Part Be
Phase
59.0
62.0
19.0
eee ee
ad
18.0
a
MC
“gee
FRED:
:
salt ae etebye OM
ek
ged”,
Sake ae
dbictn tadtenince ht i
med
als.
Observational Data, First Intensive
(August 18 -~ September 1, 1957)
NOTES:
TABLE_ke
:
Aro cal CR fl iee al arege
TABLES 4-18
HOURLY OBSERVATIONS AND DAILY SUMMARY.
These Notes apply both to Table 4 and Table 19, which presents similar observational data
Se
420
bee Pe
83.0
e.
for the second Intensive Phas
sandths of an inch, with the units and
P represents station pressure and is given to thou
tens omitted.
30.000.
ere
L76.0
exeRe 7
tower }
ee
“METER #2
iaRNe HetSag
Reees
Seas
BeIiessSRETS
«ale or
oe
LU
peerSes
In Tables 4 and 19, all values are preceded by 29, except 000, which represents
The mercurial barometer (used daily to check the microbarograph) was calibrated
January 30, 1958 and found to be 0.020 inch too low.
in the Tables.
This value should be added to those shown
In addition, unreliability is introduced because the hourly values were read
from the microbarograph and because of the lag in this instrument.
Allowing for this factor,
after 0.020 has been added te the values, the resulting values will all be correct within 0,020
10.0
(plus or minus) and half of the resulting values will be correct within 0.004.
line extreme error of 0.020 represents the maximum 10-minute change that may be expected
at Eniwetok, considering both the diurnal pressure curve and the changing synoptic situations.
(More rapid change might accompany approach of a typhcoon or an intense tropical storm, but such
eee
SMteTe, BEEret
eee
ot Stas
did not occur during these observational periods.)
The ten minute period represents the
maximum time-lag between the mercurial barometer and the microbarograph at times when the
pressure is changing rapidly.
(When it is changing very slowly the lag may be greater, but
then the error amplitude is diminished very appreciably.)
The value 0.004 is based on the
assumption that rates of change of pressure over 5-10 minute periods are distributed normally
about their mean.
Finally, it should be noted that these error estimates allow for the fact
that often in actual practice observers do not tap the microbarograph to permit the pen te
adjust to the current pressure.
TT and Ty were to be read to 0.1° F. according to standard instructions.
It is evident,
however, from the very high frequency of values ending in .0 or .5 that the observers usually
read the temperature to the nearest graduated mark (.0 or 05).
Allowing for this fact and for
an extreme instrumental error of 0.3°, all values are correct within 0.5% 67
“This assumes there is no consistent bias, either instrumental or human, and that in
borderline cases the observer can discriminate to 0.1*.
39