgoing shortwave radiation is 103 watts/m^2

Outgoing longwave radiation

is equal to 240 watts/m^2

Short-wave radiation

the high-energy visible and UV light emitted by the sun

Long-wave/thermal radiation

the energy emitted by earth which is previously absorbed shortwave radiation, this heats the atmosphere from the surface via convection and is reflected back to the surface by greenhouse gasses

Atmospheric composition

the atmosphere is:

N₂:78%

O₂: 21%

Ar: 0.9%

CO₂: 0.04%

H₂O (as water vapor): 0% to 4% depending on temp

the concentrations of these gasses control how much energy is absorbed and reflected in the atmosphere

Examples of Greenhouse Gases

CO2, CH4, H2O, and N2O

Greenhouse effect

radiatively active gasses absorb 90% of outgoing radiation and reradiate it back in all directions

the portion directed back to earth warms the planet

the earth would be 33% cooler without greenhouse gasses

Weather

the state of the atmosphere and the changing nature of the atmosphere surrounding earth

the short term state and dynamic

most of the weather we examine involves the troposphere (up to 6 miles)