text: Jacob Bjerknes names a process of this type caused by the easterly surface winds in the Walker Circulation and the zonal sea- surface temperature gradient; that Bjerknes-named process of this type affects the ENSO.
full_question: Jacob Bjerknes names a process of this type caused by the easterly surface winds in the Walker Circulation and the zonal sea- surface temperature gradient; that Bjerknes-named process of this type affects the ENSO. The non-linearity of the thermohaline circulation is driven by the following two processes of this type: the advection of salinity and the convective mixing of deep water. In many models, this type of physical process would move from a metastable state into activity by the firing of the "clathrate gun." One classic example of this type of process is the accumulation of water vapor in the atmosphere, since water vapor is a greenhouse gas; another classic example is increasing ice cover, since ice boosts a body's albedo and may lead to creation of a "Snowball Earth. For 10 points, name this type of process in which an initial change causes an additional change in the same direction, causing small perturbations to be amplified.
first_sentence: Jacob Bjerknes names a process of this type caused by the easterly surface winds in the Walker Circulation and the zonal sea- surface temperature gradient; that Bjerknes-named process of this type affects the ENSO.
raw_answer: positive feedback loops [or equivalents, such as positive feedback processes; or reinforcing feedback; or runaway process; or positive feedback after "feedback" is read; prompt on "feedback"until it is read]