Controlled burn at E12 on 3/20/97 and affected data

DQR No:                               Platforms:  sgpsirosE12
                                                  sgpebbrE12

Subject: Controlled burn at E12 on 3/20/97 and affected data

Date Submitted:  3/31/97
Submitted By: Mike Splitt             ___  Instrument Mentor
                                      ___  EST Member
                                      ___  Science Team Member
                                      _x_  Other _Site_Scientist_Team_
 
For questions or problems, please contact the ARM Experiment Center at
509-375-6898 or via email at problems@arm.gov.

Platform/Measurement:
        What level data: (raw,a0,a1,b1,c1 etc):
             all levels
    What location was the data collected at: sgp E12
 
    Period of time in question
        Begin Date   3/20/97  Time   22:55    (GMT)
        End Date      *       Time     :      (GMT)

* The "end date" is not necessarily in need of definition. The EBBR data
  appears to be directly affected for a period of about one hour. The
  effect on the local shortwave albedo will be longer lasting and could 
  be said to "end" when the vegetative state recovers to being representative
  of similar areas.

 Data should be labeled:
 ___  questionable                      ___  All data fields affected
 ___  incorrect                         ___  Only some data fields affected
 ___  wrong calibration
 _x_  others 
 
 Discussion of Problem:

This report is reflective of a change in environmental conditions thought
to be worth noting at E12, Pawhuska, and does not concern any issue of
substandard sensor performance. 

A contolled burn was conducted at the the Pawhuska Extened Facillity (E12)
by the Tallgrass Prairie Preserve. The Preserve director, Bob Hamilton,
contacted the ARM SGP Site prior to the activity which allowed Site Operations
to take precautionary steps. Danny Nelson reported the following activities by
Site Operations:

1)  Site Ops cut and removed all dried grass within the EF fence and
also to a 10' perimeter around the outside of the fence.  Final grass
height was 1-3".  This was done on Monday the 17th of March.

2)  Tallgrass Prairie Preserve personnel put down a 10' wet line around
our EF prior to the burn on the 20th, so the EF area was not burned.

3)  Site Ops had originally planned to deploy a field crew to inspect
the site on the day following the burn.  TPP director Bob Hamilton had
agreed to call us the morning of the burn, but didn't actually call us
until this morning; the day following the burn.  Due to the short
notification and prior commitment of personnel, Site Ops will not be
able to travel to the site until Monday or Tuesday of next week.

John Shatz was given the following information about the duration of
the burn:

>Bob Hamilton called and indicated that they did a control burn of the
>Tall Grass Prairie yesterday(3-20-97).  He indicated that the fire in
>our area lasted between 4:55 PM to 5:40 PM.  He also said that they
>plan to put this control burning on a two to three year cycle.

Affect on ARM Data:

Review of the EBBR temperature data (the sensor in the lower position)
shows a dramatic increase of temperature from 26 to 37 Celsius in a 
10 minute period.  The temperatures appear to have been affected for 
approximately 1 hour. 

Analysis of the broadband shortwave albedo during this period reveals
changes that appear to be related to the burn. The following is 
a listing of the daily average shortwave albedos (caluclated by running a linear
regression fit on the "curve" created by plotting the upwelling shortwave 
vs. the downwelling shortwave values from the E12 SIROS broadband instrumentation):

    Date        Broadband Shortwave Albedo
    ________   ____________________________

    3-14-97              .171
    3-15-97              .171
    3-16-97              .169
    3-17-97              .166
    3-18-97              .135
    3-19-97              .171
    3-20-97              .174
    3-21-97              .141
    3-22-97              .143
    3-23-97              .148
    3-24-97              .147

The grass cutting activity at the EF does not appear to be responsible
for the abledo change on 3-18; this is likely related to the drizzle
and overcast sky conditions in the area on that day. Note that the albedo
recovers to previous values by the next day. 

The burn occured late on the 20th, and it appears the albedo after the
burn sustained a more long-lasting decrease in value.  Examination of
both the upwelling and downwelling solar irradiance indicates that 
the albedo change was a resultant of the decrease in upwelling irradiance,
as the downwelling values were comparable to other sites.

