Rainshadow Desert

In 200 million AD, the Rainshadow Desert is a large desert near the southeastern edge of Novopangea that is cut off from the coast by a massive range of mountains.

Like a giant spinning top losing its momentum, Earth's rotation has gradually slowed, 200 million AD, this imperceptible deceleration has added an hour to Earth's cycle and a day is now 25 hours long. Furthermore, the sun's luminosity has increased, leading to a rise in air temperature. As the hot sun beats down on the surface waters, it warms up the Global Ocean, leading to frequent and very strong hurricanes.

The east coast of Novopangea is constantly battered by these powerful storms, or hypercanes. Winds gusting at over 250 miles per hour (400 kilometers per hour) blast the shoreline. As the warm surface waters fuel the growing storms, the swell gathers into huge waves on the narrow continental shelf. The resulting breakers can be over 70 feet (20 meters) high. Meanwhile, rain falls in unrelenting torrents from dark clouds.

The violent winds, and the humidity they bring, do not travel far inland. Along the eastern edge of the supercontinent runs a high coastal mountain range, not unlike the South American Andes of previous times, but much longer and a good 10 percent higher. Winds sweep up the seaward faces of the mountains, dropping all their moisture as they rise. As they reach the summits, they spill over, blow through the passes and valleys, and descend as dry gusts into the arid hinterland. Here, starved of most moisture by its own rocky boundaries, lies the Rainshadow Desert.

Despite the devastation they wreak, the hypercanes not only provide the Rainshadow Desert with residential humidity, they also supply nourishment in the form of marine life. Animals swimming near the surface of the ocean are plucked up by the suction of the hypercanes. The updrafts can sweep even quite large animals a few miles up into the atmosphere. As the energy of the wind is absorbed by friction against the mountain slopes, the blasts abate and the sea creatures (and some additional marine plants) fall as organic debris beyond the mountains and into the desert. There is a constant influx of organic matter here, whether it be plankton or other swimming organisms caught up in the spume blown from the crests of the waves, or the bodies of hapless ocean flish, carried far from their ocean home and dumped unceremoniously in the sand. In a landscape such as this, no food source goes unexploited.

All day, the sun heats the sands of the Rainshadow Desert. When night falls, the air begins to cool and the mountains cast long shadows. This allows many creatures to emerge from the shade and feed throughout the night.