My lab readings are in ug/L and the Canadian Water Guidelines are in mg/m2, I am not sure how to convert this, or if it is possible.
Thank you
1 microgram = 0.001 milligram
1 liter = 0.001 cubic meter
So using algebra we find the conversion factor to be:
0.001/0.001 = 1
When I read it correctly, the question was about the conversion between chlorophyll per volume and chlorophyll per area. This question is indeed not uncommon for comparing different aquatic systems with different depth, especially as macrophytes grow per area and also light is measured "per area". On the other hand, plankton grows (and is measured) per volume. Therefore, conversion between 1/m3 and 1/m2 needs an additional information: water depth. The per area chlorophyll is simply the integral (or sum) over all depths.
Thomas
Thank you for your answers. I have depths at least so I can figure that out.
The units are equal. They refer to the same concentration unit.
Dear Julie, one additional note about sampling. Just a single value from the water surface will not be representative for deep stratified lakes. Recommended is either an integrated sample (representatively mixed over the depth range) or a depth profile, from which you can calculate a weighted average resp. integral. R package marelac has a function for depth or volume weighted averaging.
Thank you, I will keep that in mind. In this case its a shallow slough, but it's good to know about the R package!
Dear Julie Porter
You can measure chlorophyll a content as ug/g and then convert the resulting value to mg/m2 as:
mg/m2 chl. a = (0.001 × ug chl. a) × weight of 1 m2 leaf (g)
Best wishes
Kazem Ghassemi-Golezani
On the same note, I want to convert ug/L to ug/m2.
Is this feasible? I know 1 litre = 0.01 m2.
Can I ignore the ug unit because it is the same?
Waiting for your responses.
Cla a= A*11.9 mg/L
Content of Cla by absorbance at 663 nm. Fresh sample
The two are not the same. As Thomas Petzoldt noted above, the first is per volume (1 liter = cubic meter) and the second is per area (square meter). How to compare the two would depend on what the chlorophyll values are from (e.g., a leaf, periphyton, or phytoplankton).