• -180.0 - +180.0(alt)
• Hemispheric broadband irradiance(hemisp_broadband)
• 10 meter Longwave Dome Temperature, Pyrgeometer(up_long_dome_temp)
• Diffuse Hemispheric Irradiance, MFRSR(diffuse_hemisp_narrowband)
• Direct Normal Irradiance, NIMFR(direct_norm_narrowband)
• Data logger supply voltage(logger_volt)
• Shortwave direct normal irradiance, pyrheliometer(short_direct_normal)
• Downwelling Longwave Diffuse Hemispheric Irradiance, Ventilated Pyrgeometer(down_long_diffuse_hemisp)
• Ventilated Pyrgeometer Dome Temperature(down_long_dome_temp)
• Time offset from base_time(time_offset)
• Diffuse Hemispheric Broadband Irradiance, offset corrected(diffuse_hemisp_broadband)
• MFRSR Detector Temperature(mfrsr_temp)
• Data Logger Temperature(logger_temp)
• Ventilated Pyrgeometer Case Temperature(down_long_case_temp)
• Flag fields with *4 returned from callang(flag_nighttime1-24)
• 25 meter Longwave Case Temperature, Pyrgeometer(up_long_case_temp)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer(down_short_diffuse_hemisp)
• 10 meter Upwelling Longwave Hemispheric Irradiance, Pyrgeometer(up_long_hemisp)
• MFRSR channels(channel)
• Down-welling unshaded pyranometer voltage(down_short_hemisp)
• base time in epoch(base_time)
• Thermistor Excitation Voltage, Data Logger(therm_volt)
• Flag fields with *1 returned from callang(flag_zero_divisor1-24)
• Flag fields with *3 returned from callang(flag_zero_cosine1-24)
• lon(lon)
• Hemispheric Irradiance, MFRSR(hemisp_narrowband)
• 25 meter Upwelling Shortwave Hemispheric Irradiance, Pyranometer(up_short_hemisp)
• Flag fields with *2 returned from callang(flag_ln_error1-24)
• North Latitude(lat)
• Direct Normal Irradiance, MFRSR(direct_norm_broadband)

• Battery voltage(battery_voltage)
• Right T/RH sensor temperature (resistance ratio)(temp_trh_right_rr)
• Soil moisture 3 (resistance)(soil_moisture_3_r)
• Left T/RH sensor temperature (resistance ratio)(temp_trh_left_rr)
• Time offset from base_time(time_offset)
• Wind direction vector mean (mV)(wdir_vec_mean_mv)
• lon(lon)
• base time in epoch(base_time)
• Soil heat flow 4 (mV)(soil_heat_flow_4_mv)
• Soil temperature 3 (resistance ratio)(soil_temp_3_rr)
• Net radiation (mV)(net_radiation_mv)
• Soil heat flow 1 (mV)(soil_heat_flow_1_mv)
• AEM position indicator(home_signal)
• Soil temperature 4 (resistance ratio)(soil_temp_4_rr)
• Soil moisture 2 (resistance)(soil_moisture_2_r)
• Atmospheric pressure (mV)(atmos_pressure_mv)
• Left relative humidity (mV)(rh_left_mv)
• Soil temperature 1 (resistance ratio)(soil_temp_1_rr)
• Soil heat flow 5 (mV)(soil_heat_flow_5_mv)
• Soil moisture 1 (resistance)(soil_moisture_1_r)
• Soil moisture 5 (resistance)(soil_moisture_5_r)
• Soil heat flow 2 (mV)(soil_heat_flow_2_mv)
• Soil temperature 2 (resistance ratio)(soil_temp_2_rr)
• Reference temperature in enclosure (resistance ratio)(temp_reference_rr)
• Soil heat flow 3 (mV)(soil_heat_flow_3_mv)
• Soil moisture 4 (resistance)(soil_moisture_4_r)
• Left air temperature(temp_air_left)
• Soil temperature 5 (resistance ratio)(soil_temp_5_rr)
• North Latitude(lat)
• Right relative humidity (mV)(rh_right_mv)
• Wind speed arithmetic mean(wspd_arith_mean)
• Right air temperature(temp_air_right)
• -180.0 - +180.0(alt)

