If it is pastoral, it is like looking through the window at a bleak landscape on a grey day. If this is the idea, then the use of the repeated, plaintive upward phrase is a very effective way of expressing it. I always find the hard part about writing something with ONE idea, as opposed to two or three, is that unless minimalism is the chosen effect, (and nothing wrong with that, of course) it cannot be stretched out too long. I usually find myself compelled to introduce a contrasting idea.
But there are always exceptions to anything. Jarrett sometimes goes on for ages with one motif and the effect is not unpleasant, especially in his more recent recordings.
Let us hear more of your atmospheric creations.