A sunrise most definitely cannot be associated with either of those things, the sun is most often symbolic of something good or happy. Falling snow also does not create a sense of fear or anxiety, when thinking of snow I think of peace and quiet, serenity. Some might even feel happy or joywhen thinking about snow because it is most often associated with Christmas. I also think that an open field does not stir feelings of fear, that is unless you give details or descriptions to make it scary. I would say a setting with decaying trees best creates fear and anxiety. The word decay literally means " the state or process of rotting or decomposition". It is associated with death, and death is most often viewed as frightening and mysterious. Hope this helps .