SBP/EBBR/E9 - Reprocess: Soil Heat Flow Sensor 5 Incorrect Data

Soil heat flow sensor #5 periodically outputted incorrect values during the
period above.  The output often indicated large negative heat flow.  The
sensor connections were tightened on March 20, 1995, which seems to have
corrected the problem.  The data affected (and thus incorrect) includes:

15 minute: mv_hft5
30 minute: shf5, c_shf5, g5, ave_shf, e, h.

The dates and times (GMT) of incorrect values are listed below.  Only half
hour times are listed.

03/10/95  2130
03/11/95  0100-0600, 1530-2330
03/12/95  0000-1930
03/13/95  0500
03/16/95  1830-2330
03/17/95  0000-2330
03/18/95  0000-1100
03/19/95  2100-2330
03/20/95  0000-0400, 1530-1700

The latent and sensible heat fluxes can be recalculated by using only soil
heat flows 1 through 4 to calculate the average soil heat flow,

ave_shf = (g1 + g2 + g3 + g4)/4

e = -(q + ave_shf)/(1 + bowen)

h = -(e + ave_shf + q)

• Soil heat flow 5(mv_hft5)

• 5 cm soil heat flow corrected for soil moisture content, site 5(c_shf5)
• 5 cm soil heat flow, site 5(shf5)
• h(h)
• soil heat flow, site 5(g5)
• average surface soil heat flow(ave_shf)
• latent heat flux(e)

SGP/EBBR/E9 - Temperature Portion of T/RH Probe

The Temperature portion of the right T/RH probe indicated too high a 
temperature for nearly 11 months.  I twice placed work requests to have the 
probe replaced, but no spares were available.  Spares recently became 
available and I placed a new work request to have the probe changed.  The 
replacement occurred on 18 June 1997; this fixed the problem.  The main 
results of the high temperatures were probe top and bottom temperatures
(used only for the calculation of vapor pressure) and vapor pressures that 
were too large.  Furthermore, this caused latent heat flux to be reported 
to be too large, and therefore sensible heat flux was reported to be too 
small.  Recalculation of the fluxes using thermocouple temperatures to 
calculate vapor pressure would be quite time consuming and would have to
assume that the thermocouple temperature and probe temperature were nearly 
the same.

The EBBR procedures have been changed to include comparison of the 
thermocouple and probe temperatures to make it easier for the site 
operators to detect this condition.

The data affected (and thus incorrect) includes:

15 minute: rr_thum_r 
30 minute: thum_top, thum_bot, vp_top, vp_bot, e, h, bowen.

• Battery(bat)
• Dummy altitude for Zeb(alt)
• Soil heat flow 3(mv_hft3)
• Temperature of right humidity sensor chamber(rr_thum_r)
• Soil heat flow 4(mv_hft4)
• Soil heat flow 5(mv_hft5)
• lon(lon)
• Soil heat flow 1(mv_hft1)
• Soil heat flow 2(mv_hft2)
• base time(base_time)
• lat(lat)

• bottom vapor pressure(vp_bot)
• latent heat flux(e)
• Temperature of the top humidity chamber(thum_top)
• h(h)
• top vapor pressure(vp_top)
• Temperature of bottom humidity sensor chamber(thum_bot)
• ratio of sensible/latent heat fluxes (Bowen ratio)(bowen)