Typical light levels at Mars's surface

[PolarPenguin]

Hi there!

Does anyone here know what the typical light levels are at the Martian surface (in daylight hours!) and how they vary in magnitude through time? I'd prefer a measurement close to the equator, but I'd be happy with one from anywhere at the surface.

I can easily calculate the solar irradiance and hence determine the light levels outside the atmosphere, but due to dust loading in the atmosphere that would be an approximation which does not hold at the surface. I am aware that the Mars 3 lander measured light levels of 50 lux (see: http://linkinghub.elsevier.com/retrieve/pii/0019103573901206 ) at the surface in 1971, and that that was suspected to be during a dust storm. I am also aware that the dust storms of July 2007 "blocked 99 percent of direct sunlight to [Opportunity]" (http://marsrover.nasa.gov/newsroom/pressreleases/20070720a.html ) but neither of these give me a measure of the typical light intensity/level there on a day-to-day basis in a location with no dust storm activity at that time.

Any ideas or measurements/references? Thanks in advance!

 

[mfb]

I don't find the map any more (might have been lost over the years) but the atmosphere doesn't absorb much on average - average surface levels are very close to the levels above the atmosphere, and similar to many spots on Earth where clouds lower the average a lot. There are periods where surface levels drop by a factor 10 or so (and direct light drops even more) however, relying on solar power alone is not a good idea.

 

[256bits]

Any ideas or measurements/references?

1989 study for NASA[
Worth a read.

https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19890018252.pdf
Might as well throw this one in from 1976
https://deepblue.lib.umich.edu/bitstream/handle/2027.42/22925/0000491.pdf?sequence=1

... the 1971 dust storm. Their calculations indicate that the solar radiation absorbed
by wind-blown dust was enough to increase the lower atmosphere temperature
by 25°K day-L The Mariner 9 infrared spectrometer experiment (Hand et al.,
1972) and the radio occultation experiment (Kliore et al., 1972) show that the temperature
of the atmosphere was raised about 50°K during the storm, and that the
temperature profiles became almost isothermal.