3-1 Observing Clima - USRA's Science and Technology …sti.usra.edu/TRESTE/teaching_resources/faculty_teaching...• Fahrenheit to Celsius C = 5/9 ( F - 32 ) • Celsius to Kelvin

Climate and Global Change Notes

3-1

Observing ClimateHow do we measure climate parameters?• Surface Measurements

- Temperature> Wind Chill Temperature Index> Heat Index

- Pressure

- Density - Water Vapor> Gas Laws

- Wind - Clouds

- Water - Precipitation

• Upper-air Measurements

- Temperature, Pressure (Height), Water Vapor, Wind

• Remote Sensing Measurements

Observing -

“To see a world in a grain of sand,And a heaven in a wild flower,Hold infinity in the palm of your hand,And eternity in an hour.”

Auguries of Innocenceby William Blake


3-2

Observing Climate - SurfaceTemperature

Instrument DesignThermometers

Maximum TemperatureMinimum TemperatureThermograph

Exposure

Temperature ScalesWindchillHeat Index

Science Concepts

DefinitionKinetic Energy - Molecular

Boiling Point Versus AltitudeExpansionSurface Tension

VentilationRadiational HeatingEvaporational CoolingTemperature Versus Height

Effect of WindEffect of Humidity

The Earth System (Kump, Kastin & Crane)• Chap. 3 (pp. 38-39)


3-3

Observing Climate - Temperature

Why do we need thermometers?

Are we very good thermometers?

What steps do we need to perform to “build” a thermometer?


3-4

Observing Climate - TemperatureIs there a problem here? Why do fevers give you the

chills?

When you have an infection,your body resets your internalthermostat above the normal98.6°F, say to 101°, 102° ormaybe 103°F. You then feelcold and shiver attempting toraise your body temperature tothe new reset elevated level.

When your fever breaks, yourbody sets your thermostatback to 98.6°F. That's whenyou start to sweat, throw offthe covers.

http://www.sciencenetlinks.org/sci_update.cfm?DocID=251.


3-5

Definition• Temperature is a measure of

the average molecular kineticenergy of a substance

• As the temperature of mostsubstances is increased, thesubstance expands

Thermometer• Galileo Galilei (1564-1642)

invented a thermoscope in1593

• Galileo thermometer -Galileo discovered that liquid’s density changes with temperature.Thus, fluid’s buoyancy changes with temperature. Lowest floatingsphere indicates room temperature.

• Italian Francesco Sagredo, a contemporary of Galileo’s, divided thetemperature scale into 360 divisions similar to the divisions in a circle;thus, the name degrees


http://galileo.imss.firenze.it/museo/4/eiv07.html

“Took a sip of Pepsi. …always iced it. Less heat. Lessenergy. Less motion in themolecules.”

Tony Hillerman, 1986:Skinwalkers, pp. 37-38.

Science quotes of 5th and 6th graders -

A vibration is a motion that cannot make upits mind which way it wants to go.


3-6

Observing Climate - TemperatureBoiling Point of Water at Various Altitudes and Pressures

Altitude Barometer Readings Boiling Point (feet) (mb) (in. Hg ) mm Hg °F °C-1000 1049.8 31.0 788 213.8 101.0-500 1032.8 30.5 775 212.9 100.5

0 1013.3 29.9 760 212.0 100.0 500 995.6 29.4 747 211.1 99.51000 978.7 28.9 734 210.2 99.01500 958.4 28.3 719 209.3 98.52000 941.4 27.8 706 208.4 98.02500 924.5 27.3 694 207.4 97.43000 907.6 26.8 681 206.5 96.93500 890.6 26.3 668 205.6 96.44000 873.7 25.8 655 204.7 95.94500 860.1 25.4 645 203.8 95.45000 843.2 24.9 633 202.9 94.95500 826.3 24.4 620 201.9 94.46000 812.7 24.0 610 201.0 93.96500 795.8 23.5 597 200.1 93.47000 782.3 23.1 587 199.2 92.97500 768.7 22.7 577 198.3 92.48000 751.8 22.2 564 197.4 91.98500 738.2 21.8 554 196.5 91.49000 724.7 21.4 544 195.5 90.89500 711.1 21.0 533 194.6 90.3

10000 697.6 20.6 523 193.7 89.815000 572.3 16.9 429 184.0 84.4


3-7

Observing Climate - TemperatureTemperature Scales• Olef Roemer (Danish) and Isaac Newton (English) first to stress using two

reference points to calibrate thermometers • Newton used boiling and freezing points of water to calibrate his temperature

scale.

• Roemer used the boiling point of water and the temperature of a mixture of ice, water and salt (colder than freezing) to calibrate his temperature scale, but designated 60° between the two points.

• Gabriel Fahrenheit (Dutch) developed mercury thermometer (1714 - more accurate and could be divided into smaller divisions). In 1724, like Roemer, used temperature of a mixture of ice, water and salt as 0°, but unlike Roemer, used human temperature as 96°. Scale made explicitly for meteorology.


