Gravity Waves

My next series is on peculiar weather events – the first in the series is the phenomenon of gravity waves which I have heard of but not researched until now.

Gravity Waves are physical perturbations driven by the restoring force of gravity in a planetary environment. In other words, gravity waves are specific to planetary atmospheres and bodies of water. In the case of atmospherics, as air blows across an ocean and then encounters an island, for example, that air will be forced to rise. Downwind from the island, the air will be forced to a lower altitude by gravity, but its buoyancy will work against gravity forcing it aloft again. The result is often a region of oscillating air in the atmosphere that can produce clouds in the waves’ crests (or highest points) as moisture from lower altitude condenses. Also, in the case of oceans, surface gravity waves form at the atmosphere/water interface; wind blows the surface out of equilibrium causing the restoring force of gravity to force the surface back down, while the water’s buoyancy pushes it back up. Wind-driven waves, tides and tsunamis are all examples of gravity waves.

Rippling gravity waves in the sky are usually invisible, but a satellite recently caught a rare glimpse of the phenomenon off the coast of northwestern Australia.

In the images, captured Oct. 21, air moves away from land and over the ocean, and rows of curved white lines emerge, like ripples do in disturbed water. Those thin white bands are clouds forming on the crests of atmospheric gravity waves.

Gravity waves appear following atmospheric disturbances; in this case, storms in the area produced cold air — which is denser than the warm air over land.  Interaction between cool and warm air agitated the atmosphere, and the ripples that formed are gravity’s way of restoring that lost equilibrium.


Another typical cloudy day is in store for SW Michigan with perhaps a few sprinkles – out best chance of another soaking rain comes Thursday when we may see our temps rise to near 50°.

 


 

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Jack Edwards
Jack Edwards

Fifty Sounds Nifty To Me.

Sandy (Hudsonville)
Sandy (Hudsonville)

It will be awesome!! Probably the last of the warmer temps for awhile.

Barry in Zeeland
Barry in Zeeland

Cool info on the gravity waves. I’ve heard bits and pieces of them mentioned before, but never really understood them.

Rocky (Rockford)
Rocky (Rockford)

This will make 9 out of the 11 months in Gr with below normal temps! An incredible cold pattern!

Mookie
Mookie

All this cold and GR is still below average for snow for November? Forecast looks bone dry with the exception of rainy and 50 on Thursday…

Slim

As of today, GRR has reported 6.5” of snow fall. The reported average snow fall in the first 17 days of November is 2.8” so as of today November 2019 is at above average. The average for the whole month is 6.8” We will have to see if there is any reported snow fall over the next 12 days to see how Grand Rapids ends up at. The current mean temperature at GRR for November is 32.1 (a departure of -10.6) if that were to hold (indications are it will not) this would be the 4th coldest November of record… Read more »

Rocky (Rockford)
Rocky (Rockford)

Thanks for the facts and thanks for debunking more of mookies false, fake warm weather hype!

Mookie
Mookie

Yep still below average for the month. Of course, more snow could fall in November. Then again, it may not. No big snow is anticipated for at least the next 8 days.

Rocky (Rockford)
Rocky (Rockford)

Soon and utter speculation! Ridiculous!

Slim

Yesterday here at Grand Rapids the official H/L was 39/20. For today the average H/L is now at 46/32. The record high is 70 set in 2016 and the record low is 11 set in 1959. The most snow fall on this date is 9.6” in 2014. At this time it is currently 40 here with mostly sunny skies. The snow is not all gone except for the snow piles. Last year on this date the H/L was 38/28.
Slim