In a manner related to, associated with, or similar to zones.(adverb)
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Use "zonally" in a sentence
"Zonally symmetric dynamics in the GISS model result in near-zonally symmetric ozone loss and recovery."
"Using TOMS Version 7 ozone and reflectivity data from 1979 to 1992 and the corresponding TOMS surface UV retrieval algorithm, Herman et al.  estimated that zonally averaged mean annual surface UV irradiances at 300, 310, and 320 nanometers (nm) increased by 15%, 6%, and 2% per decade, respectively, for the latitude band 60º to 70º N."
"The Coriolis force (or Coriolis effect) causes the deflection of this moving air in the upper atmosphere, and by about 30° of latitude the air begins to flow zonally from west to east."