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LBA-ECO CD-03 Nocturnal Meteorological Data, Forest and Pasture Sites, Para, Brazil
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Revision date: August 21, 2012

Summary:

This data set contains measurements of nocturnal meteorological profiles collected from tethered balloon platforms during July 2001, October 2001, and November 2003. Measurements were made near the pasture/agricultural tower site at km 77 on BR-163 just south of the city of Santarem, and near the Tapajos National Forest, km 83 tower site, Santarem, Para, Brazil.  Measurements collected include air temperature, wind speed and direction, and specific humidity. The 2003 measurements also included CO2 concentrations. Sites were near enough to allow comparison between sounding profiles and tower data. There are three comma-delimited ASCII files with this data set.

Profiles were obtained from sunset until the first hours after sunrise. 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 0.5 m per second in the first 100 m, and 2 m per second above 100 m. The time between successive samplings was 10 seconds. 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.

Data Citation:

Cite this data set as follows:

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

Implementation of the LBA Data and Publication Policy by Data Users:

The LBA Data and Publication Policy [http://daac.ornl.gov/LBA/lba_data_policy.html] is in effect for a period of five (5) years from the date of archiving and should be followed by data users who have obtained LBA data sets from the ORNL DAAC. Users who download LBA data in the five years after data have been archived must contact the investigators who collected the data, per provisions 6 and 7 in the Policy.

This data set was archived in August of 2012. Users who download the data between August 2012 and July 2017 must comply with the LBA Data and Publication Policy.

Data users should use the Investigator contact information in this document to communicate with the data provider. Alternatively, the LBA website [http://lba.inpa.gov.br/lba/] in Brazil will have current contact information.

Data users should use the Data Set Citation and other applicable references provided in this document to acknowledge use of the data.

Table of Contents:

1. Data Set Overview:

Project: LBA (Large-Scale Biosphere-Atmosphere Experiment in the Amazon)

Activity: LBA-ECO

LBA Science Component: Physical Climate

Team ID: CD-03 (Fitzjarrald / Moraes)

The investigators were Fitzjarrald, David Roy; Acevedo, Otavio C; Anabor, Vagner; Brait, Eleazar; Czikowsky, Matthew John; Da Silva, Rodrigo; Martins, Cintya de Azambuja; Parker, Geoffrey ; Sakai, Ricardo; Sampaio, Irene Cibelle Goncalves; Silva, Julio Tota da; Siqueira, Adriano Costa; Staebler, Ralf Manfred; Tsoyref, Alexander E. and Zimermann, Hans Rogerio. You may contact Acevedo, Dr. Otavio. (acevedo@pesquisador.cnpq.br).

LBA Data Set Inventory ID: CD03_Tethered_Balloon

This data set contains measurements of nocturnal meteorological profiles collected from tethered balloon platforms during July 2001, October 2001, and November 2003. Measurements were made near the pasture/agricultural tower site at km 77 on BR-163 just south of the city of Santarem, and near the Tapajos National Forest, km 83 tower site, Santarem, Para, Brazil.  Measurements collected include air temperature, wind speed and direction, and specific humidity. The 2003 measurements also included CO2 concentrations. Sites were near enough to allow comparison between sounding profiles and tower data.

Related data sets:

2. Data Characteristics:

Data are provided in three comma-delimited ASCII files.

File # 1:  CD03_Balloon_2001_July.csv

File # 2:  CD03_Balloon_2001_Oct.csv

The file contents are the same for both 2001 files and the sampling site was only the pasture/agriculture site. There are no CO2 measurements for 2001 files. Example data records from each of the 2001 files are provided following the table below.

ColumnHeadingUnits/formatDescription
1Site  Sampling location: agriculture-500 meters from the km 77 tower south of Santarem
2 YearyyyyYear of the sampling campaign
3 Monthmm Month of the year in which the sampling was done
4 Day dd Day of the month in which the sampling was done
5 Time HH:MMTime at the start of the ascent in local time on a 24 hour clock. Local time is GMT -5
6 HeightmSampling height in meters above the ground
7 T_airdegrees CAir temperature in degrees Celsius
8 Humidityg/kgSpecific humidity in grams per kilogram
9 Windspeedm/sWind speed in meters per second
10 Wind_dirdegreesWind direction in degrees from north
 
Missing data values are represented as -9999

Example data records: CD03_Balloon_2001_July.csv.

