AHATS daily status 7/05/08
Staff: Maclean, Horst, Khoung, McIntyre
Summary: Gordon is experimenting with replacing Semmer's active low-pass filter circuit with a passive filter circuit suggested by Paroscientific.
For more details, see the ahats logbook at https://wiki.ucar.edu/display/ahatslogbook
Good wind direction: For the period 7/1 13:00 through 7/5 13:00, we have
63 hours of data periods of length 20 minutes or longer with
wind directions from 295-355 degrees. This includes 52.5 hours of periods
longer than one hour and equates to good wind direction periods 66%
of the time. Sorted by stability, there are 31 hours of stable
stratification (<w'tc'> < 0) and 31.92 hours of unstable stratification.
Note that the normal to the array is 325 degrees. If the array orientation
were 315 degrees (NW: 285-345 degrees) as for HATS/SGS, then the division
is 33.83 hours stable and only 21.33 hours unstable.
Profiles:
---------
diag: ok
samples.sonic: ok
spd: ok
dir: ok
w: ok
tc: ok
sigma_w/u*: ok (1.3 at night)
u*: ok
w'tc': ok
T: ok
RH: 4m may be low by less than 1% RH
P: okay
Upwind (hts=3.5):
----------------
(+/- = ~1 std deviation)
missing sonics 5u-11u 3:10 - 07:40, July 4
missing all sonics 9:15 - 11:50, July 4
diag: ok
samples.sonic: ok
spd: ok, +/- 15 cm/s (6u has +15 cm/s offset in u)
dir: ok, +/- 3 deg
w: ok, +/- 6 cm/s
tc: ok, +/- 0.2 deg
w'w': ok, +/- 0.01 m^2/s^2 (30 min avg for second moments)
u*: ok, +/- 0.04 m/s
sigma_w/u*: ok (1.3 at night)
w'tc': ok, +/- 0.015 m/s degC
tc'tc': ok, +/- 0.06 degC^2
Lower (hts=3):
-------------
diag: ok
samples.sonic: ok
spd: ok, +/- 20 cm/s
dir: ok, +/- 5 deg
w: ok, +/- 5 cm/s
tc: ok, +/- 0.25 deg
w'w': ok, +/- 0.01 m^2/s^2 (30 min avg for second moments)
u*: ok, +/- 3 cm/s
sigma_w/u*: ok (1.3 at night)
w'tc': ok, +/- 0.02 m/s degC
tc'tc': ok, +/- 0.1 degC^2
Upper (hts=4):
-------------
diag: ok
samples.sonic: ok
spd: ok, +/- 17 cm/s
dir: ok, +/- 4 deg; 6t is about 6.5 degrees off from profile sonic
w: ok, +/- 5 cm/s
tc: ok, +/- 0.2 deg
w'w': ok, +/- 0.01 m^2/s^2 (30 min avg for second moments)
u*: ok, +/- 3 cm/s
sigma_w/u*: ok (1.3 at night)
w'tc': ok, +/- 0.02 m/s degC
tc'tc': ok, +/- 0.05 degC ^2