Aurora is the result of the interaction between high-energy particles from outside the atmosphere and atoms in the upper atmosphere. This interaction often occurs in the area around the Earth's magnetic poles. It is now known that as part of the solar wind, high-energy particles are The Earth's magnetic field captures and falls towards the magnetic poles. They collide with the atoms of oxygen and nitrogen, knocking off the electrons and making them into excited ions. These ions emit radiation of different wavelengths, producing red, green, or blue aurora characteristic colors. According to this text, what is wrong with the following statement? ['Solar wind produces aurora by self-discharge in the upper atmosphere.', "Earth's magnetic field strength affects the probability of occurrence of aurora.", 'Excited ions can emit different colors.', '"It" refers to oxygen and nitrogen atoms.']