High Resolution Satellite SST over the

Australasian region from IMOS

Helen Beggs1, Pallavi Govekar

1, Christopher Griffin

1, Leon Majewski

1, Lixin

Qi1

and Edward King2

1Bureau of Meteorology, Melbourne, Australia

2CSIRO Oceans and Atmosphere, Hobart, Australia

10th

AOMSUC, Melbourne, Australia, 4th

– 6th

December 2019

• Several satellites provide Sea Surface

Temperature (SST) data

• Spatial coverage may be improved by

merging data from satellite sensors that

have different equatorial crossing times

Introduction

Constellation of polar-orbiting satellites

(image credit: NASA)

NOAA-20

https://www.star.nesdis.noaa.gov/smcd/emb/vci/VH/vh_avhrr_ect.php

https://www.star.nesdis.noaa.gov/smcd/emb/vci/VH/vh_avhrr_ect.php

At BoM, we currently produce a range of

SST products using infrared data from

❑ Polar orbiters:

• NOAA-18 AVHRR (ECT 9 am/pm)

• MetOp-A (ECT 9 am/pm)

• MetOp-B (ECT 9:30 am/pm)

• Suomi-NPP VIIRS (ECT 1:20 pm/am)

• NOAA-20 VIIRS (ECT 1:20pm/am)

❑ Geostationary satellite:

• Himawari-8 AHI

… and microwave data from

❑ Polar orbiter:

• GCOM-W AMSR-2 (ECT 1:30 pm/am)

Which satellites does

BoM use for SST?

Constellation of polar-orbiting satellites

(image credit: NASA)

NOAA-20

IMOS GHRSST

products

• L2P (geolocated, native resolution of sensor)

• L3U (swath, gridded)

• L3C (multiple swath, gridded)

• L3S (multiple sensor, gridded)

• L4 (multiple sensor, statistically interpolated, gridded)

As a contribution to IMOS, we

provide five types of GHRSST format

Level 2, level 3 and level 4 SST

products:

Multi-Sensor, Interpolated, 1-day

L4

Australia’s HRPT AVHRR SST

• Passive infra-red sensors on polar-

orbiting satellites provide the highest

resolution SST observations from

space (~1 km at nadir) but cannot

sense SST under cloud.

• Pre-2000 (MODIS) the only wide

swath, 1 km resolution, satellite SSTs

available were direct-broadcast

AVHRR SST from NOAA polar-

orbiters.

• Australia has direct broadcast

("HRPT") 1.1 km AVHRR L0 data

back to 1992 from reception stations

in Australia and Antarctica.

• L0 data accurately geolocated and

“stitched” into swaths

IMOS HRPT AVHRR L3S Compositeshttp://imos.org.au/sstproducts.html

Resolution: 0.02º x 0.02º

1, 3, 6, 14 days or 1 month

Available: 1992 to present

Inputs: 1.1 km AVHRR radiances from NOAA-

11 to NOAA-19 (currently NOAA-18 only)

Data Access: http://portal.aodn.org.au

Uses:

• BoM ReefTemp NextGen Coral Bleaching

Nowcasting (2002 – 20 Nov 2018)

1-day night AVHRR L3S SST

29 Jul 2018

21 Feb 2016

1-day Multi-Sensor L3S SST anomaly

http://imos.org.au/sstproducts.htmlhttp://portal.aodn.org.au/

IMOS HRPT AVHRR L3S Compositeshttp://imos.org.au/sstproducts.html

Resolution: 0.02º x 0.02º

1, 3, 6, 14 days or 1 month

Available: 1992 to present

Inputs: 1.1 km AVHRR radiances from NOAA-

11 to NOAA-19 (currently NOAA-18 only)

Data Access: http://portal.aodn.org.au

Uses:

• BoM ReefTemp NextGen Coral Bleaching

Nowcasting (2002 – 20 Nov 2018)

• SSTAARS climatology (1992 – 2016)

1-day night AVHRR L3S SST

29 Jul 2018

SSTAARS Daily Climatology 15 Nov

http://imos.org.au/sstproducts.htmlhttp://portal.aodn.org.au/

IMOS HRPT AVHRR L3S Compositeshttp://imos.org.au/sstproducts.html

Resolution: 0.02º x 0.02º

1, 3, 6, 14 days or 1 month

Available: 1992 to present

Inputs: 1.1 km AVHRR radiances from NOAA-

11 to NOAA-19 (currently NOAA-18 only)

