Can you cast Leomud’s Tiny Hut upside down?

This isn’t for any practical reason other than to answer a debate I was having with a friend. The spell reads that the hut forms "above" the caster, but all descriptions of the spell pay special attention to the position of the caster, i.e. if you’re standing on a slope it will only extend to your feet and not further below. Is above you always up, or is it relative to the caster’s position (and can therefore form a bowl shape)?