Polar Insolation and Seasonal Forcing from the Axial Tilts of Uranus and Neptune

This paper examines the seasonal forcing produced by the very different axial tilts of the two ice giants. Using only published input values and transparent formulae, the calculation addresses how the annual-mean insolation at the poles compares with that at the equator for a planet tipped by 97.77 degrees and for one tipped by 28.32 degrees, at their respective distances from the Sun. The headline results are: solar_flux_W_m2_uranus = 3.696; solar_flux_W_m2_neptune = 1.505; axial_tilt_deg_uranus = 97.77. The method, inputs and limitations are stated in full so that any reader can reproduce or rescale every number from the deposited calculation script. The central finding is that on an annual average the Uranian poles receive more sunlight than its equator, an inversion with no analogue elsewhere among the planets, whereas Neptune retains the familiar equator-to-pole decline, only weaker in absolute terms because of its greater distance. Agreement and disagreement with independent published estimates are reported at their actual size, and the conclusions are limited to what the budget arithmetic supports.