*NRT - Near-Real Time data
*RAN - Reanalysis of L3S-LEO PM (Feb'2012-present) and L3S-LEO AM (Dec'2006-present). Note that reanalysis data is produced on a 8-week delay.
Please acknowledge "NOAA CoastWatch/OceanWatch" when you use data from our site and cite the particular dataset DOI as appropriate.
The NOAA Advanced Clear-Sky Processor for Ocean (ACSPO) L3S-LEO is a family of multisensor super-collated (L3S) gridded 0.02º resolution SST products from low earth orbit (LEO) satellites. The L3S-LEO family is organized into three lines: PM, AM and Daily. The AM (mid-morning orbit) and PM (afternoon orbit) lines contain SST data from satellites with 9:30am/pm and 1:30am/pm equator crossing times, respectively. Both AM and PM lines are split into day-time (solar zenith angle < 90º) and night-time (solar zenith angle >= 90º) files, resulting in 4 files per day in total, which approximately cover the 24 hours diurnal cycle in 4 points. The Daily line combines PM and AM (day and night) SSTs into a single daily L3S SST that is normalized to 1:30am viewing conditions using a statistical model informed by surface wind speed and shortwave radiation.
The AM product is produced from three (currently two) AVHRR FRACs (flown aboard METOP-A, B and C) and the PM product is produced from two VIIRSs (flown aboard NPP and N20). Adding MODIS-Terra to the AM line, and MODIS-Aqua to the PM line is being explored.
All L3S-LEO products contain information about thermal fronts, which is included in ACSPO files in two new variables ‘sst_front_position’ and ‘sst_gradient_magnitude’. The first variable is a binary indicator of SST front position. It is set to ‘1’ where a front is present, and to ‘0’ elsewhere. The second variable is the SST gradient magnitude (in units of K/km).
L3S-LEO data are provided in GHRSST Data Specification v2 (GDS2) NetCDF format, as L3S (gridded, super-collated, 0.02º). We plan to create an L3S-GEO line, and eventually consolidate the L3S-LEO and L3S-GEO into one sensor-agnostic L3S SST product.
Note that the ACSPO L3S-LEO-Daily product provided here is experimental while the PM and AM products are mature and validated. Both the L3S-LEO-Daily product, and its documentation, are currently in development and subject to change. Please contact the CoastWatch helpdesk with any questions.
Afternoon (PM): NPP, N20 / VIIRS
Measurement Oceans > Sea Surface Temperature > subskin SST
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The data does not have a specific expiration date after which it is removed, but keep in mind that this is not a long term archive.
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Twice Daily (L3S-LEO-PM/AM), Daily (L3S-LEO-Daily)
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Creator: NOAA STAR
NOAA, NPP, N20, S-NPP, NOAA-20, METOP-A, METOP-B, METOP-C, JPSS, VIIRS, AVHRR, FRAC, ACSPO, sea surface temperature, SST, L3S, multisensor
- Jonasson, O.; Gladkova, I.; Ignatov, A. Towards global daily gridded super-collated SST product from low earth orbiting satellites (L3S-LEO-Daily) at NOAA. Proc. SPIE 2022, 12118, 1211805, doi:10.1117/12.2620103, [pdf paper (link)], [mp4 presentation (link)], [ppt presentation (link)].
- Jonasson, O.; Gladkova, I.; Ignatov, A.; Kihai, Y. Algorithmic Improvements and Consistency Checks of the NOAA Global Gridded Super-Collated SSTs from Low Earth Orbiting Satellites (L3S-LEO). Proc. SPIE 2021, 11752, 1175202, doi:10.1117/12.2585819, [pdf paper (link)], [mp4 presentation (link)], [ppt presentation (link)].
- Jonasson, O.; Gladkova, I.; Ignatov, A.; Kihai, Y. Progress with Development of Global Gridded Super-Collated SST Products from Low Earth Orbiting Satellites (L3S-LEO) at NOAA. Proc. SPIE 2020, 11420, 1142002. doi:10.1117/12.2551819. [pdf paper (link)], [mp4 presentation (link)], [ppt presentation (link)].
- Gladkova, I.; Ignatov, A.; Pennybacker, M.; Kihai, Y. Towards High-Resolution Multi-Sensor Gridded ACSPO SST Product: Reducing Residual Cloud Contamination. Proc. SPIE 2019, 11014, 110140L. doi:10.1117/12.2518462, [pdf paper (link)], [ppt presentation (link)].
- Gladkova, I., A. Ignatov, M. Pennybacker, Y. Kihai, 2019: Towards High-Resolution Multi-Sensor Gridded ACSPO L3S SST Product. GHRSTT XX: Science Team Meeting, June 2019, Frascati, Italy [ppt presentation (link)].
- SQUAM: Dash, P., A. Ignatov, Y. Kihai, J. Sapper, 2010: The SST Quality Monitor (SQUAM). JTech, 27, 1899-1917, doi:10.1175/2010JTECHO756.1.
- iQuam: Xu, F., A. Ignatov, 2014: In situ SST Quality Monitor (iQuam). JTech, 31, 164-180, doi:10.1175/JTECH-D-13-00121.1.
- ARMS: Ding, Y., A. Ignatov, K. He, I. Gladkova, 2018: ACSPO Regional Monitor for SST (ARMS). GHRSTT XIX: Science Team Meeting, June 2018, Darmstadt, Germany [ppt presentation 21.5Mb (link)].
- MICROS: Liang, X., A. Ignatov, 2011: Monitoring of IR Clear-sky Radiances over Oceans for SST (MICROS). JTech, 28, 1228-1242, doi:10.1175/JTECH-D-10-05023.1.