The discount window is an instrument of monetary policy (usually controlled by central banks) that allows eligible institutions to borrow money from the central bank, usually on a short-term basis, to meet temporary shortages of liquidity caused by internal or external disruptions. The term originated with the practice of sending a bank representative to a reserve bank teller window when a bank needed to borrow money.
Stratosphere: From the Latin word “stratus” meaning a spreading out. The stratosphere extends from the troposphere’s 7 to 17 km (23,000 – 60,000 ft) range to about 50 km (160,000 ft). Temperature increases with height. The stratosphere contains the ozone layer, the part of the Earth’s atmosphere which contains relatively high concentrations of ozone. “Relatively high” means a few parts per million—much higher than the concentrations in the lower atmosphere but still small compared to the main components of the atmosphere. It is mainly located in the lower portion of the stratosphere from approximately 15 to 35 km (50,000 – 115,000 ft) above Earth’s surface, though the thickness varies seasonally and geographically.