4 ms·

I'd say you're reading it correctly. This is what I see: There's an underlying yearly cycle that goes something like: - gets hotter around March - gets colde

I'd say you're reading it correctly. This is what I see: There's an underlying yearly cycle that goes something like: - gets hotter around March - gets colder around May-June - gets hotter around August - gets colder around November This is, let's say, a sort of cyclic baseline that repeats every year. But over it there are variations. Some years are generally colder, or generally hotter. Some the differences are bigger or smaller, etc. Then, obviously, it's not a perfect curve and there's "noise" on it. It's also interesting to note that the "March peak" is generally hotter than the "August peak", and that the "November valley" is generally colder than the "June valley". All this, broadly speaking. Now, until last year, the highest temperature had happened in 2016, in the "March peak". This "makes sense". I mean, it makes sense that the hottest it got was on one of the hot peaks. What's more, it happened in the hotter one of both hot peaks. But if we look at this year, what we see is two things. One is that, as the title points out, there's been a new highest, higher than March 2016. This is pointed out because it makes an easy and simple headline. The second thing you can see is what you pointed out, that in 2023 we haven't had much of a valley in May-June and instead it has been hotter since March producing that the August peak be not only much higher than other years but even higher than the highest March peak. (And, I may add, it may still get hotter in this peak)

ethbr0 3y ago
This is the "daily average sea surface temperature between 60°N and 60°S". And southern latitudes have more exposed ocean than northern ones. See 60° to 60° on "Land Mass at Each Latitude" https://www.ecoclimax.com/2016/08/land-mass-at-each-longitude-and-latitude.html?m=1 https://www.ecoclimax.com/2016/08/land-mass-at-each-longitud... Which would make sense that southern summer (ending ~March) would be the typical yearly peak. https://en.m.wikipedia.org/wiki/March_equinox https://en.m.wikipedia.org/wiki/March_equinox
- genezeta 3y ago
  Yes, you're absolutely right. There's more sea surface in the southern hemisphere, so it makes sense that generally the peak would be determined by southern summer.
  - ethbr0 3y ago
    I'm rethinking this after puzzling over it for a minute. Since it's the average... total sea area shouldn't matter. Land heats up faster than sea, but likely doesn't transfer much of that heat into the ocean, so the sea:land ratio might be immaterial. Probably more indicative is what deep to shallow circulation currents exist in the northern vs southern oceans. From memory, the northern has many more "vertical" circulations, that might lead to cooling surface temperatures.
    - genezeta 3y ago
      Clearly we can't know for sure unless we have more information about the data itself. But my reasoning is this: If we assume a uniform number of "samples per area" then the north/south distinction does matter. Larger total sea area in the south would mean more samples taken in the south. And therefore more influence of "southern samples" on the total average. Again, we don't know unless we have more info, but it seems like a reasonable assumption to make.

ethbr0 3y ago

This is the "daily average sea surface temperature between 60°N and 60°S". And southern latitudes have more exposed ocean than northern ones. See 60° to 60° on "Land Mass at Each Latitude" https://www.ecoclimax.com/2016/08/land-mass-at-each-longitude-and-latitude.html?m=1 https://www.ecoclimax.com/2016/08/land-mass-at-each-longitud... Which would make sense that southern summer (ending ~March) would be the typical yearly peak. https://en.m.wikipedia.org/wiki/March_equinox https://en.m.wikipedia.org/wiki/March_equinox

genezeta 3y ago
Yes, you're absolutely right. There's more sea surface in the southern hemisphere, so it makes sense that generally the peak would be determined by southern summer.
- ethbr0 3y ago
  I'm rethinking this after puzzling over it for a minute. Since it's the average... total sea area shouldn't matter. Land heats up faster than sea, but likely doesn't transfer much of that heat into the ocean, so the sea:land ratio might be immaterial. Probably more indicative is what deep to shallow circulation currents exist in the northern vs southern oceans. From memory, the northern has many more "vertical" circulations, that might lead to cooling surface temperatures.
  - genezeta 3y ago
    Clearly we can't know for sure unless we have more information about the data itself. But my reasoning is this: If we assume a uniform number of "samples per area" then the north/south distinction does matter. Larger total sea area in the south would mean more samples taken in the south. And therefore more influence of "southern samples" on the total average. Again, we don't know unless we have more info, but it seems like a reasonable assumption to make.