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For more details, see the ahats logbook at https://wiki.ucar.edu/display/ahatslogbook
Good wind direction: The standard function reports 53 hours (23
unstable, 30 stable) in this configuration, all but 3 segments shorter
than 2.5 hours. Note that our longest segment changed from 820 min
to 650 min now that I've entered boom angles -- a big change for only
a few degrees of reorientation! However we have had some sensors and
data systems down so the actual numbers would be lower.
...
Pressure:
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(+/- = ~1 std deviation among variables at the same height)
We've made lots of adjustments to the pressure system over the past few
Wiki Markup
days to improve the spectra. We're now using a 25 liter reservoir
that we built from ABS pipe and stuffed with steel wool. However,
variation of the reference pressure (presumably due to tubing temperature
changes) still is about 3 times the variation of the static pressure.
We sacrificed the sensor at 11b to have it measure the reference pressure
so that we might be able to recover this signal.
p: ok, \ +/\- 0.03 mb \ [still\]
p'p': ok, \ +/\- 0.001 mb^2
w'p': ok, \ +/\- 0.002 m/s mb
t: 6b&6t are outliers by 3degC during day, others \ +/\- 1.5 degC
Pref: ok \ -\- has moved a lot during several changesunmigrated-wiki-markup
Profile: \ [,select.p\]
\
-------\-
T: ok
RH: sensor that is now at 5.5m is strange, but we're going to live with it.
P: okayunmigrated-wiki-markup
diag: ok
samples.sonic: ok
spd: ok?, 8m still lower than 7m sometimes. We'll change 8m out during
the next configuration switch.
dir: ok
w: ok
tc: ok, 8m low by \ ~0.3 degC? (related to the speeds being low as well?)
w'w': ok
u*: ok, some imaginary values with light winds
sigma_w/u*: ok (1.3 at night)
w'tc': ok
h2o: normal, 2 g/m^3 offset from dat("Q"), except in afternoon.
w'h2o': ok, 0.03 m/s g/m^3 at midday
co2: ok, 15-20 mmol/m^3 (some nights have large values, some don't \ [last
night\]). Presumably related to shallow nocturnal boundary layers,
but I haven't gone through the sodar data yet.
w'co2': ok, \ -0.01 m/s mmo/m^3 at middayunmigrated-wiki-markup
Upwind (hts=3.3): \ [,select.u\]
\
---------------\-
Has crashed each of the last 5 nights at about 10pm. Last night stayed
down due to a certain SE trying to help. We've replaced the Viper CPU
board so hopefully it will work tonight.
diag: ok
samples.sonic: ?????ok
spd: ok, +/- 20 cm/s
dir: ok, angles much better now that they have been shot
w: ok, +/- 5 cm/s
tc: ok, +/- 0.2 deg, biases somewhat larger
w'w': ok, +/- 0.005 m^2/s^2 (30 min avg for second moments)
u*: ok, +/- 2 cm/s, again some imaginary values
sigma_w/u*: ok (1.3 at night)
w'tc': ok, +/- 0.01 m/s degC
tc'tc': ok, +/- 0.05 degC^2unmigrated-wiki-markup
Downwind Lower (hts=3.3): \ [,select.b\]
\
-----------------------\-
diag: ok
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samples.sonic: ok
spd: ok, \ +/\- 20 cm/s
dir: ok, \ +/\- 3 deg
w: ok, \ +/\- 15 cm/s \ [need to check tilt angles\]. Most negative.
tc: ok, \ +/\- 0.2 deg
w'w': ok, \ +/\- 0.01 m^2/s^2 s^2 (30 min avg for second moments)
u*: ok, \ +/\- 2 cm/s, some imaginary mid-day
sigma_w/u*: ok (1.3 at night)
w'tc': ok, \ +/\- 0.01 m/s degC
tc'tc': ok, \ +/\- 0.05 degC^2unmigrated-wiki-markup
Downwind Upper (hts=4.3): \ [,select.t\]
\
-----------------------\-
diag: ok
samples.sonic: ok
spd: ok, +/- 10 cm/s, 3t lower by 20cm/s
dir: ok, +/- 2 deg, better now with boom angles shot
w: ok, +/- 5 cm/s, 5t&6t outliers
tc: ok, +/- 0.2 degC, offsets up to 0.6 degC
w'w': ok, +/- 0.01 m^2/s^2 (30 min avg for second moments)
u*: ok, +/- 2 cm/s, again imaginaries
sigma_w/u*: ok (1.3 at night)
w'tc': ok, +/- 0.005 m/s degC
tc'tc': ok, +/- 0.05 degC^2
...