Data Access: http://portal.aodn.org.au

Uses:

• BoM ReefTemp NextGen Coral Bleaching

Nowcasting (2002 – 20 Nov 2018)

• SSTAARS climatology (1992 – 2016)

• IMOS OceanCurrent maps (1992 – 2017)

http://oceancurrent.imos.org.au

1-day night AVHRR L3S SST

29 Jul 2018

SSTAARS Daily Climatology 15 Nov

13 Nov 2015

6-day night AVHRR L3S SST

13 Nov 2015

6-day night AVHRR L3S SST

http://imos.org.au/sstproducts.htmlhttp://portal.aodn.org.au/http://oceancurrent.imos.org.au/

IMOS HRPT AVHRR L3S Compositeshttp://imos.org.au/sstproducts.html

Resolution: 0.02º x 0.02º

1, 3, 6, 14 days or 1 month

Available: 1992 to present

Inputs: 1.1 km AVHRR radiances from NOAA-

11 to NOAA-19 (currently NOAA-18 only)

Data Access: http://portal.aodn.org.au

Uses:

• BoM ReefTemp NextGen Coral Bleaching

Nowcasting (2002 – 20 Nov 2018)

• SSTAARS climatology (1992 – 2016)

• IMOS OceanCurrent maps (1992 – 2017)

http://oceancurrent.imos.org.au

1-day night AVHRR L3S SST

29 Jul 2018

SSTAARS Daily Climatology 15 Nov

13 Nov 2015

6-day night AVHRR L3S SST Anomaly

http://imos.org.au/sstproducts.htmlhttp://portal.aodn.org.au/http://oceancurrent.imos.org.au/

Resolution: 0.02º x 0.02º

1, 3, 6 days or 1 month

Available: 2012 to present

Inputs: Real-time: 1.1 km NOAA-18 AVHRR, 1.1 km

MetOp-B AVHRR, 0.75 km Suomi-NPP VIIRS, 0.75 km

NOAA-20 VIIRS

Reprocessed: Additional data from NOAA-15/19 AVHRR,

MetOp-A AVHRR

Data Access:

Real-time: http://portal.aodn.org.au

Reprocessed: email ghrsst@bom.gov.au

Uses:

• BoM ReefTemp NextGen (21 Nov 2018 – now)

1-day night Multi-Sensor L3S SST

29 Jul 2018

IMOS Multi-Sensor L3S Compositeshttp://imos.org.au/sstproducts.html

19 Nov 2019

1-day Multi-Sensor SST anomaly

http://portal.aodn.org.au/mailto:ghrsst@bom.gov.auhttp://imos.org.au/sstproducts.html

Resolution: 0.02º x 0.02º

1, 3, 6 days or 1 month

Available: 2012 to present

Inputs: Real-time: 1.1 km NOAA-18 AVHRR, 1.1 km

MetOp-B AVHRR, 0.75 km Suomi-NPP VIIRS, 0.75 km

NOAA-20 VIIRS

Reprocessed: Additional data from NOAA-15/19 AVHRR,

MetOp-A AVHRR

Data Access:

Real-time: http://portal.aodn.org.au

Reprocessed: email ghrsst@bom.gov.au

Uses:

• BoM ReefTemp NextGen (21 Nov 2018 – now)

• IMOS OceanCurrent (2018 – now)

1-day night Multi-Sensor L3S SST

29 Jul 2018

IMOS Multi-Sensor L3S Compositeshttp://imos.org.au/sstproducts.html

6-day night Multi-Sensor L3S SST

13 Nov 2019

http://portal.aodn.org.au/mailto:ghrsst@bom.gov.auhttp://imos.org.au/sstproducts.html

AVHRR-only L3S (N18, N19) Multi-Sensor L3S (N18, N19, MB, NPP, N20)

L3S-01day, night only, monthly statistics, 1 Jan 2018 - 8 May 2019

Validation of L3S vs

Buoy SST

Daily Regional and Global Multi-Sensor L4 analyses

(RAMSSA and GAMSSA)http://www.bom.gov.au/marine/sst.shtml

Resolution: Daily 0.083º regional, 0.25º global

Available: RAMSSA: 2006 - present; GAMSSA: 2008 - present

Method: Optimal interpolation (Beggs et al., 2011, AMOJ, 61)

Inputs:

