Start Date | Start Time | End Date | End Time | Data Quality Metric |
---|---|---|---|---|
03/20/1997 | 2255 | 03/31/1997 | 2359 | Suspect |
Subject: | Controlled burn at E12 on 3/20/97 and affected data |
DataStreams: | sgp5ebbrE12.b1, sgp30ebbrE12.b1, sgpsirosE12.a1, sgp15ebbrE12.b1 |
Description: | 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. |
Suggestions: | |
Measurements: | sgpsirosE12.a1: more
sgp15ebbrE12.b1: more sgp5ebbrE12.b1: more sgp30ebbrE12.b1: more |