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<META
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content="Earth moves around the Sun in an elliptical orbit" >
<META
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content="2009-08-07T10:00:46-04:00" >
<META
name="dc.date.modified"
content="2009-08-07T10:00:53-04:00" >
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><strong><br>
Temperature<br>
</strong><br>
<br>
</B>Earth moves around the Sun in an <U><B>elliptical orbit </U></P
>
<P
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></B>-Aphelion = Earth is at its furthest point from the sun<FONT size="+1"> </P
><P
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><FONT size="+1">-Perihelion = Earth is at its closet point to the sun<FONT size="+1"> </P
><P
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><FONT size="+1">-Varies between 91 and 96 million miles.<FONT size="+1"> </P
><P
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><U><FONT size="+1"><B>Circle of illumination</U></B> = The line on the earth's surface dividing light from darkness<FONT size="+1"> </P
><P
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><FONT size="+1" color="#CC0000"><B>Question?<FONT color="#000000"></B>  Does the sun rise? Explain.<FONT size="+1"> </P
><P
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><FONT size="+1">Planet earth- 71% water 29% land<FONT size="+1"> </P
><P
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><FONT size="+1">Does that cause much of a role in the weather on earth?<FONT size="+1"> </P
><P
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><FONT size="+1">Does it make a difference if the water is cold or warm?<FONT size="+1"> </P
><P
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><FONT size="+1"><B>Tropic of Cancer </B>23.5 degrees N<FONT size="+1"> </P
><P
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><FONT size="+1"><B>Tropic of Capricorn</B> 23.5 degrees S<FONT size="+1"> </P
><P
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><FONT size="+1" color="#CC0000"><B>Question?<FONT color="#000000"></B> What does the Tropic's location have to do with the Arctic and Antarctic<FONT size="+1"> </P
><P
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><FONT size="+1">Circle?<FONT size="+1"> </P
><P
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><FONT size="+1">December 21== Southern Hemispheres summer<FONT size="+1"> </P
><P
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><U><FONT size="+1"><B>Specific heat</U></B> = amount of heat energy held at a specific temp. by a substance<FONT size="+1"> </P
><P
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><FONT size="+1">Highest specific heat of all liquids except ammonia = H20<FONT size="+1"> </P
><P
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><FONT size="+1">-Shallow H20 heats up faster than deep H20<FONT size="+1"> </P
><P
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><FONT size="+1" color="#CC0000"><B>Question?<FONT color="#000000"></B> Is that statement about shallow water always true? Explain.<FONT size="+1"> </P
><P
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><U><FONT size="+1"><B>Greenhouse effect</U></B> = Short wave radiation can go through atmosphere/glass but<FONT size="+1"> </P
><P
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><FONT size="+1">reflecting Long waves cannot pass through. Why does that phenomenon occur and what<FONT size="+1"> </P
><P
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><FONT size="+1">are the implications to our weather.<FONT size="+1"> </P
><P
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><FONT size="+1" color="#CC0000"><B>Question?<FONT color="#000000"></B> What does it have to do with Woburn, Mass being the former carnation<FONT size="+1"> </P
><P
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><FONT size="+1">growing center of America?<FONT size="+1"> </P
><P
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><U><FONT size="+1"><B>LCL</U></B> = That is the altitude at which clouds form.<FONT size="+1"> </P
><P
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><FONT size="+1" color="#CC0000"><B>Question?<FONT color="#000000"></B> What is the difference between condensation and precipitation?<FONT size="+1"> </P
><P
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><FONT size="+1">90% of all Earth's weather happens in the Troposphere<FONT size="+1"> </P
><P
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><FONT size="+1">Hot air rises =&gt; lighter =&gt; holds more moisture<FONT size="+1"> </P
><P
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><FONT size="+1">Cold air sinks =&gt; dense =&gt; holds less moisture<FONT size="+1"> </P
><P
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><FONT size="+1"><B>100% RH</B> (relative humidity) = precipitation<FONT size="+1"> </P
><P
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><FONT size="+1">This occurs at dew point temperature and altitude.<FONT size="+1"> </P
><P
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><FONT size="+1" color="#CC0000"><B>Question?<FONT color="#000000"></B> What has occurred that causes snow?<FONT size="+1"> </P
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<META
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content="Solar Radiation = Heated atmosphere" >
<META
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content="2009-08-07T10:10:51-04:00" >
<META
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content="2009-08-07T10:10:55-04:00" >
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><P
