AVHRR Pathfinder

Products / Announcements / Documentation / Known Problems & Issues / FAQs / Related Publications / Acronyms

Mission
Multichannel sea surface temperature (SST) products have been constructed operationally from the five-channel Advanced Very High Resolution Radiometer (AVHRR) by NOAA's National Environmental Satellite, Data, and Information Service (NESDIS) since late 1981. The most recent Pathfinder AVHHR data set is the AVHRR Pathfinder SST version 5 (listed first below). Version 5.0 of the data set is a collaborative effort between NOAA's National Oceanographic Data Center (NODC), the University of Miami's Rosenstiel School of Marine and Atmospheric Sciences (RSMAS), and NASA's Physical Oceanography Distributed Active Archive Center (PO.DAAC). The primary differences between version 5.0 of the algorithm and version 4.1 are an improved land mask, the addition of an ice mask, and the higher spatial 4km resolution. Additionally the parameters in version 5.0 are contained in separate files that are in the HDF-SDS (scientific data set) format, unlike version 4.1 that was in HDF-RASTER. The other data sets listed include climatologies, buoy comparisons and circulation/current products.

In 2009 NODC released Pathfinder version 5.1 from October of 1981 through January of 1985. This previously un-released data was from the NOAA -7 satellite. Version 5.1 uses higher resolution reference data than 5.0 for the purpose of achieving better resolution in the coastal and high gradient SST regions.

Product 216 data includes daily, 5 day, 8 day, monthly and yearly averages. As of July 2009 it includes data from October 28, 1981 through May 2, 2009. Pathfinder AVHRR data comes from NOAA-7 (10/28/1981 - 1/30/1985), NOAA -9 (1/4/1985 – 11/07/88 & 9/14/94 – 01/21/95), NOAA – 11 (11/8/88 – 9/13/94), NOAA-14 (1/22/95 – 10/11/2000), NOAA-16 (10/12/00 – 12/31/02), NOAA-17 (01/01/03 – 06/04/05), and NOAA-18 (06/05/05 – 12/31/06) satellites.

All the orbits are sun synchronous and have an ascending node of between 13:30 and 14:30 local time with the exception of NOAA-17 that has a daytime descending node of approximately 10:00.

AVHRR Pathfinder 2006 Annual Mean SST

AVHRR Pathfinder Table

Products

AVHRR Pathfinder SST v5	FTP / OPeNDAP POET / HEFT	MATLAB C IDL	1985 - 2008	Daily, 5-day, 7-day, 8-day, Monthly, Annual	4km
Documentation: User Manual / Abstract / References	Comments:	Latest version of longest running satellite SST time series spanning 6 NOAA satellites going back to 1985.

AVHRR Pathfinder and Erosion Global 9km SST Climatology (Casey, Cornillon)	FTP / HEFT	s/w	1985 - 1997 1985 - 1999	5-day, Monthly	9km
Documentation: User Manual / Abstract / References	Comments:	9km product using methodologies described in Casey & Cornillon (1999).

AVHRR Pathfinder Global 9 km SST Climatology (JPL)	FTP / HEFT	s/w	6 weeks	5-day	9km
Documentation: User Manual / Abstract / References	Comments:	9km product using methodologies described in Armstrong & Vazquez (2001).

AVHRR Oceans Pathfinder SST and Buoy Match-Up Data (Podesta et al.)	FTP / HEFT NEREIDS	s/w	1985 - 1993	Irregular	Irregular
Documentation: User Manual / Abstract / References	Comments:	Includes in-situ match ups for investigators seeking validation.

Ocean Circulation & Currents Product: Global 0.5 and 1.0 deg Grids (JPL, WOCE v3)	FTP / HEFT NEREIDS	s/w	1990 - 2001	5-day, 10-day	0.5°, 1°
Documentation: User Manual / Abstract / References	Comments:	Combines SST with SSH on the same grid patterns.

Announcements
From NOAA:
26 August 2008. Formal data 2005-2006 will soon be added to the web site, along with interim data for 2007.

25 August 2008. Data resides in sub directories ascending and descending. They will soon be classified as daytime or nighttime instead. This will mean that daytime descending NOAA-17 data (01/01/03 – 06/04/05) will be categorized with other daytime ascending data rather than nighttime descending data. Similarly nighttime ascending data will be grouped with nighttime descending data from other satellites.

Documentation
Pathfinder Version 5 NOAA Data Set Guide

Known Problems and Issues
High latitude temperatures colder than -2 degrees C should be masked out.

Frequently Asked Questions
AVHRR Pathfinder FAQ's

Related Publications
Brown J. W., Brown O. B. and Evans R. H., 1993. Calibration of AVHRR Infrared channels: a new approach to non-linear correction, Journal of Geophysical Research, 98 (NC10), 18257-18268.

Kidwell, K., 1991. NOAA Polar Orbiter User's Guide. NCDC/NESDIS, National Climatic Data Center, Washington, D.C..

McClain E. P., Pichel W. G. and Walton C. C., 1985. Comparative performance of AVHRR based multichannel sea surface termperatures, Journal of Geophysical Research 90, 11587-11601.

McMillin, L. M. and Crosby D. S., 1984. Theory and validation of the multiple window sea surface temperature technique. Journal of Geophysical Research, 89(C3), 3655- 3661.

Stowe, L. L., McClain E. P., Carey R., Pellegrino P., Gutman G. G., Davis P., Long C., and Hart S., 1991. Global distribution of cloud cover derived from NOAA/AVHRR operational satellite data, Adv. Space Research, 3, 51-54.

Casey, K.S. and P. Cornillon, A comparison of satellite and in situ based sea surface temperature climatologies, J. Climate, vol. 12, no. 6, pp. 1848-1863, 1999.

Armstrong, E.M., and J. Vazquez, A new global satellite-based sea surface temperature climatology, Geophys. Res. Letters, 28, no. 22, pp. 4199-4202, 2001