SGP/EBBR/E8 - Battery Voltage Drop

Sometime after 0000 GMT on August 19, 1994 the cable from the solar panel
to the EBBR battery was broken, presumably the result of severe weather
that was in the area.  The result was that the battery could not be charged
by the solar panel, leading to a gradual reduction in battery voltage.  By
1730 GMT on the 19th, the battery voltage had dropped to 10.8 volts and at
about 1905 GMT had dropped too low to power the AEM.  Some thirty minute data
after 1900 GMT is therefore incorrect.  By 2000 GMT the voltage had dropped to
10.7 volts and was too low to properly power the barometric pressure sensor
(it's output dropped off from then on).  At 1530 GMT on August 24, 1994 the
solar panel connection to the battery was reestablished and normal data
acquisition resumed at 1600 GMT.

The last data file to be produced was apparently 0000 GMT (15 minute file)
on 20 August.

In an apparently related incident, soil temperature #3 skyrocketed in output
beginning at about 1815 GMT; the cause for this is unknown, but is probably
a result of the inability of the CR10 data logger to correctly measure the
sensor resistance.  By 1900 GMT this situation had caused elevated average
soil heat flux, which in turn affected calculated e and h.

Data fields that are incorrect for the time period listed, follow:

5 minute:  tair_top, tair_bot, thum_top, thum_bot, hum_top, hum_bot,
           vp_top, vp_bot

15 minute: rr_thum_r, rr_thum_l, mv_hum_r, mv_hum_l, tair_r, tair_l

30 minute: tair_top, tair_bot, thum_top, thum_bot, hum_top, hum_bot,
           vp_top, vp_bot, bowen, e, h

• Top T/RH sensor temperature(temp_trh_top)
• Bottom air temperature(temp_air_bottom)
• Bottom relative humidity (fractional)(rh_bottom_fraction)
• Bottom T/RH sensor temperature(temp_trh_bottom)
• Bottom vapor pressure(vapor_pressure_bottom)
• Top relative humidity (fractional)(rh_top_fraction)
• Top vapor pressure(vapor_pressure_top)
• Top air temperature(temp_air_top)

• Right air temperature(temp_air_right)
• Left air temperature(temp_air_left)
• Left T/RH sensor temperature (resistance ratio)(temp_trh_left_rr)
• Right relative humidity (mV)(rh_right_mv)
• Left relative humidity (mV)(rh_left_mv)
• Right T/RH sensor temperature (resistance ratio)(temp_trh_right_rr)

• Bottom vapor pressure(vapor_pressure_bottom)
• Surface latent heat flux(latent_heat_flux)
• Bottom air temperature(temp_air_bottom)
• Bottom T/RH sensor temperature(temp_trh_bottom)
• Bottom relative humidity (fractional)(rh_bottom_fraction)
• Surface sensible heat flux(sensible_heat_flux)
• Top relative humidity (fractional)(rh_top_fraction)
• Top vapor pressure(vapor_pressure_top)
• Bowen ratio(bowen_ratio)
• Top T/RH sensor temperature(temp_trh_top)
• Top air temperature(temp_air_top)