NAMMA SMART-COMMIT Mobile Laboratories
Table of Contents
Introduction
Surface-sensing Measurements for Atmospheric Radiative Transfer (SMART) and Chemical, Optical, and Microphysical Measurements of In-situ Troposphere (COMMIT) consist of a suite of instruments that measure (both in-situ and by remote sensing) parameters that characterize, as completely as possible, constituents of the atmosphere at a given location. SMART and COMMIT are mobile systems that can be deployed to locations that exhibit interesting atmospheric phenomena, which allows them to participate in coordinated remote measurement campaigns such as NAMMA. These laboratories include radiometers, lidar, particle sizers, gas monitors, meteorological sensors, tethered radiosonde, and other instruments which measure radiances, irradiances, back scatter profile, atmospheric state variables, aerosol scattering/absorbing, particle size distribution, trace gas concentrations, and sky images. Some of the derived products include temperature and water vapor profiles, aerosol scattering/absorbing coefficients, aerosol optical thickness, extinction profile, surface BRDF, and cloud & dust properties.
The SMART-COMMIT goal during the NAMMA campaign was to provide near-real time (updated every 5-10 minutes) temporal monitoring of the marine boundary layer and SAL, especially using whole-sky imager & sunphotometers (sky conditions), micro-pulse lidar (vertical structure), groundbase in-situ probes (properties of aerosols & precursors), and tethersonde system (meteorological state variables), at Cape Verde to track the evolution of air mass. Additional information about SMART-COMMIT can be found here: http://smart-commit.gsfc.nasa.gov/index.html
Campaign
These data files were generated during support of the NASA African Monsoon Multidisciplinary Analyses (NAMMA) campaign, a field research investigation sponsored by the Science Mission Directorate of the National Aeronautics and Space Administration (NASA). This mission was based in the Cape Verde Islands, 350 miles off the coast of Senegal in west Africa. Commencing in August 2006, NASA scientists employed surface observation networks and aircraft to characterize the evolution and structure of African Easterly Waves (AEWs) and Mesoscale Convective Systems over continental western Africa, and their associated impacts on regional water and energy budgets. For more information about the NAMMA Campaign, go to the NAMMA web site: http://namma.nsstc.nasa.gov/
Instrument Description
The SMART-COMMIT laboratories consist of an cornucopia of scientific instruments, and those used to produce the data for this dataset are listed below:
Precision Spectral Pyranometer (PSP)
The Eppley Lab Precision Spectral Pyranometer is a radiometer designed for the measurement of sun and sky radiation, totally or in defined broad wavelength bands. Spectral range: 0.3 – 3, 0.4 – 3 and 0.7 – 3 µm
CMP 21 pyranometer
The Kipp & Zonen CMP 21 pyranometer is designed for measuring the irradiance (radiant flux, Watt/m²) on a plane surface, which results from the direct solar radiation and from the diffuse radiation incident from the hemisphere above. Spectral range: 0.3 – 3, 0.4 – 3 and 0.7 – 3 µm
Pyrgeometer (CG4)
The Kipp & Zonen CG4 Pyrgeometer is intended for high accuracy infrared radiation (IR) measurement. Spectral range: 4.5 to 42 µm
NILU – UV Meter
The Norwegian Institute for Air Research UV Irradiance Meter measures the total incoming irradiance in five channels across the UV spectrum. Spectral ranges: 305, 312, 320, 340, 380 nm and 400 - 700 nm Bandwidth is approximately 10 nm
Multi-Filter Rotating Shadow Band Radiometer (MFR)
The Yankee Environmental Systems Multi-Filter Rotating Shadow Band Radiometer (MFR-7), simultaneously measures Global, Diffuse and Direct normal components of spectral solar irradiance. Spectral range: 415, 500, 615, 670, 870, 940nm and 0.3 – 1.1 µm.
Total Sky Imager (TSI)
The Yankee Environmental Systems Total Sky Imager (TSI Model 440) is a full color sky camera and software package for sky imaging, recording up to 6 images per minute.
