Thunderstorms and gravity waves??!!
Thread Starter
Thunderstorms and gravity waves??!!
See below.
Anyone know anything about this?
What is a gravity wave - in lay terms please?
At first I thought it was b/s, but then read it is something to do with convective heating; see:
AMS Journals Online - On the Vertical Scale of Gravity Waves Excited by Localized Thermal Forcing
Edit - sorry - Google is my friend - gravity waves
THUNDERSTRUCK: Thunderstorms play a more critical role in turbulence than previously thought.
Australian researchers have discovered storms can cause turbulence more than 100km away - a revelation which they say should prompt a complete re-write of aircraft safety guidelines.
New research out of the Melbourne University's Centre of Excellence has shown thunderstorms could produce unexpected atmospheric gravity waves more than 100km away from storm cells.
Chief investigator Todd Lane said air safety guidelines worldwide did not take them into account.
"It is likely that many reports of encounters with turbulence are caused by thunderstorm generated gravity waves, making them far more important for turbulence than had previously been recognised," he said.
"Previously it was thought turbulence outside of clouds was mostly caused by jet streams and changes in wind speed at differing altitudes, known as wind shear, but this research reveals thunderstorms play a more critical role."
The research, published in the Bulletin of the American Meteorological Society, showed thunderstorms could have far more reaching effects.
Lane said it was now recognised that thunderstorms significantly modified the airflow, strengthening the jet stream and enhancing wind shear at a significant distance from the storm cell itself.
Many flights, including those operating in New Zealand, detoured around storm cells.
However, Lane said the research indicated they could still be close enough to encounter gravity waves and clear-air turbulence.
The researchers said the unexpected turbulence could lead to passenger injuries.
It is estimated about 97 per cent of injuries caused by turbulence during flight occurred because people were not wearing seatbelts. On average, around 15 people are injured every year due to turbulence.
Beyond the immediate safety concerns, it has been estimated that turbulence costs the aviation industry more than $100m a year globally due to associated rerouting and service checks, Lane said.
Despite this, he said little research was being carried out even though advances in technology now made it possible.
"Ten years ago, we didn't have the computing power and atmospheric models to answer some of the important questions around turbulence.
"Now we can answer some crucial questions but there are only a few groups working on this problem. We need more researchers to become engaged to improve the guidelines and passenger safety," Lane said.
Anyone know anything about this?
What is a gravity wave - in lay terms please?
At first I thought it was b/s, but then read it is something to do with convective heating; see:
AMS Journals Online - On the Vertical Scale of Gravity Waves Excited by Localized Thermal Forcing
Edit - sorry - Google is my friend - gravity waves
THUNDERSTRUCK: Thunderstorms play a more critical role in turbulence than previously thought.
Australian researchers have discovered storms can cause turbulence more than 100km away - a revelation which they say should prompt a complete re-write of aircraft safety guidelines.
New research out of the Melbourne University's Centre of Excellence has shown thunderstorms could produce unexpected atmospheric gravity waves more than 100km away from storm cells.
Chief investigator Todd Lane said air safety guidelines worldwide did not take them into account.
"It is likely that many reports of encounters with turbulence are caused by thunderstorm generated gravity waves, making them far more important for turbulence than had previously been recognised," he said.
"Previously it was thought turbulence outside of clouds was mostly caused by jet streams and changes in wind speed at differing altitudes, known as wind shear, but this research reveals thunderstorms play a more critical role."
The research, published in the Bulletin of the American Meteorological Society, showed thunderstorms could have far more reaching effects.
Lane said it was now recognised that thunderstorms significantly modified the airflow, strengthening the jet stream and enhancing wind shear at a significant distance from the storm cell itself.
Many flights, including those operating in New Zealand, detoured around storm cells.
However, Lane said the research indicated they could still be close enough to encounter gravity waves and clear-air turbulence.
The researchers said the unexpected turbulence could lead to passenger injuries.
It is estimated about 97 per cent of injuries caused by turbulence during flight occurred because people were not wearing seatbelts. On average, around 15 people are injured every year due to turbulence.
