"decrease towards" is correct and usable in written English.
You can use it to describe a gradual decrease in some quantity or value that is headed in a certain direction. For example, "The temperature was expected to decrease towards the evening."
This causes their intensities to decrease towards the inner heliosphere, a process referred to as modulation.
The lifetimes inside the fibre (filled circles) decrease towards the middle of the fibre due to the increase in collisions with residual gases.
The pH and buffer capacity (BC) of paraffin-stimulated saliva, for example, have been found to decrease towards late pregnancy.
A variety of activity profiles, including step-distribution and those which increase or decrease towards the pellet surface, are considered.
Strain rates decrease towards a first sharp local creep rate minimum at 0.1% strain (reached after 30 min).
Stress values decrease towards the substrate and change to tensile stress up to 2.5 GPa near the film substrate interface.
The hysteresis loop of the North American ice sheet is such that after inception of the ice sheet, its mass balance remains mostly positive through several precession cycles, whose amplitudes decrease towards an eccentricity minimum.
Micro-computed tomography determined that bone ingrowth initiated at the periphery of the SMP foam with a constant decrease towards the inside.
As the entrance substrate concentration increases, on the other hand, these values initially increase, pass through maximums, and finally decrease towards their intrinsic values.
Such stresses were observed to decrease towards the coating substrate interface where the compressive component of the stress state becomes greater than the tensile component.
Subsequently, strain rates decrease towards a global minimum at 5% (260 h), before tertiary creep (not considered in the present work) leads to final rupture.
