According to the Licor 7500 manual, there is a 0.186 second sampling lag in the 7500. This can be increased with an output delay parameter, so that it can be synchronized with the sampling of a sonic. I've verified that the output delays on our 7500's are set to 0.
Since the CSAT3 and Licor operate asynchronously, I see no advantage in further adjustment of the Licor delay to be a multiple of the CSAT3 sample period.
We have not been incorporating a 7500 lag in our data processing. We do correct for the 2 sample delay of the CSAT3 sonics. Subtracting 0.186 seconds from the 7500 samples does increase the correlation and fluxes between w and h2o and co2. The w'h2o' and w'co2' fluxes increase by about 15% when a lag of 0.186 is applied to the Licor data. These plots are of the corrected flux and the difference between the corrected and uncorrected fluxes, for 2 days, centered on Jul 18:
Here are the correlation vs lag plots between w and h2o and co2 from station 1 for Jul 17, 17:00 - 17:30 CDT. The wind was out of the south at this time:
After applying a 0.186 second lag to the Licor data, you can see that the correction is in the right direction, but there is still a lag of about 2 samples, 0.1 seconds:
(It pays to read the manual!)
For future reference, here is the splus code to plot the correlations:
dpar(start="2011 jul 17 17:00",lenmin=30,stns=1)
iod = prep(c("w.4.5m#1","h2o.4.5m#1","co2.4.5m#1"),rate=20)
x = readts(iod)
close(iod)
cwh = crosscorr(x[,1:2],lags=c(-1,1))
plot(as.numeric(utime(positions(cwh))),cwh,xlab="lag(sec)",ylab="w.4.5m#1:co2.4.5m#1")
Jul 22, 19:10 CDT (00:10 UTC)
Checked that the additional Licor 7500 delay values are set to 0. See https://wiki.ucar.edu/x/9KWTB about how to talk to Licor 7500's.
ncar1:
(Outputs ?) (Outputs (BW 20)(Delay 0)(SDM (Address 7))(Dac1 (Source CO2MMOL)(Zero 0)(Full 2.5000000e1 ))(Dac2 (Source H2OMMOL)(Zero 0)(Full 5e2))(RS232 (Baud 19200)(Freq 2e1)(Pres TRUE)(Temp TRUE)(Aux FALSE)(Cooler FALSE)(CO2Raw TRUE)(CO2D TRUE)(H2ORaw TRUE)(H2OD TRUE)(Ndx FALSE) (DiagVal TRUE)(DiagRec FALSE)(Labels FALSE)(EOL "0A")))
ncar3:
(Outputs ?) (Outputs (BW 20)(Delay 0)(SDM (Address 7))(Dac1 (Source NONE)(Zero 0)(Full 5))(Dac2 (Source NONE)(Zero 0)(Full 5))(RS232 (Baud 19200)(Freq 2e1)(Pres TRUE)(Temp TRUE)(Aux FALSE)(Cooler FALSE)(CO2Raw TRUE)(CO2D TRUE)(H2ORaw TRUE)(H2OD TRUE)(Ndx FALSE)(DiagVal TRUE)(DiagRec FALSE)(Labels FALSE)(EOL " 0A")))
Later, at 19:45 CDT (00:47 UTC) set the Dac1 and Dac2 (digital to analog converters, which we don't sample) on ncar1 to Source NONE. I don't expect that it will have any real effect - except maybe save a little power.
(Outputs (Dac1 (Source NONE)(Zero 0)(Full 5)) (Dac2 (Source NONE)(Zero 0)(Full 5)))
Some documentation for the Licor 7500 diagnostic value is in the manual:
ftp://ftp.licor.com/perm/env/LI-7500/Manual/LI-7500Manual_V4.pdf
The following excerpts are from the manual.
Setup and Operation, page 3-36:
The cell diagnostic value is a 1 byte unsigned integer (value between 0 and 255) with the following bit map:
bit 7 Chopper 1=ok
bit 6 Detector 1=ok
bit 5 PLL 1=ok
bit 4 Sync 1=ok
bit 3-0: AGC/6.25Example: a value is 125 (01111101) indicates Chopper not ok, and AGC = 81% (1101 is 13, times 6.25)
If bits 4-7 are 1 (OK), the value will be greater than or equal to 240, with the remainder being the AGC percentage. I've not seen values below 248. Note that the values on the plots and in the netcdf files are 5 minute averages.
We're seeing values of 248 and above, indicating the following:
lidiag |
Chopper |
Detector |
PLL |
Sync |
AGC % |
|---|---|---|---|---|---|
248 |
ok |
ok |
ok |
ok |
50-56 |
249 |
ok |
ok |
ok |
ok |
56-63 |
250 |
ok |
ok |
ok |
ok |
63-69 |
251 |
ok |
ok |
ok |
ok |
69-75 |
252 |
ok |
ok |
ok |
ok |
75-81 |
253 |
ok |
ok |
ok |
ok |
81-87 |
254 |
ok |
ok |
ok |
ok |
88-94 |
255 |
ok |
ok |
ok |
ok |
94-100 |
The manual doesn't define AGC, but contains this info, on pages 3-50,51, indicating that an AGC value near 100% likely indicates a water droplet remaining in the optical path, but that temporary droplets can effect the measurements without an indication in AGC:
Dew
The LI-7500 can tolerate droplets on the windows to a certain extent; the AGC value will increase, but the calibration is unchanged. If the droplets coalesce and get big enough, the AGC will go to 100%, and eventually the readings will become bad. This can be minimized by sensor orientation, and by coating the windows with a wax such as RainX®.Rain/Snow
Flying droplets and flakes in the optical path will affect the performance of the LI-7500, even if the total light blockage is small enough that the AGC does not reach 100%. The reason is that the objects are moving, and if a droplet or flake is in the path for a sample measurment, but out of the path for a reference measurement (or vice versa), it will influence the resulting reading. Figure 3-4 illustrates a strip chart trace made during a light snow shower. The occasional spikes are due to blockage changes between sample and reference readings. Notice that in some cases both CO2 and H2O are affected, and sometimes just one. Also, the spikes are equally likely to be up or down.
July 22, 15:30 CDT
Dan Rajewski (in Ames)
Summary: Stations 1-4 operational, Russ and Dan visited the NCAR stns and Kris serviced the other flux tower sites.
**2 m T/RH fans are operating at stns, 1, 3-4. No fan sound from site 2
** Stn 1 licor? making a continuous clicking noise, but there is no such noise at stn 3
Vdsm: 13.5-14 V during day, down to 12.5 at night
P: ok, stn 1 & 2 pressure slightly hither than at sites 3 & 4)
T.2m: stn 2 warmer than others during the day (fan??), about comparable to other sites during the night (0.5 degree warmer at stns 1 & 2 vs. 3 & 4)
few hrs before sunrise stn 4 about 0.5 degree cooler than other sites
RH.2m: stn 4 high during day; stn 2 lowest during late morning and afternoon
H2O.2m: stn 4 high during day and night (0.7-1.0 g/m^3 moister than other sites), stn 1 slightly lower than stns 2 & 3
Wetness: sensor wet from previous late afternoon rain showers, rain overnight at 2:30-4:00 and from 6:30-7:00; sensor dry by 10:30
T.10m: stn1 warmer than others during the day, also stns 1 & 2 are sometimes warmer than sites 3 & 4 for a few night-time periods
RH.10m: ok, mostly in agreement , daytime stn 1 few%RH lower than at other sites
H2O.10m: ok, mostly in agreement all sites within 0.3 g/m^3 of each other
Spd.10m: ok, stn 1 is 0.5 m/s higher than stns 2 &4 and stn 3 is about 1.0 m/s less than stn 1 from 23:00 (July 21) to 0:30
Dir.10m: ok, East wind before midnight, with veering to SW and eventual W by 9:00, Southerly winds after that.
