NOTICE -- The LBA-ECO Project website is no longer being supported.  This archive is a snapshot, as it existed in 2013, of the LBA-ECO website, maintained by NASA Goddard Space Flight Center, and now archived at the ORNL DAAC.  Links to external websites may be inactive. Final data products from the LBA project can be found at the ORNL DAAC.
banner
banner banner banner banner banner banner
banner banner banner banner banner banner banner
home aboutlibrarynews archivecontacts banner

spacer
banner
Investigations
Overview
Abstracts & Profiles
Publications
Research Sites
Meetings
Synthesis Groups
LBA-HYDROMET
LBA-Air-ECO
Logistics
Overview
Field Support
Travel
Visa
Shipping
Data
  Overview
Find LBA Data
Investigator Checklist
Process & Policy
Documentation & Archive
Training & Education
  Overview
Activities Summary
T&E Goals
Student Opportunities
  Folha Amazônica
 
spacer

Investigation:

CD-03 (Fitzjarrald / Moraes)

LBA Dataset ID:

CD03_TETHERED_BALLOON

Originator(s):

1. ACEVEDO, O.C.
2. FITZJARRALD, D.R.
3. SAKAI, R.K.
      4. MORAES, O.L.L.
5. DA SILVA, R.

Point(s) of Contact:

ORNL DAAC User Services Office Oak Ridge National Laboratory Oak Ridge, Tennessee 37 (ornldaac@ornl.gov)

Dataset Abstract:

The files contain the meteorological data collected by a tethered balloon during three campaigns in July 2001, November 2001 and November 2003. Sampling was done at the km 77 site (agriculture), as well as at a forested site near km 83. Measurements collected include air temperature, windspeed and direction and specific humidity. The 2003 measurements had the additional observation of CO2 concentrations.

Beginning Date:

2001-07-26

Ending Date:

2003-11-26

Metadata Last Updated on:

2012-09-05

Data Status:

Archived

Access Constraints:

PUBLIC

Data Center URL:

http://daac.ornl.gov/

Distribution Contact(s):

ORNL DAAC User Services Office Oak Ridge National Laboratory Oak Ridge, Tennessee 37 (ornldaac@ornl.gov)

Access Instructions:

PUBLIC

Data Access:

IMPORTANT: The LBA-ECO Project website is no longer being supported. Links to external websites may be inactive. Final data products from the LBA project can be found at the ORNL DAAC. Please follow the fair use guidelines found in the dataset documentation when using or citing LBA data.
Datafile(s):

LBA-ECO CD-03 Nocturnal Meteorological Data, Forest and Pasture Sites, Para, Brazil :  http://daac.ornl.gov/cgi-bin/dsviewer.pl?ds_id=1108

Documentation/Other Supporting Documents:

LBA-ECO CD-03 Nocturnal Meteorological Data, Forest and Pasture Sites, Para, Brazil :  http://daac.ornl.gov/LBA/guides/CD03_Tethered_Balloon.html

Citation Information - Other Details:

Acevedo, O.C., D.R. Fitzjarrald, R.K. Sakai, O.L.L. Moraes and R. da Silva. 2012. LBA-ECO CD-03 Nocturnal Meteorological Data, Forest and Pasture Sites, Para, Brazil. Data set. Available on-line [http://daac.ornl.gov ] from Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, U.S.A. http://dx.doi.org/10.3334/ORNLDAAC/1108

Keywords - Theme:

Parameter Topic Term Source Sensor
AIR TEMPERATURE ATMOSPHERE TERRESTRIAL ECOSYSTEMS TETHERED BALLOON THERMISTOR
ATMOSPHERIC PRESSURE ATMOSPHERE TERRESTRIAL ECOSYSTEMS TETHERED BALLOON PRESSURE SENSOR
CARBON DIOXIDE ATMOSPHERE TERRESTRIAL ECOSYSTEMS TETHERED BALLOON IRGA (INFRARED GAS ANALYZER)
HUMIDITY ATMOSPHERE TERRESTRIAL ECOSYSTEMS TETHERED BALLOON HUMIDITY SENSOR
WAVE SPEED/DIRECTION ATMOSPHERE TERRESTRIAL ECOSYSTEMS TETHERED BALLOON WIND SENSOR

Uncontrolled Theme Keyword(s):  AMAZON, METEOROLOGY, TETHERED BALLOON

Keywords - Place (with associated coordinates):

Region
(click to view profile)
Site
(click to view profile)
North South East West
    -3.01700 -3.02020 -54.88850 -54.97070

Related Publication(s):

Acevedo, O.C., O.L.L. Moraes, R. Da Silva, D.R. Fitzjarrald, R.K. Sakai, R.M. Staebler, and M.J. Czikowsky. 2004. Inferring nocturnal surface fluxes from vertical profiles of scalars in an Amazon pasture. Global Change Biology 10(5):886-894.

Acevedo, O.C., R. Da Silva, D.R. Fitzjarrald, O.L.L. Moraes, R.K. Sakai, and M.J. Czikowsky. 2008. Nocturnal vertical CO2 accumulation in two Amazonian ecosystems. Journal of Geophysical Research-Biogeosciences, 113. doi:10.1029/2007JG000612.

