I kept going back and looking at the graphic from my previous post on radiation and temperature. It kept niggling at me. It shows the change in surface temperature compared to the contemporaneous change in how much energy the surface is absorbing. Here’s that graphic again:
What I found botheracious were the outliers at the top of the diagram. I knew what they were from, which was the El Nino/La Nina of 2015-2016.
After thinking about that, I realized I’d left one factor out of the calculations above. What the El Nino phenomenon does is to periodically pump billions of cubic meters of the warmest Pacific equatorial water towards the poles. And I’d left that advected energy transfer out of the equation in Figure 1. (Horizontal transfer of energy from one place on earth to another is called “advection”).
And it’s not just advection of energy caused by El Nino. In general, heat is advected from the tropics towards the poles by the action of the ocean and the atmosphere. Figure 2 shows the average amount of energy exported (plus) or imported (minus) around the globe.
Due to the recent posts by Lord Monkton and Nick Stokes, I’ve been thinking about the relationship between radiation and temperature. So I turned to the CERES dataset. Here is a scatterplot of the monthly global average surface temperature versus the monthly global average downwelling total radiation absorbed by the surface. The total radiation is the sum of the net solar radiation at the surface and the downwelling longwave radiation at the surface. I’ve removed the seasonal variations from the data.
Note that 3.7 W/m2 is the increase in downwelling longwave radiation expected from a doubling of CO2 …
When I saw that, I thought well, maybe the increase is small because there’s a lag between the absorption of the radiation and the warming. To see if that was the case, I did a cross-correlation analysis of the relationship.
La géologie, une science plus que passionnante … et diverse