Met Pt2 Flashcards
(23 cards)
What happens to terrestial radiation, conduction, solar radiation and convection on a clear night?
Terrestrial radiation and conduction continue, solar radiation and convection cease
The amplitude of mountain waves is strongly affected by what?
Shape and size of the mountains; amplitude is greatest when the width of the mountains equals the wavelength
When absolute vorticity decreases in the upper troposphere, the result will be high level:
Divergence and the formation of a depression or front through surface convergence
The passage of a cold front over a station is characterised by:
Decrease in pressure and steady temp before the front, backing of wind at the front and good vis outside of showers after the front
What are some factors that influence a slow rate of ice accretion?
Low speed, a cold cloud base and blunt objects
What are some factors that enhance the risk of carburetor icing?
High moisture content of air, air temp between +25 and -15 degrees, low power setting
Describe the trade winds
Produced by subtropical highs, steady and reach up to about 8000ft
State prevailing winds and conditions in the australasian region during the El Nino cycle of the Southern Oscilation?
West/Southwest winds, droughts in eastern AU and eastern parts if NZ
What are the predominant factors that control the transfer if heat around the globe?
Constant angular momentum of the atmosphere and vertical and horizontal circulations
A NOSIG appears in a landing (TREND) Forecast. What is the meaning of this term in New Zealand?
No significant change from the reported weather is expected during the next two hours following the issue time of the METAR or SPECI
The purpose of issuing aerodrone QNH forecasts is to:
To provide a check system on QNH values transmitted by an ATS unit
A contour chart contains contours, which are lines:
Of constant pressure over the entire chart but each individual contour has a specific altitude
The polar Jetstream is normally found near the:
300 hPa level, in the warm sector above the intersection of the polar front and the 500 hPa level
The origin of the subtropical jet stream lies in:
Mid to high tropospheric levels where a thermal gradient is produced by the subtropical tropopause which slopes down as the result of subsidence in the semi stationary highs
What is the transfer of energy in or out of an object because of temperature differences between that object and it’s surroundings?
Heat
What is the wavelength of solar and terrestrial radiation?
Solar – 0.5 - 4 microns
Terrestrial – 4 - 80 microns
What is wavelength of the atmospheric window?
8.5-13 microns
Definition of clear air turbulence
Sudden severe turbulence occurring in cloudless regions
What synoptic situation is necessary for airmass modification within a source region?
Anticyclone with a weak pressure gradient
Where is the most turbulence likely to be encountered in a mature thunderstorm?
In the lower part of the cloud
What is the greatest danger arising from airframe icing?
Loss if life and increase in drag
With respect to the larger islands of subtropical SW Pacific, what part of the islands and during what season is the wettest weather generally experienced?
SE coast, Summer
Instability created by convective lifting is usually confined to what altitude?
8-10k feet
