So I'm currently building the geography of my world. It's supposed to be a Super Earth approximately 2.3 times the size and 1.7 times the mass. It's gravity is slightly weaker and it has slightly higher oxygen and atmospheric pressure (1.3x and 1.1x).

The issue is I need to eliminate tropics as a biome. This means I need a cool, 17C maximum equator and probably even colder poles. I won't do much with altitude because this doesn't cool the coastline enough to turn them into cold places.

Deserts can be hotter, but with little temperature variation, I need a way for the tropics to stay chilly and temperate year round. Since the ice age (last glacial maximum) wasn't high enough, how big would, compared to Earth, the polar ice caps of this world need to be?

So I'm currently building the geography of my world. It's supposed to be a Super Earth approximately 2.3 times the size and 1.7 times the mass. It's gravity is slightly weaker and it has slightly higher oxygen and atmospheric pressure (1.3x and 1.1x).

The issue is I need to eliminate tropics as a biome. This means I need a cool, 17C maximum equator and probably even colder poles. I won't do much with altitude because this doesn't cool the coastline enough to turn them into cold places.

Deserts can be hotter, but with little temperature variation, I need a way for the tropics to stay chilly and temperate year round. Since the ice age (last glacial maximum) wasn't high enough, how big would, compared to Earth, the polar ice caps of this world need to be?

Edit: I think I didn't explain myself well enough. I'm asking how big would the ice caps be on Earth if the temperature on the tropics was as low as it was at higher latitudes despite receiving more energy from the sun. This means "being more exposed" since I assumed the radiation coming from the world's star is already going to be less than that of our sun in our Earth.

Like, would the ice caps end up, on average, near Mexico?