Fern Pass (elevation 1212 m) is a mountain pass in the Tyrolean Alps in Austria. It is located between the Lechtal Alps on the west and the Mieming Mountains on the east. The highest peak in Germany, the Zugspitze is only 13.5 km away to the northeast.
How does the foehn effect work?
When the approaching winds are insufficiently strong to propel the low-level air up and over the mountain barrier, the air is said to be ‘blocked’ by the mountain and only air higher up near mountain-top level is able to pass over and down the lee slopes as foehn winds.
Where does the foehn wind originate?
Foehn winds can arise as a result of humid airflow over a mountain range. The air is drawn up on the windward side of the mountains and rises wet adiabatically (reduction in temperature around 0.6°C/100m).
Why is harmattan called Doctor wind?
The Harmattan blows during the dry season, which occurs during the months with the lowest sun. … On its passage over the Sahara, the harmattan picks up fine dust and sand particles (between 0.5 and 10 microns). It is also known as the “doctor wind”, because of its invigorating dryness compared with humid tropical air.
What are daily wind shifts called?
(Blank), winds are a by-product of the daily heating and cooling of the earth’s surface referred to as the diurnal cycle. … As the terrain such as a mountain or hill rises, the heat will create an up-slope local wind. The air at this point will increase in temperature.
In which season do foehn winds occur?
This warm, dry air can be quite pleasant in summer, but in the winter, particularly in the second half of the season, it causes havoc in resorts that lie in the lee.
How does katabatic winds develop?
Katabatic winds occur when air is cooled from below over sloping terrain. Such cooling causes a shallow blanket of air adjacent to the surface to become colder and therefore heavier than the atmosphere above, thus forming a thermally distinct layer that exchanges little energy with the overlying air.
What causes critical fire weather?
The four critical weather elements that produce extreme fire behavior are low relative humidity, strong surface wind, unstable air, and drought. … The surface pressure patterns of most concern are those associated with cold fronts and terrain-induced foehn winds.
What is Foehn wind called in South Africa?
Berg wind (from Afrikaans berg “mountain” + wind “wind”, i.e. a mountain wind) is the South African name for a katabatic wind: a hot dry wind blowing down the Great Escarpment from the high central plateau to the coast.
Is wind bad for mental health?
The experiment concluded that, even after adjusting for other weather variables, wind direction had a notable effect on mental health; specifically, a southeasterly wind raised anxiety and lowered energy levels. In other words, it blew no good.
Why do I get sick when its windy?
He found that those in the wind showed an increase in the secretion of serotonin, a blood vessel constrictor. “High levels of serotonin tended to cause migraines, sleeplessness, nausea, and intense but unfocused ‘irritation.
Is Bora a wind?
Bora, originally defined as a very strong cold wind that blows from the northeast onto the Adriatic region of Italy, Slovenia, and Croatia.
Which wind is called snow eater?
According to the Weather Doctor, the winds can easily vaporize a foot of snow within hours. Because of this, chinook winds are often known as the “snow eaters.” An extreme example of a Chinook wind was recorded in South Dakota in January 1943, according to Black Hills Weather.
Is Fohn a local wind?
Foehn is a local wind of Switzerland. A föhn or foehn is a type of dry, warm, down-slope wind that occurs in the lee of a mountain range. Central Europe enjoys a warmer climate due to the Föhn, as moist winds off the Mediterranean Sea blow over the Alps.
What are the two types of katabatic winds?
Warm, dry katabatic winds occur on the lee side of a mountain range situated in the path of a depression. Examples for these descending, adiabatically warmed katabatic winds are the Foehn winds. Cold and usually dry katabatic winds, like the Bora, result from the downslope gravity flow of cold, dense air.
Is a katabatic wind?
Katabatic wind, also called downslope wind, or gravity wind, wind that blows down a slope because of gravity. It occurs at night, when the highlands radiate heat and are cooled.
What is katabatic and Anabatic wind?
Anabatic Winds are upslope winds driven by warmer surface temperatures on a mountain slope than the surrounding air column. Katabatic winds are downslope winds created when the mountain surface is colder than the surrounding air and creates a down slope wind.
What is the effect of wind?
Continuous strong winds may damage the vines and impede growth. On the other hand, wind causes rain or dew to dry more quickly thus reducing the risk of fungal infection. However, wind also affects the thermal conditions of a vineyard.
What is harmattan wind?
Definition. Harmattan, is a cool dry wind that blows from the northeast or east in the western Sahara and is strongest from late November to mid-March. It usually carries large amounts of dust, which it can transport hundreds of miles out over the Atlantic Ocean; the dust often interferes with local aircraft operations …
Why foehn winds are hot and dry?
When winds blow over elevated terrain, air forced upwards expands and cools due to the decrease in pressure with height. … The subsequent removal of moisture as precipitation renders this heat gain by the air irreversible, leading to the warm, dry, foehn conditions as the air descends in the mountain’s lee.
Which is an example of a fine fuel?
Fast-drying dead or live fuels, generally characterized by a comparatively high surface area-to-volume ratio, which are less than 1/4-inch in diameter and have a timelag of one hour or less. These fuels (grass, leaves, needles, etc.)
What is called local wind?
A local wind is a flow of air that tends to happen in a predictable way in a particular, local area. … Examples of local winds include sea breezes, which blow from the sea to the land and keep coastal temperatures more mild, and land breezes, which blow from the land toward the sea, usually at night.
What are two effects of air movement in relation to fire behavior?
Wind increases fire spread by carrying heat and burning embers to new fuels (spotting). Wind bends the flames closer to the unburned fuels, pre-heating the fuels ahead of the fire front. Changes in wind direction and speed can rapidly change fire behavior from inactive to active.