AVHRR Polar Pathfinder Twice-Daily 5 km EASE-Grid Composites
Entry ID: NSIDC-0066

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Summary
Abstract: This data set is no longer available due to errors in the data. See the Error Sources section of the data set documentation for details. If you have further questions, please contact NSIDC User Services by e-mail or telephone at +1 303.492.6199. The Advanced Very High Resolution Radiometer (AVHRR) Polar Pathfinder Twice-Daily 5 km EASE-Grid Composites are a collection of products for both poles, consisting of twice-daily calibrated and gridded satellite channel data and derived parameters. Data include five AVHRR channels, clear sky surface broadband albedo and skin temperature, solar zenith angle, satellite elevation angle, sun-satellite relative azimuth angle, surface type mask, cloud mask, and Universal Coordinated Time (UTC) of acquisition. AVHRR Polar Pathfinder data extend pole ward from 48.4 degrees north and 53.2 degrees south latitudes, from 24 July 1981 through 30 June 2005. Data are in 1-byte and 2-byte integer grid format and are available by FTP. Note: Due to a problem with the NOAA-16 scan motor, all the channel data is shifted sporadically between 2001 and 2005, causing the channels to contain data from another channel; thus, the derived parameters also contain errors during this time-period. See Table 12 in the Error Sources section of this document for specific dates.

Related URL
Link: VIEW PROJECT HOME PAGE
Description: AVHRR Data at NSIDC


Link: VIEW PROJECT HOME PAGE
Description: NOAA/NASA Pathfinder Program


Link: VIEW PROJECT HOME PAGE
Description: Polar Pathfinders at NSIDC


Link: VIEW RELATED INFORMATION
Description: All About EASE-Grid


Link: VIEW RELATED INFORMATION
Description: All About EASE-Grid


Geographic Coverage
 N: -53.2 S: -90.0  E: 180.0  W: -180.0
 N: 90.0 S: 48.4  E: 180.0  W: -180.0

Data Set Citation
Dataset Originator/Creator: W. Emery, C. Fowler, T. Haran, J. Key, J. Maslanik, T. Scambos
Dataset Title: AVHRR Polar Pathfinder Twice-Daily 5 km EASE-Grid Composites
Dataset Release Date: 2000-09-01
Dataset Release Place: Boulder, Colorado USA
Dataset Publisher: NSIDC: National Snow and Ice Data Center
Version: 3
Online Resource: http://nsidc.org/data/NSIDC-0066


Temporal Coverage
Start Date: 1981-07-24
Stop Date: 2005-06-30


Location Keywords
CONTINENT > ANTARCTICA
GEOGRAPHIC REGION > ARCTIC
GEOGRAPHIC REGION > POLAR


Data Resolution
Temporal Resolution: 12 hour


Science Keywords
ATMOSPHERE >ATMOSPHERIC RADIATION >ALBEDO    [Definition]
CRYOSPHERE >SNOW/ICE >ALBEDO    [Definition]
TERRESTRIAL HYDROSPHERE >SNOW/ICE >ALBEDO    [Definition]
LAND SURFACE >SURFACE RADIATIVE PROPERTIES >ALBEDO    [Definition]
SPECTRAL/ENGINEERING >INFRARED WAVELENGTHS >BRIGHTNESS TEMPERATURE    [Definition]
SPECTRAL/ENGINEERING >INFRARED WAVELENGTHS >INFRARED RADIANCE    [Definition]
LAND SURFACE >SURFACE THERMAL PROPERTIES >LAND SURFACE TEMPERATURE    [Definition]
LAND SURFACE >SURFACE THERMAL PROPERTIES >SKIN TEMPERATURE    [Definition]
SPECTRAL/ENGINEERING >INFRARED WAVELENGTHS >THERMAL INFRARED    [Definition]
SPECTRAL/ENGINEERING >PLATFORM CHARACTERISTICS >VIEWING GEOMETRY    [Definition]
SPECTRAL/ENGINEERING >VISIBLE WAVELENGTHS >VISIBLE RADIANCE    [Definition]
ATMOSPHERE >CLOUDS >CLOUD PROPERTIES >CLOUD FREQUENCY    [Definition]


ISO Topic Category
CLIMATOLOGY/METEOROLOGY/ATMOSPHERE
INLAND WATERS
GEOSCIENTIFIC INFORMATION
IMAGERY/BASE MAPS/EARTH COVER


Platform
NOAA-11 >National Oceanic & Atmospheric Administration-11    [Information]
NOAA-14 >National Oceanic & Atmospheric Administration-14    [Information]
NOAA-16 >National Oceanic & Atmospheric Administration-16    [Information]
NOAA-7 >National Oceanic & Atmospheric Administration-7    [Information]
NOAA-9 >National Oceanic & Atmospheric Administration-9    [Information]


