Poison Ivy was currently on a small island in the Pacific Ocean. There was a modest rainforest on the island, where she had always cultivated her vine-like plants.
But now the island was covered in snow. Many trees had been snapped by the snow and sea winds, and even the waters around the island had frozen over.
Due to its salt content, seawater generally did not freeze, though there were exceptions.
The physical process of seawater freezing was rather complicated. Cold weather lowered the temperature above the sea surface, while strong winds churned the water, causing the surface layer to lose heat and cool down.
As the temperature of the surface seawater dropped, excess salt precipitated out and formed condensation nuclei, increasing the density of the upper layer and causing it to sink. The lower layer, being relatively less dense, rose to the surface.
The upper and lower layers then mixed through convection. As cooling continued, the chilled surface water was carried downward, while the crystallization heat released when ice crystals formed in the lower layers was brought to the surface. The seawater cooled again, until the densities throughout the rising and sinking water layers became uniform and stable.
When the seawater temperature fell to its freezing point and continued losing heat, it began to freeze. If the hot-and-cold convection reached all the way to the seabed, ice could even form on the ocean floor.
That was just some idle speculation, but it could at least show that Poison Ivy's island was not within an ocean current belt. It also meant that the global cold spell had been going on for quite some time.
After teleporting onto the island, Harley found Red with Superman-like sensory abilities. More precisely, she saw a dialogue box floating above a snowdrift at the center