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

Example data records: CD03_Balloon_2001_Oct.csv

Site,Year,Month,Day,Time,Height,T_air,Humidity,Windspeed,Wind_dir
Agriculture,2001,10,3,21:51,0,21.81,16.25193,-0.2,355
Agriculture,2001,10,3,21:51,0,21.83,16.27219,-0.1,350
Agriculture,2001,10,3,21:51,2.4,21.85,16.27597,-0.2,351
...
Agriculture,2001,10,8,18:57,447,26.1,15.98569,5.9,100
Agriculture,2001,10,8,18:57,449.4,26.09,15.97601,5.8,100
Agriculture,2001,10,8,18:57,452.4,26.05,15.93738,5.8,100
...
Agriculture,2001,10,11,7:04,144,23.59,16.89559,4.8,94
Agriculture,2001,10,11,7:04,148.8,23.58,16.92194,4.6,95
Agriculture,2001,10,11,7:04,150,23.52,16.84124,4.7,112

File # 3:  CD03_Balloon_2003_Nov.csv

This file includes data on atmospheric CO2 concentrations. Sampling sites included the agriculture site and the forest site.

ColumnHeadingUnits/formatDescription
1Site  Sampling location: Pasture/agriculture was 500 meters from the km 77 tower; Forest was 5 km from the km 83 towers all south of Santarem
2 YearyyyyYear of the sampling campaign
3 Monthmm Month of the year in which the sampling was done
4 Day dd Day of the month in which the sampling was done
5 Time HH:MMTime at the start of the ascent in local time on a 24 hour clock. Local time is GMT -5
6 HeightmSampling height in meters above the ground
7 T_airdegrees CAir temperature in degrees Celsius
8 Humidityg/kgSpecific humidity in grams per kilogram
8 CO2ppmAtmospheric CO2 concentration in parts per million
9 Windspeedm/sWind speed in meters per second
10 Wind_dirdegreesWind direction in degrees from north
 
Missing data are represented as -9999

Example data records : CD03_Balloon_2003_Nov.csv

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,2003,11,18,22:46,255,30.2,16.81,349.42,5,100
Agriculture,2003,11,18,22:46,260,30.37,16.65,349.27,5.1,102
Forest,2003,11,23,19:11,0,-9999,-9999,-9999,0,334
...
Forest,2003,11,26,2:36,145,26.61,16.47,370.36,5.22,90
Forest,2003,11,26,2:36,150,26.73,16.41,369.81,5.3,87
Forest,2003,11,26,2:36,155,26.84,16.4,370.19,5.71,86

Site boundaries: (All latitude and longitude given in decimal degrees)

Site (Region) Westernmost Longitude Easternmost Longitude Northernmost Latitude Southernmost Latitude Geodetic Datum
Para Western (Santarem) - km 77 Pasture Tower Site (Para Western (Santarem)) -54.88850 -54.88850 -3.02020 -3.02020 World Geodetic System, 1984 (WGS-84)
Para Western (Santarem) - km 83 Logged Forest Tower Site (Para Western (Santarem)) -54.97070 -54.97070 -3.01700 -3.01700 World Geodetic System, 1984 (WGS-84)

Time period

Platform/Sensor/Parameters measured include:

3. 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 systems 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.

4. Quality Assessment:

The manufacturer specifies precision of the DX6100 gas analyzer to be 1 ppm CO2. 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.

5. Data Acquisition Materials and Methods:

Sites 

Measurements were made near the pasture/agricultural tower site at km 77 on BR-163 just south of the city of Santarem, and the near the Tapajos National Forest, km 83 tower site, Santarem, Para, Brazil.

Campaigns 

Intensive tethered balloon campaigns were performed in 2001 during July and October, and in November, 2003.

2001 Campaigns:

2003 Campaign:

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) (Acevedo et al., 2004).

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 during 2003 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 (Acevedo et al., 2008).

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 real time 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.

6. Data Access:

This data is available through the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

Data Archive Center:

Contact for Data Center Access Information:
E-mail: uso@daac.ornl.gov
Telephone: +1 (865) 241-3952

7. References:

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.

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.