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><U><FONT size="+1" color="#000000"><B>Solar Radiation</U></B> = Heated atmosphere<FONT size="+1"> </P
><P
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><FONT size="+1">Vaporizes H20 = formation of clouds<FONT size="+1"> </P
><P
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><FONT size="+1">100% moisture = precipitation<FONT size="+1"> </P
><P
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><FONT size="+1">Depending on temperature precipitation is either liquid or solid<FONT size="+1"> </P
><P
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><FONT size="+1">Moved by upper air movement =&gt; Jet stream moves surface air<FONT size="+1"> </P
><P
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><U><FONT size="+1"><B>Vector</U></B> = Direction of wind<FONT size="+1"> </P
><P
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><FONT size="+1">Low pressure gives higher temp.<FONT size="+1"> </P
><P
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><FONT size="+1" color="#CC0000"><B>Question?<FONT color="#000000"></B> What is the relationship between low temperature and high pressure?<FONT size="+1"> </P
><P
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><FONT size="+1">Thermometry = measurement of infrared heat<FONT size="+1"> </P
><P
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><FONT size="+1">-Calorie = amount of heat necessary to raise 1 gram by 1 degree Celsius<FONT size="+1"> </P
><P
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><FONT size="+1">-Calibrated by Fahrenheit, Celsius, or Kelvin Scales.<FONT size="+1"> </P
><P
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><FONT size="+1" color="#CC0000"><B>Question?<FONT color="#000000"></B> How are those scales interchangeable? Do they measure the same things?<FONT size="+1"> </P
><P
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><FONT size="+1">Thermometers<FONT size="+1"> </P
><P
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><FONT size="+1">-Mercury = silver<FONT size="+1"> </P
><P
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><FONT size="+1">-Alcohol = red or blue<FONT size="+1"> </P
><P
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><FONT size="+1">-Bio-metallic = aluminum &amp; copper<FONT size="+1"> </P
><P
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><FONT size="+1" color="#CC0000"><B>Question?<FONT color="#000000"></B> Why are mercury thermometers becoming obsolete?<FONT size="+1"> </P
><P
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><U><FONT size="+1"><B>Calories</U></B> measure energy and the ability to do work<FONT size="+1"> </P
><P
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><FONT size="+1">Suns energy comes to earth as <U><B>potential energy </U></P
><P
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><FONT color="#CC0000">Question?<FONT color="#000000"></B> Is that the only kind of energy? Can we create energy?<FONT size="+1"> </P
></DIV
><DIV

><P
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><FONT size="+1">Barometers = measure air pressure<FONT size="+1"> </P
><P
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><FONT size="+1">-Aneroid =&gt;14.7 psi (BP @ sea level)<FONT size="+1"> </P
><P
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><FONT size="+1">-Torricelli =&gt;mercury ex. 29.92 inches<FONT size="+1"> </P
><P
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><FONT size="+1">-Barograph =&gt; graph based on millibars ex. 1013.2<FONT size="+1"> </P
><P
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><FONT size="+1">-Hair Hygrometer<FONT size="+1"> </P
><P
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><FONT size="+1">Barometric pressure often goes up or down<FONT size="+1"> </P
><P
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><FONT size="+1" color="#CC0000"><B>Question?<FONT color="#000000"></B> What can cause the barometric tendency to vary?<FONT size="+1"> </P
><P
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><FONT size="+1">-Warmer, moisture, stormy = Low pressure<FONT size="+1"> </P
><P
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><FONT size="+1">-Cooler, drier, clearer = High pressure<FONT size="+1"> </P
><P
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><FONT size="+1">-29.92 = neutral point<FONT size="+1"> </P
><P
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><FONT size="+1" color="#CC0000"><B>Question?<FONT color="#000000"></B> Why is it not only important to observe the difference between mean<FONT size="+1"> </P
><P
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><FONT size="+1">barometric pressure, but also its prior reading or value?<FONT size="+1"> </P
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<META
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content="Storm =They may be episodic or long term (gale vs" >
<META
name="dc.date"
content="2009-08-07T10:18:12-04:00" >
<META
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content="2009-08-07T10:18:16-04:00" >
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><P
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><U><FONT size="+1" color="#000000"><B>Storm</U></B> =They may be episodic or long term (gale vs. tornado). It is a condition of the<FONT size="+1"> </P
><P
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><FONT size="+1">atmosphere that brings an extreme weather condition to a specific area for a different<FONT size="+1"> </P
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><FONT size="+1">period of time.<FONT size="+1"> </P
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><FONT size="+1">-Drought<FONT size="+1"> </P
