and longitude of the observation, exactly as used in the
ship synoptic reports. The MMMULaULo group is a
second location reporting group, which contains the
Marsden Square number of the location, MMM (see
Appendix II) and Marsden sub-grid locations ULa (a
repeat of the units digit of the latitude) and ULo (a
repeat of the units digit of the longitude). Some
computers use only the Marsden group to enter the
position of the upper-air report in the analysis program.
The latitude and longitude groups are used by people to
determine the exact location.
Both groups must be
correct.
In place of the latitude, longitude, and Marsden
Square groups, permanent shore stations report only
one group: IIiii. This is the WMO block (11) and station
number (iii) exactly as used, and described in module 1,
for the Land Synoptic code. Mobile land stations
include an additional group (hOhOhOhOim) that reports
the station elevation in either meters or feet.
The breakdown of all the different upper-air
reporting codes and code formats is contained in the
WMO Publication 306, Manual on Codes, Volume 1,
International Codes. The majority of these coded
messages are "read" automatically by computers and
entered into analysis programs for use. In selected
situations where manual decoding is required, the
observer should consult WMO Publication 306. Both
the TEMP code and the PILOT code forms are routinely
used by observers to encode observed data. We will
discuss these codes in the following text.
TEMP CODE
LEARNING OBJECTIVES: Identify the
differences and similarities in the four forms of
the TEMP code. Describe the information
contained in each part of the TEMP coded
report. Explain the format and the meaning of
each coded part of the TEMP report. Describe
the modifications added to the International
code form in WMO Region IV. Describe the
format and contents of an Early Transmission
Message.
PART A
PART C
Mandatory Levels SFC Mandatory Levels 100 hPa
to 100 hPa
and higher
PART B
PART D
Significant Levels SFC
Significant Levels 100 hPa
to 100 hPa
and higher
Although used by computers, the TEMP coded
upper-air information is also used extensively in many
manual applications. For detailed analysis, TEMP
coded data is decoded and plotted on a Skew-T, Log P
Diagram, or on horizontal or time section diagrams.
The TEMP code is the primary upper-air reporting
code. Every observer must be thoroughly familiar with
this code.
The different forms of the TEMP codes are used to
report data gathered in the rawinsonde, radiosonde, or
rabal observations, depending on the site used to launch
the balloon. However, aircraft-launched dropsondes
use a slightly different code format. The four different
forms of the TEMP code are listed in table 1-7.
COMPOSITION OF THE REPORTS
(MESSAGE)
All four forms of the TEMP code are broken down
into four parts to speed distribution. Additionally, each
code part is divided into data sections. The data sections
contain information in five-digit groups, although
letters are used in one or two groups in the identification
data section. Each figure in each group is significant to
its position in the group and to its position in the
message. Therefore, the established order of the groups
in the messages must be maintained. When observed
data is not available for an element, a slant (/) is used
instead. This is done to preserve continuity of the
groups and sections as required.
Message Parts
Each TEMP code part may be transmitted as an
independent message. This is done to speed distribution
of the reports, because a sounding usually takes a
considerable amount of time. A radiosonde may
continue to report usable data 2 to 3 hours after release.
The parts are identified as A, B. C, and D. Data at and
below the 100-hPa level is reported in Parts A and B,
and data above 100 hPa is reported in Parts C and D.
Parts A and C contain data pertinent to the
standard atmospheric pressure surfaces, which are
also called the mandatory reporting levels. Parts B and
D contain data pertinent to the significant levels. These
are the levels that have been determined significant due
to temperature and/or humidity change. and changes in
wind speed or direction. The following diagram may
help clarify what data IS included in each section:
All military stations designated to encode and
transmit upper-air observations encode and transmit the
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