– NAVOCEANO GAC AVHRR (METOP-A/B) L2P SST

– JAXA AMSR-2 (GCOM-W) L2P SST

– NOAA ACSPO VIIRS L3U (NOAA-20, NPP) SST (RAMSSA only)

– Buoy and ship in situ SST (GTS)

– NCEP 9 km Sea Ice Analyses

Access: http://portal.aodn.org.au , https://podaac.jpl.nasa.gov

Uses: BoM NWP and seasonal prediction models

• Validating ocean models

RAMSSA L4 SST (20 Nov 2019)

GAMSSA L4 SST (20 Nov 2019)

http://www.bom.gov.au/marine/sst.shtmlhttp://www.bom.gov.au/jshess/papers.php?year=2011#http://www.bom.gov.au/jshess/papers.php?year=2011%20http://portal.aodn.org.au/https://podaac.jpl.nasa.gov/

Daily Regional and Global Multi-Sensor L4 analyses

(RAMSSA and GAMSSA)http://www.bom.gov.au/marine/sst.shtml

Resolution: Daily 0.083º regional, 0.25º global

Available: RAMSSA: 2006 - present; GAMSSA: 2008 - present

Method: Optimal interpolation (Beggs et al., 2011, AMOJ, 61)

Inputs:

– NAVOCEANO GAC AVHRR (METOP-A/B) L2P SST

– JAXA AMSR-2 (GCOM-W) L2P SST

– NOAA ACSPO VIIRS L3U (NOAA-20, NPP) SST (RAMSSA only)

– Buoy and ship in situ SST (GTS)

– NCEP 9 km Sea Ice Analyses

Access: http://portal.aodn.org.au , https://podaac.jpl.nasa.gov

Uses: BoM NWP and seasonal prediction models

• Validating ocean models

• GHRSST Multi-Product Ensemble

• Monitoring Marine Heatwaves

RAMSSA L4 SST (20 Nov 2019)

GAMSSA – GMPE SST (13 Nov 2019)

RAMSSA L4 SST Anomaly (20 Nov 2019)

http://www.bom.gov.au/marine/sst.shtmlhttp://www.bom.gov.au/jshess/papers.php?year=2011#http://www.bom.gov.au/jshess/papers.php?year=2011%20http://portal.aodn.org.au/https://podaac.jpl.nasa.gov/

Resolution: 10 min, 2 km2

at nadir, full disk

Available: 8 Mar 2016 to real-time over full disk on H-8 GEO

projection

Inputs: ~2 km 10 min radiances from AHI radiometer on JMA's

geostationary Himawari-8 satellite

Method: JMA H-8 AHI radiances trained to one day of ACSPO

VIIRS L2P SST

Access: NCI (contact ghrsst@bom.gov.au)

Uses: Ingesting into CSIRO's IMOS

OceanCurrent 4-hourly, 2 km L3 SST maps for

Fisheries applications

H-8 L2P SST

BoM Himawari-8 L2P Products

29 Jul 2018

CSIRO 4-hour L3 SST

13 Nov 2019

mailto:ghrsst@bom.gov.au

IMOS Himawari-8 L3C Composites

29 Jul 2018 1400 UTC

L2P

L3C

Less cloud cover

Higher definition

Resolution: Hourly, 4-hourly and Daily night-time, 0.02º x

0.02º

Domain: IMOS Australian grid (70ºE to 190ºE, 70ºS to

20ºN)

Available: 1 Oct 2017 to present

Aim to reprocess back to July 2015

Inputs: BoM Himawari-8 L2P SST

Access: Contact ghrsst@bom.gov.au

Uses:

• Coastal model verification

H-8 1-hour L3C SST

H-8 1-day night L3C SST

mailto:ghrsst@bom.gov.au

IMOS Himawari-8 L3C Composites

29 Jul 2018 1400 UTC

L2P

L3C

Less cloud cover

Higher definition

Resolution: Hourly, 4-hourly and Daily night-time, 0.02º x

0.02º

Domain: IMOS Australian grid (70ºE to 190ºE, 70ºS to

20ºN)

Available: 1 Oct 2017 to present

Aim to reprocess back to July 2015

Inputs: BoM Himawari-8 L2P SST

Access: Contact ghrsst@bom.gov.au

Uses:

