We also looked at cancelling out the dropdown overload taking place. This would entail each individual menu bar target having its own, more comprehensive page. This would also require more clickthroughs, but less user fatigue, since each intermediate page would require less intense examination.
This might require a brief sidebar of popular links at the left or bottom of the front page, or a breakdown of the “Popular Data Sets” box. Another possibility would be a direct navbar to the various data sets, which could possibly fit next to the slimmed down main page:
Climate Data Guide Redesign 