having personal experience at a particular station can use climatology as a refresher for the overall weather patterns that can be expected for the ensuing season. This knowledge can help them to be more perceptive in their   everyday   analyses,   to   be   alert   for   changing patterns  with  the  seasons,  and  to  produce  a  higher quality forecast. The  personnel  who  have  had  no  experience  at  a particular   station   must   rely   on   climatology   as   a substitute    for    their    experience. Forecasters    and assistant  forecasters  cannot  be  expected  to  become familiar  overnight  with  the  weather  peculiarities  of their new area of responsibility. The station certification  period  can  be  greatly  reduced  if  the  new people are furnished with “packaged experience” in a form  that  can  place  them  more  nearly  on  a  par  with those  forecasters  already  experienced  at  that  station. The   Local   Area   Forecaster’s   Handbooks   are   good examples of this type of packaged information. The Naval Meteorology Oceanography Command makes  many  uses  of  climatological  data.  In  using  the data, however, it must be clear that climatology has its limitations  in  the  field  of  meteorology.  It  may  be  put this  way.  Climatology  is  an  essential  supplement  to meteorology,   but   it   must   never   be   considered   a substitute    for    the    meteorological    situation    that constitutes current weather conditions. REVIEW QUESTIONS Q6-15. What    is    the    correct    method    to    obtain climatology information? Q6-16. What publication is also useful for obtaining climatology   information   for   a   particular weather station? WORLD WEATHER LEARNING OBJECTIVE: Identify the various  types  of  weather  and  climate  of  the oceans and continents. Aerographer’s Mates are stationed, and may travel, around  the  world.  Ships  and  aircraft  are  constantly  in global transit. Therefore, the Aerographer’s Mate must have    a    general    knowledge    of    types    of    weather encountered   during   various   seasons   in   regions   all around   the   world.   This   knowledge   also   increases insight into atmospheric circulation, weather development  and  movement,  weather  effects  on  the environment,    and    credibility    as    a    knowledgeable analyst, interpreter, and briefer. NOTE:  You  will  find  that  a  world  atlas  can  be extremely useful and informative if used in conjunction with the information that follows. OCEANIC WEATHER Naval   vessels   of   the   United   States   operate   in virtually  all  the  oceanic  areas  of  the  world;  therefore, the   Aerographer’s   Mates   must   be   acquainted   with oceanic  weather.  Some  general  considerations  of  the weather encountered over ocean areas are discussed in this lesson. Because  land  and  water  heat  and  cool  at  different rates,  the  location  of  continents  and  oceans  greatly affects   the   Earth’s   pattern   of   air   temperature   and therefore influences the weather.   The upper layers of the ocean are almost always in a state of motion. Heat loss or gain occurs at the sea surface and is distributed throughout large volumes of water. This mixing process sharply reduces the temperature contrasts between day and night and between winter and summer. Oceanic Weather Control It has long been recognized that the ocean plays an important  part  in  climate  and  weather,  particularly  in the realms of temperature, humidity, and precipitation. This   is   only   natural,   since   three-fourths   of   Earth’s surface is covered by water. The two climatic extremes that relate to water and land distribution over Earth are maritime and continental.   A   wide   range   in   annual   and   diurnal temperatures,  little  cloudiness,  and  little  precipitation generally  evidences  Continental  climate.  Continental climate  is  a  product  of  a  minimal  influence  from  the oceans. Maritime climate prevails over the oceans and is  characterized  by  a  small  temperature  range,  both annual and diurnal, and considerable precipitation and cloudiness. Water    vapor    is    considered    one    of    the    most important  variables  in  meteorology.  The  state  of  the weather is largely expressed in terms of the amount of water vapor present and what is happening to the water vapor. Two principal elements of climate, precipitation and  humidity  are  dependent  upon  water  vapor.  Since the oceans are the main source of water vapor, it follows that the oceans largely control weather. Effects of Air-Sea Interchange The  atmosphere  and  the  oceans  have  tremendous effects  on  each  other.  These  effects  are  principally  in 6-17