solar radiation.

Hello there,
i am a bit confused and would like to ask you for your thoughts. I also wonder if i measure solar Radiation.

At the beginning of my measurements, in October 2017, the CPM values at daytime and the CPM values at nighttime were not significant different.
Now, since the 26th of November, i measure very different values at night and day.
The value rises by sunrise and goes down in the evening when sun sets. Every day.
(See the attached pictures or http://www.radmon.org/radmon.php?function=showuserpage&user=kaiserkarl )

My Geiger Counter is not able to measure Alpha radiation, so the Alphe Radiation from Radon shouldn't be a thing.
The tube is located at the outside of our building with free view heading east.

Could my measurements be related to our tiny snowfall in the last weeks?
(Approx. 1-2cm snow on the grount) that reflects the sunlight more than before without snow?

I am happy to hear your thoughts.

Best Wishes
Karl

Hi Karl,
It looks like radon to me.
Radon decays to stable lead in a few stages and emits different types of radiation as it does so.
http://www.ccnr.org/radon_chart.html
The different progeny like to attach to particles and moisture in the air and this happens very well at higher humidity -
I wonder if your chart peeks also indicate peek humidity for that period?

I hope this helps
Juzzie

Hi Juzzie,
thanks for your Infos, the chart peeks could be equivalent to the humidity the last days.
I will Check and let you guys know the next days.

Thanks and Greets
Karl

Hello again,
it seems that you were right and the peaks are presumably related to air temperature and humidity.
(See attached charts if interested)

Today it got warmer, I will watch the progress this week and reconcile the data.
The values should stay low as today until it gets colder again.

I also found intersting Information on the influence of solar irradiance on radon signals (In this case at 1km depth) if anyone else is interested.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3780823/

Greets
Karl

That paper on Radon measurements is fascinating. It quashes my prior notions of why Radon measurements vary. The pressure influence seems to be not there. Daily variations clearly exist but may be related to earth's actual rotation or solar radiation such as Neutrinos (lab was under 1 km of rock), or even sun rotation (not related to the planet at all). Very complicated.

Hi Bert,
then this Article should also be interesting for you:

On the claim of modulations in radon decay and their association with solar rotation
http://www.sciencedirect.com/science/article/pii/S0927650517302323

The annual cycle of daily peaks follows the expected pattern of solar irradiance in Israel with respect to timing and amplitude. The transient cycles in the nocturnal count rates may be related to the rise and fall of humidity in the electronics, most notably after rain showers driven by southern winds.

In my case this would "explain" the Peaks in my Measurements, but i will still compare the results of next weeks Data with local Temperature and Humidity and Keep you guys up to date.

Greets
Karl