• Coastal model verification

• Studying coastal upwelling

H-8 1-hour L3C SST

H-8 1-day night L3C SST 6 Dec 2017

mailto:ghrsst@bom.gov.au

IMOS Himawari-8 L3C GHRSST Products

29 Jul 2018 1400 UTC

L2P

L3C

Less cloud cover

Higher definition

Resolution: Hourly, 4-hourly and Daily night-time, 0.02º x

0.02º

Domain: IMOS Australian grid (70ºE to 190ºE, 70ºS to

20ºN)

Available: 1 Oct 2017 to present

Aim to reprocess back to July 2015

Inputs: BoM Himawari-8 L2P SST

Access: Contact ghrsst@bom.gov.au

Uses:

• Coastal model verification

• Studying coastal upwelling

• Studying diurnal warming

H-8 1-hour L3C SST

H-8 1-day night L3C SSTskin (QL≥4)

H-8 1-hour L3C 1-9 Sep 2018

mailto:ghrsst@bom.gov.au

Summary

• Different SST products suit different applications…

• IMOS produces several high-resolution, regional satellite SST products

useful for monitoring Marine Heatwaves, coastal upwelling, diurnal

warming and climate trends over Australasian waters

• Available via http://portal.aodn.org.au

• Book chapter on selecting SST products for Australasian applications

available:

Search for: "Researchgate Beggs 2019 Temperature"

• Contact: helen.beggs@bom.gov.au

http://portal.aodn.org.au/mailto:helen.beggs@bom.gov.au

Supplementary Slides

Annual mean SST and gradient from SSTAARSResolution: 0.02º x 0.02º

Depth: Drifting buoy depths (approx. 0.2 m)

Available: 1992 to 2016 over Australian domain

Inputs: IMOS daily night-time AVHRR L3S SST

(debiased, QL ≥ 4). v2: 1992-2014, v1:2015-2016

Method: Robust fitting algorithm applied to cloud-

free de-biased pixels, using 4 seasonal harmonics.

For each 0.02°pixel: daily climatological SST, mean, decadal trend, monthly seasonal harmonics

and percentiles

Uses: Reference for IMOS OceanCurrent SST

anomalies and percentiles.

Access: http://portal.aodn.org.au (search for

"SSTAARS")

Info: Wijffels et al (2018) J. Marine Systems

https://doi.org/10.1016/j.jmarsys.2018.07.005

CSIRO SSTAARS 2 km SST Atlas Developers: S. Wijffels, M. Cahill, E. King, H. Beggs, C. Griffin

http://portal.aodn.org.au/https://doi.org/10.1016/j.jmarsys.2018.07.005

Useful sites for information on IMOS

GHRSST products

GHRSST products: https://www.ghrsst.org/quick-start/

IMOS HRPT AVHRR GHRSST Products: http://imos.org.au/facilities/srs/sstproducts/sstdata0/

IMOS Multi-sensor GHRSST Products:

http://imos.org.au/fileadmin/user_upload/shared/SRS/SST/Beggs_2019_IMOS_Multi-

sensor_L3S_article_21Feb2018.pdf

IMOS GHRSST SST Validation: http://imos.org.au/facilities/srs/sstproducts/sstdata0/sstdata-

validation/

Access to IMOS GHRSST Products: http://portal.aodn.org.au and

http://thredds.aodn.org.au/thredds/catalog/IMOS/SRS/SST/ghrsst/catalog.html

IMOS OceanCurrent maps of IMOS L3U and L3S products: http://oceancurrent.imos.org.au

GHRSST L4 (inc GAMSSA) Validation/Inter-comparison:

http://www.star.nesdis.noaa.gov/sod/sst/squam

Regional SST Maps (inc RAMSSA L4, IMOS L3S and other GHRSST L2P, L3U, L4 products):

https://www.star.nesdis.noaa.gov/sod/sst/arms/

https://www.ghrsst.org/quick-start/http://imos.org.au/facilities/srs/sstproducts/sstdata0/http://imos.org.au/fileadmin/user_upload/shared/SRS/SST/Beggs_2019_IMOS_Multi-sensor_L3S_article_21Feb2018.pdfhttp://imos.org.au/facilities/srs/sstproducts/sstdata0/sstdata-validation/http://portal.aodn.org.au/http://thredds.aodn.org.au/thredds/catalog/IMOS/SRS/SST/ghrsst/catalog.htmlhttp://oceancurrent.imos.org.au/http://www.star.nesdis.noaa.gov/sod/sst/squamhttps://www.star.nesdis.noaa.gov/sod/sst/arms/