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In solar physics and observation, supergranulation is a pattern of convection cells in the Sun's photosphere. The individual convection cells are typically referred to as supergranules . The pattern was discovered in the 1950s by A.B. Hart [ 1 ] using Doppler velocity measurements showing horizontal flows on the photosphere (flow speed about ...
Atmospheric convection is the vertical transport of heat and moisture in the atmosphere.It occurs when warmer, less dense air rises, while cooler, denser air sinks. This process is driven by parcel-environment instability, meaning that a "parcel" of air is warmer and less dense than the surrounding environment at the same altitude.
In many real-life applications (e.g. heat losses at solar central receivers or cooling of photovoltaic panels), natural and forced convection occur at the same time (mixed convection). [4] Internal and external flow can also classify convection. Internal flow occurs when a fluid is enclosed by a solid boundary such as when flowing through a pipe.
Convection is often categorised or described by the main effect causing the convective flow; for example, thermal convection. Convection cannot take place in most solids because neither bulk current flows nor significant diffusion of matter can take place. Granular convection is a similar phenomenon in granular material instead of fluids.
(Correction: An earlier version of this story misstated how far Pluto is from the sun. The correct number is 3.7 billion miles.) What was discovered in Flagstaff, Arizona, and killed off in Prague?
The Sun warms the ground, which in turn warms the air directly above. [2] The warm air near the surface expands, becoming less dense than the surrounding air. The lighter air rises and cools due to its expansion in the lower pressure at higher altitudes. It stops rising when it has cooled to the same temperature, thus density, as the ...
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This was a short work containing an estimation of the angle of depression of the sun at the beginning of the morning twilight and at the end of the evening twilight, and an attempt to calculate on the basis of this and other data the height of the atmospheric moisture responsible for the refraction of the sun's rays. Through his experiments, he ...