A negatively buoyant jet (NBJ) corresponds to the physical phenomenon that develops when a fluid is discharged upwards into a lighter environment or downwards into a heavier receptor fluid. In a NBJ the flow is initially driven mostly by the momentum. so it basically behaves as a simple jet released withthe same angle. while far from the outlet the buoyancy prevails. https://www.markbroyard.com/top-super-pet-naturals-busy-butter-calming-peanut-butter-for-cheap-limited-save/