|Salt Lake Valley residents awoke to a shallower but dirtier layer of pollution this morning|
Over the past two days, however, the inversion has lowered, tightening the noose on the Salt Lake Valley. You can clearly see this in the soundings from Monday morning (top) and this morning (bottom). In the Monday morning sounding, the inversion was about 1 km above the valley floor, and the atmospheric temperature profile allowed for mixing through that 1-km deep layer. In contrast, this morning the inversion is based pretty much on the valley floor.