I have a jagged 3-inch red scar on my temple after removal of a melanoma. Is there any way I can improve the appearance of it?

Ow, sympathies – but yes. In terms of procedures, microneedling or radiofrequency microneedling can really help with remodelling/ smoothing scars – once the skin is sufficiently healed that you can treat it. If it’s still in the healing phase, try a product like Solutions for Scars from Science of Skin, which was developed by a plastic surgeon for exactly this purpose, and make sure to use lots of SPF over the scar, too, as scar tissue is really vulnerable to UV light.