Temperature inversion layers (hereafter inversion layers) frequently develop at a height of 4 km over the Indochina Peninsula in the month prior to the onset of the rainy season, but the inversion layers have not been systematically studied. These inversion layers are considerably higher than those of the trade inversions that typically occur over the tropical ocean at 2 km height
For some reason the forum software thinks this message is/was less then 10 characters unless I add this bit.
Subsidence inversions at similar heights are common in the North West of Australia, and you would notice the performance degradation climbing through them. Once you notice the temperature increasing as you climb, it was usually worth winding back the speed thirty knots or so to zoom-climb through the layer.
You would also notice the dust held below the inversion, so the air was much cleaner and smother above them.
Are you sure the question related to 10,000ft and not 1,000ft?
It makes more sense to talk about the 1,000ft case, I think.
In one case (for the B747-400)
"TEMPERATURE INVERSION If a significant temperature inversion is forecast or there is reasonable evidence of it's presence due to conditions (i.e. clear, calm, conditions at night) and the temperature is above ISA+15°C, then 3°C should be added to the reported tower temperature prior to calculating the TOPL weight and applicable Reduced Thrust."
On reaching the inversion level, by definition, the SAT increases and the without a thrust reduction the EGT will rise, possibly exceeding limits and requiring a (manual) thrust reduction. If you are seriously performance limited, this can result in the inability to accelerate and hence retract flaps and may even require a shallow descent to accelerate!
This effect is often noticeable in the Middle East at night as the surface temps drop after hot desert days or taking off from places like Entebbe over Lake Victoria where many people have experienced the phenomena.
10,000 ? I have seen 10 deg C sudden increase well above 30,000'. So if you are in descent, no problem, if you are in climb & heavy your climb rate will slow down a lot....
