昜 is the old form behind 阳 (sun / yang) and is not used on its own today. It gives the sound and 'bright' flavor in 阳 (sun), 场 (field / venue), 扬 (to raise), 杨 (poplar), and 汤 (soup).
The lower part is read as sun-rays streaming down; together with the sun above it builds the 'open daylight' idea that 昜 passes to its phonetic family.
