Disappearance of vapour trails - more warming?

[wildoats]

TL;DR

As we observe the almost complete disappearance of vapour trails as aircraft fleets are grounded under Coronavirus restrictions, I'm wondering if any research is being done on the effects on climate, if any, by the reduction in consequent cloud cover.

I think it was back around the 9-11 events that South African researchers happened to notice that solar radiation received at ground level increased by around 10% during the grounding of airline fleets world wide. If I remember correctly, this led to a measurable increase in plant growth over that short period.
We are now experiencing a similar situation, where the lack of vapour trails, which often seed the development of cloud cover, is resulting in much clearer skies.
On the one hand, the extra cloud cover would reflect some radiation back into space, resulting in a degree of cooling, but on the other hand the cloud blanket at night would act as an insulator and reduce overnight heat loss. Meanwhile unrestricted skies in daytime would allow, I feel, much higher levels of radiation to reach ground level.
So - does anyone know of any hard research taking place on this - I think it may have significant impact on crop production.

 

[.Scott]

An increase in the temperature difference between night and day was noted: Travis Paper.
That link is to: NATURE | VOL 418 | 8 AUGUST 2002

I did enjoy the night sky last night - no contrails - no landing lights - no blinking red or green lights.
If I had gotten out earlier, I could have spotted satellites more easily.