﻿F. 
  H. 
  Bigelow 
  — 
  International 
  Cloud 
  Work. 
  443 
  

  

  interior 
  of 
  the 
  anticyclone. 
  The 
  entire 
  system 
  of 
  high 
  and 
  low 
  

   areas 
  seems 
  to 
  be 
  constructed 
  by 
  the 
  counterflow, 
  chiefly 
  in 
  the 
  

   cumulus 
  and 
  strato 
  cumulus 
  levels, 
  of 
  long 
  currents 
  due 
  to 
  

   horizontal 
  convection, 
  the 
  double 
  action 
  on 
  the 
  pressure, 
  that 
  

   is 
  the 
  formation 
  of 
  high 
  and 
  low 
  pressures 
  simultaneously 
  in 
  

   adjacent 
  districts, 
  being 
  referred 
  to 
  the 
  general 
  circulation 
  of 
  

   the 
  atmosphere, 
  especially 
  the 
  deflecting 
  and 
  centrifugal 
  forces, 
  

   rather 
  than 
  to 
  local 
  temperature 
  accumulations. 
  The 
  ISTorth 
  

   American 
  Continent 
  is 
  the 
  region 
  where 
  cyclones/orm 
  in 
  large 
  

   numbers, 
  and 
  Europe- 
  Asia 
  the 
  region 
  where 
  they 
  dissipate, 
  so 
  

   that 
  the 
  violent 
  general 
  circulation 
  over 
  the 
  United 
  States 
  in 
  

   the 
  lower 
  strata, 
  as 
  compared 
  to 
  that 
  of 
  Europe, 
  is 
  chiefly 
  

   responsible 
  for 
  this 
  excess 
  in 
  the 
  production, 
  near 
  or 
  in 
  the 
  

   United 
  States, 
  of 
  the 
  local 
  storms 
  of 
  the 
  northern 
  hemisphere. 
  

   A 
  careful 
  study 
  of 
  these 
  vectors 
  in 
  all 
  strata 
  up 
  to 
  11,000 
  

   meters, 
  7 
  miles 
  high, 
  reveals 
  the 
  very 
  important 
  fact 
  that 
  there 
  

   is 
  little 
  disposition 
  to 
  conform 
  to 
  the 
  canal 
  theory 
  of 
  the 
  circu- 
  

   lation- 
  over 
  the 
  hemisphere, 
  as 
  ordinarily 
  taught, 
  namely 
  con- 
  

   sisting 
  of 
  a 
  southward 
  movement 
  in 
  the 
  lower 
  strata 
  from 
  the 
  

   polar 
  zone 
  towards 
  the 
  tropics, 
  with 
  reversal 
  of 
  the 
  component 
  

   from 
  east 
  to 
  west 
  at 
  latitude 
  35°, 
  together 
  with 
  an 
  overflow 
  

   northward 
  in 
  the 
  higher 
  strata 
  from 
  the 
  tropics 
  towards 
  the 
  

   poles. 
  While 
  the 
  general 
  circulation 
  conforms 
  to 
  this 
  type 
  in 
  

   many 
  features, 
  there 
  has 
  always 
  been 
  the 
  greatest 
  difficulty 
  in 
  

   accounting 
  for 
  the 
  comparatively 
  slow 
  eastward 
  drift 
  in 
  the 
  

   upper 
  strata 
  of 
  the 
  higher 
  latitudes. 
  Ferrel 
  attributed 
  a 
  large 
  

   part 
  of 
  the 
  required 
  retardation 
  to 
  the 
  effect 
  of 
  friction, 
  but 
  

   this 
  is 
  in 
  reality 
  a 
  comparatively 
  small 
  term. 
  Also 
  he 
  stated 
  

   that 
  the 
  difference 
  in 
  the 
  eastward 
  velocity 
  of 
  the 
  northward 
  

   and 
  southward 
  moving 
  strata 
  at 
  different 
  elevations 
  represented 
  

   the 
  expenditure 
  of 
  retardational 
  energy. 
  As 
  a 
  matter 
  of 
  fact 
  

   the 
  lower 
  strata 
  do 
  not 
  move 
  southward 
  as 
  a 
  whole, 
  and 
  our 
  

   observations 
  do 
  not 
  indicate 
  that 
  the 
  higher 
  strata 
  are 
  vigor- 
  

   ously 
  moving 
  northward, 
  because 
  that 
  component 
  is 
  very 
  small. 
  

   What 
  takes 
  place 
  is 
  this 
  : 
  in 
  each 
  stratum 
  from 
  the 
  surface 
  to 
  

   the 
  cirrus 
  level 
  about 
  as 
  much 
  air 
  moves 
  north 
  as 
  south, 
  for 
  

   there 
  are 
  enormous 
  counter 
  currents 
  passing 
  hy 
  each 
  other 
  at 
  

   the 
  same 
  level, 
  and 
  not 
  over 
  one 
  another 
  at 
  diffei^ent 
  elevations. 
  

   This 
  puts 
  a 
  new 
  aspect 
  on 
  the 
  entire 
  problem 
  of 
  the 
  general 
  

   circulation. 
  It 
  looks 
  as 
  if 
  the 
  solar 
  radiant 
  energy 
  was 
  

   absorbed 
  chiefly 
  in 
  the 
  lower 
  strata, 
  and 
  that 
  instead 
  of 
  going 
  

   the 
  rounds, 
  overflowing 
  above 
  from 
  the 
  tropics, 
  there 
  is 
  devel- 
  

   oped 
  a 
  continuous 
  leakage 
  in 
  the 
  lower 
  strata, 
  which 
  is 
  observed 
  

   as 
  our 
  persistent 
  winds 
  from 
  the 
  south. 
  These 
  meet 
  the 
  north 
  

   winds 
  which 
  flow 
  in 
  obedience 
  to 
  the 
  general 
  circulation, 
  as 
  

   figured 
  by 
  the 
  form 
  of 
  the 
  land 
  and 
  ocean 
  areas. 
  This 
  escape 
  

   from 
  the 
  tropical 
  belt 
  diminishes 
  the 
  pressure 
  in 
  low 
  latitudes, 
  

  

  