1: Monitoring the Weather Flashcards
Weather vs Climate
Weather is the state of the atmosphere at a place at any given time
Climate is the long term average of weather conditions
What are the atmospheric variables of weather
CHPWPT
Cloud
Humidity
Precipitation
Wind
Pressure
Temperature
How is climate determined
Atmospheric variables: CHPWPT
and weather data that is averaged over 30 years or more
Is climate constant throughout the world?
No, the tropics have warm and humid climate
Poles have cold and dry climate
It is rare that the elements of the weather equal to the climatic normals
State of atmosphere (10)
Maximum Temperature
Minimum Temperature
Dewpoint or Relative humidity
Rainfall amount (in mm)
Snowfall amount (in cm)
Wind direction
Wind speed
Air pressure (weight of air column)
Sky cover (fraction of cloud cover)
Weather Watch or Weather Warning
When does the day’s minimum temperature occur?
sunrise
What is in Fernie, BC? and the type of data it collects
automated surface weather station. Collects data on
Rainfall
Humidity
pressure
Temperature
Radiation
Wind speed and direction
What is the global surface observation network
Monitors the land and ocean. Has blind spots like in high latitudes and desert regions
Where and how many surface observations in Canada and how often is it recorded
Most stationed at the US border:
Land: 10k stations
Ocean: 1k buoys and 7k commercial ships
Recorded at 0000, 0600, 1200, and 1800 UTC (every 6 hours)
Radiosonde and examples
Upper air observations. package of instruments that measure pressure, temperature, height, and moisture and send this information back to the surface through radio transmissions
Ex: weather balloon. Bursts at 25km altitude
Ex: sounding: vertical profile of the atmosphere that is generated
Vertical atmospheric profile
From sounding. Also called Skew T log P
one line is temperature and the other is dew point
- when temperature and dew point are closer together it is humid and when they are far apart it is dry
- wind barbs gives wind direction and speed
-gives mixing ratio
image 1
Weather radar
emits pulses of microwave energy which is then reflected by raindrops, snowflakes, or hailstone → shows structure and intensity of rainfall
can locate and track movement of precipitation and thunderstorms
produces composite radar image
limitations of weather radar
5-200km limitation due to curve of earth
cone of silence: can’t measure above
Satellite based observation, types, and example
satellites can see in other wavelengths not visible to us so can give info on stuff like water vapor in atmosphere
Ex: GOES satellite imagery → Geostationary Operational Environmental Satellite
Types:
1. geostationary satellite
2. polar orbiting satellite
Which direction does atmosphere move in midlatitudes and example
west to east
Ex: jet stream
geostationary satellite
-36k km above earth’s surface
-sub satellite point lies on equator
-samples good data in tropics and subtropics because of fixed position
-completes a cycle in 24 hours
image 2
polar orbiting satellite
-1k km above Earth’s surface
-samples overlapping north-south strips while Earth rotates eastwards
-sun-synchronous satellites sample each point on Earth twice daily
-combine geostationary and polar orbiting to get complete picture
image 3
Types of satellite imgaes
visible satellite
infrared satellite
water vapor (IR) satellite
Visible satellite
-Shows reflected sunlight so depends on surface and its albedo
-Only available during the day
-Brightness indicates amount of water → ex: cloud
-Cloud pattern can be estimate
infrared satellite image
-Depends on temperature of emitting object
-IR image depicts temperature of clouds or Earth’s surface and estimates cloud top heights
Energy emitted/transmitted per surface area is E = T^4
water vapor satellite
-means high water vapor
-shows transport of moist air
-indicates upper clouds
surface weather map
-atmospheric variables monitored by both surface and space based stations to make a weather map
-have special symbols to represent state of the atmosphere
image 4
temp behind cold and warm front on surface weather map
behind cold front: cold air mass
behind warm front: warm air mass