BOMP definitions

Energy

having the capacity for doing work

kinetic energy

energy associated with an object by virtue of its motion

potential energy

the potential or capacity to do work

temperature

measure of the average kinetic energy of molecules or atoms in a substance

heat

energy transferred into or out of an object because of temperature differences between that object and its surroundings

latent heat

heat released or absorbed when water changes phase

sensible heat

heat we can feel or measure with a thermometer tht does not involve a phase change

conduction

energy transferred that takes place through contact and touch; only energy is transferred, not necessarily matter. Least significant energy transfer our atmosphere

convection

actual movement or circulation of a substance to transfer heat

weather

the state of the atmosphere at a given time and place

climate

the average of all wx data, including extremes, that helps to describe the environment of a place or region

radiation

transfer of thermal energy through the vacuum of space (waves)

transmission

energy passes through the atmosphere without interacting with the gases or other particles

absorption

certain gases/particles in the earth's atmosphere capture and retain energy from incoming solar radiation

reflection

leight bouncing back from an object at about the same angle and intensity as it was received

scattering

radiation bounces off an obstacle in many directions

albedo

fraction of radiation that is reflected by an object

diffused light

energy scattered in different directions by dust and gas molecules

rayleigh scattering

the reason the sky is blue

water vapor and carbon dioxide

principal absorbing gases

greenhouse gases

gases that absorb longwave radiation

annual energy budget

the annual balance of incoming and outgoing radiation, as well as the energy balance that exists between earth's surface and atmosphere

isotherm

line of constant temperature

temperature gradient

amount of temperature change per unit of distance

hydrologic cycle

continuous exchange of water among the oceans, the atmosphere, and the continents

hydrogen bonds

attractive forces that exist between hydrogen atoms in one water molecule and oxygen atoms of any other water molecule

adiabatic temperature changes

heat energy is neither added nor subracted

parcel

imaginary volume of air

dry adiabatic lapse rate

rate of cooling or heating that applies to unsaturated air

lifting condensation level

the height at which a parcel reaches saturation and cloud formation begins

wet adiabatic rate

slower rate of cooling of saturated parcels

environmental lapse rate

rate of change in the actual temperature of the atmosphere with height

absolute stability

ELR is less than the wet adiabatic rate (ELR < MALR < DALR)

absolute instability

ELR is greater than the dry adiabatic lapse rate (ELR > DALR > MALR)

conditional instability

moist air has an ELR between the dry and wet adiabatic rates (MALR < ELR < DALR)

hygroscopic

water-seeking nuclei

hydrophobic

water-repelling nuclei

cirrus

high, white, thin clouds. Form delicate veil-like patches or wisplike strands and have feathery appearance

cumulus

globular cloud masses that look like cotton balls. Normally exhibit a flat base and appear as rising domes or towers. Form in a layer where instability leads to rising air and convection

stratus

sheets or layers that cover much of the entire sky. NO individual cloud units. Form in a stable atmosphere

nimbus

precipitation producing cloud distinction

high clouds

bases above 6000 meters/20,000 feet (cirrus, cirrocumulus, cirrostratus)

middle clouds

heights from 2000-6000 meter (6500 to 20,000 feet) (altocumulus, altostratus)

low clouds

up to 2000 meters (6500 feet) (stratus, stratocumulus, nimbostratus)

cumulus and cumulonimbus

clouds of vertical development

radiation fog, advection fog, upslope fog

fogs formed by cooling

steam fog, precipitation fog

evaporation fogs

supercooled water

water in the liquid state below 0 degrees C

terminal velocity

maximum speed at which an object falls; air resistance equals gravitational pull on the object

rain

droplets of water that fall from the cloud and have a diameter of at least 0.5mm

drizzle

droplets of water with a diameter between 0.5mm and 0.05mm

mist

smallest of water droplets with diameter less than 0.05mm

virga

rain that evaporates before reaching the ground

fallstreaks

ice crystals that sublimate before reaching the ground

snow

winter precipitation in the form of ice crystals or aggregates of ice crystals

graupel

rimed snowflake continues to rime until original six-sided shape of the snowflake is unidentifiable and produces a soft ice pellet that easily falls apart

