a weather instrument that measure the height of clouds and estimates the amount of cloud cover is called a(n)?

Answer 1

Ceilometer.

Answer 2

Interesting question, though in terms of AGW, I'm not sure what information you could garner from such a technique; solar radiation incident at the Earth's surface does not represent clouds singly, and even if it did it would still only be half of the cloud issue. To obtain an estimate of the cloud feedback we would need dSW+LW/dt. I'm not aware of any papers that use your described method, but I'm only one person that reads a limited number of climatology papers. I've seen a few that attempt to infer cloudiness from surface solar radiation [1], but as I've described above this can be problematic, and all such datasets have issues themselves [2]. I suppose you could use such a method, but you wouldn't need Beer's Law or clear-sky irradiance to measure *trends* in surface solar radiation due to atmospheric absorption/scattering -- you would only need to remove trends in TSI from pyranometer readings, I'd think. However, with the advent of satellites it's easier to measure trends in all-sky transmittance directly at, say, 11 um where the atmosphere is relatively transparent (save for weak O3 and H2O absorption) and where clouds are opaque. Relate that with the trends in SW reflectance and ideally you might be able to discern cloud types, total cloudiness, cloud location.

Answer 3

try