Data Characteristics (Entity and Attribute Overview):

Data Characteristics:

Data are provided in three comma-delimited ASCII files:

CD03_Balloon_2001_July.csv

CD03_Balloon_2001_Oct.csv

CD03_Balloon_2003_Nov.csv





File contents and organization of the 2001 data files:

CD03_Balloon_2001_July.csv:

CD03_Balloon_2001_Oct.csv:



Column Column Variable description

heading

1 Site Sampling location:

Agriculture was 500 meters from the km 77 tower;

Forest was 5 km from the km 83 towers all south of Santarem

2 Year Year of the sampling campaign

3 Month Month of the year in which the sampling was done

4 Day Day of the month in which the sampling was done

5 Time Time at the start of the ascent in local time on a 24 hour clock.

6 Height Sampling height in meters above the ground

7 T_air Air temperature in degrees Celsius

8 Humidity Specific humidity in grams per kilogram

9 Windspeed Wind speed in meters per second

10 Wind_dir Wind direction in degrees from north

Missing data values are represented as -9999



File contents and organization of CD03_Balloon_2003_Nov.csv:



Column Column Variable description

heading

1 Site Sampling location:

Agriculture was 500 meters from the km 77 tower;

Forest was 5 km from the km 83 towers all south of Santarem

2 Year Year of the sampling campaign

3 Month Month of the year in which the sampling was done

4 Day Day of the month in which the sampling was done

5 Time Time at the start of the ascent in local time on a 24 hour clock.

6 Height Sampling height in meters above the ground

7 T_air Air temperature in degrees Celsius

8 Humidity Specific humidity in grams per kilogram

9 CO2 Atmospheric CO2 concentration in parts per million (not available in 2001 data)

10 Windspeed Wind speed in meters per second

11 Wind_dir Wind direction in degrees from north

Missing data values are represented as -9999







Example data records -- 2001:

Site,Year,Month,Day,Time,Height,T_air,Humidity,Windspeed,Wind_dir

Agriculture,2001,7,26,0:33,0,21.16,15.60558,-0.2,316

Agriculture,2001,7,26,0:33,1.2,21.24,15.60442,-0.2,324

Agriculture,2001,7,26,0:33,3.6,21.46,15.70767,-0.2,320

Agriculture,2001,7,26,0:33,8.4,21.54,15.80251,-0.2,319

Agriculture,2001,7,26,0:33,12,21.56,15.83845,-0.2,324





Example data records -- 2003:

Site,Year,Month,Day,Time,Height,T_air,Humidity,CO2,Windspeed,Wind_dir

Agriculture,2003,11,11,23:11,0,-9999,-9999,-9999,0,228

Agriculture,2003,11,11,23:11,5,24.07,18.88,442.56,0,213

Agriculture,2003,11,11,23:11,10,24.27,19,438.28,0,193.44

Agriculture,2003,11,11,23:11,15,24.4,19.11,437.62,0,191

Agriculture,2003,11,11,23:11,20,24.52,19.1,438.35,0.16,194.56

Agriculture,2003,11,11,23:11,25,24.65,19.08,437.52,0.73,204

Agriculture,2003,11,11,23:11,30,24.82,19.01,434.93,0.8,207.67

Agriculture,2003,11,11,23:11,35,25,18.98,430.94,0.97,203.67

Data Application and Derivation:

These data were used to improve our estimations of ecosystem carbon budgets on calm nights when there is insufficient turbulence for eddy flux calculations. In tropical forest system calm conditions at night are frequent and result in significant uncertainty in carbon budgets developed based on eddy flux approaches. These measurements allow an accurate determination of the nocturnal boundary layer thickness and trace the changes in the same over the course of the night.

Quality Assessment (Data Quality Attribute Accuracy Report):

Quality Assessment:

The manufacturer specifies precision of the DX6100 gas analyzer to be 1 ppm. To estimate accuracy, this sensor was compared with a model LI-7000 gas analyzer (Li-Cor, Inc., USA) both in the laboratory and in the field and with a LI-820 gas analyzer during profiling.

Even though both temperature and pressure could potentially influence the measurements from the IRGA, our tests indicated that only temperature compensation needed to be applied here to the DX6100 signal. We found that the temperature influence on the CO2 concentration data may be significant, a consequence of the small dimensions of the optical chamber and the fact that the small aluminum instrument body is in direct contact with the chamber that provides the readings. The corrections for the temperature were done by comparing the DX6100 signal to the outputs provided by a Licor LI-7000 IRGA.

Process Description:

Data Acquisition Materials and Methods:

Sites

The agricultural (deforested) site consists of a 500-ha area of forest that was converted into pasture in 1992. It is surrounded by primary and secondary forest, 25 km east of the Tapajos River. Topography, soil properties and vegetation are described by Sakai et al. [2004]. Originally used as pasture for cattle ranching, the pasture was burned in November 2001 and the land was tilled and prepared for the planting of first rice and later soybeans.

