Recovery Strategy Geometry

All trained agents exhibit a consistent three-phase sequence after plume loss: surge upwind, lateral casting with oscillating forward motion, then downwind return. The surge-cast-return structure emerges naturally from optimization under turbulent plume statistics without being explicitly programmed. Dense plumes require early downwind returns to prevent overshooting, while sparse plumes demand prolonged upwind search to avoid entrapment, placing the two imperatives in direct conflict. Surge length increases strongly and monotonically with plume sparsity because longer inter-detection intervals mean the clock at plume loss encodes more information about distance from the last known plume position. Cast width shows no strong monotone trend with sparsity; wind speed is identified as a primary determinant of cast width and downwind return extent.