• Top vapor pressure(vapor_pressure_top)
• Time offset from base_time(time_offset)
• Top air temperature(temp_air_top)
• Wind speed arithmetic mean(wspd_arith_mean)
• Bottom air temperature(temp_air_bottom)
• Reference temperature in enclosure(temp_reference)
• AEM position indicator(home_signal)
• lon(lon)
• Wind direction vector mean standard deviation(wdir_vec_std)
• base time in epoch(base_time)
• Atmospheric pressure(atmos_pressure)
• Bottom T/RH sensor temperature(temp_trh_bottom)
• Top relative humidity (fractional)(rh_top_fraction)
• Top T/RH sensor temperature(temp_trh_top)
• North Latitude(lat)
• -180.0 - +180.0(alt)
• Bottom vapor pressure(vapor_pressure_bottom)
• Wind speed vector mean(wspd_vec_mean)
• Wind direction vector mean(wdir_vec_mean)
• Bottom relative humidity (fractional)(rh_bottom_fraction)
• Net radiation(net_radiation)

• Soil temperature mean 3(soil_temp_3)
• Soil temperature 2(soil_temp_2)
• Half hour averaged soil temperature 5(soil_temp_5)
• Half hour averaged soil temperature 4(soil_temp_4)
• North Latitude(lat)
• Soil temperature 1(soil_temp_1)
• -180.0 - +180.0(alt)
• Surface soil heat flux, average of fluxes 1-5(surface_soil_heat_flux_avg)
• Soil heat capacity 5(soil_heat_capacity_5)
• Soil heat capacity 3(soil_heat_capacity_3)
• Soil heat capacity 4(soil_heat_capacity_4)
• Soil heat capacity 1(soil_heat_capacity_1)
• Soil heat capacity 2(soil_heat_capacity_2)
• AEM position indicator 0 to 15 mins(home_signal_15)
• Surface soil heat flux 4(surface_soil_heat_flux_4)
• Surface soil heat flux 5(surface_soil_heat_flux_5)
• Surface soil heat flux 2(surface_soil_heat_flux_2)
• Surface soil heat flux 3(surface_soil_heat_flux_3)
• Surface soil heat flux 1(surface_soil_heat_flux_1)
• Bottom air temperature(temp_air_bottom)
• Soil heat flow 5, corrected for soil moisture(corr_soil_heat_flow_5)
• Soil moisture 1, gravimetric(soil_moisture_1)
• Soil heat flow 4, corrected for soil moisture(corr_soil_heat_flow_4)
• Soil heat flow 3, corrected for soil moisture(corr_soil_heat_flow_3)
• Soil heat flow 2, corrected for soil moisture(corr_soil_heat_flow_2)
• Soil moisture 4, gravimetric(soil_moisture_4)
• Soil heat flow 1, corrected for soil moisture(corr_soil_heat_flow_1)
• Soil moisture 5, gravimetric(soil_moisture_5)
• Soil moisture 2, gravimetric(soil_moisture_2)
• Soil moisture 3, gravimetric(soil_moisture_3)
• Soil heat flow 2(soil_heat_flow_2)
• Soil heat flow 1(soil_heat_flow_1)
• Top vapor pressure(vapor_pressure_top)
• Soil heat flow 5(soil_heat_flow_5)
• Soil heat flow 4(soil_heat_flow_4)
• Soil heat flow 3(soil_heat_flow_3)
• Atmospheric pressure(atmos_pressure)
• Change in energy storage 1, 0-5 cm soil layer(energy_storage_change_1)
• Change in energy storage 2, 0-5 cm soil layer(energy_storage_change_2)
• AEM position indicator 15 to 30 mins(home_signal_30)
• Change in energy storage 5, 0-5 cm soil layer(energy_storage_change_5)
• Change in energy storage 3, 0-5 cm soil layer(energy_storage_change_3)
• Change in energy storage 4, 0-5 cm soil layer(energy_storage_change_4)
• Surface sensible heat flux(sensible_heat_flux)
• base time in epoch(base_time)
• Time offset from base_time(time_offset)
• Bottom relative humidity (fractional)(rh_bottom_fraction)
• Wind direction vector mean standard deviation(wdir_vec_std)
• Top T/RH sensor temperature(temp_trh_top)
• Bowen ratio(bowen_ratio)
• Top relative humidity (fractional)(rh_top_fraction)
• Wind speed arithmetic mean(wspd_arith_mean)
• Net radiation(net_radiation)
• Reference temperature in enclosure(temp_reference)
• Wind direction vector mean(wdir_vec_mean)
• Surface latent heat flux(latent_heat_flux)
• lon(lon)
• Wind speed vector mean(wspd_vec_mean)
• Top air temperature(temp_air_top)
• Bottom vapor pressure(vapor_pressure_bottom)
• Bottom T/RH sensor temperature(temp_trh_bottom)