Geoportal

Details

.

General

Meta data ID	{31F4499F-5F0F-4500-967B-6C275082A3AD}
Last modified	2020-09-23T11:50:32

Dataset creators

Contact person

First name	Kristin
Last name	Böttcher
Email	kristin.bottcher [at] ymparisto.fi
Organisation	Finnish Environment Institute

Dataset creators

First name	Kristin
Last name	Böttcher
Organisation	Finnish Environment Institute

Dataset creators

First name	Mikko
Last name	Kervinen
Organisation	Finnish Environment Institute

Project

Project name	Monimet - "Climate change indicators and vulnerability of boreal zone applying innovative observations and modeling techniques 2013-2017; SnowCarbo - Monitoring and assessment of carbon balance related phenomena in Finland and northern Eurasia 2009-2012
Project funder	EU Life+ 2012 Environment Policy and Governance; EU LIFE+ 2007 Environment Policy and Governance
Project identifier	LIFE12ENV/FI/000409; LIFE07ENV/FIN/000133

Description

Basic information

Dataset title	Kasvukauden alku havumetsissä / Start of vegetation period in coniferous forest
Theme	Biology and Ecology
Description	The data set consists of yearly maps of the start of the vegetation active period (VAP) in coniferous forest (Day of Year), which is defined as the day when coniferous trees start to photosynthesize in spring. The data set was derived from Moderate Resolution Imaging Spetroradiometer (MODIS) satellite observation of Fractional Snow Cover. The day when snow cover decreases during spring melt was used as a proxy indicator for the beginning of the start of the vegetation active period.
Language (dataset)	English
Keyword	vegetation phenology
Keyword	coniferous forest
Keyword	boreal zone
Keyword	phenology

Data processing steps

sampling

Description

Moderate Resolution Imaging Spectrometer (MODIS) Terra Level 1B (1 km, 500 m),version 5 (V005) data were manually selected from the Level-1 and Atmosphere Archive and Distribution System (LAADS DAAC, https://ladsweb.modaps.eosdis.nasa.gov/) for the period 2001-2008. For years 2009 onwards data were obtained from the satellite receiving station of the Finnish Meteorological Institute (FMI)in Sodankylä, Finland and gap-filled with data from LAADS DAAC.

Data processing steps

Data processing steps	processing
Description	MODIS Level 1B data were calibrated to top-of-atmosphere reflectances and projected to a geographic latitude/longitude grid (datum WGS-84) using the software envimon by Technical Research Centre of Finland (VTT). Fractional Snow Cover (FSC)[0 1] was determined using the method by Metsämäki et al. (2012). FSC product specification are detailed in Böttcher et al. (2017). Cloud covered observations were removed using an automatic cloud masking algorithm by the Finnish Environment Institute. Metsämäki, S., Mattila, O.-P., Pulliainen, J., Niemi, K., Luojus, K., & Böttcher, K. (2012). An optical reflectance model-based method for fractional snow cover mapping applicable to continental scale. Remote Sensing of Environment, 123, 508-521. Böttcher, K., Kervinen, M., Keto, V., Luojus, K., Manninen, T., Metsämäki, S., & Rautiainen, K. (2017). Report on EO products and comparison with in situ data, Monimet project deliverable,http://monimet.fmi.fi/index.php?style=warm&page=Deliverables&p=2 (accessed 27.07.2017).
Additional information (URL)	http://dx.doi.org/10.1016/j.rse.2013.09.022; http://monimet.fmi.fi/index.php?style=warm&page=Deliverables&p=2

Data processing steps

Data processing steps	processing
Description	For the extraction of the start of vegetation active period (VAP), FSC was averaged at a spatial resolution of 0.05 x 0.05 degrees for MODIS pixels with dominant coverage of coniferous forest according to the CORINE Land Cover classification. A sigmoid function was fitted to the averaged FSC-time series and the start of the VAP was determined when FSC equals 0.99. The yearly maps were filtered with a median filter to remove spurious outliers and fill spatial gaps and the product was re-projected to EUREF-FIN (ETRS-TM35FIN). Lakes were masked. Böttcher, K., Aurela, M., Kervinen, M., Markkanen, T., Mattila, O.-P., Kolari, P., Metsämäki, S., Aalto, T., Arslan, A.N., & Pulliainen, J. (2014). MODIS time-series-derived indicators for the beginning of the growing season in boreal coniferous forest — A comparison with CO2 flux measurements and phenological observations in Finland. Remote Sensing of Environment, 140, 625-638.
Additional information (URL)	http://dx.doi.org/10.1016/j.rse.2012.04.010

