The negatively buoyant energy exerted on an air parcel is a result of the air parcel being cooler ( denser ) than the air which surrounds it, which causes the air parcel to accelerate downward.
42.
On a mesoscale point of view, an air parcel moving vertically will cross isolines of potential temperature and it will be unstable if the value of those lines decrease with altitude, or stable if they increase.
43.
As an air parcel moves about in the atmosphere, its relative, planetary and stretching vorticities may change but equation ( 17 ) shows that the sum of the three must be conserved following the geostrophic motion.
44.
Unlike shear dominated turbulence in the surface layer, large eddies associated with rise of warm air parcels that transport heat from hot to cold, regardless of the local gradient of the background environment exit in the mixed layer.
45.
Horizontal shear has two effects on an air parcel; it tends to rotate the parcel ( think of placing a wheel at a point in space and as the wind blows, the wheel rotates ) and deform the parcel through stretching and shrinking.
46.
However, your last question is meaningless because an air parcel can be saturated at any given temperature ( at least within the " usual " temperature range normally experienced at or near the Earth's surface ) by adding more water vapor into it.
47.
The balance of forces acting on an atmospheric air parcel in the vertical direction is primarily between the gravitational force acting on the mass of the parcel and the buoyancy force, or the difference in pressure between the top and bottom surfaces of the parcel.
48.
If, on the contrary, the upper air is cooler than predicted by the adiabatic lapse rate, then when the air parcel rises to its new height it will have a higher temperature and a lower density than its surroundings, and will continue to accelerate upward.
49.
The resulting momentum equation is integrated over height to yield the kinetic energy of the parcel on descending to the surface and is found to be the negative CAPE of a dry air parcel injected into the storm, plus de motion of the convective cell.
50.
In a Lagrangian scheme, individual air parcels are traced but there are clearly certain drawbacks : the number of parcels can be very large indeed and it may often happen for a large number of parcels to cluster together, leaving relatively large regions of space completely empty.