sleet

partially melted snowflake that refreezes before reaching the ground

freezing rain

supercooled raindrops that freeze on contact with the earth's surface

hail

precipitation in the form of hard, rounded pellets or irregular lumps of ice with diameters of 5mm (0.2in) or greater

standard rain gauge

has a diameter of about 20cm (8in) at the top with a funnel that leads to a smaller cylindrical measuring tube

tipping-bucket gauge

consist of two compartments, at the base of the funnel, that can each hold 0.025cm (0.01 in) of rain

weighing gauge

collects precipitation in a cylinder that rests on a spring balance. As the cylinder fills, the movement from the spring balance is transmitted t oa pen that records the data

atmospheric pressure

weight of the air above a location

ridges

elongated high-pressure areas that extend toward the poles and are associated with warm air moving poleward

troughs

elongated areas of low pressure that sweep equatorward and are associated with cool air moving toward the equator

hydrostatic balance

balance between the upward push of air toward space and downward pull of gravity

pressure gradient force

the force that causes air to move from high pressure to low pressure

convergence

net flow of air into a region

divergence

net ouflow of air

geostrophic wind

Balance between the Coriolis force and PGF, flow parallel to lines of constant height

gradient winds

Winds around cells of high or low pressure that follow highly curved paths, Blow roughly parallel to curved isobars

cyclones/cyclonic flow/trough

centers of low pressure

anticyclones/anticyclonic flow/ridge

centers of high pressure

prevailing wind

wind consistently blowing more often from one direction than any other

monsoons

seasonal changes in wind direction that tend to produce wet summers and dry winters

rossby waves

Large-scale waves in westerly flow

the westerlies

Coriolis force redirects poleward-moving air to create westerly flow

jet streams

Fast streams of air occurring near the top of the troposphere with widths that vary from less than 100 km to 500 km, wind speeds exceed 100 km/hr and can approach 400 km/hr

subtropical jet stream

semipermanent jet located at about 30 degrees latitude in both hemispheres

meridional

north-south flow

zonal

east-west flow

el nino

warmer-than-normal sea surface temperatures to the equatorial Pacific off the west coast of South America; Associated with wet conditions in coastal South America and drier-than-normal conditions in Indonesia

la nina

strengthening of normal conditions; Drier-than-normal conditions in western South America and flooding in northeastern Australia and Indonesia

air mass

Large body of air having generally uniform conditions of temperature, moisture, and stability; form when air is stagnant over large areas and take on the characteristics of the water/land surface beneath them

air mass weather

generally constant weather conditions over several days caused by an air mass traversing an area

source regions

areas in which air masses originate

midlatitudes

Area of North America between Southern Alaska and Florida. Area of the prevailing westerlies.

fronts

a boundary surface that separates air masses of different densities - one of which is normally warmer & contains more moisture than the other

overrunning

Process of warm air gliding up and over a cold air mass

warm front

Warmer air invades territory formerly occupied by cooler air

cold front

Cold air advancing into a region occupied by warmer air

backdoor cold front

sometimes affect eastern seaboard and approach from the northeast

stationary front

relatively fixed in position, separate warm air on one side and cold on the other

occluded front

warm or cold type. New front that forms between advancing cold air and the cool air over which warm air is gliding

drylines

Boundary between warm, dry air and warm, moist air. Common in southern Great Plains

midlatitude cyclones

synoptic-scale low pressure systems with diameters that often exceed 1000 km and travel from west to east coast across the middle latitudes in both hemispheres

polar front theory

first model to explain the development and evolution of the midlatitude cyclone

cyclogenesis

formation and strengthening of these storm systems

blocking highs

stagnant anticyclones

cut-off lows

blocked low-pressure systems