Scanning Microwave Radiometer (SMiR)
A NASA/GSFC in-house product, the SMiR is able to take measurements at three different microwave frequencies. The data is used to determine the amount of water vapor in the atmosphere. Microwave frequencies: 23.0 GHz, 23.8 GHz, 36.5 GHz. Accessories: Ground surface temperature, Soil moisture.
Aerodynamic Particle Sizer (APS)
The TSI Incorporated APS provides the aerodynamic size of particles from 0.5 to 20 µm, and also measures light scattering intensity in the equivalent optical size range of 0.37 to 20 µm.
Aethalometer
The Magee Scientific Company AE3- series Aethalometer is used to measure light absorption due to aerosol particles at 7 wavelengths spanning ultraviolet, visible and near-infrared. Spectral ranges: 370, 470, 520, 590, 660, 880 and 950nm.
Particle / Soot Absorption Photometer (PSAP)
The Radiance Research PSAP is used to measure light absorption due to aerosol particles at a green wavelength. Spectral ranges: 467, 530 and 660nm.
TSI Nephelometer
The TSI Incorporated Nephelometer is used to measure light scattering due to aerosol particles at three different wavelengths (Red, Green and Blue). Spectral channels: 450, 550 and 700 nm.
RR Nephelometer
The Radiance Research M903 Nephelometer is used to measure light scattering due to aerosol particles at a green wavelength. Three identical instruments are installed to measure light scattering under three different relative humidity (RH) levels (dry, ambient and wet) to derive RH dependency of light scattering. Spectral channel: 530nm.
Gas Monitors
The COMMIT ground based unit is equipped with Thermo Fisher Scientific gas sensors that measure the concentration of trace gases such as CO, CO2, O3, SO2, NO and NOx.
Micro Pulse Lidar (MPL)
The Micro Pulse Lidar is a compact and eye-safe lidar system capable of determining the range of aerosols and clouds in the atmosphere by firing a short pulse of laser light (at 523nm). This instrument is also a part of the global network (MPLNET).
Atmospheric Emitted Radiance Interferometer (AERI)
The AERI instrument (manufactured by Bomem Inc.) is a fully automated ground-based passive infrared interferometer that measures atmospheric downwelling radiances from 550-3000 cm -1 (3.3-18 m m). The instrument uses a 2-channel (sandwiched HgCdTe/ InSb) detector providing sensitivity in the 3.3-5.5 and 5.5-18 m m spectral regions for channels 1 and 2 respectively. AERI also uses 2 blackbody references for calibration, one which is allowed to float at the ambient temperature and the other which is fixed at 65C.
Meteorological Sensors
The SMART ground based unit also collects meteorological data, using a Vaisala WXT510, including atmospheric pressure, temperature, relative humidity, wind speed and wind direction.
Tethered Balloon
A tethered, helium-filled, weather balloon also is used during field campaigns to take measurements of pressure, temperature, relative humidity, wind speed and wind direction in the atmosphere.
