Weather and Climate II

7/26/2019 Weather and Climate II

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WEATHER

AND

CLIMATE


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WEATHERWhat is weather? Weather generally refers to day-to-day temperature

and precipitation activity.

The state of the atmosphere at a given time and place,

with respect to variables such as temperature, moisture, wind velocity, and barometric pressure.

What causes weather?

Because the Earth is round and not flat, the Sun's rays don'tfall evenly on the land and oceans. The Sun shines more

directly near the equator bringing these areas more warmth.

However, the Polar Regions are at such an angle to the Sun

that they get little or no sunlight during the winter, causing

colder temperatures.


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CLIMATEWhat is climate?

Climate (from Ancient Greekklima, meaninginclination) is

commonly defined as the weather averaged over a long period. The

standard averaging period is 30 years

The climate of a location is affected by its latitude, terrain,

and altitude, as well as nearby water bodies and their currents.


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CLIMATE AND

WEATHER

The difference between weather and

climate is a measure of time. Weather is

what conditions of the atmosphere are

over a short period of time, and climate is

how the atmosphere "behaves" overrelatively long periods of time.


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LATITUDEWhat is latitude? Latitude describes the location of a place north or south of

the equator. A line connecting all the points with the same

latitude value is called a line of latitude.

Latitude has a big effect on climate because latitude controlshow much solar energy a location receives. The tropics, which

are places on or near the equator, are warm all year long

because they get about the same amount of sunlight during

the year. The Polar Regions, which include places at or near

the poles, have a cold climate and don't get much (if any)sunlight on winter days. The area between the tropics and the

poles is called the mid-latitudes. The mid-latitudes have

several different seasons during the year because the amount

of sunlight changes from summer to winter.


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FACTORS

AFFECTINGCLIMATE


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ELEVATIONAltitude height of object at a point of reference

Elevation height of object above sea level

NOTE: The definition of Altitude is the same as

Elevation, the only difference is the point of reference.


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As the Altitude increases, the air temperature drops

For every 1000 meters, there is a temperature drop of6.5C

Higher ElevationsLess Airair spread further apart

less dense

Light Air cannot absorb much heat making air

temperature lower

Decrease of air pressureless heat generatedLower

air temperature


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HEAT

CAPACITY Water

-transparent fluid which forms the world's oceans and rain,and is the major constituent of the fluids of organisms

Heat capacity

- amount of heat required to raise the temperature of anobject or substance one degree.


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AFFECT

CLIMATE?

Soil absorbs heat faster than water.

Water has higher heat capacity.

Bodies of water regulate the temperature


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Average Temperatures

Moscow: 21 Celsius at Maximum and -8 Celsiusat Minimum

British: 17 Celsius at Maximum and 0 Celsius at

Minimum


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TOPOGRAPHY


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TOPOGRAPHY

What is topography?

It came from the Greek wordstoposandgraphia.

The description of the physical features of a

place.


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AFFECTS RAIN

DEPOSITSTopographic barriers such as mountains force

prevailing winds up and over their slopes. As

air rises, it cools. Cool air is capable of holdingless water vapour than warmer air, depositing

rain or snow on windward slopes. This creates

an effect known as the Rain Shadow on their

leeward (sheltered) sides, where the air contains

very little moisture. This results to the

formation of deserts.


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CLIMATECHANGE


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CHANGEWhat is climate change? Climate change is the long-term change in average weather

conditions, including temperature, precipitation and wind.

Key points:

Climate scientists reconstruct the Earths climate history by

studying proxy records including ice cores, corals, and tree

rings. These records show natural variability in the Earths

climate such as distinct colder glacial periods and warmerinterglacial periods.


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CLIMATE

RECORDClimate scientists glean information about past

climates by studying ice cores, sediments fromthe ocean, corals, tree rings and the geological

record. From these proxy records, they

reconstruct Earths climate history and compare

climate changes of the past with observations ofrecent climate changes and the projections of

climate change in the twenty-first century.


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EFFECT

What is greenhouse effect?

The greenhouse effect is the process by which radiation from

a planet's atmosphere warms the planet's surface to a

temperature above what it would be in the absence of its

atmosphere.

Greenhouse Gases

Water vapor, 3670%

Carbon dioxide, 926%

Methane, 49%

Ozone, 37%


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EL NIO

AND LANIA


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EL NIOWhat is El Nio?

El Nio meansThe Little Boy, orChrist Childin Spanish

The term El Nio refers to the large-scale ocean-atmosphere

climate interaction linked to a periodic warming in sea

surface temperatures across the central and east-centralEquatorial Pacific.

Typical El Nio effects are likely to develop over North

America during the upcoming winter season. The presence of

El Nio can significantly influence weather patterns, oceanconditions, and marine fisheries across large portions of the

globe for an extended period of time.


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El Nio, warmer than average waters in the

Eastern equatorial Pacific (shown in orange on

the map), affects weather around the world.


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NIO


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LA NIAWhat is La Nia? La Nia meansThe Little Girlin Spanish. La Nia is also

sometimes calledEl Viejo,anti-El Nio, or simply "a cold

event.

La Nia episodes represent periods of below-average seasurface temperatures across the east-central Equatorial

Pacific. Global climate La Nia impacts tend to be opposite

those of El Nio impacts. In the tropics, ocean temperature

variations in La Nia also tend to be opposite those of El

Nio. During a La Nia year, winter temperatures are warmer than

normal in the Southeast and cooler than normal in the

Northwest.


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LA NIA El Nio and La Nia are opposite phases of what is known as

theEl Nio-Southern Oscillation(ENSO) cycle. The ENSOcycle is a scientific term that describes the fluctuations in

temperature between the ocean and atmosphere in the east-

central Equatorial Pacific (approximately between the

International Date Line and 120 degrees West).

La Nia is sometimes referred to as thecold phaseof ENSO

and El Nio as thewarm phaseof ENSO. These deviations

from normal surface temperatures can have large-scale

impacts not only on ocean processes, but also on

global weather and climate. El Nio and La Nia episodes typically last nine to 12

months, but some prolonged events may last for years. While

their frequency can be quite irregular, El Nio and La Nia

events occur on average every two to seven years. Typically, El

Nio occurs more frequently than La Nia.


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LA NIA

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