><P
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><FONT size="+1">-Ram<FONT size="+1"> </P
><P
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><FONT size="+1">-Wind<FONT size="+1"> </P
><P
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><FONT size="+1">-Snow<FONT size="+1"> </P
></DIV
><DIV

><P
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><FONT size="+1">1.) <U><B>Convectional storm</U></P
><P
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></B>-Dew point has reached the saturation point. Rising air from the surface reaches<FONT size="+1"> </P
><P
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><FONT size="+1">the condensation point (LCL). While the warm air is rising, cold dense air is sinking or a<FONT size="+1"> </P
><P
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><FONT size="+1">rain event that results from unequal heating of the land surface such that a rising column<FONT size="+1"> </P
><P
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><FONT size="+1">of air cools beyond the dew point and becomes unstable producing a cumulonimbus<FONT size="+1"> </P
><P
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><FONT size="+1">cloud, typically exhibiting violent local wind, high intensity rainfall over a small area and<FONT size="+1"> </P
><P
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><FONT size="+1">for a short duration, hail, thunder and lightening.<FONT size="+1"> </P
><P
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><FONT size="+1">2.) <U><B>Monsoon</U></P
><P
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></B>-  Any major seasonal wind system reverses its direction causing wet and dry<FONT size="+1"> </P
><P
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><FONT size="+1">seasons. Most of the large monsoons are in Africa and southern Asia, the<FONT size="+1"> </P
><P
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><FONT size="+1">smaller ones can be found all over the world, such as in the Gulf Coast of the<FONT size="+1"> </P
><P
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><FONT size="+1">US and Central Europe. Could be 7 months of wet weather. It is very regular<FONT size="+1"> </P
><P
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><FONT size="+1">around 5-15 degrees north or south of the equator. It is primarily caused by a<FONT size="+1"> </P
><P
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><FONT size="+1">reversal of oceanic and land Pressures. Stations on the ground usually<FONT size="+1"> </P
><P
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><FONT size="+1">experience 10 times normal monthly amount of rain along with a short dry<FONT size="+1"> </P
><P
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><FONT size="+1">period. This is also used to describe a climate that has monsoon rains.<FONT size="+1"> </P
><P
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><FONT size="+1">3.) <U><B>Orographic Storm</U></P
><P
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></B>-Deals with weather near and around mountainous regions .It is cased by<FONT size="+1"> </P
><P
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><FONT size="+1">mountain barriers and mechanically forced rising of winds. They are relater to continental<FONT size="+1"> </P
><P
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><FONT size="+1">location and cold ocean currents.<FONT size="+1"> </P
><P
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><FONT size="+1">-Air cools at about 5.5 degrees Fahrenheit for every 1000 feet in altitude. In<FONT size="+1"> </P
><P
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><FONT size="+1">precipitation it is 3 degrees for every 1000 feet.<FONT size="+1"> </P
><P
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><FONT size="+1">-When mountain is near ocean (windward side), the cool moist ocean winds rise<FONT size="+1"> </P
><P
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><FONT size="+1">up the mountain and cool according to the rise in altitude, once wind reach peak of<FONT size="+1"> </P
><P
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><FONT size="+1">mountain they fall down dry side (leeward side) and warm according to altitude.<FONT size="+1"> </P
><P
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><FONT size="+1">-As the moist wind rises up windward side the condensation point and dew point<FONT size="+1"> </P
><P
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><FONT size="+1">are reached and the air can no longer hold moisture, thus precipitation will fall. Once<FONT size="+1"> </P
><P
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><FONT size="+1">wind reaches peak pr&eacute;cis stops. The wind has now reached the LCL. As the wind goes<FONT size="+1"> </P
><P
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><FONT size="+1">down the leeward side (Chinook wind) it now warms and expands causing deserts.<FONT size="+1"> </P
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<META
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content="downaj" >
<META
name="dc.title"
content="Hadley Cell = Low latitude air movement toward the equator that with heating, rises" >
<META
name="dc.date"
content="2009-08-07T10:28:33-04:00" >
<META
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content="2009-08-07T10:28:36-04:00" >
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<DIV class="Sect"

><DIV

><P
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><U><FONT size="+1" color="#000000"><B>Hadley Cell</U></B> = Low latitude air movement toward the equator that with heating, rises<FONT size="+1"> </P