Instrument
AVHRR >Advanced Very High Resolution Radiometer    [Information]
Radiometers    [Information]


Project
ESIP >Earth Science Information Partners Program    [Information]
NOAA/NASA PATHFINDER >NOAA/NASA Pathfinder Program    [Information]
EOSDIS >Earth Observing System Data Information System    [Information]


Quality
Product validation is a continuing process that takes advantage of comparative data as they become available. Comparisons were made between AVHRR Polar Pathfinder clear sky skin temperatures and surface-based measurements obtained at the South Pole over a seven-day period in 1995. These field data were collected by Robert Stone of the Cooperative Institute for Research in Environmental Sciences (CIRES) using a sled-mounted KT-19 pyrometer. Excluding observations when cloud cover was present, the agreement was generally within 0.5 kelvin. For data averaged over a four-hour period, temperatures were within 0.1 kelvin. A mean of -38.15 degrees Celsius for the AVHRR Polar Pathfinder observations, versus a mean of -38.25 degrees Celsius for the field data. Evaluations were also performed for the AVHRR Polar Pathfinder retrievals of surface albedo over the Greenland Ice Sheet through comparisons with albedo measured at 14 Automatic Weather Stations (AWS) around the Greenland Ice Sheet from January 1997 to August 1998. Results show that AVHRR-derived surface albedo values are, on average, 10 percent less than those measured by the AWS stations. However, station measurements tend to be positively biased by about four percent, and the differences in absolute albedo may be less, about six percent. In regions of Greenland where the albedo variability is small, such as the dry snow facies, the AVHRR albedo uncertainty exceeds the natural variability. Stroeve concluded that while further work is needed to improve the absolute accuracy of the AVHRR-derived surface albedo, the data provide temporally and spatially consistent estimates of the Greenland Ice Sheet albedo (Stroeve et al. 2001) and (Stroeve 2002). Analyses of the AVHRR Polar Pathfinder data, compared with data from the Surface Heat Budget of the Arctic Ocean (SHEBA) project, are in progress. See (Maslanik et al. 2000) for preliminary results. The cloud masking process was assessed and refined throughout the duration of the project to optimize the algorithm for the entire areas of coverage. Comparisons of areally-averaged cloud fractions from the AVHRR Polar Pathfinder Twice-daily 5 km EASE-Grid Composites with field observations at the SHEBA field site show that the AVHRR data were within nine percent of the cloud lidar/radar observations averaged from April to July 1998 with Pathfinder data underestimating cloud fraction relative to the field measurements. Differences in monthly means for this period ranged from 2 percent in June to 21 percent in July. Comparison of all-sky skin temperature and albedo values derived from the AVHRR Polar Pathfinder Twice-daily 5 km EASE-Grid Composites with SHEBA observations is described in (Maslanik et al. 2000). Other validation studies of surface temperature and albedo retrieval procedures included surface observations from a NOAA research site near Barrow, Alaska, 71.32 degrees north latitude, 156.61 degrees west longitude. Daily AVHRR data from a preliminary Pathfinder data set from mid-1992 to mid-1993 were used for this validation (Meier et al. 1997). Surface temperature estimates agreed with observations, with a correlation coefficient of 0.98, a bias of -0.97, and a RMSE of 4.70. For surface albedo, the bias (mean error) in the estimates was near zero, r=0.81, bias=0.00, RMSE=0.17, but the individual observations exhibited significant variability, attributed to surface inhomogeneity and retrieval scheme sensitivity to changes in atmospheric aerosol and water vapor amounts. Accuracies of the products are difficult to determine given the limited nature of existing case studies. Also, conditions vary substantially across the large product domains and over time. Plans are being developed to further define product accuracies for snow-covered areas, sea ice, and ice sheets. Based on studies to date, accuracies in general are approximately ± 2 kelvin for AVHRR-derived clear sky skin temperatures and ± 0.06 kelvin for albedo. Much of this error is likely due to uncertainties in the performance of the cloud detection methods. For clear sky conditions, accuracies for albedo and temperature products are expected to be in the range noted in the Greenland Barrow case studies. Data and related information will be updated as appropriate.


