You surprise me ian...I thought at least you would jump on the spelling error or the formatting mistake.
Yes, I did notice the spell checker insertion of condition for convection, and the double s instead of double f. I figured you were copying something that you couldn't cut and paste.
That still left an idea that couldn't be ignored, even if you didn't add the context.
I re-examined my understanding of the concept of convection, and found it to be too simplistic, too general. There are other mechanisms that can power convection besides gravity, or that focusing on the rising bolus of energetic mass ignores the descending fluid and the reconditioning of the fluid as it turns the corner between rising and falling.
It gives me pleasure to re-think old topics in a deeper fashion, and for that I thank you.
Next, I wanted to find outside corroboration. Convection is too general a term, convective transfer of heat brings better and more specific information.
"
Convective heat transfer is one of the major types of
heat transfer, and convection is also a major mode of
mass transfer in fluids. Convective heat and mass transfer take place both by
diffusion – the random
Brownian motion of individual particles in the fluid – and by
advection, in which matter or heat is transported by the larger-scale motion of currents in the fluid. In the context of heat and mass transfer, the term "convection" is used to refer to the sum of
advective and diffusive transfer.
[1] In common use the term "convection" may refer loosely to heat transfer by convection, as opposed to mass transfer by convection, or the convection process in general. Sometimes "convection" is even used to refer specifically to "free heat convection" (natural heat convection) as opposed to forced heat convection. However, in mechanics the correct use of the word is the general sense, and different types of convection should be qualified for clarity
"
As usual, physics is a complicated subject that is governed by simple Laws, but those laws can seldom be totally separated out from the complexity of reality.
In the case of the Earth's sun/surface/atmosphere/space flow of energy the three components of radiation/conduction/convection cannot be fully compartmentalized because they are all happening at the same time. You can however make general estimates of the amounts following any of the three pathways.
Your description of convection seems to include all three of the pathways. That is the opposite of informative. You have again taken a statement out of context and imbued it with your own interpretation.
The generally accepted meanings for the three modes of heat transfer are-
Conduction, energy passed along by physical contact.
Radiation, energy passed along via emitted packets of energy with no contact necessary.
Convection, energy passed along by bulk movement of the mass containing the energy.
