Seriously? I'm a scientist, it's not about the department it's about ur contributions in the theoretical development of whatever department u are in.

Any field u want,being a scientists is not a field of science. Its using ur knowledge for solving real problems

If u keep doing research on ur field and provide solutions and new discoveries u r a scientist. For now it is better if u choose agriculture, geology, chemistry, biology, sociology and so on. I don't mean the rest are not suitable but this are wt u could do better.

Computer scientist