Keywords
Antarctic
Arctic
AVHRR
Cryosphere
DAAC
EOSDIS
NASA
NOAA
NSIDC
Pathfinder
Polar
Radiance
Remote Sensing
Satellite


Data Set Progress
COMPLETE


Data Center
NASA National Snow and Ice Data Center Distributed Active Archive Center    [Information]
Data Center URL: http://nsidc.org/daac/index.html

Data Center Personnel
Name: NSIDC USER SERVICES
Phone: +1 (303) 492-6199
Fax: +1 (303) 492-2468
Email: nsidc at nsidc.org
Contact Address:
National Snow and Ice Data Center
CIRES, 449 UCB
University of Colorado
City: Boulder
Province or State: CO
Postal Code: 80309-0449
Country: USA


National Snow and Ice Data Center    [Information]
Data Center URL: http://nsidc.org

Data Center Personnel
Name: NSIDC USER SERVICES
Phone: +1 (303) 492-6199
Fax: +1 (303) 492-2468
Email: nsidc at nsidc.org
Contact Address:
National Snow and Ice Data Center
CIRES, 449 UCB
University of Colorado
City: Boulder
Province or State: CO
Postal Code: 80309-0449
Country: USA



Distribution
Distribution_Media: FTP
Distribution_Size: 3.26 MB
Distribution_Format: Binary

Distribution_Media: FTP
Distribution_Size: 6.52 MB
Distribution_Format: Binary


Personnel
JEFFREY KEY
Role: INVESTIGATOR
Contact Address:
Space Science and Engineering Center
University of Wisconsin at Madison
1225 W. Dayton St.
City: Madison
Province or State: WI
Postal Code: 53706


JIM MASLANIK
Role: INVESTIGATOR
Phone: (303) 492-6199
Fax: (303) 492-2468
Email: nsidc at kryos.colorado.edu
Contact Address:
National Snow and Ice Data Center
CIRES, 449 UCB
University of Colorado
City: Boulder
Province or State: CO
Postal Code: 80309


TED SCAMBOS
Role: INVESTIGATOR
Phone: 303 492 1113
Email: teds at nsidc.org
Contact Address:
National Snow and Ice Data Center
CIRES, 449 UCB
University of Colorado
City: Boulder
Province or State: CO
Postal Code: 80309-0449
Country: USA


WILLIAM EMERY
Role: INVESTIGATOR
Contact Address:
Colorado Center for Astrodynamics Research
University of Colorado
City: Boulder
Province or State: CO
Postal Code: 80309-0431
Country: USA


CHUCK FOWLER
Role: INVESTIGATOR
Contact Address:
Colorado Center for Astrodynamics Research
University of Colorado
City: Boulder
Province or State: CO
Postal Code: 80309-0431
Country: USA


TERRY HARAN
Role: INVESTIGATOR
Phone: 303-492-1847
Email: tharan at nsidc.org
Contact Address:
National Snow and Ice Data Center
CIRES, 449 UCB
University of Colorado
City: Boulder
Province or State: CO
Postal Code: 80309-0449
Country: USA


NSIDC USER SERVICES
Role: TECHNICAL CONTACT
Phone: +1 (303) 492-6199
Fax: +1 (303) 492-2468
Email: nsidc at nsidc.org
Contact Address:
National Snow and Ice Data Center
CIRES, 449 UCB
University of Colorado
City: Boulder
Province or State: CO
Postal Code: 80309-0449
Country: USA