T.10m - T.2m: stn 2 most negative during day; see T.2m, stn 3 & 4 less negative than stn 4, stn 1 least negative during day
H2O.10m - H2O.2m: stn 4 most negative during night/day; see H20.2m, other stations in close agreement for night and day
spd.4.5m: ok, see comments for Spd.10m
dir.4.5m: ok
w.4.5m: ok, interpretation muddled with several rainy periods
tc.4.5m: ok, night: few periods where stn 1 is about 0.7-1.-0 degrees warmer; all sites agree within +/- 0.5 degC much of daytime
ldiag: ok
kh2oV: some improvement to voltage (50 mV) after cleaning the sensors, very low voltage ~0 at night because of the rainfall in the evening and overnight periods
kh2o: anomalous increase at 2 & 4 during night, somewhat higher than stns 1 & 3 before cleaning the sensors; afterwards readings from 2 & 4 are about 2.0 g/m^3 and 1.0 g/m^3 drier, respectively
h2o(licor): ok, sensors good after the last morning rain fall
lidiag (licor): spikes at both 3 and 1
TKE.4.5m: ok, mostly in agreement except from 22:30-0:00, stn 1 slightly more TKE than at stn 2and about 0.3 units more than stns 3 & 4
w'w': ok, similar to TKE.4.5m, also seen in u'u' and v'v'
u*: ok, not as clear separation of the sites for the aforementioned period in the TKE.45m
w'tc': ok
tc'tc': ok
w'h2o': ok, stn 2 significantly low during day, stn 1 &3 about the same, stn 4 between stn 2 and stns 1 & 3; night: stns 2 & 4 do not give much transpiration, stn 1 & 3 slightly positive
h2o'h2o' (licor): ok, spikes during rain fall events
kh2o'kh2o': stns 4 & 2 (somewhat) anomalous high reading at night, stn 4 close to stns 1 & 3 daytime value, stn 2 a bit lower; some improvement after cleaning the krypton sensors
w'co2': ok, stn 1 somewhat slightly higher flux than stn 3 for several periods of the night; close daytime agreement
co2'co2': ok, variances similar in day/night except during rainfall occurrences
July 21, 12:45 CDT and past three days
Tom Horst (in Boulder)
Summary: Stations 1-4 operational, no ISFS staff on site
** Need to check on 2 m TRH fans. Visit all stations, but 2 and 4 are suspicious from data.**
** I don't know how to interpret lidiag. w'h2o' at stn 1 significantly low during day.**
Vdsm: 13.5-14 V during day, down to 12.5 at night
P: ok, relative pressures suggest site rises from south to north(?)
T.2m: stn 2 warmer than others during the day (fan??)
RH.2m: stn 4 high during day; stn 2 lowest at night
H2O.2m: stn 4 high during day
Wetness: Rain/dew on the nights of July 18-19 and 19-20
T.10m: stn1 warmer than others during the day
RH.10m: ok
H2O.10m: ok
Spd.10m: ok
Dir.10m: ok
T.10m - T.2m: stn 2 most negative during day; see T.2m
H2O.10m - H2O.2m: stn 4 most negative during day; see H20.2m
spd.4.5m: ok, see comments for Spd.10m
dir.4.5m: ok
w.4.5m: ok
tc.4.5m: ok, all sites agree within +/- 0.5 degC
ldiag: ok
kh2oV: anomolous increase at stn 4 night of July 18-19
kh2o: anomolous decrease at 4 and increase at 2 night of July 18-19
h2o(licor): ok
lidiag (licor): numerous spikes at 3 only a few at 1
TKE.4.5m: ok
w'w': ok
u*: ok
w'tc': ok
tc'tc': ok
w'h2o': ok, stn 1 significantly low during day
h2o'h2o' (licor): ok
kh2o'kh2o': stn 4 similar to licors; stn 2 low
w'co2': ok
co2'co2': ok
July 20, 18:40 CDT
Dan Rajewski (in Ames)
Summary: Stations 1-4 operational, no ISFS staff on site
clear/hazy skies hot and muggy, generally SW wind, breezy in the morning and afternoon
all stations were powered down and restarted from 13:15-14:00
Vdsm: 13.5-13.8 V during day, down to 12.4 at night,
P: ok, pressure generally dropping 2mb from 970 mb the evening of July 19 to
T.2m: ok, night: stns 1 and 4 cooler than stns 3 by 0.5-0.7 degree from 21:30-22:30 [July 18]
stn 1 cooler by 1.0 degrees than other sites from 23:00-1:00
rest of night stns within 0.3 degrees
day: stn 2 about 0.5-1.0 degree warmer than sites 1 & 3 from 11:00-18:00
stn 2 about 1.0-1.5 degree warmer than stn 4 for same period
RH.2m: 85-100% nighttime; dropping to 65-80% by afternoon
night: stn 4 5% RH higher than other sites;
few hours after sunrise: stn 4 few%RH higher than other sites
afternoon stn 4 ~10-15%RH higher than stns 2, and ~7-10%RH higher than stn 1 & 3 [moisture effects due to mature corn with larger Potential evapotranspiration at Stn 4?]
H2O.2m: ok, nighttime from 27 to 19.5 g/m^3, up to 26 g/m^3 by mid afternoon
night: stn 1 about 1.0 g/m^3 drier than stn 4 most of the night, from 23:00 (July 19) to 0:30 about 1.7 g/m^3 drier
stns 2 & 3 about 0.5 g/m^3 drier than stn 4
day: similar pattern as during night with stn 4 most moist and stns 1-3 about 1.0 g/m^3 drier
Wetness: dew formation from 22:30 (July 19) through 2:30, wetness slightly decreases until 6:00 with a small rise before 7:00 before going dry by 7:30
T.10m: ok, range of 24 to 33.5 degrees
night: stn 2 about 0.5 degrees warmer than other sites from 22:00-0:00
stns 1 & 2 about 0.5 degrees cooler than other sites from 0:00-1:30
day: stn 1 0.5 degrees warmer than other sites late morning through afternoon
RH.10m: ok, night: stns within a few%RH of each other
daytime: close agreement at all sites (well-mixed windy condition)
H2O.10m: ok, most of night: stn 4 about 0.5 g/m^3 less than stn 2 (other sites in between)
day: stn 4 about 0.3-0.5 g/m^3 less than other sites
Spd.10m: ok, before midnight stn 2 about 0.5-0.7 m/s higher than other sites
stn 1 about 0.7 m/s less than other sites for short period before sunrise
daytime: no big differences btwn stns
Dir.10m: ok, wind backing from SW to SSE before midnight then mostly SSW until sunrise, rest of the day SW flow
T.10m - T.2m: ok, night: about the same positive thermal gradient at all sites (slightly warmer at 10 m at stn 1 & 4 before 1:00)
day: stn3 nearly zero thermal gradient, stn 1 & 4 about 0.5 degree cooler at 2m vs. 10 m, stn 2 about 1.0 warmer at 2 m vs. 10 m
H2O.10m - H2O.2m: ok, stns 2 & 3 have little nighttime moisture gradient, slightly positive at stn 1 from 23:00 (July 19)-1:00
stn 4 is about 1.0 g/m^3 greater at 2 m vs. 10 m than at the other sites
day: stn 4 largest negative moisture gradient (+4.0 g/m^3 larger H2O at 2 m vs. 10 m), other sites about 2.0 g/m^3 more vapor at 2m vs. 10 m
spd.4.5m: ok, see comments of Spd.10m,
dir.4.5m: ok, see comments of dir.10m, more SE wind at stn 1 than at 10 m from 23:00-1:00
w.4.5m: ok, less downward motion during night when wind is from an angle away from 180 degrees
from 2:00-5:00 w slightly positive at stns 1 & 4, w~0.1 m/s at stns 2 & 3
much of morning and afternoon stns 1 & 4 have w~0 or slightly positive (0.02 m/s) and stns 2 & 3 have w<0 (-0.12 m/s)
tc.4.5m: ok, night: stns 1 & 2 about 0.5 degrees cooler than other sites from 0:00-1:30
day: stns 3 & 4 about 0.3-0.5 degrees warmer than stn 1 & 2 for peak of late afternoon
ldiag: ok,
vh2ov: not ok, stn 2 mostly btwn 30-80 mV
stn 4 mostly btwn 30-60 mV
kh2o: not ok, stn 2 about 1-1.5 g/m^3 lower than stns 1 & 3
stn 4 within 0.5 g/m^3 of stns 1 & 3
h2o(licor): ok, btwn 20-27 g/m^3 for night to day behavior
stn 1 about 0.5 to 0.7 g/m^3 more vapor than stn 3 during much of night
daytime: close agreement btwn stn 1 & 3, about 0.5 g/m^3 greater than at stn 4 during late afternoon
lidiag (licor): ok, few samples missing in overnight hours
TKE.4.5m: before midnight stn 2 has 0.15-0.20 m^2/s^2 more TKE than other sites, then a few post-midnight periods where stn 1 TKE is 0.1 units smaller than at other sites
close agreement for daytime
w'w': ok, see comment for TKE.4.5m, also similar nighttime pattern in u'u' and v'v'
u* : ok, similar to pattern in TKE.4.5m, also seen in v'w' stress
w'T' : ok, nighttime bump in TKE corresponding to larger negative flux at stn 2 by -0.01 C m/s
