quadrant 7 (north of equator, west of prime meridian) as 12.238° North, 095.139° West, whereas 71224/09514/ is  the  same  position  reported  only  to  the  nearest hundredth of a degree. The  last  part  of  the  identification  section  is  the optional   group   6Q₁Q_tQ_A/.   This   group   is   based   on WMO Code Table 3334 and is used as a quality control indicator, with Q₁ and Q_A used for position and Q_t for time. This group must be encoded manually. See table 2-4. METEOROLOGICAL   DATA Within the meteorological data section, winds, air temperature,   dewpoint   temperature,   and   relative humidity  may  be  reported.  In  addition,  pressure  data, such as station pressure, sea level pressure, and 3 hour pressure tendency, may also be reported. Each group in section 1 is only reported if the buoy actually measures the  information.  All  groups  are  identical  to  the  ship Synoptic code (WMO 13-X SHIP), except for the use of the group indicator 0 for the wind data group and the relative humidity group (29UUU). The  meteorological  section  is  identified  by  the group  111Q_dQ_x.  The  code  figure  Q_d  is  the  quality control indicator, and Q_x indicates the position of any one group in this section that is not good, if applicable. Otherwise,  Q_x  is  encoded  as  a  9.  In  our  example,  the groups 00308 10255 29075 30132 40133 52003 report winds  from  030°  true  at  08  knots,  air  temperature 25.5°C,  relative  humidity  of  75%,  station  pressure  of 1013.2 hPa, and sea-level pressure at 1013.3 hPa. The last  group  is  the  pressure  tendency  and  amount  of change (hPa) during the past 3 hours. Only three codes are  used  for  tendency  (2  =  pressure  increasing,  4  = pressure  steady,  7  =  pressure  decreasing).  In  our  ex- ample, the pressure is indicated as rising and up 0.3 hPa. SURFACE  MARITIME  DATA As  with  the  meteorological  data,  each  section  2 surface  maritime  data  group  is  only  included  if  the information  is  measured  by  the  buoy.  The  indicator 222Q_dQ_x  will  always  precede  any  surface  maritime data, but is itself omitted if no groups from section 2 are reported.  The  group  0s_nT_wT_wT_w  is  used  to  report  the sea-surface temperature. The code figure s_n is the sign of  the  temperature  (0  =  positive,  1  =  negative).  For example,  the  group  00262  reports  sea-surface temperature at 26.2°C. Q_d  =  Quality  control  indicator Q_d1  =  Quality  control  indicator  for  temperature/ salinity. Q_d2   =   Quality   control   indicator   for   current (set/drift)   profile. Q₁Q_A  =  Quality  control  indicator  for  position. Q_t  =  Quality  control  indicator  for  time. Code Figure 0  =  Data  not  checked 1  =  Data  good 2  =  Data  inconsistent 3  =  Data  doubtful 4  =  Data  wrong 5 = Data value has been changed Some buoys contain a sensor that measures wave action. If  the  sensor  measures  wave  period  to  the nearest  second  and  wave  height  to  the  nearest  half- meter,   code   group   1P_waP_waH_waH_wa   is   used.   In   our example, 10302 reports a wave period of 3 seconds, and a  wave  height  as  2  half-meters  (3  feet).  Other  buoys contain  more  accurate  instruments  that  measure  wave period to the nearest tenth of a second and wave height to  the  nearest  tenth  meter.  These  buoys  report  wave period  to  the  nearest  tenth  of  a  second  in  the  group 20P_waP_waP_wa,   and  wave  height  to  the  nearest  tenth meter  in  the  group  21H_waH_waH_wa. OCEANOGRAPHIC   DATA Section 3 is used to report readings obtained from sensors on a drifting buoy’s tail. Sensors are normally fixed to the tail at set intervals. Most drifting buoys only measure  temperature,  but  more  sophisticated  buoys may   include   salinity   measuring   devices   and   water current measurement devices at various levels. The  data  groups  in  the  first  portion  of  section  3 following  the  333Q_d1Q_d2  8887k₂  indicator  groups  are used   to   report   seawater   temperature   and   salinity readings.  The  Q_d1  and  Q_d2  are  used  to  indicate  the quality  of  the  temperature/salinity  profile  and  the quality   of   the   current   (set   and   drift)   profile, respectively. The indicator k₂ is the method used for the salinity measurement as per WMO Code 2263 (0 = no measurement,  1  =  electronic  sensor  with  better  than 0.02%  accuracy,  2  =  electronic  sensor  with  less  than 0.02%  accuracy,  and  3  =  sample  analysis).  As  of  the late 1990s few buoys carry salinity sensors. Table 2-4.—WMO Code Table 3334 2-19