><P
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><FONT size="+1">vertically, with pole ward movement in the upper atmosphere. This forms a convection.<FONT size="+1"> </P
><P
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><FONT size="+1">cell that dominates tropical and sub-tropical climates.<FONT size="+1"> </P
><P
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><FONT size="+1" color="#CC0000"><B>Question?<FONT color="#000000"></B> Does this have anything to do with the jet streams and our weather?<FONT size="+1"> </P
><P
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><U><FONT size="+1"><B>Synoptic Weather</U></B> = Structure and behavior of atmospheric circulation systems, practical<FONT size="+1"> </P
><P
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><FONT size="+1">weather analysis and forecasting techniques. This directly involves acquisition,<FONT size="+1"> </P
><P
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><FONT size="+1">manipulation and display of real-time data sets. This is primarily a descriptive process<FONT size="+1"> </P
><P
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><FONT size="+1">based on factual observations.<FONT size="+1"> </P
><P
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><FONT size="+1">For ever)? 1000 feet air rises in altitude, the temperature drops an average of 5.5 degrees<FONT size="+1"> </P
><P
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><FONT size="+1">in unsaturated air. The rate differs m saturated air. It is 3.0 degrees/ lOOQfeet.<FONT size="+1"> </P
><P
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><FONT size="+1" color="#CC0000"><B>Question?<FONT color="#000000"></B> Why are there differences between saturated and un saturated air?<FONT size="+1"> </P
><P
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><U><FONT size="+1"><B>Saturation point</U></B> =&gt;condensate =&gt; precipitate<FONT size="+1"> </P
><P
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><FONT size="+1">-Solid = snow, hail, sleet<FONT size="+1"> </P
><P
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><FONT size="+1">-Liquid = rain, drizzle, mist, fog<FONT size="+1"> </P
><P
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><FONT size="+1">-Precipitation less than 150mm is drizzle<FONT size="+1"> </P
><P
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><U><FONT size="+1"><B>Relative Humidity</U></B> = the ratio of the amount of water vapor actually present in the air to<FONT size="+1"> </P
><P
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><FONT size="+1">the greatest amount possible at the same temperature<FONT size="+1"> </P
><P
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><U><FONT size="+1"><B>Humidity </U></B>= read by a hydrometer, it is the specific amount of vapor in the air<FONT size="+1"> </P
><P
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><U><FONT size="+1"><B>Dew point</U></B>= the temperature at which a vapor begins to condense is the location at which<FONT size="+1"> </P
><P
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><FONT size="+1">a cloud becomes saturated, altitude/temperature/ amount of moisture<FONT size="+1"> </P
></DIV
><P
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><FONT size="+1"><B>Howard&rsquo;s Clouds Classification </P
><P
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></B> </P
><P
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>-Lower Altitudes =&gt; Sea level to 6500 feet<FONT size="+1"> </P
><P
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><FONT size="+1">-Stratus (ST) Stratiform = layers of clouds, low clouds<FONT size="+1"> </P
><P
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><FONT size="+1">-Alto Stratus = higher end<FONT size="+1"> </P
><P
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><FONT size="+1">- Middle Altitudes @6500 feet =&gt;Cumuliform = middle clouds, fluffy<FONT size="+1"> </P
><P
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><FONT size="+1">-Anvil cloud/ thunderhead = Cumulonimbus<FONT size="+1"> </P
><P
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><FONT size="+1">-Point of anvil = direction of cloud movement<FONT size="+1"> </P
><P
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><FONT size="+1">-Alto cumuli = up higher<FONT size="+1"> </P
><P
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><FONT size="+1">-High Altitude@ 20,000 to 75,000 feet. Cirroform are wispy clouds.<FONT size="+1"> </P
><P
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><FONT size="+1" color="#CC0000"><B>Question? <FONT color="#000000"></B>Why do we have less of the sky covered with high clouds and more of the sky<FONT size="+1"> </P
><P
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><FONT size="+1">covered with low clouds? How does that differ for CN clouds?<FONT size="+1"> </P
><P
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><U><FONT size="+1"><B>Blanket effect</U></B> = Clouds keep in the heat and insulate the earth, especially at night.<FONT size="+1"> </P
><P
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><FONT size="+1" color="#CC0000"><B>Question?<FONT color="#000000"></B> Why does an early and continuous snow protect ground cover?<FONT size="+1"> </P
><P
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><FONT size="+1"><B>  <U>Wind</U></B> = horizontal movement of air from a region of high pressure to a region of low<FONT size="+1"> </P
><P
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><FONT size="+1">pressure<FONT size="+1"> </P
><P
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> </P
