What phenomenon does Doppler ultrasound research identify as occurring during pressure decreases?

Doppler ultrasound research identifies bubble formation from nitrogen as a key phenomenon occurring during pressure decreases. When divers ascend to shallower depths or experience a reduction in ambient pressure, the surrounding pressure on dissolved gases in body tissues, particularly nitrogen, drops. This decrease in pressure can lead to the supersaturation of nitrogen in the body, as the gas is no longer as soluble under the lower pressure conditions.

As a result, nitrogen can come out of solution and form bubbles in the tissues and bloodstream. This is commonly associated with decompression sickness, also known as "the bends," which divers need to be cautious about during and after their dives. Understanding this process is crucial for safe diving practices, including adherence to ascent rates and proper use of decompression stops to allow the dissolved nitrogen to safely exit the body without forming harmful bubbles.