day: stn 3 about a 0.02 C m/s greater positive flux than other sites (especially from 10:00-16:00)
w'h2o': ok, small difference in fluxes during nighttime,
much of daytime: stn 1 & 3 about 0.04 g/m^2/s greater than stn 4, and 0.12 g/m^2/s greater than stn 2
h2o'h2o': stns 1 &3 in close agreement night and day; stn 1 & 3 are about 2.0 (g/m^3)^2 more than variance at stn 2
kh2o'kh2o': not ok, elevated variance at stn 4 all night
daytime: stn 2 0.8 (g/m^3)^2 less than stn 4, stn 4 about 0.2 (g/m^3)^2 less than stns 1 & 3
co2: ok,
w'co2': ok, night: mostly in agreement a few periods with more positive flux at site 3 and also brief period around 1:00 with site 1 > site 3
daytime: stns seem to be in close agreement much of the morning and afternoon, slightly more negative flux at stn 3
co2'co2': ok, nighttime "ramp" event at both sites around 23:00-1:00 (stn 1 > stn 3) but similar flux rest of the night and early morning
daytime: sites are in close agreement
July 19, 10:45 CDT [July 20]
Dan Rajewski (in Ames)
Summary: Stations 1-4 operational, Russ and Dan cleared the weeds out of the access paths and around the base of each flux tower and wind cube sites. Kris and Jimmy serviced the ISU sites and the wind cubes
clear/hazy skies hot and muggy, generally SW wind, much less wind speed in the morning and early afternoon (turbines hardly turning 10:30-13:30)
Vdsm: 13.5-13.8 V during day, down to 12.4 V at night,
P: ok, pressure steady around 974 mb overnight through early morning; dropping to ~971 mb by early evening
T.2m: ok, night: stn1 cooler than stn 3 by 1.0 degree from 21:00-22:00 [July 18]
stn 2 cooler than stn 4 by 1.0 degree from 23:00-0:00
stn 1 warmer than other sites by 1.0 degree from 0:30 to 3:00
stn 4 has error (wet sensor?) from 6:15-6:30
day: stn 2 1.0 degrees warmer than other sites in mid morning and early evening
stn 2 1.5-2.0 degrees warmer than other sites in late morning-late afternoon
stn 4 0.5 degrees cooler than stns 1 & 3 from 15:00-19:00
RH.2m: 85-100% nighttime; dropping to 70-80% by afternoon
night: stn 4 5% RH higher than other sites; stn 4 has error (due to wet sensor?) from 6:00-6:15
morning/evening stn 4 10% RH higher than stn 2, 5% RH higher than stns 1,3
afternoon stn 4 ~10-15%RH higher than stns 2, and ~5-7%RH higher than stn 1 & 3 [moisture effects due to mature corn with larger Potential evapotranspiration at Stn 4?]
H2O.2m: ok, nighttime from 28 to 20 g/m^3, up to 27-29 g/m^3 by mid afternoon
night: stn 1 about 1.0 g/m^3 drier than other sites from 20:30-22:30 [July 18]
stn 2 about 1 g/m^3 more moist than stn 3 & 4 from 11:00-0:30
stn 2 & 3 about 0.5 g/m^e drier than sites 2 & 4 from 0:30 to 2:30
stn 4 about 0.5 g/m^3 more moist than other sites from 2:30 to 4:00
Wetness: dew formation from 21:00 (July 18) through 7:00, sensor dry by 9:00
T.10m: ok, range of 24 to 33.5 degrees
night: stn 1 about 0.5 degrees warmer than other sites from 1:00-2:00
stn 2 about 0.5 degrees cooler than other sites from 3:30-5:00
day: stn 1 0.5 degrees warmer than other sites in morning/ late afternoon and 1.0 degree warmer in early to middle afternoon
RH.10m: ok, night: stns within a few%RH of each other
day: stn 1 about 5%RH less than other sites
H2O.10m: ok, before midnight stn 4 about 0.5 g/m^3 more vapor than other sites
nighttime: stn 2 0.3-0.5 g/m^3 more moist than other stns
day: close agreement at all sites
Spd.10m: ok, before midnight stn 2 about 0.5-0.7 m/s higher than other sites
daytime: stn 4 about 1.0 m/s less than other sites from 10:30 to 14:30; and 0.5 m/s less from 16:30-18:00
Dir.10m: ok, WSW flow before midnight, slightly WNW before changing to E and veering to SSE by sunrise
SSW to SW morning and early afternoon, hovering to S or SSW rest of the period
T.10m - T.2m: ok, night: most of time a few tenths within each site except for 0.5-0.75 degree cooler at 10 m vs. 2m for stn 1 than for other sites from 1:00-2:30
day: stn1 nearly zero thermal gradient, stn 3 & 4 about 1.0 to 1.5 degree warmer at 2m vs. 10 m, stn 2 about 2.0-3.0 warmer at 2 m vs. 10 m
H2O.10m - H2O.2m: ok, stns 2 & 3 have earlier nighttime stabilization of moisture gradient vs. stn 1 & 4
day: stn 4 largest negative moisture gradient (4.0 g/m^3 larger H2O at 2 m vs. 10 m), other sites about 2.0 to 3.0 more vapor at 2m vs. 10 m
spd.4.5m: ok, see comments of Spd.10m, similar differences but not identical in intensity and duration to spd.10m, winds only reaches 2.5 m/s max in daytime
dir.4.5m: ok, see comments of dir.10m
w.4.5m: ok, night: (20:00-22:00 [July 18]) stn 1 & 4 have least w<0 ~-0.02 m/s stn 2 & 3 are about -0.05 m/s
from 3:00-6:30 stn 4 more descent than other sites
tc.4.5m: ok, night: from 1:00-3:00 stn 2 about 0.7 to 1.0 degrees cooler than stn stn 1, about 0.5 degrees cooler than stn 3 & 4
day: stns 3 & 4 about 0.3-0.5 degrees warmer than stn 1 & 2
ldiag: ok,
vh2ov: not ok, stn 2 mostly btwn 10-40 mV
stn 4 mostly at or above 25 mV, spike voltage during overnight up to 100mV then 250 mV but back down to around 50 mV
kh2o: not ok, stns 2 & 4 are about 1-1.5 g/m^3 lower than stns 1 & 3
stn 2 & 4 have anomalous spikes/drops during 4:00-6:00 (dew effects?)
daytime: stn 2 about 1.0-1.5 g/m^3 drier than stn 4; ~2.0 g/m^3 drier than stns 1 & 3
h2o(licor): ok, btwn 18-27 g/m^3 for night to day behavior
stn 1 about 0.5 to 0.7 g/m^3 more vapor than stn 3 during much of night
daytime: close agreement btwn stn 1 & 3
lidiag (licor): ok, few samples missing in overnight hours
TKE.4.5m: before 23:00 stn 1 has 0.1-0.15 m^2/s^2 less TKE than other sites, then a few post-midnight periods where stn 1 TKE is 0.1 units larger than other sites
and also stn 2 0.1 units larger than other sites; close agreement for daytime
w'w': ok, see comment for TKE.4.5m, also similar nighttime pattern in u'u' and v'v'
u* : ok, similar to pattern in TKE.4.5m, also seen in u'w' stress and somewhat in v'w' stress
w'T' : ok, nighttime bump in TKE corresponding to larger negative flux by -0.02 C m/s
day: stn 3 over all about a 0.02 to 0.04 C m/s greater positive flux than other sites (especially from 12:00-14:00)
w'h2o': ok, no big difference in fluxes during nighttime, spikes at stn 2 related to krypton noise?
much of daytime: stn 1 & 3 about 0.04 g/m^2/s greater than stn 4, and 0.12 g/m^2/s greater than stn 2
h2o'h2o': stns 1 &3 in close agreement night and day; stn 1 & 3 are about 2.0 (g/m^3)^2 more than variance at stn 2
kh2o'kh2o': not ok, spikes in nighttime variance at stn 4, several spikes at stn 2
daytime: stn 2 1.6 g/m^2/s less than stn 4, stn 4 about 0.02-0.04 g/m^2/s less than sites 1 & 3
co2: ok,
w'co2': ok, night: slightly more positive flux at Site 3 vs. Site 1 before midnight-1:00
than about same fluctuations in spikes for both sites rest of the night
daytime: stns seem to be in close agreement much of the morning and afternoon
co2'co2': ok, very small values but less or about the same nighttime variance at stn 3 vs. stn 1; daytime sites are in close agreement
July 18, 20:50 CDT
Dan Rajewski (in Ames)
Summary: Stations 1-4 operational, Russ and Dan visited the sites from 13:00-15:15 pm (CDT) to check growth stages/ heights of crop (in an upcoming blog post); Hazy skies, hot and muggy conditions with light SSW to SW winds
Vdsm: 13.5-13.8 V during day, down to 12.4 at night,
P: ok, pressure steady around 977 mb overnight through early morning; dropping to 974 mb by early evening
T.2m: ok, night: stn1 & 4 about 0.3-0.5 degree cooler than other stn 2
dayt: stn 2 about 0.5 degrees warmer than stn 1 & 3, 0.7 warmer than stn 4 (stn 2 max near 34 C!)
RH.2m: 95-100% nighttime; dropping to 75-80% by afternoon
night: stn 4 5% RH higher than other sites
daytime stn 4 ~7-10%RH higher than stns 2, and ~5%RH higher than stn 1 & 3 [moisture effects due to mature corn with larger Potential evapotranspiration at Stn 4?]
H2O.2m: ok, nighttime from 27 to 21 g/m^3, up to 27-28 g/m^3 by mid afternoon
night: stn 1 about 1.0 g/m^3 drier than stn 4, 0.7 g/m^3 drier than stn 2, 0.5 g/m^3 drier than stn 3
day: stn 1 about 1.0-1.5 g/m^3 drier than stn 4, 0.5 g/m^3 more dry than stns 2 & 3
Wetness: dew formation from 20:30 (July 17) through 7:00, sensor dry by 9:00
T.10m: ok, range of 24.5 to 33 degrees
night: stn 2 about 0.3-0.5 degree warmer than other sites from 1:00-6:30
day: stn 1 has 0.3-0.5 degrees warmer than other sites from 11:30-17:00
RH.10m: ok, before midnight stn 4 few%RH lower other sites; afternoon stn 2 few%RH higher than other sites, stn 1 few%RH lower than stn 2-4 from 4:30-5:30
H2O.10m: ok, nighttime: stn 2 0.3-0.5 g/m^3 more moist than other stns
morning and afternoon stn 4 sometimes 0.5-0.7 g/m^3 less than stn 2 (Sites 1 & 3 in between stn 2 & 4)
Spd.10m: ok, stn 1 about 1.0-1.2 m/s less than stn 2, and 0.5 m/s less than stn 3 & 4 much of overnight (influence of a turbines from 8:30 (July 17)-8:00?
daytime: close agreement for all sites
Dir.10m: ok, SSW to SW flow before sunrise, WSW to SW flow morning and afternoon (turbines in afternoon mostly from SSW to SW)
T.10m - T.2m: ok, night: most sites in agreement with about 0.7 to 1.0 degrees warmer at 10m vs. 2m
day: stn2 1.0 to 1.5 degree warmer at 2m vs. 10 m than stns 1 & 4, 0.7 degrees warmer at 2m vs. 10 m than at stn 3
H2O.10m - H2O.2m: ok, stn 4 slightly drier gradient (0.7-1.0 g/m^3 more moist at 2m v.s 10m) than site 1 & 3, 0.5 more moist at 2m than for stn 2
daytime stn 4 is 1.0-1.5 g/m^3 drier at 10m vs. 2m than other other sites (again earlier planted corn drawing out more water?)
stn 2 & 3 about 0.3-0.5 g/m^3 drier at 10m vs. 2m than for stn 1
spd.4.5m: ok, see comments of Spd.10m, speed difference about same (1.0 m/s less at stn 1 vs. other sites)
dir.4.5m: ok, see comments of dir.10m
w.4.5m: ok, night: stn 1 & 4 have least w<0 ~-0.02 m/s stn 2 & 3 are about -0.06 m/s
morning and afternoon stn 1 & 4 have slightly positive vertical motion, stn 2 about -0.06 m/s and stn 3 -0.12 m/s
tc.4.5m: ok, night: stn 1 about 0.5 degrees cooler than stn 4, other stns in between from 2:00-6:00
day: stns 3 & 4 about 0.3-0.5 degrees warmer than stn 1 & 2
ldiag: ok, a few samples missing right at moment of dew accumulation before midnight
vh2ov: not ok, stn 2 mostly btwn 30-50 mV
stn 4 mostly at or above 20-50 mV, spike voltage during overnight up to 150 mV
kh2o: not ok, stns 2 & 4 are about 1-1.5 g/m^3 lower than stns 1 & 3
stn 4 has anomalous drop during 4:00-6:00 (dew/fog effects?)
daytime: stn 2 about 1.5-2.0 g/m^3 drier than stn 4; ~2.5-3.0 g/m^3 drier than stns 1 & 3
h2o(licor): ok, btwn 20-27 g/m^3 for night to day behavior
stn 1 about 0.5 to 0.7 g/m^3 more vapor than stn 3 during much of night
daytime: stn 1 about 1.0-1.5 g/m^3 more vapor than stn 3 most of morning an daytime
lidiag (licor): ok
TKE.4.5m: most of night stn 1 about 0.2 units less TKE than other sites, few periods with stns 3 & 4 in btwn stn 2 and stn 1 values (0.1 m^2/s^2 less than at stn 2)
mid morning inversion breakup period 9:00-11:00 shows slightly higher TKE at stns 3-4 vs. 1-2
w'w': ok, see comment for TKE.4.5m, also similar nighttime pattern in u'u' and somewhat in v'v'
u* : ok, similar to pattern in TKE.4.5m, also seen in v'w' stress
w'T' : ok, stn 2 & 4 about -0.02 C m/s more negative flux than stn 1 for overnight
day: stn 3 about 0.02 C m/s more positive flux than other sites (especially stn 2 & 4) from 9:30 to 15:00
w'h2o': ok, no big difference in fluxes during nighttime
much of daytime: stn 1 & 3 about 0.04 g/m^2/s greater than stn 4, and 0.1-0.12 g/m^2/s greater than stn 2
(full height of corn reached at site 4 over the weekend so transpiration decreased?)
h2o'h2o': stns 1 &3 in close agreement night and day; stn 1,3-4 are about 0.6-1.0 (g/m^3)^2 more than variance at stn 2
kh2o'kh2o': not ok, spikes in nighttime variance at stn 4,
daytime: stn 2 0.6 g/m^2/s less than stn 4, stn 4 close to Sites 1 & 3
stn 2 seems still low reading than at stn 4
co2: ok,
w'co2': ok, night: mostly in agreement
daytime: stn 3 greater co2 uptake than stn 1 most of mid morning through late afternoon
co2'co2': ok, very small values (10^-4 (g/m^3)^2) but less nighttime variance at stn 3 vs. stn 1; daytime sites are in close agreement
July 17, [July 18 19:45 CDT ]
Dan Rajewski (in Ames)
Summary: Stations 1-4 operational, no ISFS staff on site
clear to partly cloudy skies in the morning, few sprinkles over noon hour, hot and muggy with light winds from the S to SSW the rest of the day/evening
Vdsm: 13.5-13.8 V during day, down to 12.4 at night,
P: ok, pressure rising in morning up to 979 mb, drop down to 977 mb during/after noon-time sprinkles/light showers
T.2m: ok, before midnight stn4 about 0.3-0.5 degree cooler than other sites
stn 2 warmer by 0.5-0.7 degrees than other stns 1 & 3 most of daytime; stn 4 cooler than stns 1 & 3 by 0.5-0.7 degrees
RH.2m: 90-100% nighttime; dropping to 75-80% by afternoon
night: stn 4 3-5% RH higher than other stns 2 and about 7%RH higher than other stn 1 & 3
daytime stn 4 ~7-10%RH higher than stns 1&2, and ~5%RH higher than stn 3 [moisture effects due to mature corn with larger Potential evapotranspiration at Stn 4?]
H2O.2m: ok, nighttime from 27 to 19 g/m^3, up to 27-28 g/m^3 by mid afternoon
night: stn 1 about 1.0 g/m^3 drier than stn 4, few tenths drier than stns 2 & 3
day: stn 1 about 1.5-2.0 g/m^3 drier than stn 4, 0.5 g/m^3 more dry than stns 2 & 3
Wetness: dew formation from 0:30 to 7:00, sensor dry by 8:30 but wet again from thundershower at 11:30-12:00, wetness disappears by 13:45
T.10m: ok, range of 24.5 to 33 degrees Celsius
stn 1 about 0.3-0.5 degree warmer than other sites for late morning to afternoon (except for period of clouds and rain fall)
RH.10m: ok, before midnight stns 1 few%RH lower other sites; afternoon stn 1 few%RH lower than other sites
H2O.10m: ok, nighttime: stn 2 0.3-0.5 g/m^3 more moist than stn 4 (other sites in btwn 2 & 4)
morning and late afternoon stn 4 sometimes 0.3-0.5 g/m^3 less than stn 2 (other sites in between stn 2 & 4)
Spd.10m: ok, stn 1 about 1.0 m/s less than stn 2 & 4, and 0.7 m/s less than stn 3 much of overnight (influence of a turbines from 21:00 (July 16)-7:00
daytime: close agreement for all sites
Dir.10m: ok, SSE to S flow before midnight, SSW before clouds and rain shower (WSW) then back to S and SSW by evening
T.10m - T.2m: ok, night: stn 4 is about 0.3-0.5 degree warmer at 10 m vs. 2m than other sites at least from 20:00 (July 16) - 1:00, no difference btwn sites 3:00-7:00
day: stn2 0.7 to 1.0 degree warmer at 2m vs. 10m than for mid morning (before rainfall) and mid-late afternoon and evening
during rain event thermal gradient differences are negligible
H2O.10m - H2O.2m: ok, stn 4 slightly drier gradient (0.7-1.0 g/m^3 more moist at 2m v.s 10m) than site 1 & 3, 0.5 more moist at 2m than for stn 2
daytime stn 4 is 1.0 g/m^3 drier at 10m vs. 2m than other other sites (again earlier planted corn drawing out more water?)
stn 2 & 3 about 0.5 g/m^3 drier at 10m vs. 2m than for stn 1
spd.4.5m: ok, see comments of Spd.10m, difference of speed seems less (0.5-0.7 m/s)
dir.4.5m: ok, see comments of dir.10m
w.4.5m: ok, before midnight: stns 1 & 2 less descent (-0.02 m/s) than stns 3 & 4 (-0.06, -0.04 m/s)
after midnight-sunrise, stn 3 & 4 have w<0 of around -0.1 m/s
morning before rain stn 4 close to stns 1 & 2 (-0.05 m/s), stn 3 has w~-0.10 m/s
afternoon (after rain) stn 2 slightly positive , stns 1 & 4 ~ 0, stn 3 w~-0.12 m/s
tc.4.5m: ok, night: stn 4 about 0.5 degrees warmer than stn 1, other stn in between
day: before rain, stns in close agreement; late afternoon-evening stn 1 & 2 about 0.3-0.5 degrees cooler than stn 3 & 4
ldiag: ok
vh2ov: not ok, stn 2 mostly btwn 40-60 mV, down and up spike during rain (10 mv to ~100 mV)
stn 4 mostly at or above 40 mV, spike in overnight up to 150 mV; also down/up spike during rain event
kh2o: not ok, stns 2 & 4 are about 1-1.5 g/m^3 lower than stns 1 & 3
stn 4 has anomalous drop during 2:00-7:30 (dew/fog effects?)
daytime: stn 2 about 0.7-1.0 g/m^3 drier than stn 4; ~2g/m^3 drier than stns 1 & 3
h2o(licor): ok, btwn 18-24 g/m^3 for night to day behavior
stn 1 about 0.5 to 0.7 g/m^3 more vapor than stn 3 during much of night
daytime: close agreement or at most 0.3 g/m^3 drier at stn 3 vs. 1 for late afternoon/evening
lidiag (licor): ok, few samples missing during rain shower
TKE.4.5m: most of night stn 1 about 0.2 units less TKE than other sites, stns 2 & 4 slightly higher than stn 3,
mid morning inversion breakup period 9:00-11:00 shows slightly higher TKE at stns 1-2 vs. 3 & 4
w'w': ok, see comment for TKE.4.5m, also similar pattern in u'u' and somewhat in v'v'
u* : ok, similar to pattern in TKE.4.5m, also seen in v'w' stress
w'T' : ok, stn 2 & 4 about -0.02 C m/s more negative flux than stn 1 & 3 for overnight
day: mostly in agreement except during 9:00-11:00 stn 4 slightly less positive heat flux than stns 1 & 3, stn 2 in between those and 4
w'h2o': ok, no big difference in fluxes during nighttime
stn 1 & 3 about 0.04 g/m^2/s greater than stn 4, and 0.08 g/m^2/s greater than stn 2
h2o'h2o': stns 1 &3 in close agreement night and day, stn 1, 3-4 are about 0.05 to 0.1 (g/m^3)^2 more than variance at stn 2
kh2o'kh2o': not ok, spikes in nighttime variance, stn 2 0.5 g/m^2/s less than stn 4, stn 4 close to Sites 1 & 3
daytime: stn 2 seems to be reading low (compared to stn 4)
co2: ok,
w'co2': ok, night: most in in agreement
daytime: stn 3 a bit greater co2 uptake than stn 1 from 8:30-11:30 and 2:30-5:30
co2'co2': ok, similar pattern to w'co2', but slightly less noticeable of differences in morning/afternoon
July 16, 13:15 CDT
Dan Rajewski (in Ames)
Summary: Stations 1-4 operational, no ISFS staff on site
partly cloudy skies much of overnight and morning from remnant thunderstorm complex that originated in KS/NE
clouds and haze in the afternoon
Vdsm: 13.5-13.8 V during day, down to 12.4 at night,
P: ok, pressure mostly steady at 973 mb until 7:00, rise to around 975 mb by 11:00
T.2m: ok, before midnight stn4 about 0.5 degree cooler than other sites
stn 2 warmer by 0.5 degrees than other sites most of daytime
RH.2m: 90-100% nighttime; dropping to 75-80% by afternoon
night: stns 4 3-5% RH higher than other stns 2 & 3 and about 7%RH higher than other stn 1
daytime stns 4 ~5-7%RH higher than stns 1 & 2, and ~few%RH higher than stn 3 [moisture effects due to mature corn with larger Potential evapotranspiration at Stn 4?]
H2O.2m: ok, nighttime from 26 to 19 g/m^3, up to 26-27 g/m^3 by mid afternoon
night: stn 1 about 1.0 g/m^3 drier than stn 4, few tenths drier than stns 2 & 3
day: stn 1 about 1.0 g/m^3 drier than stn 4, 0.3-0.5 g/m^3 drier than stns 2 & 3
Wetness: from last evening rain shower sensor dry by 23:00 Jul 15; another shower from 5:00-6:00, sensor dry by 8:45
T.10m: ok, before midnight stn 4 slightly cooler than stns 1-3; close agreement at all site after midnight
stn 1 about 0.3-0.5 degree warmer than other sites for late morning to afternoon
RH.10m: ok, before midnight stns 1 few%RH lower other sites; daytime from 8:30 to 14:00 stn 1 few%RH lower than other sites
H2O.10m: ok, nighttime: stn 2 0.3-0.5 g/m^3 more moist than stn 4 (other sites in btwn 2 & 4)
stn 4 sometimes few tenths g/m^3 less than other sites for the mid morning and late afternoon
Spd.10m: ok, sites mostly with same speed for much of overnight except for a ~0.5 m/s less at stn 1 than other sites from 1:00-2:00
daytime: close agreement for all sites
Dir.10m: ok, E to ESE flow before midnight, veering to SE and eventually SSE around sunrise, mostly SSE into the morning/afternoon
T.10m - T.2m: ok, night: stn 4 is about 0.3-0.5 degree warmer at 10 m vs. 2m than at stn 2, less so for stn 1 & 3
day: stn2 0.7 to 1.0 degree warmer at 2m vs. 10m than for stn 1 from 9:30-11:00
stn2 about 0.5-0.7 degrees more unstable than other sites rest of morning/afternoon
H2O.10m - H2O.2m: ok, stn 4 slightly drier gradient (0.7-1.0 g/m^3 more moist at 2m v.s 10m) than site 1, 0.5 more moist at 2m than for stns 2 & 3
daytime stn 4 is 1.0 g/m^3 drier at 10m vs. 2m than other other sites (again earlier planted corn drawing out more water?)
stn 2 & 3 about 0.5 g/m^3 drier at 10m vs. 2m than for stn 1
spd.4.5m: ok, see comments of Spd.10m, less clear of stn 1 drop at 1:00-2:00 also slightly higher speed at stn 1 than other sites around 22:00 (Jul 15)
dir.4.5m: ok, see comments of dir.10m, also slightly more ESE flow vs. SE flow at stn 1 vs. other sites during 1:00-2:00
w.4.5m: ok, before midnight: stns 1 & 2 less descent (-0.04 m/s) than stns 3 & 4 (-0.14, -0.10 m/s)
after midnight-sunrise, stations in close agreement, still more negative spikes by stn 3 and positive ones by stn 2
early to mid morning: same feature, stability forces controlling the pattern are being damped by 'cloud cover'
tc.4.5m: ok, before midnight: stns in close agreement
after midnight SE flow: stn 1&2 about 0.5 degree cooler than sites 3 & 4
daytime stns in close agreement except during PBL transition period 7:00-8:30? (0.5 degrees cooler at stn 2 vs. stn 3&4)
ldiag: ok few 100s of samples missing during morning/afternoon after the rainfall
vh2ov: ok, stn 2 mostly btwn 50-80 mV, down to near zero during rain periods
stn 4 mostly btwn 40-70 mV, similar pattern as at Site 2
kh2o: ok, stns 2 & 4 are about 1-1.5 g/m^3 lower than stns 1 & 3
night and day: stn 2 about 0.5 g/m^3 drier than stn 4
h2o(licor): ok, btwn 18-24 g/m^3 for night to day behavior
stn 3 about 0.5 to 0.7 g/m^3 more vapor than stn 1 during much of night
daytime: close agreement except in early-mid morning
lidiag (licor): ok, few missing samples at stn3 around time of rainfall
TKE.4.5m: ok, sites mostly in agreement, short nighttime 1hr periods for stn 2 and stn 1 with about 0.15 (m/s)^2 less TKE than for other stns
w'w': ok, see comment for TKE.4.5m, also similar pattern in u'u' and v'v'
u* : ok, similar to pattern in TKE.4.5m, also seen in u'w' stress
w'T' : ok, most sites have very close flux (within 0.01 C m/s or less)
w'h2o': ok, similar agreement as in w'T' except for daytime stn 2 slightly lower than other sites during mid morning
h2o'h2o': stns 1 &3 in close agreement night and day, stn 1, 3-4 are about 0.05 to 0.1 (g/m^3)^2 more than variance at stn 2
kh2o'kh2o': not ok during night stn 4 about 0.05 units higher than at stn 2 (close to other sites)
daytime: stn 2 seems to be reading low (compared to stn 4)
co2: ok,
w'co2': ok, slight period of night when flux >0 (2.5^10-4 g/m^2/s) at stn 3 vs. stn1 from 23:00 (Jul 15) thru 2:00
daytime stn 3 a bit greater co2 uptake before haze took over around 10:30
close agreement in afternoon
co2'co2': ok, similar pattern to w'co2', but slightly more variance in afternoon at stn 3 vs. stn 1
In the CWEX11 S directory at EOL is a file of Splus code, latlonalt.q, for computing averages of the GPS values of latitude, longitude and altitude.
I ran it on 6 days of data from Jul 9 11:15 to Jul 15 16:00 (arbitrary period), and it returned the following:
stn |
Lat(deg) |
Lat stddev(deg) |
Lon(deg) |
Lon stddev(deg) |
Alt(m) |
Alt stdev(m) |
|---|---|---|---|---|---|---|
1 |
42.06605 |
1.101896e-05 |
-93.28521 |
9.501855e-06 |
339.0 |
1.8 |
2 |
42.06977 |
1.317406e-05 |
-93.28515 |
1.091214e-05 |
340.4 |
1.8 |
3 |
42.07344 |
1.417124e-05 |
-93.28522 |
1.358779e-05 |
340.0 |
2.0 |
4 |
42.07679 |
1.39572e-05 |
-93.28523 |
1.211881e-05 |
341.6 |
2.0 |
Note that the GPS does not provide a highly accurate estimate for altitude, the std deviations are about 2 meters.
Here's a kml file viewable in GoogleEarth, cwex_ncar.kml, with the above positions.
July 15, 19:55 CDT
Dan Rajewski (in Ames)
Summary: Stations 1-4 operational, ISU crew serviced towers 2 & 4 to clean krypton sensors
SSE to S flow, rain shower toward end of the afternoon
after cleaning sensors, krypton voltage still a bit low (high humidity impact still creating anomalous variances and means?)
Vdsm: 13.5-13.8 V during day, down to 12.5 at night, morning clouds/showers reduced voltage until 11:00 CDT
P: ok, pressure mostly steady at 973 mb until early afternoon 13:00; falling to 971 mb and leveling off during shower onset ~16:30
T.2m: ok, before midnight stn4 about 0.7-1.0 degree cooler than other sites
stn 2 warmer by 0.7-1.0 degrees than other sites most of daytime (before rain shower occurrence)
RH.2m: 85-100% nighttime; dropping to 80% by afternoon
night: stns 4 5-7% RH higher than other stns 1 & 3 and about few&RH higher than other stn 2
daytime stns 4 ~5-7%RH higher than stns 1 & 2, and ~few%RH higher than stn 3 [moisture effects due to mature corn with larger Potential evapo-transpiration at Stn 4?]
H2O.2m: ok, nighttime from 21 to 18 g/m^3, up to 26 g/m^3 by mid afternoon
night: stn 1 about 0.5-0.7 g/m^3 drier than stn 4, 0.5 g/m^3 drier than stn 2 and somewhat stn 3
day: stn 1 about 1.0-1.5 g/m^3 drier than stn 4, 0.5 g/m^3 more dry than stn 2, few g/m^3 more moist than stn3
Wetness: dew collection on sensor from 3:30-7:00, wetness disappears by 8:00, rainfall 17:30-18:00, sensor still wet afterward
T.10m: ok, before midnight stn 4 about 0.5 degree cooler than stn 1, stn 2 and 3 in between 1 & 4
stn 1 about 0.5-0.7 degree warmer than other sites for later morning to afternoon (before rain, then stn differences are negligible)
RH.10m: ok, before midnight stns 1 few%RH lower other sites; daytime from 8:30 to 14:00 stn 1 few%RH lower than other sites
H2O.10m: ok, nighttime: stn 2 0.3 g/m^3 more moist than stn 4 (other sites in btwn 2 & 4)
stn 4 sometimes few g/m^3 less than other sites for the mid morning and late afternoon
Spd.10m: ok, sites mostly with same speed for much of overnight except for a ~1.0 m/s less at stn 1 than other sites (LLJ 'ramp-down' occurrence for SE flow from 3:00-6:00)
daytime: close agreement for all sites, slightly less speed at stn 3 and slightly higher speed at stn 2
Dir.10m: ok, ESE flow before midnight, shifting to SE in period of LLJ cascade? , SSE in early-mid morning followed by S to slightly SSW around noon then back to SSE
T.10m - T.2m: ok, night: stn 4 is about 0.3-0.5 degree warmer at 10 m vs. 2m than for other sites
day: stn2 1.0 to 1.5 degrees warmer at 2m vs. 10m than for stn 1, about 0.7 degrees more unstable than stns 3 & 4
later afternoon rainfall: stn 4 about 0.5-0.7 warmer at 10 m vs. 2 m than for stn 2, few tenths difference btwn stn 4 and stn 1 &3
H2O.10m - H2O.2m: ok, stn 4 slightly drier gradient (0.7-1.0 g/m^3 more moist at 2m v.s 10m) than sites 1 & 3, 0.5 more moist at 2m than for site 2
daytime stn 4 is 1.0 g/m^3 drier at 10m vs. 2m than other other sites (again earlier planted corn drawing out more water?)
stn 2 about 0.5 g/m^3 drier at 10m vs. 2m than for stn 1
spd.4.5m: ok, see comments of Spd.10m, also higher speed at stn 1 than other sites a 1-1.5 hours before midnight (more ESE flow?)
dir.4.5m: ok, see comments of dir.10m
w.4.5m: ok, night: stns 1 & 2 less descent (-0.02 m/s) than stns 3 & 4 (-0.08-to -0.12 m/s)
early to mid morning: 3 & 4 more w<0 (-0.14 m/s) (-0.12 m/s) than stn 1 (-0.02 m/s) or stn 1 (-0.06 m/s)
later morning to early afternoon w in agreement at all sites; after rain, stn3 &4 more w<0 than other stations
tc.4.5m: ok, before midnight ESE flow: stns 1 about 0.5 degree warmer than other sites
after midnight SE flow: stn 1&2 about 0.5 degree cooler than sites 3 & 4
late morning to afternoon stn 3 & 4 slightly warmer than stn 2
ldiag: ok
vh2ov: ok, stn 2 mostly btwn 50-100 mV, down to near zero during rain periods, leveling to 70 mV by early evening
stn 4 mostly btwn 50-70 100 mV, similar pattern as at Site 2 but lower voltage by late afternoon (under 50 mV)
kh2o: ok, after cleaning sensors? nighttime is fiar agreement except for drop at Stn 4 (sensor getting wet?)
daytime: stn 4 about 0.5-0.7 degree warmer than stn 2
h2o(licor): ok, btwn 14-24 g/m^3 for night to day behavior
stn 3 about 0.5 to 0.7 g/m^3 more vapor than stn 1 during much of night
daytime: close agreement
lidiag (licor): ok
TKE.4.5m: ok, stn 4 slightly lower TKE (~0.20 m^2/s^2) than Sites 1 & 2 from 9:30 (July 14) to midnight (during LLJ ramp-up?)
stn 1 0.2 m^2/s^2 lower than other sites from 3:00-6:00 (during LLJ cascade-down?)
w'w': ok, see comment for TKE.4.5m, also similar pattern in u'u' and somewhat in v'v'
u* : ok, similar to pattern in TKE.4.5m, also seen in u'w' and v'w' stress
w'T' : ok, before midnight slightly more negative flux at stn 3 &4
from 3:00-6:00 about -0.02 C m/s more negative flux at sites 3 &4 than 1 &2
daytime: close to same heat flux at all sites
w'h2o': ok, all sites in close agreement for nighttime flux
stn 2 least daytime vapor flux of all sites: max~0.10 g/m^2/s, other stns 1&3 flux max at about 0.18 g/m^2/s
h2o'h2o': more variance (0.10 (g/m^3)^2) at stns 1 & 3-4 than sits 2, Sites 1 & 3 in close agreement
kh2o'kh2o': not ok night through early morning: spikes during raising/lowering the tower masts and the evening rain events,
early-mid afternoon: stn 2 about 0.30 (g/m^3)^2 smaller flux than stn 4, ~0.40 (g/m^3)^2 less than at stns 1 & 3
co2: ok,
w'co2': ok, slight period of night when flux >0 (2.5^10-4 g/m^2/s) at stn 3 vs. stn 1 (during LLJ ramp-up and ramp-down period?)
daytime stn 3 a bit greater co2 uptake mostly from 14:00-15:30 and from 19:00-20:00
after rain event more flux >0 at site 3 vs. site 1 (but small as in the previous night)
co2'co2': ok, similar pattern to w'co2' from 14:00-15:00 otherwise Site 1 & 3 in good agreement
Summary: Stations 1-4 operational, no ISFS staff on-site,
northerly to ENE nighttime flow, NE to E flow in daytime,
periods where krypton sensor have voltage blw 100 mV and correspondingly anomalous variances and mean
Vdsm: 13.5-13.8 V during day, down to 12.5 at night, morning clouds/showers reduced voltage until 11:00 CDT
P: ok, pressure steady until 13:00; falling 4mb from 976mb until 17:00; generally hovering around 973 mb
T.2m: ok, stn4 about 0.7-1.0 degree cooler than stns 1 & 2 most of overnight; stn 3 about 0.3-0.5 warmer than stn 4
stn 2 warmer by 0.5-0.7 degrees than other sites most of daytime
RH.2m: 90-95% nighttime; dropping to 80% by afternoon
night: stns 4 5-10% RH higher than other stn 1 and about 3-5% higher than other stns
daytime stns 4 ~5-7%RH higher than stns 1&3, and ~10% higher than stn 2
[Are moisture effects due to more mature corn with larger Potential evapo-transpiration at Stn 4?]
H2O.2m: ok, 15-17 g/m^3 before midnight night, drop to under 14 g/m^3 before sunrise, steady rise to 21 g/m^3 in late afternoon
night: stn 1 about 0.5-0.7 g/m^3 drier than stn 4, 0.2 g/m^3 drier than stns 2 & 3
day: stn 1 about 1.0 g/m^3 drier than stn 4, 0.5-0.7 g/m^3 more dry than stn 3, few g/m^3 more dry than stn2
Wetness: slight wetness around 21:00-21:30 (Jul 13), showers made sensor wet from 6:00-9:00 10:00-11:30, 14:30-15:00
T.10m: ok, stns 1 & 2 about 0.3-0.5 degree warmer than stns 2 & 4 from 10:00 (Jul 13) to 4:00
stn 1 about 0.5 degree warmer than other sites for several daytime hours
RH.10m: ok, most of night stns 1 & 2 few%RH lower than stns 3 & 4; daytime stn 1 few%RH lower than other sites
H2O.10m: ok, nighttime: most sites within a few tenths g/m^3 of each other
stn 4 sometimes 0.3-0.5 g/m^3 less than other sites for the mid morning and late afternoon
Spd.10m: ok, sites mostly with same speed for much of overnight except for a 1.0 m/s separation from stn 1 and stn 3 from 2:00-4:00 (also during a ramp-up in possible LLJ signature?)
daytime: close agreement for all sites, slightly lower wspd at Site 3 during mid-late afternoon
Dir.10m: ok, E flow before midnight, shifting to ESE in period of LLJ? , more SE in the daytime
T.10m - T.2m: ok, most sites giving same positive gradient in nighttime temperature
daytime stn2 1.0 to 1.5 degrees warmer at 2m vs. 10m than for stn 1, about 0.5 degrees more unstable than stns 3 & 4
H2O.10m - H2O.2m: ok, stn 4 slightly drier gradient (0.5-0.7 g/m^3 more moist at 2m v.s 10m) than sites 1 & 2, sometimes stn 3 much of the night
daytime stn 4 is 1.0 g/m^3 drier at 10m vs. 2m than other other sites (again earlier planted corn drawing out more water?)