The measurements on the forested site were made in a 50 m by 80 m clearing surrounded by secondary forest with an approximately 35-m high canopy. These measurements were made 5 km from the LBA-ECO km83 flux towers, where sensors on two towers have monitored the surface flux evolution in an area subject to selective logging [Miller et al., 2004].



Campaigns

Three intensive tethered balloon campaigns were performed at the agricultural site: 24 through 30 July 2001, 4- 11 October 2001 and 11-18 November 2003. No CO2 measurements were made during the first two campaigns. During the first two campaigns the site was in pasture. The weather during the first campaign included the passage of a squall line on the night of 24 July 2001. Normally steady easterly winds were weaker than normal, owing to penetration of a cold air mass into the western Amazon basin (Silva Dias et al., 2003). Northerly winds were observed before the passage of the system, and in the following nights the usual pattern of easterlies dominated. During the second campaign no major synoptic events happened, and a consistent pattern was observed from night to night. During the third campaign, the land was tilled during the week of the observations and there was no vegetation above the surface. During the third campaign measurements were also made at the forested site.



Sampling design

First and second campaign:

The tethered balloon soundings were done in the field 500m from the pasture tower, near enough to allow comparison between sounding profiles and tower data. Each sounding provided information on temperature, humidity, horizontal wind magnitude and direction as the balloon went up and down. Typical soundings went up to 300 to 400 m. During most of the night, soundings were performed hourly. The balloon rose at a rate of 0.5m per second in the first 100 m, and 2m per second above it. The time between successive samplings was 10 s. Intensive periods of shallow, successive soundings were performed starting at dawn, to catch the early development of the convective boundary layer (CBL). These early morning soundings went up only to the capping inversion.



Third campaign:

Profiles for all campaigns were obtained from sunset until the first hours after sunrise. During the night, the soundings were taken every hour, going either to 300 m altitude, or to the level at which the wind speed reached 12 m per second. The balloon ascended at 1 m per second.



Methods

Pressure, temperature and humidity were determined by the PTH module, developed at the Atmospheric Sciences Research Center (ASRC) by J. Berndt. The pressure observation is used for the determination of the sounding height. The pressure sensor is a model OMEGA PX72030AV (Omega Engineering, Inc., USA).



Relative humidity was determined by a sensor HIH3605 (Honeywell, Inc., USA) and for the temperature observations a thermoresistor SI44006 (YSI, Inc., USA) was used. The temperature and humidity measured by the PTH module were calibrated against values measured independently provided by a Humitter 50Y/50U. The calibrations for these sensors are described in detail by da Silva (2006).



CO2 gas concentration was measured by a differential, nondispersive infrared gas analyzer (DX6100, RMT, Ltd., Moscow, Russia) that works on detection of the selective absorption of infrared radiation by the gas molecules. The sampling cell volume is 4.7 ml, the pump flow rate used was 1 liter per minute and the highest sampling frequency is 1 Hz.



The data were stored during sounding by a Tattletale 5F-LCD data logger (Onset Computer Corporation, USA). The sounding signal is transmitted by a radio system consisting of a transmitter AM-TXHP-433 and a receiver AM-HRR6-433 (ABACOM Technologies, USA), which is connected to a computer, at the ground. It allows the realtime monitoring of the observations and provides a backup to the data stored in the data logger. Data were also recorded on board the sonde as a backup.



The combined sensors were fitted into a sonde that was installed below a tethered balloon, model Blimp 130 (BlimpWorks, USA). The balloon can operate up to 1000-m height. A Tethersonde (AIR, Inc., USA) provided wind speed and direction observations and an alternate set of temperature, humidity and pressure measurements. These data were recorded by a ground receiver.

References:

da Silva, R. 2006. Avaliacao dos fluxos superficiais noturnos de escalares

atraves do metodo de balanco da camada limite atmosferica, Doctorate

dissertation, Univ. Fed. de Santa Maria, Santa Maria, Rio Grande do Sul,

Brazil.



Miller, S.D., M.L. Goulden, M.C. Menton, H.R. Rocha, H.C. Freitas, A.M.S. Figueira, and C.A.D. Sousa. 2004. Biometric and micrometeorological measurements of tropical forest carbon balance, Ecol. Appl. 14(4), S114-S126.



Sakai, R K., D.R. Fitzjarrald, O.L.L. Moraes, R.M. Staebler, O.C.Acevedo, M.J. Czikowsky, R.Silva, E.Brait, and V. Miranda. 2004. Land-use effects on local energy, water and carbon balances in an Amazonian agricultural field, Global Change Biol., 10, 895-907.



Silva Dias M.A.F., P.L. Silva Dias, M. Longo et al. 2004. River breeze circulation in Eastern Amazon: observations and modeling results. Theoretical Applied Climatology.

Skip navigation linksHOME | ABOUT | LIBRARY | NEWS ARCHIVE | CONTACTS | INVESTIGATIONS | LOGISTICS | DATA |TRAINING & EDUCATION

NASA logo
ORNL DAAC
Get Acrobat Reader