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Air is affected by friction. A brief search of AMS journals shows over 14,000 times friction is mentioned. How it is manifested in the equations that describe the atmosphere is complicated. Let's think of wind as 'air moving' or perhaps space moving which air occupies. At some point, called the roughness length, the wind is 0 m/s (or knots or mph). If such a ...


Optical LIDAR systems for marine use are being developed and are being used for accurate mapping of archaeological remains under water. See However if a sonar is too big and impractical, I imagine oceanographic LIDAR is similarly out of scope.


I hope this thread is not noticed by our good friends in Australia, who might point out that in their frame of reference January and February are not noted for their coldness! You might be interested to know that there is an astronomical effect which the other answers have overlooked: on about January 6th, the Earth passes through the perihelion point in its ...


Why are January and February the coldest months although 21 December is the shortest day? For the same reasons that the warmest part of the day generally occurs hours after noon. The daytime temperature only can start decreasing after the outgoing thermal radiation exceeds the incoming solar radiation. Another reason is that water, ground, and even the ...


Short answer: air, land and water take a while to cool down (or rise in temperature; we see the same thing happening with July and August being the warmest months on average – not June, while June 21st is the longest day). In December, the fall just ended, and everything is relatively warm. Also, depending on how far North you go, the difference between day ...


It seems that attenuation is much greater at ultrasound frequencies: 50 khz 12-15 dB/km 0.5khz 0.024 dB/km It depends on what distance and resolution you need.


A completely frozen river is equivalent to a glacier There are glaciers that move, and there are glaciers that are static over periods of time. So the answer is yes However. Could play a definition of words in time and space game with this question. When the river is completely frozen it is not a river anymore. In that case the answer is no


We have TONS OF water. question is .. Is it potable does withdraw rate of water capable of being sustained by periodic recharge (Rain/percolation) Because storage capacity How much water do you need/society Industry/agriculture are the largest water users...... human personal needs (drinking/bathing) surprisingly low. Africa, has been predicted to have 75 ...

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