TWI has various meanings in the Scientific & Educational category. Discover the full forms, definitions, and usage contexts of TWI in Scientific & Educational.
Partial illumination by sunlight during interval between Sun's upper limb being on horizon and his Center being 18deg below it Caused by the scattering, refraction, and reflection of light by Earth's atmosphere See 'Civil', 'Nautical', and 'Astronomical' twilights.
Scientific & EducationalLast updated: