lakes and Baltic Sea during

(1)

Water quality EO in Finnish lakes and Baltic Sea during

the Sentinel era

Sampsa Koponen and Jenni Attila (SYKE)

National Satellite Data Centre’s services in Finland -seminar 24.5.2016

Vesa Keto, Hanna Alasalmi, Mikko Kervinen, Kari Kallio, Saku

Anttila, Timo Pyhälahti, Eeva Bruun, Sofia Junttila

(2)

www.syke.fi/earthobservation 2

Earth observation services at SYKE

(3)

 Sentinels will bring huge improvement for the water quality monitoring in comparison to the gap-filling years without optical ESA satellite instruments.

 S3 OLCI & SLSTR:

 Continuing operational production (MERIS, MODIS) for the Baltic Sea

 Starting operational production for large lakes

 Chl-a, algae blooms, turbidity, CDOM, transparency, SST (with SLSTR)

 S2 MSI:

 High resolution: smaller lakes, coastal areas

 Algae blooms, turbidity and transparency + Reed belts and other macrophytes?

3

Future with Sentinels

(4)

2007

2011 2003

OLCI: Continuation of accurate assessment information on the state of the Baltic Sea

Products prepared with MERIS era for users:

national, HELCOM, EU EO data-flow to ICES

MS

EO

(5)

Sentinel-2 coastal potential

 S2 MSI will answer to many specific user needs related to our coastal waters.

 1 100 km coast line with the Baltic Sea (a lot of islands, bays and peninsulas).

 Derivation of water quality parameters in scattered coastal waters.

 Hot spot areas (dredging and factory

impact areas, harbor areas).

(6)

Cyanobacteria blooms

LS8 18.8.2015

Coastal waters and recreational areas

Swimming areas, popular sailing regions in the

archipelago

(7)

S2 MSI 16.5.2016 Hanko harbour and beach areas

Detection of algae blooms and coastal processes near

popular beaches and visiting harbors

(8)

S2 MSI 13.5.2016

River blooms are clearly visible

even in small bays

(9)

S2 MSI 8.5.2016

Impact areas of rivers can be determined

all the way to the open sea areas

(10)

Preparations

 Finland has a good position in the north, overpasses within 3 – 5

days.

 High-quality use of Sentinel series requires ground-truth data

collection.

 The routine sampling at intensive stations will be adjusted according to S2 MSI overpasses.

 Ensures the best possible set of match-ups for water quality

algorithm development and

validation.

(11)

Motivation and objectives for lakes

 Lakes in Finland:

 Over 56 000 lakes (area > 1 ha) covering ~10% of land area

 About 4700 lake waterbodies defined for WFD (area > about 0.5 km ² )

 Increasing monitoring demands (e.g. WDF)

 Roughly half of the WFD lake water bodies (total 4700) are not currently sampled

 Declining resources for monitoring

 Alternate methods are needed to improve:

 Spatial and temporal coverage

 Cost efficiency  Earth observation

 Modelling

 Automated measurements

 Citizen observations

 Combination of data sources

(12)

12 MERIS Chl-a, 300 m pixels

mg/m ³ ₀

2006-06-13 65

(13)

 Many Finnish lakes are small and have irregular shapes

 Reguire an instrument with high spatial resolution

 MERIS/OLCI can monitor less than 1000 Finnish lakes

 Many contain large amounts of CDOM

 Strong absorption in blue (unusual spectral shape not considered on most EO processors)

 Low signal level (low SNR)

13 EO challenges with lakes

400 450 500 550 600 650 700 750

0 1 2 3 4 5 6 x 10

^-3

wavelength nm

R rs N a d 1 /sr

Pääjärvi a(400) = 12, TSM=1.8, Chl-a=3.0, Garda a(400) = 0.14, TSM=1.2, Chl-a=2.7

Photo: Kari Kallio Photo: Kymenlaakson liitto

Sentinel 2 will be important

(14)

14

Kuvia muutama kalvo

S2 MSI RGB, Aug 20, 2015

New sensors require research (algorithm development) and validation

Small pixels, dark waters…

Is there enough signal/sensitivity?

(15)

Contact us:

 Lakes: sampsa.koponen@ymparisto.fi

 Baltic Sea: jenni.attila@ymparisto.fi

 Operational services:

eotuki.syke@ymparisto.fi

(16)

16 There is hope! Research still needed

400 500 600 700

0 0.005 0.01

IS CDOM = 2.58 IS Chl = 5.2 IS Turb = 2

400 500 600 700

0 0.005 0.01

IS CDOM = 5.29 IS Chl = 10 IS Turb = 2

400 500 600 700

0 0.005 0.01

IS CDOM = 11.4 IS Chl = 9.8 IS Turb = 3.4

400 500 600 700

0 0.005 0.01

IS CDOM = 18.4 IS Chl = 25 IS Turb = 4.5

R rs (sr

-1

)

400 500 600 700

0 0.005 0.01

IS CDOM = 1.85 IS Chl = 0.81 IS Turb = 1

400 500 600 700

0 0.005 0.01

400 500 600 700

0 0.005 0.01

400 500 600 700

0 0.005 0.01

Wavelength (nm)

400 500 600 700

0 0.005 0.01

IS CDOM = 1.14 IS Chl = 2.7 IS Turb = 1.7 HL

MIP

Landsat-8 & MIP atmospherically

corrected reflectances vs. HydroLight

simulations

(17)

lakes and Baltic Sea during

Water quality EO in Finnish lakes and Baltic Sea during

the Sentinel era

Sampsa Koponen and Jenni Attila (SYKE)

National Satellite Data Centre’s services in Finland -seminar 24.5.2016

Vesa Keto, Hanna Alasalmi, Mikko Kervinen, Kari Kallio, Saku

Anttila, Timo Pyhälahti, Eeva Bruun, Sofia Junttila

www.syke.fi/earthobservation 2

Earth observation services at SYKE

 Sentinels will bring huge improvement for the water quality monitoring in comparison to the gap-filling years without optical ESA satellite instruments.

 S3 OLCI & SLSTR:

 Continuing operational production (MERIS, MODIS) for the Baltic Sea

 Starting operational production for large lakes

 Chl-a, algae blooms, turbidity, CDOM, transparency, SST (with SLSTR)

 S2 MSI:

 High resolution: smaller lakes, coastal areas

 Algae blooms, turbidity and transparency + Reed belts and other macrophytes?

3

Future with Sentinels

2007

2011 2003

OLCI: Continuation of accurate assessment information on the state of the Baltic Sea

Products prepared with MERIS era for users:

national, HELCOM, EU EO data-flow to ICES

MS

EO

Sentinel-2 coastal potential

 S2 MSI will answer to many specific user needs related to our coastal waters.

 1 100 km coast line with the Baltic Sea (a lot of islands, bays and peninsulas).

 Derivation of water quality parameters in scattered coastal waters.

 Hot spot areas (dredging and factory

impact areas, harbor areas).

Cyanobacteria blooms

LS8 18.8.2015

Coastal waters and recreational areas

Swimming areas, popular sailing regions in the

archipelago

S2 MSI 16.5.2016 Hanko harbour and beach areas

Detection of algae blooms and coastal processes near

popular beaches and visiting harbors

S2 MSI 13.5.2016

River blooms are clearly visible

even in small bays

S2 MSI 8.5.2016

Impact areas of rivers can be determined

all the way to the open sea areas

Preparations

 Finland has a good position in the north, overpasses within 3 – 5

days.

 High-quality use of Sentinel series requires ground-truth data

collection.

 The routine sampling at intensive stations will be adjusted according to S2 MSI overpasses.

 Ensures the best possible set of match-ups for water quality

algorithm development and

validation.

Motivation and objectives for lakes

 Lakes in Finland:

 Over 56 000 lakes (area > 1 ha) covering ~10% of land area

 About 4700 lake waterbodies defined for WFD (area > about 0.5 km 2 )

 Increasing monitoring demands (e.g. WDF)

 Roughly half of the WFD lake water bodies (total 4700) are not currently sampled

 Declining resources for monitoring

 Alternate methods are needed to improve:

 Spatial and temporal coverage

 Cost efficiency  Earth observation

 Modelling

 Automated measurements

 Citizen observations

 Combination of data sources

12

MERIS Chl-a, 300 m pixels

mg/m 3 0

2006-06-13 65

 Many Finnish lakes are small and have irregular shapes

 Reguire an instrument with high spatial resolution

 MERIS/OLCI can monitor less than 1000 Finnish lakes

 Many contain large amounts of CDOM

 Strong absorption in blue (unusual spectral shape not considered on most EO processors)

 Low signal level (low SNR)

13

 About 4700 lake waterbodies defined for WFD (area > about 0.5 km ² )

mg/m ³ ₀