Global climate ch 5-10 (exam 2)

cumulonimbus

- most violent of all clouds = thunderstorms - indicate inherently unstable conditions - from base to top may extend fully through the troposphere - anvil top form as ice crystals are blown horizontally

cumulus congestus

-more organized development as cloud towers appear -cells are short lived but are constantly replaced -each tower progresses higher

three cell model

A model of global wind systems that depicts three convection cells in each hemisphere and was proposed by Ferrel

global scale

Interactions occurring at the scale of the world, in a global setting

semipermanent cells

Large area of high or low pressure present year after year usually with size and location changing seasonally

terminal velocity

The final speed obtained by an object falling through the atmosphere, when friction with the surrounding air balances the force of gravity

overcast

When clouds comprise more than 9/10ths of the sky

westerlies

Winds that blow from west to east

polar jet stream

a fast stream of air sometimes called 'rivers'

ice nuclei

a rare temperature dependent substance similar in shape to ice (6-sided)

fog

a surface cloud when air either cools to the dew point, has moisture added, or when cooler air is mixed with warmer moister air

humidity

amount of water vapor in air

polar highs

areas of high pressure

subpolar lows

areas of low pressure

rain

associated with warm clouds and when surface temperatures are above freezing, cool clouds

sleet

begins as ice crystals which melt into rain as they fall through the atmosphere. Before reaching the surface they solidify into a frozen state

raindrop shape

begins as spherical but as frictional drag increases, it changes to a mushroom shape

collision-coalescence

causes precipitation for warm clouds

Polar cell

circulates air at the poles

Hadley cell

circulates air between the tropics and subtropics

Ferrel cell

circulates air in the middle latitudes. not quite a cell

clear

cloud coverage less than 1/10th

adiabatic process

cloud formation typically involves temperature changes with no exchange of energy

polar easterlies

cold winds that blow from the east to the west near the North Pole and South Pole

nacreous clouds

composed of supercooled water or ice, are stratosphere clouds sometimes called mother of pearl clouds

mesoscale

covers just a few square km to hundreds of square km

single-cell model

describes the general movement of the atmosphere and was proposed by George Hadley

second law of thermodynamics

dictates that energy is always transferred from areas of high temperature toward those of lower temperatures

foehn winds

flow down the side of mountain slope

lenticular clouds

form as a result of turbulence downwind of mountain ranges and exhibit a lens shape

noctilucent clouds

form in the mesosphere and are typically illuminated after sunset

cumulus humilis/fair weather cumulus

form when rising air parcels have areas of weak downdrafts between them

hail

forms a concentric layers of ice built around graupel, as it is carried around in the updrafts until it falls

freezing rain

forms similarly to sleet, however, the drop does not completely solidify before striking the surface

cool clouds

have temperatures above 0°C in the lower range and subfreezing conditions in the higher range

warm clouds

have temperatures above 0°C throughout and can be found in the tropics but also the mid-latitudes during the warm season

cold clouds

have temperatures below 0°C and consist of ice crystals

synoptic scale

high and low pressure patterns over large parts of the continents occur at this

mares' tails

horizontal swirls, occur in turbulent conditions

ocean currents

horizontal water motions that, at the surface, are often found along the rings of the major basins

graupel

ice crystals that undergo riming and lose their six-sided shape

sublmation

ice or snow (solid) can turn directly into water vapor (gas) during

monsoons

indicates a seasonal reversal in surface winds

intertropical convergence zone

intense heating at the equator of low pressure

saturation vapor pressure of ice

is less than that of supercooled water and water vapor

subtropical jet stream

jet stream that can bring up warm weather conditions from the south

subtropical highs

large bands of high pressure

collector drops

large droplets with high terminal velocities

dew

liquid condensation on surface often occurring during the early morning hours

stratocumulus

low, layered clouds with some vertical development

fall streaks

may appear below as ice crystals descend

evaporation

molecules escape into the overlying volume as water vapor

cirrus

most common cloud

zonal winds

move in an east/west or west/east direction

meridional winds

move in north/south or south/north direction

Santa Ana winds

occur in California during the transitional seasons, especially autumn, when high pressure is located to the east

cirrocumulus

occurs due to thickening causing a billowy appearance which resembles fish scales

cirrostratus

occurs when cirrus thickens and stretch across the sky

riming

occurs when liquid water freezes onto ice crystals producing rapid growth

frozen dew

occurs when normal dew formation processes occur followed by a dropped temperature to below freezing

upwelling

occurs when string offshore winds along a coastal region drag warmer surface waters seaward

aggregation

occurs when the joining of multiple ice crystals through the bonding of surface water builds ice crystals to the point of overcoming updrafts

diabatic process

one that involves the addition of removal of energy

dry adiabatic lapse rate

parcels expand and cool at

saturated adiabatic lapse rate

parcels then cool at

condensation nuclei

particles into which water droplets form

nimbostratus

precipitation associated with these kinds of clouds is usually very light

rain showers

precipitation events associated with convective activity

snow

precipitation that reaches the surface without melting and forms by the Bergeron process, riming, and aggregation

mircoscale

refers to a very small scale, like ripples that form on snow or a sandy beach

hydrologic cycle

refers to the cycle of water through the Earth and atmosphere

supercooled water

refers to water having a temperature below the melting point of ice but nonetheless existing in a liquid state

mammatus

sack-like protrusions from the base of a cloud, indicate low level turbulence common in cumulonimbus clouds

frost

similar to dew except that it forms when surface temperatures are below freezing

banner clouds

similar to lenticular but are anchored to individual mountain peaks

chinooks

similar winds on the eastern side of the Rocky Mountains and form when low pressure systems occur east of the mountains

haze

small condensation nuclei lead to very tiny water droplets

polar fronts

strong boundaries that occur between warm and cold air

vapor pressure

the amount of pressure exerted on the atmosphere by water vapor

relative humidity

the amount of water vapor relative to the maximum that can exist at a particular temperature

ridges

the bulges of heights extending towards the poles

Bergeron Process

the coexistence of ice and supercooled water is critical to the creation of cool cloud precipitation

lifting condensation level

the height at which saturation occurs

Rossby waves

the largest of the atmospheric long waves

dew point temperature

the temperature at which saturation occurs in the air

trough

the valley of low heights extending towards the equator

saturation vapor pressure

the vapor pressure of the atmosphere when it is saturated

saturation

there is an equilibrium between evaporation and condensation.

North and South Equatorial Currents

turns water westward and helps to create the Equatorial Countercurrent

drag and gravity

two forces acting on a falling object

altostratus

typically thick enough to almost fully obscure the sun or moon and blanket the sky from the horizon to horizon

altocumulus

typically typified by a banded arrangement of billowy clouds

hailstones

very heavy and capable of tremendous amounts of damage

thermally direct circulation

warm air rises and cold air sinks

katabatic winds

warm by compression but originate when air is locally chilled over high elevations. The air becomes dense (with low temperature) and flows downslope.

hygroscopic

water attracting

deposition

water vapor (gas) can change directly into ice or snow (solid) during

condensation

water vapor miles randomly collide with the water surface and bond with adjacent molecules

scattered

when coverage is between 1/10th and 6/10ths

broken

when coverage is in between 6/10ths and 9/10ths