Dawn mist, also known as radiation fog is formed by the cooling of land after sunset by thermal radiation in calm conditions under a clear sky.
The cool ground produces condensation in the nearby air by heat conduction. In perfect calm the fog layer can be less than a meter deep but turbulence can promote a thicker layer. Radiation fogs occur at night, and usually do not last long after sunrise, though can persist all day in the winter months especially in areas bounded by high ground such as the Vale of York in England. Radiation fog is most common in autumn and early winter.
The prime time ingredients for radiation fog are saturated soil, light wind, initially clear skies, and a low afternoon dewpoint depression. The more factors that are present, the more likely the fog will be. Saturated soils continuously evaporate moisture into the air, insuring the dewpoint depression (difference between temperature and dewpoint) will remain low. Light wind reduces the amount of mixing of air in the lower troposphere. If winds are light, moisture evaporating from the surface will remain near the surface and not mix with drier air aloft. If wind is calm, expect fog to be very close to the ground or non-existent. In a calm situation with a low dewpoint depression and moist soils, expect a thick dew or frost instead of radiation fog.
Clear skies allow the maximum amount of longwave radiation to leave the earth. The absence of clouds will prevent any of the radiation from being trapped between the cloud and the ground. The more temperatures cool, the quicker the temperature will reach the dewpoint. A low dewpoint depression can occur by adding moisture to the air while at the same time cooling the air. The best way to rapidly decrease the dewpoint depression is for it to rain. An afternoon rain increases the likelihood of overnight fog dramatically. The afternoon rain saturates the soil and reduces the afternoon dewpoint depression. If skies begin to clear at night and winds are from 5 and 10 miles per hour after rain occurred the preceding day, fog is extremely likely. Other processes can produce fog such as upslope flow and contact cooling.
The animal on the left is a Black Hereford which is a beef cattle breed, derived mainly from Hereford cattle (normally red and white as is the smaller animal on the right), but with some mixture from black Angus cattle, resulting in black cattle with a white head and finching.
Like red Herefords, Black Herefords are becoming known for their feed efficiency and docile temperament. If a registered Black Hereford is crossed with a registered red Hereford and the resulting progeny is black, then it may be registered with the Black Hereford Association. The Black Hereford breed was formed to create cattle that would pass on the desirable traits of the red Hereford, but with black and white coloring. Like red Herefords, Black Herefords are often crossed with black Aberdeen Angus cattle to produce heterosis ("hybrid vigor") in the progeny, producing a type commonly known as the Black Baldy. The Black Herefords are usually the breeds Angus and Hereford combined.
The Red Hereford in the right is also a beef cattle breed, widely used both in intemperate areas and temperate areas, mainly for meat production.
Originally from Herefordshire, England, United Kingdom, more than five million pedigree Hereford cattle now exist in over 50 countries. The Hereford cattle export trade began from United Kingdom in 1817, starting in Kentucky, United States, spreading across the United States and Canada through Mexico to the great beef-raising countries of South America. Today, Hereford cattle dominate the world scene from Australasia to the Russian steppes. They can be found in Israel, Japan and throughout continental Europe and Scandinavia.
They are found in the temperate parts of Canada, the United States and Russia, as well as the temperate parts of Australia, the centre and east of Argentina, in Uruguay, and New Zealand, where they make up the largest proportion of registered cattle. They originally found great popularity among ranchers of the American Southwest, testament to the hardiness of the breed; while originating in cool, moist Britain, they have proven to thrive in much harsher climates on nearly every continent.
The World Hereford Council is based in the United Kingdom; the Secretary General, Mrs. Jan Wills, is from New Zealand. There are currently 17 member countries with 20 Hereford societies and 10 nonmember countries, with a total of eight societies.
This view is from Basingstoke Common in Old Basing, which was provided to replace the original Common in London Road, and was incorporated into War Memorial Park aspart of the new town development. In summer the land is often grazed by cattle, so dogs are recommended to be kept on leads.
The layered thorn hedges, magpies and rabbits are a familiar sight on the Common. From its highest point the view towards Basingstoke has the distinctive skyline of Festival Place,Basing View and the AA building.
Although Basingstoke Common is totally within the parish of Old Basing the common is provided by Basingstoke Council. It is bounded by London Road (A30), Redbridge Lane, Crown Lane and Park Lane. From the A30 end of Park Lane, there are views across to the office towers of Basingstoke. This area, which stretches as far as Basing House is popular with walkers, particularly those with dogs. The common is always considered sacrosanct when developers come looking for land. The fear, though, that one day it will house a new estate is always there.
en.wikipedia.org/wiki/Radiation_fog#Types
www.theweatherprediction.com/habyhints/22/
en.wikipedia.org/wiki/Black_Hereford_%28breed%29
en.wikipedia.org/wiki/Hereford_cattle