File Naming Convention
The following example files are available on a daily basis throughout the NAMMA campaign:
namma_sal-sonde_yyyymmdd_atm-profile-over-smart-commit.jpg
namma_smart_yyyymmddhhMMss_TSI.jpg
namma_smart_yyyymmdd_AERI.jpg
namma_smart_yyyymmdd_AERI-radiance-C1.cdf
namma_smart_yyyymmdd_AERI-radiance-C2.cdf
namma_smart_yyyymmdd_MPL.gif
where,
namma = the field campaign
sal-sonde = data is from a tethered radiosonde
smart = data is from a SMART instrument
yyyymmdd = year,month,day
hhMMss = hour,minute,second
TSI = total sky imager
AERI = Atmospheric Emitted Radiance Interferometer
MPL = Micro Pulse Lidar
jpg = Joint Photographic Experts Group (JPEG) image format
gif = Graphics Interchange Format image format
cdf = Common Data Format
The following example cumulative files cover longer periods of time throughout the NAMMA campaign.The first date is the start date, and the second date is the stop date, with the same format as above:
namma_smart_20060904-20060926_AERI-radiances_3houravg.tif
namma_smart_20060905-20060922_SMiR.jpg
namma_smart_20060905-20060926_TotalSkyImager_hourly.mov
namma_smart_20060906-20060907_AERI.jpg
namma_smart_20060907-20060926_UV-1.GIF
namma_smart_20060907-20060926_UV-2.GIF
namma_smart_20060907-20060926_UV-3.GIF
namma_smart_20060907-20060926_UV_preliminary_1hravg.txt
namma_smart_20060909-20060926_MFR109-1.GIF
namma_smart_20060909-20060926_MFR109-2.GIF
namma_smart_20060909-20060926_MFR109-3.GIF
namma_smart_20060909-20060926_MFR109-4.GIF
namma_smart_20060909-20060926_MFR109-5.GIF
namma_smart_20060909-20060926_MFR109-6.GIF
namma_smart_20060909-20060926_MFR109-7.GIF
namma_smart_20060909-20060926_MFR109_Rawdata_1hravg.txt
namma_smart_20060910-20060926_IR-Irradiance-1hravg.txt
namma_smart_20060910-20060926_IR-Irradiance.jpg
namma_smart_20060910-20060926_SolarDiffuseIrradiance.jpg
namma_smart_20060910-20060926_SolarDirectIrradiance.jpg
namma_smart_20060910-20060926_SolarGlobalIrradiance-1hravg.txt
namma_smart_20060910-20060926_SolarGlobalIrradiance.jpg
namma_commit_20060905-20060928_APS_dNdlogD_preliminary_1hravg.txt
namma_commit_20060905-20060928_APS.JPG
namma_commit_20060906-20060928_Aethalometer.GIF
namma_commit_20060906-20060928_Aethalometer_preliminary_1hravg.txt
namma_commit_20060906-20060928_CO2.jpg
namma_commit_20060906-20060928_CO.jpg
namma_commit_20060906-20060928_NOx.jpg
namma_commit_20060906-20060928_PSAP.GIF
namma_commit_20060906-20060928_PSAP_preliminary_1hravg.txt
namma_commit_20060906-20060928_SO2.jpg
namma_commit_20060908-20060924_TSI-Neph-1.GIF
namma_commit_20060908-20060924_TSI-Neph-2.GIF
namma_commit_20060908-20060924_TSI_Neph_preliminary_1hravg.txt
namma_commit_20060908-20060928_RR-Nephlometer-Dry.jpg
namma_commit_20060908-20060928_RR-Nephlometer-Wet.jpg
namma_commit_20060914-20060925_Precipitation.jpg
namma_commit_20060914-20060927_Meteorology@1.5m-T-RH-P.jpg
namma_commit_20060914-20060927_Meteorology@1.5m-Wind.jpg
namma_commit_20060914-20060927_Meteorology@3.5m-T-RH-Wind.jpg
namma_commit_20060914-20060927_Surface-Skin-T.jpg
where,
SMiR = Scanning Microwave Radiometer
TotalSkyImager = from the total sky imager
UV = data from the UV Irradiance Meter
UV-1 = Downward UV-A flux
UV-2 = Downward UV-B flux
UV-3 = Downward PAR flux
MFR109-(1-7) = Multi-Filter Rotating Shadow Band Radiometer (415, 500, 615, 670, 870, 940nm and 0.3 – 1.1 µm)
IR-Irradiance = data from Pyrgeometer
SolarDiffuseIrradiance - data from Multi-Filter Rotating Shadow Band Radiometer
SolarDirectIrradiance - data from Multi-Filter Rotating Shadow Band Radiometer
SolarDirectIrradiance - data from Multi-Filter Rotating Shadow Band Radiometer
APS - Aerodynamic Particle Sizer
Aethalometer - data from a Magee Scientific Company AE3- series Aethalometer
CO2 - data from Thermo Fisher Scientific gas sensors
CO - data from Thermo Fisher Scientific gas sensors
NOx - data from Thermo Fisher Scientific gas sensors
SO2 - data from Thermo Fisher Scientific gas sensors
PSAP - data from a Radiance Research Particle / Soot Absorption Photometer
TSI-Neph - data from the TSI Incorporated Nephelometer
RR-Nephlometer - data from the Radiance Research M903 Nephelometer
Precipitation - graph of rain accumulation, duration, and intensity
Meteorology - meteorological data, from a Vaisala WXT510 sonde
Surface-Skin-T - ground temperature chart
tif - Tagged Image File Format
mov - QuickTime’s native movie format
txt - data files in ASCII text form, usually tab delimited, with headers
Data Format
Most of the data files are simple ASCII text files, with an extension of ".txt". These files have headers that explain the dataset, and are usually tab delimited.