Data processing steps

Data processing steps	quality control
Description	The product was compared to the start of VAP (the day when the Gross Primary Production (GPP) exceeded 15% of its summer maximum) from ground observations at three eddy covariance measurement sites in Finland. Satellite observations were highly correlated (R2=0.7) with the ground observations of VAP and the accuracy was 9 days for the period 2001-2016. The satellite product was in average 3 days late compared to the ground observations. The accuracy was higher (6 days, R2=0.84) and no bias was observed in pine forest compared to spruce forest that showed larger deviations to ground observations. The product is based on a proxy indicator for the start of VAP from optical satellite time series of FSC and it is therefore not a direct observation of the beginning of photosynthesis in trees. For years with very few snow, the direct effect of low temperature and high light are more relevant for the restriction of photosynthetic recovery in spring and therefore the method based on FSC may fail. A main source of uncertainty in the detection method is the frequent cloud cover. The temporal resolution of the FSC time series is one day, but missing observations due to cloud cover lead to gaps. Especially long temporal gaps (up to 1 month) were observed in northern Finland for year 2002, therefore the area of northern Finland was masked for this year. FSC time series with gaps longer than two weeks during the snow melt were discarded.
Additional information (URL)	http://dx.doi.org/10.1016/j.rse.2013.09.022

Material time period

Start date	2001-01-01
End date	2019-12-31

Area

West Bounding Longitude	19
East Bounding Longitude	32
South Bounding Latitude	58
North Bounding Latitude	71

Distribution

Contact person

First name	Kristin
Last name	Böttcher
Email	kristin.bottcher [at] ymparisto.fi
Organisation	Finnish Environment Institute

Resources

Resource content description	Web map application presenting yearly maps and averages of the start of vegetation active period for coniferous forests and for deciduous vegetation during 2001-2019 in Finland.
Web-address (URL)	http://syke.maps.arcgis.com/apps/webappviewer/index.html?id=a446e987496b4d8794b307e882da718a

Resources

Resource content description	Dataset for download consists of yearly files for the period 2001-2019(GEOTIFFS) for the start of the vegetation active period in coniferous forest in Finland. For 2002 only Southern Finland is available, because of missing observation.
Web-address (URL)	http://www.syke.fi/en-US/Open_information/Spatial_datasets#P

Resources

Resource content description	WMS interface
Web-address (URL)	http://paikkatieto.ymparisto.fi/arcgis/services/Projektit/VegetationPhenology/MapServer/WmsServer?

Resources

Resource content description	ESRI REST interface
Web-address (URL)	http://paikkatieto.ymparisto.fi/arcgis/rest/services/Projektit/VegetationPhenology/MapServer

Reference publications

Reference

Böttcher, K., Aurela, M., Kervinen, M., Markkanen, T., Mattila, O.-P., Kolari, P., Metsämäki, S., Aalto, T., Arslan, A.N., & Pulliainen, J. (2014). MODIS time-series-derived indicators for the beginning of the growing season in boreal coniferous forest — A comparison with CO2 flux measurements and phenological observations in Finland. Remote Sensing of Environment, 140, 625-638, http://dx.doi.org/10.1016/j.rse.2013.09.022.

The license for open SYKE's open datasets is Creative Commons Attribution 4.0 International.

The data described here can be freely used to all purposes, provided that the source of the data is mentioned.

The citation for the dataset as given above.

Further information on the license:
https://creativecommons.org/licenses/by/4.0/legalcode (English)
https://creativecommons.org/licenses/by/4.0/legalcode.fi (Finnish)

/geoportal/rest/document?f=html&id=%7B31F4499F-5F0F-4500-967B-6C275082A3AD%7D