The phrase "seesaw pattern" refers to a back and forth or up and down movement, similar to the motion of a seesaw on a playground. It is often used to describe a repeating or alternating pattern or trend. Full definition
The leading modes of simulated North American precipitation and soil water storage are characterized essentially by qualitatively similar meridional seesaw patterns associated with the activity of the westerly jet. (link.springer.com)
(The opinions of the informed respondents do not show a clear seesaw pattern.) (educationnext.org)
The resulting first EOF mode (middle panels in Fig. 4) shows the same meridional seesaw pattern as the leading EOFs of unfiltered annual mean precipitation and water storage. (link.springer.com)