The AERI datasets are in CDF (Common Data Format). The National Space Science Data Center's (NSSDC) Common Data Format (CDF) is a self-describing data abstraction for the storage and manipulation of multidimensional data in a discipline-independent fashion.
The data provider has supplied an informative readme file which describes the AERI instrument, how it was used, and the type of data that were collected. It also describes the CDF data format, and how to read the data files. You may read or download the readme document (word) here: ftp://ghrc.nsstc.nasa.gov/pub/doc/namma/namsmart/namma_smart_AERI_readme.doc
References
Tsay S. C., and J. Q. Li. 2004. SAFARI 2000 Surface Atmospheric Radiative Transfer (SMART), Dry Season 2000. Data set. Available on-line [http://daac.ornl.gov/] from Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, U.S.A.
Campbell, J. R., E. J. Welton, J. D. Spinhirne, Q. Ji, S. C. Tsay, S. J. Piketh, M. Barenbrug, and B. N. Holben. 2003. Lidar observations of tropospheric aerosols over northeastern South Africa during the ARREX and SAFARI-2000 Dry Season Experiments. J. Geophys. Res., 108, doi:10.1029/2002JD002563.
Christopher, S. A., J. Wang, Q. Ji, and S. C. Tsay. 2003. Estimation of diurnal shortwave dust aerosol radiative forcing during PRIDE. J. Geophys. Res., 108, doi:10.1029/2002JD002787.
Hansell, R., S. C. Tsay, Q. Ji, K. N. Liou, and S. Ou. 2003. Surface aerosol radiative forcing derived from collocated ground-based radiometric observations during PRIDE, SAFARI, and ACE-Asia. Appl. Opt., 42(27): 5533-5544.
Reid, J. S., J. E. Kinney, D. L. Westphal, B. N. Holben, E. J. Welton, S. C. Tsay, D. P. Eleuterio, J. Campbell, S. A. Christopher, H. H. Jonsson, J. M. Livingston, H. B. Maring, M. M. Meier, P. Pilewskie, J. Prospero, E. A. Reid, L. A. Remer, P. B. Russell, D. L. Savoie, A. A. Smirnov, and D. Tanre. 2003. Measurements of Saharan dust by airborne and ground-based remote sensing methods during the Puerto Rico Dust Experiment (PRIDE). J. Geophys. Res., 108, doi:10.1029/2002JD002493.
S. C. Tsay, Q. Ji, M. J. Jeong, and N. C. Hsu. SMART - A mobile Laboratory for Ground-based Remote Sensing of Atmospheric Radiation. To be submitted to Bull. Amer. Met. Soc., 2007.
Q. Ji, S. C. Tsay, M. J. Jeong, and N. C. Hsu. COMMIT - A mobile laboratory for Ground-based In-situ Measurement of Atmospheric Aerosols. To be submitted to Bull. Amer. Met. Soc., 2007.
Contact Information
Address Scientific issues to:
Dr. Qiang “Jack” Ji, Senior Research Scientist
Earth System Science Interdisciplinary Center
University of Maryland
College Park, MD 20742
e-mail: ji@climate.gsfc.nasa.gov
To order these data or for further information, please contact:
Global Hydrology Resource Center
User Services
320 Sparkman Drive
Huntsville, AL 35805
Phone: 256-961-7932
E-mail: support-ghrc@earthdata.nasa.gov
Web: http://ghrc.nsstc.nasa.gov/
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