Beyond the immediate safety concerns, it has been estimated that turbulence costs the aviation industry more than $100m a year globally due to associated rerouting and service checks, Lane said.
Despite this, he said little research was being carried out even though advances in technology now made it possible.
"Ten years ago, we didn't have the computing power and atmospheric models to answer some of the important questions around turbulence.
"Now we can answer some crucial questions but there are only a few groups working on this problem. We need more researchers to become engaged to improve the guidelines and passenger safety," Lane said.
Last edited by tartare; 27th Jun 2012 at 05:16.
Thread Starter
yes - apparently so.
If I understand this correctly - it's saying thunderstorms can in effect cause ripples in the atmosphere that spread up to 100km from the storm cell itself?
Am I right?
If I understand this correctly - it's saying thunderstorms can in effect cause ripples in the atmosphere that spread up to 100km from the storm cell itself?
Am I right?
Ripples in the atmosphere? Sure.
Ripples in gravity? Sounds very doubtful
Basically I think they are trying to say that thunderstorms seem to impact the atmosphere and generate turbulence to a distance further than what we currently think. Sounds reasonable.
Thunderstorms affecting gravity? Only the quantum theorists can answer that.
Ripples in gravity? Sounds very doubtful
Basically I think they are trying to say that thunderstorms seem to impact the atmosphere and generate turbulence to a distance further than what we currently think. Sounds reasonable.
Thunderstorms affecting gravity? Only the quantum theorists can answer that.
Last edited by alphacentauri; 27th Jun 2012 at 06:29.
The atmosphere has mass, so presumably has an effect on gravity, so maybe waves in the atmosphere has some very slight effect on the gravity, but I must say it sound like someone taking the p!ss.
Similar names, entirely different things. Gravitational waves are the things generated by collapsing black holes and pairs of rotating neutron stars.
Gravity waves are what we're talking about here - so named because gravity is the controlling force behind the phenomenon. Mountain waves are probably a more commonly known example.
A parcel of air is pushed up by something like a thunderstorm or mountain and because it has higher density to the surrounding air, gravity causes it to return from whence it came. But it now has momentum so the parcel overshoots downwards until buoyancy overcomes it, pushing the parcel up. Again momentum causes overshoot and this cycle repeats setting up a wave.
tartare is correct.
Gravity waves are what we're talking about here - so named because gravity is the controlling force behind the phenomenon. Mountain waves are probably a more commonly known example.
A parcel of air is pushed up by something like a thunderstorm or mountain and because it has higher density to the surrounding air, gravity causes it to return from whence it came. But it now has momentum so the parcel overshoots downwards until buoyancy overcomes it, pushing the parcel up. Again momentum causes overshoot and this cycle repeats setting up a wave.
tartare is correct.
Lemme see now....
The first of April was some time back....
We have just had our 'Solstice'....the Druids have had their fun...
We are approaching the end of the 'Financial Year'....
Wot else is there... I wonder.....
Unless I stand to be fully eddycated..??
Can't wait....
The first of April was some time back....
We have just had our 'Solstice'....the Druids have had their fun...
We are approaching the end of the 'Financial Year'....
Wot else is there... I wonder.....
Unless I stand to be fully eddycated..??
Can't wait....
Moderator
Now, I'm dumb as........ but this seems to be a sensible explanation I can understand:
My bold. Symplistically, gravity waves must coexist with ripples or waves on the sea surface or in the atmosphere.
Learn something every day.
"In fluid dynamics, gravity waves are waves generated in a fluid medium or at the interface between two media (e.g., the atmosphere and the ocean) which has the restoring force of gravity or buoyancy.
When a fluid element is displaced on an interface or internally to a region with a different density, gravity tries to restore the parcel toward equilibrium resulting in an oscillation about the equilibrium state or wave orbit".
When a fluid element is displaced on an interface or internally to a region with a different density, gravity tries to restore the parcel toward equilibrium resulting in an oscillation about the equilibrium state or wave orbit".
Learn something every day.
