geog 1301 isom

Weather

Atmospheric conditions occurring at a given time and place

Climate

Sum of all weather that describes a place or region

Climate has NO component that acts on the atmosphere

True

Five Fundamental Atmospheric Elements

Solar energy (insolation), temperature, atmospheric pressure, wind, precipitation

What absorbs heat in the lower atmosphere?

Water Vapor

What is the greatest greenhouse & climate/weather GAS?

Water Vapor

What is the GREATEST modifier of temperature

Water Vapor

What is condensation nuclei?

Dust,pollen, spores, salt, smoke,ash, volcanic emissions...

Stratospheric ozone layer

Ozone (Ov3)- Ozone in the upper atmosphere protects us from damaging UV radiation

Vertical layers of the atmosphere

Defined by 3 systems on protective layers, chemical composition, diff in temp and rates of temp change

Differences in temperature and rates of atmosphere change:

Troposphere, Stratosphere, Mesosphere, and Thermosphere

Troposphere

Closest to Earth's surface, where most weather takes place, water vapor and particulates. Isothermal boundary with the stratosphere

How is lower atmosphere heated?

Radiation, Conduction, Convection, Advection

Radiation

All objects (bodies) with a temperature above absolute zero radiate energy (Shortwave=Solar) (Longwave Terrestrial.= Earth)

Conduction

Contact

Convection

Vertical

Advection

Horizontal

Daily effects of insolation

Diurnal changes, daily temperature lag, minimum near sunrise

What is the overall effect of cloud cover

A reduction in the diurnal/nocturnal temperature range

Differential heating of land and water

Bodies of WATER heat and cool more slowlycompared to the heating and cooling of LAND

Maritime (Marine Air)

Moderate temps and ranges

Continentality

Larger annual+diurnal temperature range

Albedo

Capacity of surface to reflect sun's energy

Normal lapse rate (Average)

6.5*C / 1000m

Temperature inversion

Normal lapse reversed, where temp increases w/ height

Inversion layer

Acts as cap or lid preventing vertical mixing of the atmosphere like troposphere

Upper Air Inversion (Temp increases w/ height)

Subsidence

Ground Inversion (Coolest air at surface)

Radiation

Latitude is the ____ _________ control on temperature

Most Important

Land and Water Distribution

Specific heat of water vs land (Differential heating)

Ocean Currents

Clockwise in Northern Hemisphere, Counterclockwise in Southern

Altitude (Major Controls of Earth Surface Temps)

Temperature usually decreases with height

Landform Barriers (Major Controls of Earth Surface Temps)

Large mountain ranges block air movement

Human activity (Major Controls of Earth Surface Temps)

Urban heat islands, deforestation, landscape changes

Horizontal pressure variation causes

Thermal (Equator receives more insolation than Poles)

More Horizontal pressure variation causes

Dynamic (due to Coriolis force and cooling air)

Warm/hot air is less dense and wants to rise

Creates Low pressure near the equator (~ 0 degrees)

Cold air is more dense and wants to sink

Creates High pressure near the poles (~90 N/S

Rising air at equator cools adiabatically and begins to sink onits journey poleward along with Coriolis force deflecting air

Creates High pressure in the subtropics ( ~30 N/S)

Low level convergence between Polar High and SubtropicalHigh in upper middle latitudes

Creates Low pressure in the subpolar (~60 N/S)

Mapping pressure distribution is..

adjusted to sea level pressure

Isobars are..

lines on maps that connect points of equal sea level pressures

Strong pressure gradient

sobars close together =stronger winds

Weak pressure gradient

isobars farther apart =weaker winds

Wind

Movement of air in response to differences in air pressure

Velocity

(strength) of thewind depends on thepressure gradient

Coriolis effect

Apparent deflection of the wind. Northern Hemisphere:deflected to the right

Anticyclone

Clockwise

Cyclone

Counterclockwise

Trade Winds

tropical easterlies

Subtropical highs

variable or calm winds

Westerlies

strong winds

Polar winds

Easterly winds

Seasonal pressure differences in January (NH)

Little change in tropics Middle and high latitudes are cold▪ High pressure develops over land (Siberian and▪ Canadian High)▪ Subpolar Lows develop over watero Icelandic Lowo Aleutian Low▪ Subtropical Highs slip southward and weaken

