Freshwater Abiotic Factors and Limnology Vocabulary

Flashcards defining core vocabulary from the lecture on abiotic properties of water, thermal stratification, lake mixing regimes, and fluid mechanics.

Hydrides

Chemical compounds formed by hydrogen bound to another element, such as $H_2S$, $H_2Se$, or $H_2Te$.

Specific Heat Capacity

The amount of energy required to raise the temperature of one gram of a substance by 1^\text{ }^\text{o}\text{C}.

Polar Molecule

A molecule in which electrons are shared unequally between atoms, resulting in partial positive and partial negative charges.

Cohesion

The chemical property of water molecules being attracted to and sticking to other water molecules.

Adhesion

The chemical property of water molecules being attracted to and sticking to other polar substances.

Surface Tension

A physical force created at the water surface due to cohesive interactions among polar water molecules and repulsion from nonpolar air.

Isothermal

Having an equal water temperature throughout the entire depth profile of a water column.

Epilimnion

The warm, uniformly mixed surface water layer of a stratified lake.

Metalimnion

The middle layer of a stratified lake that experiences a rapid drop in temperature and a rapid increase in water density.

Hypolimnion

The cold, dense bottom water layer of a stratified lake.

Thermocline

The specific depth within the metalimnion where the rate of temperature change and relative thermal resistance are highest.

Relative Thermal Resistance

The amount of energy required to mix two layers of water at different temperatures compared to a standard baseline.

Lake Turnover

A period of complete mixing throughout the entire water column of a lake, which replenishes oxygen to the hypolimnion and redistributes nutrients.

Dimictic Lake

A lake that undergoes full water column turnover twice per year, mixing during spring and fall while stratifying in summer and winter.

Monomictic Lake

A lake that undergoes full turnover only once a year, remaining stratified throughout the remaining season.

Amictic Lake

A lake that does not undergo mixing, often found in polar regions under permanent ice cover.

Polymictic Lake

A shallow lake (typically $3\text{ m}$ depth or less) that experiences frequent or continuous mixing throughout the year without forming persistent thermal stratification.

Meromictic Lake

A rare type of lake where high salt or ion concentrations at the bottom create a permanently dense layer that never mixes with upper waters.

Inertia

The physical resistance of a body to any change in its state of motion.

Viscosity

The measure of a fluid's resistance to deformation or flow, representing its thickness.