# PAR of natural sunlight?



## Current USA (Jun 5, 2013)

I just tested it for you. In Vista California today, the PAR is about 1000 micromoles


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## sarahspins (Sep 24, 2012)

Holy wow


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## wheatiesl337 (Mar 30, 2011)

http://www.clearskycalculator.com/


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## germanyt (Jul 8, 2013)

I wonder if putting one of my not so healthy plants in a small cup of tank water outside for the day will bring it back to life.


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## jeffkrol (Jun 5, 2013)

Cthulhu said:


> What is the PAR of natural sunlight? On a clear day in the tropics? Or a clear day vs cloudy day at a lattitude like New York?
> 
> I'm just very curious! But is seems the Internets don't want to share this secret easily...


just averages in einsteins/meter (sq)/day
http://www.terrapub.co.jp/journals/JO/pdf/6303/63030493.pdf










http://oceancolor.gsfc.nasa.gov/staff/franz/papers/frouin_et_al_2013_spie.pdf



> An einstein is a unit defined as one mole (6.022×1023) of photons, regardless of their frequency. For photons of a given wavelength, einsteins per square metre is a measure of irradiance.
> 
> The einstein is used in studies of photosynthesis since the light requirement for the production of a given quantity of oxygen is a fixed number of photosynthetically active photons. Photosynthetically active radiation (PAR) is usually reported in microeinsteins per second per square meter (μE/m2/sec).


1000 μE = E


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