spd.4.5m: ok, see comments of Spd.10m
dir.4.5m: ok, see comments of dir.10m
w.4.5m: ok, night: stn 2 less descent (-0.02 m/s) than stns 3 & 4 (-0.08-to -0.12 m/s)
daytime stns 3 & 4 more w<0 (-0.14 m/s) (-0.12 m/s) than stn 1 (-0.02 m/s) or stn 1 (-0.06 m/s)
tc.4.5m: ok, before midnight E flow stns 3&4 0.5-0.7 degree cooler than stns 1&2;
after midnight during [LLJ occurrence?] stn 1 about 0.5 degree warmer than other sites
late afternoon stn 3 & 4 slightly warmer than stns 1 &2
ldiag: ok
vh2ov: ok, stn 2 mostly above 100mV, down to near zero during rain periods, leveling to 80 mV by late afternoon
stn 4 mostly above 100 mV, similar pattern as at Site 2 but lower voltage by late afternoon (70 mV)
kh2o: ok, night: stn 4 is reading about 1.0-1.2 g/m^ more moist than stns 1 & 2, about 0.5 m^3 more moist than at stn 3
h2o(licor): ok, btwn 13-20 g/m^3 for night to day behavior
stn 1 & 3-4 give 1.0 g/m^3 higher reading than stn 2 for late afternoon
lidiag (licor): ok
TKE.4.5m: ok, stns 3 & 4 slightly lower TKE (~0.20 m^2/s^2) than Sites 1 & 2 from midnight through 4:00 (especially during LLJ ramp-up)
daytime, all sites are in agreement
w'w': ok, see comment for TKE.4.5m, also similar pattern in u'u' and v'v'
u* : ok, not as clear of nighttime separation of sites as in TKE.4.5m;
v'w' signature has greater absolute stress at stns 1 & 2 (-0.08 (m/s)^2) than at 3 & 4 (-0.02 to -0.04 (m/s)^2) during LLJ ramp up
also daytime more v'w' stress < 0 at stn 4 vs. stn 3
w'T' : ok, nighttime: most stations in agreement within -0.01 C m/s
daytime: slightly lower at stn 4 than other sites but stations mostly in agreement
w'h2o': ok, stn 3 slightly higher nighttime vapor flux than other sites
stn 2 least daytime vapor flux max~0.08 g/m^2/s, other stns 1&3 flux max at about 0.14 g/m^2/s
h2o'h2o': ok, morning: more variance (0.05 (g/m^3)^2) at stns 1 & 3 than sites 2 & 4
early-mid afternoon: stn 2 about 0.10 (g/m^3)^2 smaller flux than stn 4, ~0.20 (g/m^3)^2 less than stns 1 & 3
kh2o'kh2o': ok, some spikes during morning rain events
co2: ok,
w'co2': ok, slight period of night when flux >0 (2.5^10-4 g/m^2/s) at stn 3 vs. stn 1
daytime stn 3 a bit greater co2 uptake mostly from 16:00-18:00
co2'co2': ok, similar pattern to w'co2'
July 13, 17:02 CDT
Dan Rajewski (in Ames)
Summary: Stations 1-4 operational, no ISFS staff on-site
NE nighttime flow, ENE wind in mid morning switching to E before noon
long afternoon period of easterly flow to capture likely 'wake influences' from the turbines at stns 1 & 2 and less so at stns 3-4
Vdsm: 13.5-13.8 V during day, down to 12.5 at night,
P: ok, for night and early morning: stns 1&2 about 0.5 mb higher than stn 3, stn3 about 0.25 mb lower than stn 4
T.2m: ok, stn4 about 0.5 degree cooler than stns 1 & 3 1 hr before midnight;
stn 2 warmer by 0.25 degrees than other sites for most of night and early morning
late morning to afternoon stn 2 about 1.0-1.5 degree warmer than other sites
RH.2m: 90-95% nighttime; dropping to 70%-75% by afternoon
night: stns 4 5% RH higher than other sites around midnight, few%RH higher rest of night
daytime stns 4 ~5%RH higher than stns 1 & 3, stn 2 about 5%RH lower than stns 1 & 3
H2O.2m: ok, 18 g/m^3 before midnight night, drop to around 13 g/m^3 before sunrise, back to 17 g/m^3 in late afternoon
stn 1 about 0.3 g/m^3 drier than other sites all of nighttime
stn 4 about 0.5 to 1.0 g/m^3 more moist than stns 1-2, 3 from late morning-late afternoon
stns 1-2 slightly drier than stn 3 also in afternoon
Wetness: sensor lost wetness around 19:00 (Jul 12) from previous afternoon showers and remained dry for next daily cycle
T.10m: ok, stn4 1hr before midnight: see comments for T.2m,
other sites in pretty good agreement for daytime and nighttime, stns 1 &2 slightly warmer than 3-4
RH.10m: ok, most of night stn 2 few%RH higher than other sites; daytime stn 1 few%RH lower than other sites
H2O.10m: ok, nighttime: stn 2 about 0.5 g/m^3 more moist than stn 4, stns 1&3 are in between these sites
stn 4 about 0.5 g/m^3 lower than other sites in daytime, stn 3 generally highest
Spd.10m: ok, before midnight: stn 1 fastest speed vs. stns 2 & 3 slowest speed (difference of close to 1.0 m/s)
after midnight: sites in close agreement except stns 1&3 slightly higher speed than stn 2 from 6:00-7:00
daytime: no discernible differences among the sites
Dir.10m: ok, NE flow much of night and early morning. ENE to E by late morning, Easterly in the afternoon
more stn scatter of direction (Site 1 & 2) to E winds (overlapping wakes from several turbines?)
T.10m - T.2m: ok, stn 2 is slightly warmer at 2m vs. 10 m for much of overnight, other stations have no to little temp gradient in nighttime
daytime stn2 1.0 to 1.5 degrees warmer at 2m vs. 10 m than other sites
H2O.10m - H2O.2m: ok, stn 4 slightly drier gradient than sites 1-3 much of the night,
daytime stn 4 is 1.0 g/m^3 drier at 10m vs. 2m than other other sites (earlier planted corn drawing out more water?)
spd.4.5m: ok, see comments of Spd.10m
dir.4.5m: ok, see comments of dir.10m
w.4.5m: ok, night: stn 4 less descent (-0.02 m/s) than stns 2 & 3 (-0.06 m/s), less fluctuation in w (-0.04 m/s) for stn 1
daytime stn 3 more w<0 (-0.12 m/s) 9:00-13:00 and again at 16:00
daytime stn 2 w~-0.1 m/s mid morning but going slightly positive to -0.02 m/s after 11:00-16:00 (multiple turbine wake influence?)
tc.4.5m: ok, stn 2 about 0.3 degree cooler than other sites most of night
ldiag: ok
vh2ov: ok, stn 2 above 100mV, early morning rise to over 200 mV and returning to 150mV by late afternoon
stn 4 above 100 mV, similar pattern as at Site 2
kh2o: ok, stn 4 is reading about 0.5 g/m^ more moist than other sites in night, 1.0 g/m^3 more moist than stn 2 in daytime
h2o(licor): ok, btwn 17-13 g/m^3 for night to day behavior
stn 1 slightly drier than stn 3 for night,about 0.3 g/m^3 drier than stn 3 in daytime
lidiag (licor): ok, a few samples are questionable from 13:00 to 17:00
TKE.4.5m: ok, stn 3 slightly higher TKE than other stns up through 3:00
stns 2 & 4 lowest TKE of the group for nighttime
daytime, all sites have comparable values with the significant scatter (intersecting wakes reaching the towers for E wind?)
w'w': ok, see comment for TKE.4.5m, also similar pattern in u'u'
u* : ok, stn 3 about 0.05 m/s higher from 1:00-3:00; see comment for TKE.4.5m, also pattern seen in u'w'
w'T' : ok, nighttime: most stations in agreement
daytime: stn 4 less heat flux than other sites, stn 3 has highest heat flux; about 0.06 C m/s between the two
w'h2o': ok, stn 2 least daytime vapor flux ~0.12 g/m^2/s, other stns 1&3 about 0.16 g/m^2/s
h2o'h2o': ok, morning: more variance (0.05 (g/m^3)^2) at stns 1 & 3 than sites 2 & 4
early afternoon: stn 1&3 about ~0.80 max, stn 4 about 0.6, stn 1 about 0.45
kh2o'kh2o': ok,
co2: ok,
w'co2': ok, no consistent night pattern of flux > 0 at one site more than other
daytime stn 3 greater co2 uptake several periods in afternoon (more Easterly wind vs. NE in late night/early morning)
co2'co2': ok, fairly similar among both site 1 & 3
This table summarizes the sonic and prop vane azimuths. Azimuth angles were shot relative to magnetic north with the datascope.
date |
stn |
whom |
sonic (measured,magnetic) |
sonic Vazimuth (calculated,true) |
prop (measured,magnetic) |
prop azimuth (calc,true) |
notes |
|---|---|---|---|---|---|---|---|
6/29 |
1 |
Kurt, Rus |
356.3, 356.7 |
267.8 |
92.3, 92.6 |
273.8 |
|
|
|
|
|
|
|
|
|
6/24 |
2 |
Gordon, Dan |
357.0 |
268.3 |
93.3 |
274.6 |
|
6/29 |
2 |
Kurt |
357.0 |
268.3 |
93.3 |
274.6 |
good agreement with 6/24 |
|
|
|
|
|
|
|
|
6/29 |
3 |
Kurt |
353.0 |
264.3 |
93.2 |
274.5 |
|
|
|
|
|
|
|
|
|
6/24 |
4 |
Gordon, Dan |
354.3 |
265.6 |
92.6 |
273.9 |
|
6/29 |
4 |
Kurt |
353.5 |
264.8 |
88.9 |
270.2 |
prop disagrees (-3.7 deg) with 6/24 |
7/5 |
4 |
Dan, Kris |
354.2 |
265.5 |
|
|
Magnetic declination = 1.3 deg E
sonic: Vazimuth = measured + declination - 90
Vazimuth is the direction that the sonic V axis is pointing, and is the rotation angle of horizontal wind components from instrument to geographic coordinates.
prop: azimuth = measured + declination + 180
prop azimuth is the angle that is added to the wind directions measured by the propvane, so that they are relative to true north.