Seasonal pressure differences in July (NH)

Subpolar lows shift poleward and weaken▪ Subtropical highs shift northward and strengtheno Bermuda (Azores) Higho Pacific High▪ Thermal Low pressure develops over land (NorthAmerica/ Asia)

Differential Heating

Land vs Water, breaks up belts of pressure

Winds in latitudinal zones

Westerlies, Polar Front (sub-polar low)

Generally Westerly flow in the upper troposphere:

Upper-Air as Westerlies

Monsoon Winds

Seasonal reversal of the winds

Land breeze-Sea breeze

Diurnal (daily reversal of wind), diff heating of land+water

Mountain Breeze-Valley breeze

Dirunal daily reversal of wind, dff heating between mtns and valley

Katabatic are..

extremely strong drainwage winds

ENSO, El Nino, or La Nina and global weather

Oscillations in Tropical Pacific can cause weatherd isruptions in many regions of the world

(Positive NAO) Eastern U.S. may be ____ ___ ___ during winter

mild and wet

(Negative NAO) Eastern U.S. may be ______ ___ _______

colder and snowier

Water

necessary for photosynthesis, soil formation, and the absorption of nutrients by animals and plants

Hydrologic Cycle (also called water cycle)

Circulation of water from one of Earth's systems to another

Energy transfers

Latent heat (heat taken from environment, heat released to environment) (i.e ice to liquid to vapor, vice versa)

What is the significance of water vapor in theatmosphere?

Water vapor is also the most important greenhouse gasin the atmosphere (over 95% of greenhouse effect

Moisture capacity

Warmer air holds more water vapor than colder air

Saturation

air of a given temperature holds all the water vapor that it possibly can

Dew point temperature

temperature at whichair cannot hold anymore water vapor

Humidity

amount of water vapor in the air

Relative humidity (expressed as percent)

Actual content of water vapor in air / maximum watervapor air can hold at that temperature × 100

Evaporation from..

Transpiration, Evapotranspiration (Ground +Vegetation)

Condensation

Water vapor turns into liquid

Condensation nuclei

Example: sea salt spray, dust, smoke, pollen, andvolcanic ash

Fog

A cloud at ground level. Impacts travel, drip factor coastal deserts(dew)

Radiation fog (AM Fog)

Ground fog, nighttime COOLING by loss of terrestrial radiation causes cold surface temperatures on clear calm nights

Advection Fog

Warm, moist air moving over cool water or land surface

Clouds develop from..

cooling as air parcels rise and condense parcels' water vapor

Adiabatic Heating and Cooling: Stable

Adiabatic cooling rate exceeds the lapse rate

Adiabatic Heating and Cooling: Unstable

Adiabatic cooling rate is less than the lapse rate

Collision-coalescenceProcess

Warm clouds- Cloud drops collide and coalesce- Until heavy enough to fall to Earth- May break apart when falling if too large

Bergeron Process (Ice Crystal Process)

Cold clouds, ice nuclei, ice grows through freezing and deposition, may fall as rain or snow(Sublimation->Condensation->Freezing

Forms of precipitation

Rain, drizzle, snow, sleet, hail, ice storm

Convectional

Air heated near the surface

Orographic

Air rising-up a land barrier (Mtn, hilly region, or escarpment)

Air masses

Homogeneous in Temperature and Moisture characteristics

mP = maritime polar

not as cold as cP

cA= continental arctic

Occasionally impacts the United States inwinter with record low temperatures

mP=maritime polar and in winter..

Oceans tend to be warmer than land in winter. Thus, mP Warmer than their LAND counterparts (cP)

Atmospheric Disturbances

Middle Latitude Cyclones with associated Fronts

Atmospheric Disturbances isobars

Concentric isobars. High: increasing pressure toward the center. Low: decreasing pressure toward the center

Anticyclones

Cell of HIGH Pressure

Mid-Latitude Cyclones (Extratropical Cyclcones)

Cells of LOW Pressure

Hurricanes

Tropical Cyclonic system, Atmospheric Distrubance

Coastal communities cover..

17% of U.S. land mass, but its home to over half the U.S.'s population/infrastructure and is growing

Hurricane center of storm is..

relatively calm with SINKING air

Hurricane lack of clouds in center is called

EYE of the Storm