The January global temperature had an anomaly of +0.72C, which is the warmest January in the 32 years of satellite temperature measurements.
Dr Spenser thinks this is probably a function of sea surface temperature and he says:
I’m sure part of the reason is warm El Nino conditions in the Pacific. Less certain is my guess that when the Northern Hemisphere continents are unusually cold in winter, then ocean surface temperatures, at least in the Northern Hemisphere, should be unusually warm. But this is just speculation on my part, based on the idea that cold continental air masses can intensify when they get land-locked, with less flow of maritime air masses over the continents, and less flow of cold air masses over the ocean. Maybe the Arctic Oscillation is an index of this, as a few of you have suggested, but I really don’t know.
Also, remember that there are always quasi-monthly oscillations in the amount of heat flux from the ocean to the atmosphere, primarily in the tropics, which is why a monthly up-tick in tropospheric temperatures is usually followed by a down-tick the next month, and vice-versa.
So, it could be that all factors simply conspired to give an unusually warm spike in January…only time will tell.
So keep tuned. To see Spencer’s full post click here.