Ambrose was born in 1933, and grew up in Auckland, New Zealand. He earned a Diploma in Fine Arts, and then worked with Jack Golson at the University of Auckland, being employed as a technician in 1955. There Ambrose was involved in excavation, photography, and illustration, as well as in writing and editing papers. Golson was appointed as a Fellow in Prehistory at the Australian National University in 1961, and Ambrose followed two years later, as a research assistant. While Ambrose had studied geology and anthropology courses at undergraduate level during his time at Auckland, the credits he had earned were not recognised by the ANU, and he did not gain his bachelor's degree. He did earn, however, a Diploma of Archaeological Conservation at the Institute of Archaeology in London, spending two years in London with his wife and children.[1]
Ambrose was one of the first conservators in Australia. He is known for establishing the Conservation Section of the School of Pacific Studies at the Australian National University. He remained at ANU until 1981.[2]
Ambrose studied in the field in Australia and Papua New Guinea, at Kuk Swamp with Winifred Mumford, and Motupore, with Jim Allen. In 1970 he established the archaeology laboratory at the University of Papua New Guinea. He developed new techniques for preserving and freeze-drying wet wooden artefacts.[1]
Ambrose retired in 1998. In 2006, he was awarded a Doctor of Letters by the ANU, on the basis of 42 published papers.[1]
Ambrose died on 9 January 2024.[3]