paulHarkonen t1_ja0f231 wrote on February 25, 2023 at 10:23 PM

Reply to comment by epi10000 in how accurate is the greenland ice core oxygen isotope study in regards to earth's climate history ? by Additional-Rhubarb-8

That's fair, I'm more familiar with tracking things that have more local sources/sinks (which arguably CO2 has as well at the surface) which is why I noted that while all constituents have local variation it may not be very large in the case of CO2.

I appreciate the clarification though. I should really go look into some of the datasets and see how much surface variation you actually get when not intentionally chasing sources/sinks.

The fog bank example was intended to highlight how distinct different atmospheric "chunks" can be, not necessarily that the CO2 content would change. But again, the clarification is worthwhile here.

CrustalTrudger t1_ja0iu29 wrote on February 25, 2023 at 10:51 PM

The idea that there are remote areas where even the lower troposphere is sufficiently well mixed enough that sampling in one location represents a reasonable approximation of a global average is the whole concept behind the Mauna Loa Observatory and Keeling Curve.

paulHarkonen t1_ja0wg8r wrote on February 26, 2023 at 12:33 AM

Oooooh, I see what you're saying. You can find sample points that are sufficiently far from sources/sinks that your local measurements are (essentially) just measuring the aggregate of the troposphere.

That's different from saying that a local measurement at an arbitrary location is representative. Ok, I'm onboard now that I understand what you're saying. I was just commenting that local measurements are not necessarily reflective of larger scale measurements (which it sounds like is accurate with the exception of a few selective spots where the local readings happen to be better reflections of the average).