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Tropospheric Aerosol Radiative Forcing Observational eXperiment (TARFOX) Langley DAAC Data Set Document |
Aerosol effects on atmospheric radiation are a leading source of uncertainty in predicting future climate. TARFOX was designed to reduce this uncertainty by measuring and analyzing aerosol properties and effects in the U.S. eastern seaboard, where one of the world's major plumes of industrial haze moves from the continent over the Atlantic Ocean.
The TARFOX Intensive Field Campaign was conducted July 10-31, 1996. It included coordinated measurements from four satellites (GOES-8, NOAA-14, ERS-2, LANDSAT), four aircraft (ER-2, C-130, C-131A, and a modified Cessna), land sites, and ships. A variety of aerosol conditions was sampled, ranging from relatively clean behind frontal passages to moderately polluted with aerosol optical depths exceeding 0.5 at mid-visible wavelengths. Gradients of aerosol optical thickness were sampled to aid in isolating aerosol effects from other radiative effects and to more tightly constrain closure tests, including those of satellite retrievals. Early results from TARFOX include demonstration of the unexpected importance of carbonaceous compounds and water condensed on aerosol in the US mid-Atlantic haze plume, chemical apportionment of the aerosol optical depth, measurements of the downward component of aerosol radiative forcing, and agreement between forcing measurements and calculations. A wide variety of closure studies is currently in progress.
This document provides information for the following data sets:
| TARFOX_UWC131A_SUNP: | Tropospheric Aerosol Radiative Forcing Observational eXperiment - Ames Sun Photometer flown on University of Washington C-131A aircraft |
| TARFOX_UWC131A: | Tropospheric Aerosol Radiative Forcing Observational eXperiment - University of Washington instrumented C-131A aircraft |
| TARFOX_WALLOPS_MET: | Tropospheric Aerosol Radiative Forcing Observational eXperiment - meteorological data from Wallops ground station |
| TARFOX_WALLOPS_SMPS: | Tropospheric Aerosol Radiative Forcing Observational eXperiment - Scanning Mobility Particle Sizer data taken at Wallops ground station |
| TARFOX_WALLOPS_SONDE: | Tropospheric Aerosol Radiative Forcing Observational eXperiment - Radiosonde data from balloons launched at Wallops ground station |
Aerosol particles can change the Earth's radiation budget both directly by scattering and absorption and indirectly by affecting cloud properties. Changing the net flux of radiation above or within the atmosphere changes the energy available for driving climatic processes. Hence, such a net flux change is termed a radiative forcing of climate. Negative forcings tend to cool the climate, and positive forcings tend to warm it. Current estimates of the global, annually-averaged, direct radiative forcing by anthropogenic aerosols (e.g., sulfates, soots, mineral dust, biomass smokes) range from about -0.3 to -1.0 W m-2, with an uncertainty factor of about two. Analogous, but even less certain, estimates for the indirect effect are 0 to -1.5 W m-2. These values are comparable in magnitude, but opposite in sign, to the current estimates of +2.1 to +2.8 W m-2 for the forcing caused by increases in greenhouse gases over the past century.
Because of the great spatial variability in aerosol concentrations that results from their short lifetime, there are many regions - principally over and downwind of major source areas - where the best estimates of aerosol negative forcing exceed the greenhouse positive forcing. Some studies show that aerosol effects appear to be present in global and regional twentieth-century temperature records, and that inclusion of aerosol effects in numerical models improves agreement with observed temperature patterns in both time (decadal and diurnal) and space. Although these studies suggest that anthropogenic aerosols can play an important role in determining current and future climates, their results are far from conclusive. Major questions remain about the realism with which models represent the great diversity of actual aerosol properties, processes, and radiative effects. Error analyses show that the uncertainty in the aerosol radiative forcing is unacceptably large - larger, in fact, than the uncertainty in climate forcing by all greenhouse gases released over the past century.
As a result of both the potential importance of aerosols and the large uncertainties in their radiative effects, the International Global Atmospheric Chemistry (IGAC) Project has established a Focus on Atmospheric Aerosols (FAA) and endorsed a series of aerosol field campaigns. TARFOX is the second in the IGAC/FAA series. TARFOX was designed to reduce uncertainties by measuring and analyzing a wide range of aerosol properties and effects in the US eastern seaboard. This is the region where one of the world's major plumes of industrial haze moves from the continent over the Atlantic Ocean.
The overall goal of TARFOX is to reduce uncertainties in the effects of aerosols on climate by determining the direct radiative impacts, as well as the chemical, physical, and optical properties, of the aerosols carried over the western Atlantic Ocean from the United States. Subsidiary objectives of TARFOX are to:
An important component of the closure studies is tests and improvements of algorithms that retrieve aerosol properties and effects from satellite and aircraft radiometers. The resulting validated algorithms will permit extensions of the TARFOX results to other times and locations that have aerosol properties similar to those of the TARFOX Intensive Field Campaign (IFC).
PARTICULATE OPTICAL DEPTH
RAYLEIGH OPTICAL DEPTH
TOTAL OPTICAL DEPTH
AEROSOL BACKSCATTERING COEFF
AEROSOL SCATTERING COEFF
CONDENSATION NUCLEI
DROPLET CONCENTRATION
EFFECTIVE DROPLET RADIUS
LIQUID WATER CONTENT
OZONE MIXING RATIO
PARTICLE NUMBER CONCENTRATION
PRESSURE
RELATIVE HUMIDITY
TEMPERATURE
WIND DIRECTION
WIND SPEED
PARTICLE NUMBER CONCENTRATION
ALTITUDE
PRESSURE
RELATIVE HUMIDITY
TEMPERATURE
More detailed information on TARFOX can be obtained from the TARFOX Web Site.