3-8

Observing Climate - TemperatureThermometer Types

• Liquid-in-glass thermometer wasinvented about 1650 by theGrand Duke of Tuscany,Ferdinand II. Used “spirits ofwine” as the liquid.

- Mercury (Freezes at-38.9°F)

- Alcohol

- Max-Min thermometer

Note: Scales are reversed on the right and left sides of the thermometer

1020

-10

30

-20

40

-30

50

-40 5040302010

0-10-20-30-40

0

Maximumside

Minimumside

Note:Read thebottom of

the“barbells”

Mercury

http://www.e-sci.com/genSci/9/1044/1100/9952.html

SecondLiquid Air


3-9

Observing Climate - TemperatureThermometer Types (Con’t)

- Max-Min thermometer (Con’t)

> Belfort maximum-minimumthermometer - Model 6042

‡ Maximum thermometer

§ Mercury filled bulb tilted with bulb end 5° above horizontal

‡ Minimum thermometer

§ Magnet used to reset metal barbell§ Alcohol filled bulb tilted with bulb end 5° below horizontal

http://www.belfortinstrument.com/products/temphumid/m6042.html


3-10

Thermometer Types (Con’t)• Metallic expansion

- Bimetallic strip

> Furnace thermostat

"Thermostat," Microsoft® Encarta® Online Encyclopedia 2001http://encarta.msn.com © 1997-2001 Microsoft Corporation. All rights reserved.


Brass

Invar


3-11

Thermometer Types (Con’t)• Metallic expansion (Con’t)

- Bimetallic strip (Con’t)

> Thermograph

‡ Thies Clima Thermograph -Measures and recordstemperature


http://www.thiesclima.com/temperatur/clarith_e.htm


3-12


MercurySwitch

BimetallicCoil

SecondBimetalic

Coil

Thermometer Types (Con’t)• Metallic expansion (Con’t)

- Coiled bimetallic strip

> Furnace thermostat

http://www.howstuffworks.com/home-thermostat5.htm


3-13

Observing Climate - TemperatureThermometer Types (Con’t)• Electric

- Resistance

Thermometer Exposure• Shade

• Ventilation

• Dry

• Height - Shelter 4 ft above ground

• Location - Grassy area away from trees

• Forestry Suppliers cotton region instrumentshelter - Wood construction with 48” wood ormetal legs. Painted white. Louvered on allsides and vented through the bottom to provide

ambient conditions inside while excluding radiation and precipitation. A doubleroof provides added protection against direct solar radiation.

http://www.forestry-suppliers.com/product_pages/View_Catalog_Page.asp?ID=5505


3-14

Observing Climate - TemperatureTemperature Scales (Con’t)• Today's Fahrenheit (Daniel Gabriel 1686-1736) scale based on freezing point

(32°) and boiling point (212°) of water. Human temperature is 98.6°.

• 1742 Swedish astronomer Anders Celsius (1701-1744) revised a temperature scale using, like Newton, the freezing and boiling points of water as calibration points, but used 100° between the two points, i.e., the Centigrade scale.

http://www.astro.uu.se/history/Celsius_eng.html


3-15

Observing Climate - TemperatureTemperature Scales (Con’t)• 1848 Lord Kelvin (William Thomson

1824-1907) proposed the Absolute or Kelvin scale (based on his study of gases and thermodynamics) that led to more physical meaning of zero.

http://www-gap.dcs.st-and.ac.uk/~history/Mathematicians/Thomson.html


3-16

Observing Climate - TemperatureTemperature Scales (Con’t)

Temperature Conversions• Fahrenheit to Celsius

°C = 5/9 ( °F - 32 )• Celsius to Kelvin

K = ( °C + 273 )

CelsiusFahrenheit Kelvin orAbsolute

212 100 373

32 0 273

-459 -273 0

Boiling Point of Water

Freezing Point of Water

Absolute Zero


3-17

Quote“The wind was particularly bitter, even for January in Holloman, Connecticut. WhenDr. Joshua Christian strode round the corner from Cedar Street onto Elm Street it hithim full in the face, a stream of arctic air with fangs and talons of ice chewing andclawing at the little sections of facial skin he had to expose to see where he going.”

Colleen McCullough, "A Creed For The Third Millennium"

What is wind chill?

Definition• Wind Chill Temperature Index (WCTI) is an effective

temperature not an actual temperature

• Wind Chill Temperature Index is related to an object'srate of cooling

Observing Climate - Wind ChillQuote“The wind was particularly bitter, even for January in Holloman, Connecticut. WhenDr. Joshua Christian strode round the corner from Cedar Street onto Elm Street it hithim full in the face, a stream of arctic air with fangs and talons of ice chewing andclawing at the little sections of facial skin he had to expose to see where he going.”

Colleen McCullough, "A Creed For The Third Millennium"

What is the wind chill temperature? How cold was it?

When the farmers wentto milk their cows, theygot ice cream.

