Temperature

Daily Web Guide

| Syllabus | Schedule | Email Kerry Magruder |

Reading Assignment	None. But browse through the Audubon Field Guide to the Weather.
Reminders	Find out the computer lab schedule, and begin working on the Web Worksheet.

Hottest Temperatures

• Hottest summer average: Death Valley, CA 116°F
• Hottest year-round average: Ethiopia, 94°F
• Hottest USA average: Key West, Florida, 74°F
• Hottest recorded: Libya, 134°F

Coldest Temperatures

• Coldest average winter USA: Barrow, Alaska, -9°F
• Coldest recorded: Vostok, Antarctica, -134°F
• February, 1899: Mississippi River froze over its entire length, with ice 2 inches thick in New Orleans!
• Oklahoma extremes: 120°F & -27°F

What is El Niño?

• "The Child" often peaks around Christmas
• Recurs about every 4 years
• World's oldest child: Evidence from sediments in Andean lakes suggests El Niño has recurred for 2,500 years
• Cyclical change in the flow of cold and warm currents in the Pacific ocean: Disruption of cool current west of South America
• El Niño effects
  • South America west coast waters 5-15°F warmer than normal
  • Droughts in Africa
  • Flooding in western North America
  • Heavy rain in southeastern United States
  • Mild winter in midwest
  • Mild hurricane season in SE US
  • Western Canada warmer

Humiture

• Effect of humidity upon perceived temperature
• Percent water in air
• Decreases evaporation of sweat from skin
• Makes hot days seem hotter

Wind Chill

• Effect of wind speed upon perceived temperature
• If calm, heated air layer develops near skin.
• If winds are stirring, heat loss is greater.
• Makes cold days feel colder.

Global Warming

• James Hansen, 1988, Goddard Institute for Space Studies
• Greenhouse effect
• Polar ice-cap melting
• Inundation of coastal cities
• Empirical data that winters may be milder than usual in recent years
• Global warming, criticism
  • Patrick J. Michaels, University of Virginia
  • No clear empirical trends
  • Computer models unsophisticated
  • Inter-glacial period?
  • Balancing systems of Earth not understood. Polar warming would lead to increased Snowfall that would compensate for melting.

Groundhog day

• Hedgehogs; groundhogs.
• Ends hibernation at noon on February 2.
• If frightened by its shadow, it hibernates some more: six more weeks of winter.
• If it's a cloudy day (no shadow), it stays awake and good weather is ahead.
• Accurate 3 years out of 10.

Weather folklore

• Crickets chirp faster when it's hotter.
• Dogs hunt better before a rain.
• Swallows fly high, clear blue sky. Swallows fly low, rain we shall know.
• Flies gather at screen doors before a rain.
• When folks complain more about pain, expect the morrow to be full of rain.
• Faraway objects appear closer before a storm (due to upper warm air)
• Sounds (e.g., church bells) travel farther before a rain (greater humidity)

Journal weather observations

• Meteorological Journals
  • Begin spending time outdoors with the Audubon Field Guide to the Weather!
• Focus next time:
  • cloud types
  • atmospheric moisture
  • predicting weather patterns on the basis of clouds.