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<META
name="dc.title"
content="The change in pressure measured across a given distance is called a pressure gradient" >
<META
name="dc.date"
content="2009-08-07T11:10:03-04:00" >
<META
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content="2009-08-07T11:10:06-04:00" >
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><P
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><FONT size="+1" color="#000000"></B>The change in pressure measured across a given distance is called a pressure gradient. </P
><P
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>The steeper the gradient is, the greater velocity of the wind. </P
><P
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><FONT color="#CC0000"><B>Question?<FONT color="#000000"></B> Why do hurricanes have winds greater than 75 miles per hour? </P
><P
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>The pressure <U><B>gradient force</U></B> is responsible for triggering the initial movement of air </P
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>-The higher the pressure gradient the greater the wind. </P
><P
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><FONT color="#CC0000"><B>Question?<FONT color="#000000"></B> How does the Beaufort Scale relate to wind velocity/ Why is it possible that a </P
><P
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>gale may do more damage to Boston Harbor than a hurricane? </P
><P
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>Air also moves vertically, light warm air rises while cold dense air sinks<FONT color="#CC0000"> </P
><P
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><U><FONT color="#000000"><B>Planetary winds </U></P
><P
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></B>-Between 60 degrees and 90(H) degrees north = Polar easterly </P
><P
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>-Between 30 degrees and 60(L) degrees north = South West Trades </P
><P
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>-Between the equator and 30(H) degrees north = North East Trades </P
><P
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>-Equator = ITCZ (L) </P
><P
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>-Between equator and 30(H) degrees south = South East Trades </P
><P
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>-Between 30 degrees and 60(L) degrees south = North West trades </P
><P
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>-Between 60 degrees and 90(H) degrees south = Polar easterly </P
><P
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>At this point you should really consult the text for diagrams on planetary winds. </P
><P
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>Understanding this concept is key to critical understanding of the course. </P
><P
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><FONT color="#CC0000"><B>Question?<FONT color="#000000"></B> What are calms, doldrums and horse latitudes? </P
></DIV
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><P
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><U><B>Local Winds </U></P
><P
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></B>Winter winds </P
><P
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>-Land (H) ==&gt;H2O (L) = land breeze </P
><P
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>Summer winds </P
><P
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>-H20(H) ==&gt;land(L) = sea breeze </P
><P
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>Those are specific for the northern hemisphere. </P
><P
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><FONT color="#CC0000"><B>Questions?<FONT color="#000000"></B> Will the same be true in the southern hemisphere? </P
><P
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>Define Foehn, Chinook. Mistral, Bora, Scirocco and Santa Ana winds. </P
><P
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><U><B>Nautical mile</U></B> is equal to 6069 feet (just distance) </P
><P
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><U><B>Knots</U></B> are computed by nautical distance/time </P
><P
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>The earth completes a full rotation (360 degrees) at a speed of 1000 mph </P
><P
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><U><B>Beaufort Scale</U></B> is used to determine the force of wind </P
><P
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>-Hurricane = wind in excess of 75 mph </P
><P
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>-Full gale is 60 mph </P
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>-There is also gale, light breeze, full breeze, calm... </P
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><P
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><FONT size="+1" color="#000000"></B>4.) <B>Frontal Storms or Air Mass Storms </P
><P
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></B>-The transition zone or interface between two air masses of different density usually </P
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>means different temperatures. For example, the area of convergence between warm, </P
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>moist air and cool, dry air will produce a frontal storm. </P
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>The clash between a cold frontal air mass and a warm frontal air mass will produce </P
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>differing forms of precipitation depending upon temperature. </P
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>-Cold air travels 2x faster than warm air. </P
