"zone below" is correct and usable in written English.
You can use it when referring to an area or region that is lower or farther down than the one you are currently in. Example: We can see the snow-covered mountains in the zone below.
The kick struck the left upright and bounced into the end zone below.
American and British jets that patrol the southern "no flight" zone, below the 32nd parallel, were not flying that day and were unable to scramble quickly enough to challenge the Iraqi plane before it left, military officials said.
When I last saw her, for a lunchtime pint and a rag pudding (see the bakery zone, below) in Rochdale's excellent Baum, she gave me a hard time for offering my spare room to a Syrian refugee.
Under intense pressure from the mayor, Ms. Quinn and their allies that continued almost until the voting began, council members approved the plan to charge most drivers $8 to enter a zone below 60th Street by a vote of 30 to 20, with no abstentions and one absence.
Mr. Paterson's blessing, which came as Bloomberg aides have been furiously lobbying the city and state lawmakers who must approve the program, could prove crucial in making the proposal to charge most drivers $8 to enter the zone below 61st Street a reality.
The proposal, which is part of a plan known as congestion pricing, had taken a major step forward on Monday when the New York City Council approved the plan, which would charge most drivers $8 to enter a zone below 60th Street in Manhattan.
Mr. Paterson's blessing, which came as Bloomberg aides have been furiously lobbying the city and state lawmakers whose approval is needed for the program, could prove crucial in making the proposal to charge most drivers $8 to enter the zone below 61st Street on weekdays a reality.
Martensite (bright phase), heat affected zone below martensite and pearlite matrix.
It was also the 6th month in what ECB President Mario Draghi has called "the danger zone" below 1%.
Measurements revealed a stable thermal gradient in the upper portion of the cavity and a convective zone below it.
Below the redox zone (below 5 m depth) concentrations of H2S and all nutrients decreased by a factor of two.
