Mirages don't just appear in the desert. When light passes through the air, if the air density is uneven due to the sudden change of temperature, it may cause light refraction, thus creating a mirage.

2. Northern Lights

Since the northern lights were discovered, people have been deeply attracted by its mystery and beauty. The Northern Lights usually occur when the sun releases high-energy charged particles, which are released from space at a speed of 300- 1200 km per second. The cloud structure formed by these charged particles is called plasma.

3. Melting icicles

Melting icicles look very much like ice spears, mainly in alpine glaciers, and their sizes vary from a few centimeters high to 5 meters high. At first, the sun shines on the surface of snow or alpine glaciers and melts, forming irregular dents. Once dimples like this are formed, the sun's rays will be reflected in the dimples, increasing the sublimation of local substances. With the gradual deepening of micro-depressions, deep grooves are formed, and finally the ice spear structure is formed.

4. Tubular clouds, breast clouds and gravity wave clouds.

This kind of cloud is called tubular cloud, and it also has the nickname "morning glory". Besides tubular clouds, such as milky clouds and gravity wave clouds are also very rare weather landscapes.

5. Ice ring

The phenomenon of "ice circle" is very rare in the world, usually only in the Arctic, Scandinavia, Canada and other regions. At the corner of the river, the accelerated water flow will produce a force called "rotational shear", which will cut off the ice and then the ice will slowly rotate. The cut ice rubs against the surrounding ice and finally forms a perfect circle.