Chapter One - Test One Flashcards
Meteorology
“anything that fell from or was seen high in the sky.”
Weather:
the specific conditions of the atmosphere at a particular place or time
Climate:
“average weather” or the mean conditions of the atmosphere over an extended period of time
Means
(> or = 30 yrs of data)
Extremes
(period of record)
Adage: Climate is what you expect…
but weather is what you get
Specific or mean conditions are defined by ____ major elements
six (Temperature, Moisture, Clouds, Precipitation, Pressure, and Wind)
Temperature -
the degree of hotness or coldness
[ ºFahrenheit, ºCelsius, Kelvin]
Moisture
- a measure of water content
- relative humidity [ %]
- dewpoint [ ºF, ºC, K ]
Clouds
- visible mass of suspended water droplets and/or ice crystals
[cloud type, amount and height]
Precipitation
- any form of water falling to the surface
[precipitation type and amount ]
Pressure
- the weight of the air above an area [ inches of mercury, millibars]
Wind
- movement of the air
- speed [mph, knots, m/s]
- direction [quadrants, degrees]
In the U.S., the responsibility for gathering and dissemination weather related information, including forecasts and warnings, lies with the:
National Weather Service (NWS)
forecasts / warnings are disseminated through
regional Weather Forecast Offices
Ours is located on Centennial Campus here at NCSU!
Because __ percent of all declared emergences are weather-related, the NWS maintains two specialized centers
80%
Storm Prediction Center in Norman, OK
Issue severe thunderstorm and tornado watches
National Hurricane Center in Miami, FL
Issue hurricane watches and warnings
Measurements of four of these elements (temp., moisture, press. and wind) are collected by balloon-borne instrument packages called:
Radiosondes or Rawinsondes
which are launched twice daily at 92 stations in the U.S. (Fig. 1.8b).
Radiosonde data can then be disseminated Nationwide and displayed using a variety of plots and maps including the:
synoptic weather map (Fig. 12.5a, Box 12-2).
The word synoptic is derived from the Greek words “syn” which means together and “optikos” which means seen……seen together.
provide hourly information of the elements at a particular location over an extended time period.
Meteograms
The ____ experiences more varied and more severe weather than any other nation
United States (In a typical year we have: ~ 100,000 thousand thunderstorms 10,000 of which are severe 1,000 of which produce tornadoes)
The number one killer in an average year:
Heat Waves
NWS developed ____ to warn people about heat waves
Heat Index
The number two killer:
Floods
The Atmosphere
Atmosphere is a thin gaseous envelope
- 99% lies within 30 km (~20 miles) of the earth’s surface
- Although thin, the atmosphere protects us from harmful ultraviolet (uv) radiation from the sun and space debris
The Hydrosphere
Water makes Earth unique among all know planets
- 71% of the surface is covered by oceans, which contain 97% of the Earth’s water (Fig. 1.14). - Hydrological Cycle (Fig. 1-15) - Evaporation, Sublimation, Transpiration - Condensation, Deposition, Precipitation
Three gases comprise 99.96% of the volume of the dry
(excluding H2O) atmosphere (Fig 1-17, Table 1-2).
- ? 78.08%
- ? 20.95%
- ? 0.93%
Nitrogen (N2), Oxygen (O2), Argon (Ar)
- each of these gases are considered permanent
- these gases are of little or no direct importance to weather
The concentration of some gases, such as Carbon Dioxide or Ozone are so small that we also call these:
trace gases
Carbon Dioxide (CO2) Concentrations
0.039% 390 ppm
Ozone (O3) Concentrations
0.000004% 40.0 ppb
Though a trace gas, it presence and variability are important because CO2 is a _____.
Greenhouse Gas
Greenhouse Gas:
a gas that absorbs earth’s (longwave) radiation, and like a “Greenhouse” or blanket, keeps the earth and it’s atmosphere warm (and inhabitable)
CO2 concentrations have risen dramatically since the beginning of the industrial revolution as illustrated by the:
“Keeling Curve” (Fig. 1.18)
Measurements of CO2 recorded at Mauna Loa, Hawaii, since 1958 indicate ~ ____ increase (from 315 ppm to 390 ppm).
20%
CO2 Levels are Rising
This is attributable to anthropogenic (human-made) activities:
- Burning of fossil fuels (i.e. coal, oil, natural gas) which releases carbon
- Deforestation
- decrease in photosynthesis (sink)
- increase in decay (source)
- Deforestation
Nearly all scientists now believe that the earth’s atmosphere is warming as a direct consequence of _____.
human activities
An Intergovernmental Panel on Climate Change (IPCC) concluded:
- Global temperatures have increased 0.7 degrees C (1.3 degrees F) since 1900 (Fig. 14.14)
- The first decade of this century was the warmest on record with: 2005, then 2010, then 2014 and now 2015 being warmest year on record.
Ozone is a critical gas for all life forms because it is a:
- photoreceptor of lethal uv solar radiation, which prevents it from reaching the surface. - greatest concentration is found in the stratosphere, between 10 and 50 km, with a peak at 25 km
a decrease in concentrations of O3 in the stratosphere due to emissions of:
CFCs (Chlorofluorocarbons)
A very successful international agreement, called the _____ was signed in 1987 which established a timetable for reducing CFC emissions and hence eventual recovery of the O3 layer.
Montreal Protocol
Air pressure (p) is defined as the:
“weight of the atmosphere above a given point”
At sea level, the mean air pressure is:
- 14.7 lb in^-2
- 29.92 inches of mercury (“ Hg)
- 1013.25 millibars (mbs)
Air pressure always ____ with respect to (wrt) height (z) (Fig 1.23)
decreases; ∆p/ Δz
We can approximate the air pressure (mb) for different heights (km), using the equation
(where z = height in kms):
p = 1000 mb x 0.5^ (z / 5.6)
Ex. Mt. Everest at 8.8 km in elevation:
p = 1000 mb x 0.5^(8.8 / 5.6) = 336 mb
From the surface to ~ 12 km, the T generally ____ wrt height:
decreases; ΔT/Δz
The average rate at which the T decreases is called the:
“Environmental Lapse Rate”
ΔT/Δz = -6.5ºC/1000 meters
Within the troposphere:
- The air is very well mixed.
- Molecules can circulate through the entire depth within a day or so.
- Most of what we call “weather” occurs within this region.
The depth of the troposphere varies (Fig. 1.26).
Lower in polar regions, higher in tropical regions
Around 12 km, the Temperature no longer decreases wrt height, and the Lapse Rate becomes ____:
zero; ΔT/Δz = 0
- this is called an isothermal layer which means “Equal Temperature”
The word “stratus” means stratified, not well mixed.
- within the stratosphere the temperature generally ____ wrt height
increases; ΔT/Δz > 0
- such an increase is called a Temperature Inversion.
Inversions ____ vertical mixing, as a result conditions become stratified and air molecules tend to remain within this region for long periods of time.
inhibit
The source of the “heating” in the stratosphere is:
the absorption of the sun’s uv radiation by O3 which as discussed earlier has its max concentration in this area
