On Monday this week I posted an image showing a strong warm anomaly over a large part of the Arctic Ocean, easily accessed. Similar anomalies have covered the same area for the last two days and again today, the last of which is posted below.. Monday’s letter was about the disappearing sea ice problem that is generating great concern. Today I will have an explanation of the cause of the anomaly and also why it is so durable, thereby creating a new concern. Refreezing of sea ice has already been set back a few days, and no one wants to have this situation continue any longer with a new melting season set to begin in just five months.
What about the cause? You already know about my devotion to the idea that anomalies like this, including the cold ones, can largely be explained by how much water vapor is passing over any designated region at a high altitude compared with how much was normally (on an average day) passing over the region during the base period for the anomaly. Whatever amount passes over on a given day, always in the form of pulses of varying size that are constantly in motion, imparts an independent greenhouse effect that, while present, is physically added to the more stationary effect of the water vapor and all other greenhouse gases belonging to the remainder of the atmosphere closer to the surface. Especially in higher latitude regions the relative size of the addition can make a considerable difference in air temperatures at the surface. Today’s activity in the Arctic provides us with a vivid demonstration of this effect.
The next two maps are placed in close proximity to simplify visual comparisons of certain features. The first one offers a different perspective of the same Arctic anomaly seen in the map above. The second provides a clear indication of the total volume of precipitable water present in the entire atmosphere at the same time and place. The overlap between these two features is unmistakable, actually quite dramatic. Sadly, I am unable to reveal any data related to the normal level of precipitable water for the appropriate base period but I’m utterly confident that it would be well below the coded level you see in this image, probably no more than half in places where the temperature anomaly is around +10C.
The source of this vapor concentration, as observable on the lower map, appears to be set by the late stages of two streams of vapor that originated in the Pacific Ocean. I think this is true for today at least, but the animated version of vapor stream flows over the last five days has other ideas. It creates an image of numerous inputs of remnant vapor entering the polar zone day after day from streams that have otherwise disintegrated. These vapors appear to briefly linger on while circulating and possibly reconcentrating deep within the zone. In Antarctica remnants of the same type appear every day, like we saw in my letter yesterday, but then seem to vanish much more quickly. Maybe worth noting, but no conclusion. Lastly, while you have these two maps on the screen, look for more overlaps between large warm anomaly areas and obvious high concentrations of streaming water vapor. There are plenty to be seen.
Carl