Is a micromol the same as PAR?

[evan127]

Is the unit umol second-1 meters-2 the same as PAR? A micromol is typically 400-700 nanometers and PAR is measured the same way, no?

[gus6464]

A micromol is a form of measurement. When one says "200 PAR" it really means 200 micromols of photosynthetically active radiation. They are not mutually exclusive as you can measure other things with micromols as well.

 

I am really simplifying it though and it's more complicated than that. When you buy a par meter like apogee or licor it will give you the measurement in micromols.

[evan127]

Thanks for the response!

 

So, umol s-1 m-2 is really photosynthetic active radiation? So when I visit the AIMS site http://weather.aims.gov.au/#/station/1 and light is measured in umol s-1 m-2 its equivalent to how we measure light in our aquariums with PAR?

[gus6464]

Thanks for the response!

 

So, umol s-1 m-2 is really photosynthetic active radiation? So when I visit the AIMS site http://weather.aims.gov.au/#/station/1 and light is measured in umol s-1 m-2 its equivalent to how we measure light in our aquariums with PAR?

 

Correct. 2000 PAR might seem like a lot but once you take into account how much it has to penetrate to get to corals in the ocean it makes sense.

[evan127]

I think their readings for light are recorded at the surface.