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Looming of the Canadian coast as seen from Rochester, New York, on April 16, 1871. Looming is the most noticeable and most often observed of these refraction phenomena. It is an abnormally large refraction of the object that increases the apparent elevation of the distant objects and sometimes allows an observer to see objects that are located below the horizon under normal conditions.
Temperature inversions like this are common. An increase in air temperature or lapse rate of 0.11 Celsius degrees per metre of altitude would create an illusion of a flat canal, and all optical measurements made near ground level would be consistent with a completely flat surface. If the lapse rate were higher than this (temperature increasing ...
For example, oil droplets in a salad dressing are spherical but the interface between water and air in a glass of water is mostly flat. Surface tension is the physical property which rules interface processes involving liquids. For a liquid film on flat surfaces, the liquid-vapor interface keeps flat to minimize interfacial area and system free ...
is the heat transfer coefficient (assumed independent of T and averaged over the surface) (SI unit: W/(m 2 ⋅K)), is the temperature of the object's surface (SI unit: K), is the temperature of the environment; i.e., the temperature suitably far from the surface (SI unit: K),
Earth's average surface temperature due to its albedo and the greenhouse effect is currently about 15 °C (59 °F). If Earth were frozen entirely (and hence be more reflective), the average temperature of the planet would drop below −40 °C (−40 °F). [17]
The temperature of the air near the surface of the Earth is measured at meteorological observatories and weather stations, usually using thermometers placed in a shelter such as a Stevenson screen—a standardized, well-ventilated, white-painted instrument shelter. The thermometers should be positioned 1.25–2 m above the ground.
Surface roughness has a strong effect on the contact angle and wettability of a surface. The effect of roughness depends on if the droplet will wet the surface grooves or if air pockets will be left between the droplet and the surface. [10] If the surface is wetted homogeneously, the droplet is in Wenzel state. [11]
A meteorological index that posits the apparent temperature perceived by the average human being who is exposed to a given combination of air temperature and relative humidity in a shaded area. For example, when the air temperature is 32 °C (90 °F) with 70% relative humidity, the heat index is 41 °C (106 °F). heat lightning heat wave