Publications/References
Cracknell, A. P. 1997. The Advanced Very High Resolution Radiometer. London: Taylor & Francis. Csiszar, I. and G. Gutman. 1999. Mapping Global Land Surface Albedo from NOAA AVHRR. Journal of Geophysical Research 104(D6):6215-6228. Diner, D. J., J. V. Martonchik, C. Borel, S. A. W. Gerstl, H. R. Gordon, Y. Knyazikhin, R. Myneni, B. Pinty, M. M. Verstraete. 1999. MISR Level 2 Surface Retrieval Algorithm Theoretical Basis. Jet Propulsion Laboratory. Goodison, B. E. 1989. Determination of Areal Snow Water Equivalent on the Canadian Prairies Using Passive Microwave Satellite Data. IGARSS '89 Proceedings 3:1243-1246. Goodrum, Geoffrey, Katherine B. Kidwell, Wayne Winston. 2000. NOAA KLM User's Guide with NOAA-N, -N' Supplement. National Oceanic and Atmospheric Administration. Gustafson, G. B. et al. 1994. Support of Environmental Requirements for Cloud Analysis and Archive (SERCAA), Phillips Laboratory, Hanscom Air Force Base, Scientific Report No. 2, PL-TR-94-2114, 100 pp. Hapke, B. 1993. Theory of Reflectance and Emittance Spectroscopy. Cambridge: Cambridge University Press. Key, J. 1999. The Cloud and Surface Parameter Retrieval (CASPR) System for Polar AVHRR. Cooperative Institute for Meteorological Satellite Studies, University of Wisconsin, Madison. Key, J. and A. J. Schweiger. 1998. Tools for Atmospheric Radiative Transfer: Streamer and FluxNet. Computers and Geosciences 24(5):443-451. Key, J., J. Collins, Chuck Fowler, and R. S. Stone. 1997. High-latitude Surface Temperature Estimates from Thermal Satellite Data. Remote Sensing of the Environment 61:302-309. Kidwell, K. D. 1995. NOAA Polar Orbiter Data User's Guide. U.S. Dept. of Commerce, National Oceanic and Atmospheric Administration, NESDIS. Maslanik, J. A., J. Key, Chuck Fowler, T. Nguyen. 2000. AVHRR-derived Regional Cloud and Surface Conditions During SHEBA and FIRE-ACE. Journal of Geophysical Research, in press. Maslanik, J., Chuck Fowler, J. Key, Ted Scambos, T. Hutchinson, and W. Emery. 1998. AVHRR-based Polar Pathfinder Products for Modeling Applications. Annals of Glaciology 25:388-392. Meier, W. N., J. A. Maslanik, J. R. Key, and Chuck Fowler. 1997. Multiparameter AVHRR-derived Products for Arctic Climate Studies. Earth Interactions 1. Rao, C. R. N. 1993. Nonlinearity Corrections for the Thermal Infrared Channels of the AVHRR: Assessment and Recommendations. NOAA Technical Report, NESDIS 69:31. Rao, C. R. N. and J. Chen. 1994. Post-launch Calibration of the Visible and Near-infrared Channels of the Advanced Very High Resolution Radiometer on NOAA-7, -9, and -11 Spacecraft. NOAA Technical Report NESDIS 78:22 . Rao, C. R. N. and J. Chen. 1999. Revised post-launch calibration of channels 1 and 2 of the Advanced Very High Resolution Radiometer on board the NOAA-14 spacecraft. http://noaasis.noaa.gov/NOAASIS/ml/aboutn14vis.html. Rosborough, G. W., D. G. Baldwin, and W. J. Emery. 1994. Precise AVHRR Image Navigation. IEEE Transactions in Geosciences and Remote Sensing 32(3):644-657. Saunders, R. W. and K. T. Kriebel. 1988. An Improved Method for Detecting Clear Sky and Cloudy Radiances from AVHRR Data. International Journal of Remote Sensing 9(1):123-150. Schweiger, A., Chuck Fowler, J. Key, J. Maslanik, J. Francis, Richard Armstrong, Mary Joe Brodzik, Ted Scambos, Terry Haran, M. Ortmeyer, S. Khalsa, D. Rothrock, and Ron Weaver. 1999. P-Cube: A Multisensor Data Set for Polar Climate Research. Proceedings on the 5th Conference on Polar Meteorology and Oceanography, American Meteorological Society, Dallas, TX, 15-20 Jan., 136-141. Schweiger, A. J. and J. R. Key. 1992. Arctic Cloudiness: Comparison of ISCCP-C2 and Nimbus-7 Satellite-derived Cloud Products with a Surface-based Cloud Climatology. Journal of Climate 5(12):1514-1527. Stowe, L.L., E.P. McClain, R. Carey, P. Pellegrino, and G.G. Gutman. 1991. Global Distribution of Cloud Cover Derived from NOAA/AVHRR Operational Satellite Data. Advances in Space Research 11(3): 51- 54. Stroeve, Julienne C., J. E. Box, Chuck Fowler, Terry Haran, and Jeffrey Key. March 2001. Intercomparison Between in Situ and AVHRR Polar Pathfinder-derived Surface Albedo Over Greenland. Remote Sensing of the Environment 75(3):360-374. Stroeve, Julienne C. 2002. Assessment of Greenland Albedo Variability from the AVHRR Polar Pathfinder Data Set. Journal of Geophysical Research 106(D24):33,989-34,005. Suttles, J. T., R. N. Green, P. Minnis, G .L. Smith, W. F. Staylor, B. A. Wielicki, I. J. Walker, D. F. Young, V. R. Taylor, and L. L. Stowe. 1988. Angular Radiation Models for Earth-Atmosphere System. Shortwave Radiation, NASA Reference Publication 1(1184):144. Walton, C. C., J. T. Sullivan, C. R. N. Rao, and M. P. Weinreb. 1998. Corrections for Detector Nonlinearities and Calibration Inconsistencies of the Infrared Channels of the Advanced Very High Resolution Radiometer. Journal of Geophysical Research 103(C2):3323-3337. Yamanouchi, T., K. Suziki, and S. Kawaguchi. 1987. Detection of Clouds in Antarctica from Infrared Multispectral Data of AVHRR. Journal of Meteorological Society Japan 65(6):949-961.

Creation and Review Dates
DIF Creation Date: 2000-09-01
Last DIF Revision Date: 2015-04-17

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