Tropospheric Aerosol Radiative Forcing Observational eXperiment (TARFOX)
Coordinated measurements were made from four satellites (GOES-8, NOAA-14, ERS-2, LANDSAT), four aircraft (ER-2, C-130, C-131A, and a modified Cessna), land sites, and ships. A variety of aerosol conditions was sampled, ranging from relatively clean behind frontal passages to moderately polluted with aerosol optical depths exceeding 0.5 at mid-visible wavelengths. Gradients of aerosol optical thickness were sampled to aid in isolating aerosol effects from other radiative effects and to more tightly constrain closure tests, including those of satellite retrievals.
| TARFOX_UWC131A_SUNP | UW C131 |
| TARFOX_UWC131A | UW C131 |
| TARFOX_WALLOPS_MET | Ground Station |
| TARFOX_WALLOPS_SMPS | Ground Station |
| TARFOX_WALLOPS_SONDE | Ground Station |
See the TARFOX Science and Implementation Plan, June 1996.
PARTICULATE OPTICAL DEPTH
RAYLEIGH OPTICAL DEPTH
TOTAL OPTICAL DEPTH
AEROSOL BACKSCATTERING COEFF
AEROSOL SCATTERING COEFF
CONDENSATION NUCLEI
DROPLET CONCENTRATION
EFFECTIVE DROPLET RADIUS
LIQUID WATER CONTENT
OZONE MIXING RATIO
PARTICLE NUMBER CONCENTRATION
PRESSURE
RELATIVE HUMIDITY
TEMPERATURE
WIND DIRECTION
WIND SPEED
PARTICLE NUMBER CONCENTRATION
ALTITUDE
PRESSURE
RELATIVE HUMIDITY
TEMPERATURE
See the TARFOX Operations Summary Document, November 1996.
| Data Set Name |
Min Lat |
Max Lat |
Min Lon |
Max Lon |
|---|---|---|---|---|
| TARFOX_UWC131A_SUNP | 36.01 | 39.78 | -76.53 | -72.56 |
| TARFOX_UWC131A | 36.02 | 39.79 | -76.54 | -72.58 |
| TARFOX_WALLOPS_MET | 37.85 | 37.85 | -75.48 | -75.48 |
| TARFOX_WALLOPS_SMPS | 37.85 | 37.85 | -75.48 | -75.48 |
| TARFOX_WALLOPS_SONDE | 37.85 | 37.85 | -75.48 | -75.48 |
U.S. eastern seaboard
TARFOX_UWC131A_SUNP: ...
TARFOX_UWC131A: ...
TARFOX_WALLOPS_MET: Point Measurements
TARFOX_WALLOPS_SMPS: Point Measurements
TARFOX_WALLOPS_SONDE: ...
07/10/1996 - 07/31/1996
TARFOX_UWC131A_SUNP: 3 second
TARFOX_UWC131A: 1 second
TARFOX_WALLOPS_MET: ...
TARFOX_WALLOPS_SMPS: 5 minutes
TARFOX_WALLOPS_SONDE: 2 seconds
PARTICULATE OPTICAL DEPTH
RAYLEIGH OPTICAL DEPTH
TOTAL OPTICAL DEPTH
AEROSOL BACKSCATTERING COEFF
AEROSOL SCATTERING COEFF
CONDENSATION NUCLEI
DROPLET CONCENTRATION
EFFECTIVE DROPLET RADIUS
LIQUID WATER CONTENT
OZONE MIXING RATIO
PARTICLE NUMBER CONCENTRATION
PRESSURE
RELATIVE HUMIDITY
TEMPERATURE
WIND DIRECTION
WIND SPEED
PARTICLE NUMBER CONCENTRATION
ALTITUDE
PRESSURE
RELATIVE HUMIDITY
TEMPERATURE
A general description of data granularity as it applies to the IMS appears in the EOSDIS Glossary.
There are no plans for reprocessing.
The Langley DAAC performs an inspection process on this data received by the data producer via ftp. The DAAC checks to see if the transfer of the data completed and were delivered in their entirety. An inspection software was developed by the DAAC to see if the code was able to read every granule. The code also checks to see if every parameter of data falls within the ranges which are included in the granule. This same code extracts the metadata required for ingesting the data into the IMS. If any discrepancies are found, the data producer is contacted. The discrepancies are corrected before the data are archived at the DAAC.
To reduce uncertainties in the effects of aerosols on climate by determining the direct radiative impacts, as well as the chemical, physical, and optical properties, of the aerosols carried over the western Atlantic Ocean from the United States.
Unavailable at this time.
The software can be obtained through the Langley DAAC. Please refer to the contact information below. The software can also be obtained at the same time the user is ordering this data set.
The Langley DAAC provides multiple interfaces to access its data holdings. The graphical and character user interfaces allow users to search and order data; and web interfaces allow direct access to some data holdings for immediate downloading or placing media orders, for searching the data holdings, and downloading electronically available holdings, and for ordering prepackaged CD-ROMs and videocassettes. All of these methods are easily obtained from the Langley DAAC web site.
The Langley DAAC will continue to archive this data.
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