Bulk density depth gradient

In submerged soils there tends to be a gradient of bulk density with depth as a result of the settling of disturbed sediment. As a result, the bulk density is... 

The well has a diameter of 25 cm and is installed in an aquifer having a hydraulic conductivity of 0.03 cm/sec, a porosity of 0.25, and a saturated depth of 17 m. The regional hydraulic gradient is 0.014. Aquifer bulk density is 2.2 kg/liter. The area receives about 1 m/yr of rain, of which roughly half goes into aquifer recharge. Thus, an estimated radius of influence is about 1400 m. 

In short, the Marangoni convection induced by surface tension gradient and the Rayleigh convection induced by density gradient are the two main interfacial effects. Marangoni convection displays on the interface and underneath (the depth of Marangoni convection underneath is about 10 " m in our observation) and the Rayleigh convection appears vertically from interface to the bulk fluid with accompanied action of interfacial renewal. When the critical point of each convection is reached, the interfacial effect will be initiated. 

The dimensionless snow-pore space partition coefficient Ksa is notably lower in the sub-Arctic snow pack largely because of the influence of temperature on ATja (see Equation 18.2). The bulk of the snow packin sub-Arctic regions consists of depth hoar that exhibits both low density and SSA, which further contributes to this discrepancy. The differences in partitioning of PCB-28 within the sub-Arctic and Arctic snow pack cause significantly different concentration gradients between snow cover and lower atmosphere and thus, different exchange behavior. While PCB-28 is released from the sub-Arctic snow pack, the comparably low pore space concentration in the Arctic snow leads to a net deposition of this chemical (Table 18.1). 

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