In
the case of the air the circulation changes are very quick.
Not exact matches
As far as this historic period is concerned, the reconstruction
of past temperatures based on deep boreholes in deep permafrost is one
of the best past temperature proxies we have (for the global regions with permafrost — polar regions and mountainous regions)-- as a signal
of average temperatures it's even more accurate than historic direct measurements
of the
air temperature, since the earth's upper crust acts as a near perfect conservator
of past temperatures — given that no water
circulation takes place, which is precisely the
case in permafrost where by definition the water is frozen.
This is not the
case with surface - to -
air heat exchange (which involves evapo - transpiration, sensible heat flows, and radiation) or even within the troposphere where impacts
of latent heating on atmospheric
circulations are realized on scales ranging from hundreds
of meters to thousands
of kilometers.
According to their modeling studies, the difference in the amount
of incoming solar radiation, in this
case, primarily in the ultraviolet (UV) wavelengths, during the minima and maxima
of the 11 - yr solar cycle are large enough to produce a characteristic change in the winter
circulation pattern
of the atmosphere over North America... When the NAO is in its negative phase, more cold
air can seep south from the Arctic and impact the lower latitudes
of Europe and the eastern U.S., which helps spin up winter storm systems.