The horizontal (left-right) dimension is called longitude. The vertical (top-bottom) is called latitude. However, I'm not sure how to adjectivize and adverbize those terms.
The best shot expressing the meaning I can think of is "latitude-wise" for the vertical case. Here, I have two questions.
Is there a more sophisticated term for that? And if not...
What is the most recommended way to express the work-around of mine?
c. latitude wise
Of course, the same wonderings go for the horizontal dimension, i.e. "longitude-wise". However, I'd be strongly surprised if it differed in principle from the vertical one.