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>-Degree of frontal slope = wind velocity. </P
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>-As fronts approach wind velocity increases, precipitation will occur in collision </P
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>area, warm front over rides cold front, wind shifts, high pressure takes over and the storm </P
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>passes and weather clears. In this area it means that the wind now is coming from the </P
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>northwest. </P
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><B>Warm front: </P
><P
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></B>-  The interface between an advancing mass of air that is warmer than the one it </P
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>is replacing, usually at the point of contact with the ground surface. This is </P
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>associated with a low barometric pressure. </P
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><B>Cold Front: </P
><P
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></B>-The interface between an advancing mass of air that is colder than the one it is </P
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>replacing, usually at the point of contact with the ground surface. This is usually </P
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>associated with a high barometric pressure. </P
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><B>Stationary front </P
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></B>-Locks everything in place for a while creating temperature inversion. Episodic. </P
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>This is referred to as an occluded front. </P
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><FONT color="#CC0000"><B>Question?<FONT color="#000000"></B> What is the relationship to public health and summer stationary fronts? </P
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>-At night reverse blanket effect. </P
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>-Traps Nitrous Oxide in atmosphere (bad air day) </P
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>-Happens in summer: Haze =&gt; smaze: photochemical smog </P
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><B>Side note on pollutants: </P
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>-Iron and steel are brutal on environment, manufacturing of these leads to </P
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>poor air quality </P
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>-Air quality hazardous occupations: Traffic cop, diesel mechanics </P
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></B>Due to temperature inversion, another type of episodic storm is a Hurricane </P
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>-Low-pressure storms originate over warm ocean water and have winds in excess </P
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>of 75 miles per hour. </P
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>-Torrential precipitation </P
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>-Seasonal </P
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>-Ocean Currents </P
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src="images/geo 225 lecture notes pg.7_img_0.jpg" ><br>
<br>
New England Blizzard of 78' was actually a hurricane.<FONT size="+1">
<P
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><FONT size="+1">-Struck from SE 158 miles offshore<FONT size="+1"> </P
>
<P
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><FONT size="+1">-Extreme Low pressure<FONT size="+1"> </P
>
<P
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><FONT size="+1">-Highest tide of the year<FONT size="+1"> </P
>
<P
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><FONT size="+1"><B>Hurricane</B> season is usually July through October<FONT size="+1"> </P
>
<P
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><FONT size="+1">-Wettest Months in the tropics are August and September<FONT size="+1"> </P
>
<P
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><FONT size="+1">-Northern Hemisphere Cyclone spins counter clockwise.<FONT size="+1"> </P
>
<P
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><FONT size="+1">-Point of intersection is maximum wind and pressure drop<FONT size="+1"> </P
>
<P
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><FONT size="+1">-These storms produce Surplus of electronic energy: lightning and thunder<FONT size="+1"> </P
>
<P
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><FONT size="+1"><B>Thunderstorms</B> are episodic 1 to two hours or even 30 minutes<FONT size="+1"> </P
>
<P
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><FONT size="+1"><B>Twister or Tornado</B> also episodic, usually five minute in one area of path<FONT size="+1"> </P
>
<P
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><FONT size="+1">-Winds in excess of 200 mph<FONT size="+1"> </P
>
<P
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><FONT size="+1">-Over ocean twister is called a water spout<FONT size="+1"> </P
>
<P
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><FONT size="+1" color="#CC0000"><B>Question? <FONT color="#000000"></B>Why can tornados be among the most destructive storms?<FONT size="+1"> </P
>
<P
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><FONT size="+1">Is it possible to find them in New England?<FONT size="+1"> </P
>
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