Subset of lakes with v. low DOC concentrations

[diatomdaniel]

JC suggested that lakes in our data set close to the Great Lakes region w. very low DOC concentrations may be unit issues. We need to extract these data and check whether we have made any errors with our unit conversions.

[dnguyen2017]

@diatomdaniel @LinneaRock @mcstreamy I've looked into this more closely (see code that I pushed).

Summary of findings:
There is a subset of lakes from the LAGOS data set around the great lakes region with very low DOC. For these low DOC lakes that have multiple measurements, all DOC readings are low. I have trouble believing it is a unit issue, because if it were, then all lakes in the LAGOS data set should be similarly effected.

There are also some rivers from the ECN dataset in southern England that have 2 oddly low readings of DOC. Most of the readings at these sites were in a normal range. These DOC of these rivers was at baseline both before and after the drop in DOC. This may be instrumentation error or perhaps some strange event.

[diatomdaniel]

Nice work @dnguyen2017. I guess we will discuss this on Friday...

[mcstreamy]

Yes well done @dnguyen2017 - we will discuss. Were other parameters out of wack in those LAGOS sample dates? PIs might have some insight on why DOC could be that low or issues with LAGOS dataset consistency (which I've heard mentioned before by Sarah)

[LinneaRock]

Thanks @dnguyen2017 et al.!! I took a look back through the workflows, original LAGOS datasets, and our compiled datasets. I believe those data are as reported in the LAGOS database.