Winter sea ice is a significant atmospheric contribution of bromine. Organic bromine gases such as CHBr, CHBr, CHIBr are emitted by microorganisms in sea ice and snow at ten-fold higher rates than from other environments. In polar areas, decreasing sea ice releases bromine and at the Arctic and Antarctic boundary layer, bromine is released in the spring when the ice melts.
Inorganic bromine is found in the atmosphere and is quickly cycled between its gas and its particulate phase. Bromine gas (Br) undergoes an autocatalytic cycle known as the bromine explosion, which occurs in the ocean and salt lakes such as the Dead Sea, where a high quantity of salts are exposed to the atmosphere. Bromine contributes to 5-15% of tropospheric ozone layer losses.