Bulletin of the AmericanMeteorological Society,2005: Coin-a-phenomenon #3, 86,1221.


3-18

Observing Climate - Wind ChillDefinition (Con’t)• Late 40s, Siple and Passel, Antarctic explorers, measured time it took to freeze

250 g of water in a plastic contained on a pole in different temperature andwind conditions

• Developed empirical equations relating these data to the rate of heat loss fromexposed human skin

T (Chill) = 33 - ( 10.45 + 10 * SQRT ( V ) - V ) * ( 33 - T ) / 22.04

where V is in units of m / s and T is in °C

or

T (Chill) = 0.0817 ( 3.71 * SQRT ( V ) + 5.81 - 0.25 V ) * ( T - 91.4 ) + 91.4

where V is in units of mph and T is in °F. At wind speeds of 4 mph or less,the Wind Chill Temperature Index is the same as the actual air temperature.

Siple, P.A., and C.F. Passel, 1945: Measurements of dry atmosphericcooling in subfreezing temperatures. Proc. Amer. Philos. Soc., 89, 177-199.


3-19

Observing Climate - Wind ChillDefinition (Con’t)• 1 November 2001, the Weather Service began using a new Wind Chill

Temperature Index (WCTI) equation. New WCTI equation uses:

- Calculated wind speed at an average height of 5 ft (typical height of anadult human face)

- A human face model- Modern heat transfer theory- A calm wind threshold of 3

mph- A consistent standard for

skin tissue resistance- No impact from the sun

(i.e., clear night sky).

T (Chill) = 35.74 + 0.6215 T- 36.75 V0.16 + 0.4275 T V0.16

where V is in mph and T in °F.For wind speeds less than 3 mph,the new Wind Chill TemperatureIndex equals the actual airtemperature. http://www.nws.noaa.gov/om/windchill/

Osczevski, R., and M. Bluestein, 2005: The new wind chill equivalenttemperature chart. Bull. Amer. Meteor. Soc., 86, 1453-1458.


3-20

Observing Climate - Wind Chill Wind Speed (mph)

(°F) 5 10 15 20 25 30 35 40 45 5040 36 34 32 30 29 28 28 27 26 2635 31 27 25 24 23 22 21 20 19 1930 25 21 19 17 16 15 14 13 12 1225 19 15 13 11 9 8 7 6 5 420 13 9 6 4 3 1 0 -1 -2 -315 7 3 0 -2 -4 -5 -7 -8 -9 -1010 1 -4 -7 -9 -11 -12 -14 -15 -16 -17 5 -5 -10 -13 -15 -17 -19 -21 -22 -23 -24 0 -11 -16 -19 -22 -24 -26 -27 -29 -30 -31 -5 -16 -22 -26 -29 -31 -33 -34 -36 -37 -38-10 -22 -28 -32 -35 -37 -39 -41 -43 -44 -45-15 -28 -35 -39 -42 -44 -46 -48 -50 -51 -52-20 -34 -41 -45 -48 -51 -53 -55 -57 -58 -60-25 -40 -47 -51 -55 -58 -60 -62 -64 -65 -67-30 -46 -53 -58 -61 -64 -67 -69 -71 -72 -74-35 -52 -59 -64 -68 -71 -73 -76 -78 -79 -81-40 -57 -66 -71 -74 -78 -80 -82 -84 -86 -88-45 -63 -72 -77 -81 -84 -87 -89 -91 -93 -95

Frostbite occurs in 5 minutesFrostbite occurs in 10 minutesFrostbite occurs in 30 minutes


3-21

What is the Heat Index?

Definition• Heat Index is also an effective temperature not an actual temperature

• Heat Index is related to an object's rate of cooling

• Heat Index relates to how our body feels?

Observing Climate - Heat Index

What is the Heat Index?


3-22

Observing Climate - Heat Index AIR TEMPERATURE (°F)

RH (%) 70 75 80 85 90 95 100 105 110 1150 64 69 73 78 83 87 91 95 99 103

10 65 70 75 80 86 90 95 100 105 11120 66 72 77 82 87 93 99 105 112 12030 67 73 78 84 90 96 104 113 123 13540 68 74 79 86 93 101 110 123 137 15150 69 75 81 88 96 107 120 135 15060 70 76 82 90 100 114 132 14970 70 77 85 93 106 124 14480 71 78 86 97 113 136 15790 71 79 88 102 122 150 170

100 72 80 91 108 133 166

Heat Index 90-104Prolonged exposure and physical activity (especially if in poor physical conditionand overweight, sedentary lifestyle) likely to lead to heat exhaustion.

Heat Index 105-129Heat exhaustion possible with prolonged exposure and physical activity, even ifin good physical condition unless hydration is maintained.

Heat Index >130Do not engage in strenuous physical activity.

Documents

3-1 Observing Clima - USRA's Science and Technology …sti.usra.edu/TRESTE/teaching_resources/faculty_teaching...• Fahrenheit to Celsius C = 5/9 ( F - 32 ) • Celsius to Kelvin