Geoportal

Details

.

General

Meta data ID	{45D3F820-DA63-47FE-8ABA-53047CDCEF37}
Last modified	2020-09-23T11:52:29

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 lehtimetsissä /Start of vegetation period in deciduous vegetation
Theme	Biology and Ecology
Description	The data set consists of yearly maps of the start of the vegetation active period in deciduous vegetation(Day of Year), which is defined as the day when deciduous trees unfold new leaves in spring. It is also often referred to as the green-up or greening day. The data set was derived from time series of the Normalized Difference Water Index (NDWI)calculated from Moderate Resolution Imaging Spetroradiometer (MODIS) satellite observation.
Language (dataset)	English
Keyword	vegetation phenology
Keyword	boreal zone
Keyword	green-up
Keyword	phenology

Data processing steps

sampling

Description

Moderate Resolution Imaging Spectrometer (MODIS) Terra Level 1B (1 km, 500 m and 250 m),version 5 (V005) satellite 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

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). The Normalized Difference Water Index (NDWI, Gao et al.1996) was calculated from near-infrared (MODIS band 2) and mid-infrared (MODIS band 6)reflectance. Cloud covered observations were removed using an automatic cloud masking algorithm by the Finnish Environment Institute.

Data processing steps

Data processing steps	processing
Description	Daily NDWI time series were averaged and smoothed for MODIS pixels with vegetation cover at a spatial grid resolution of 0.05 x 0.05 degrees. The day of the start of vegetation active period (VAP) was determined from NDWI time series applying the method by Delbart et al.(2005) and further described in Böttcher et al. (2016). 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. Delbart, N., Le Toan, T., Kergoat, L., & Fedotova, V. (2006). Remote sensing of spring phenology in boreal regions: A free of snow-effect method using NOAA-AVHRR and SPOT-VGT data (1982-2004). Remote Sensing of Environment, 101, 52-62. Böttcher, K., Markkanen, T., Thum, T., Aalto, T., Aurela, M., Reick, C., Kolari, P., Arslan, A., & Pulliainen, J. (2016). Evaluating biosphere model estimates of the start of the vegetation active season in boreal forests by satellite observations. Remote Sensing, 8, 580.
Additional information (URL)	http://dx.doi.org/10.1016/j.rse.2005.03.011; http://dx.doi.org/10.3390/rs8070580

Data processing steps

Data processing steps	quality control
Description	The product was compared to the visual observation of the bud break of birch from the phenological network of the Natural Resource Institute of Finland (Luke). Satellite observations were highly correlated with the ground observations of birch bud break. The accuracy was 7 days for the period 2001-2015 based on 84 site-years. The bias was negligible (0.4 days). The product is based on the NDWI which is sensitive to surface water and the water content of vegetation. Standing water e.g. in wetland areas can therefore have an effect on the detection of the vegetation greening. The satellite product has not been validated for wetland areas. A main source of uncertainty in the detection method is frequent cloud cover. The temporal resolution of the NDWI time series is one day, but missing observations due to cloud cover lead to gaps. For years 2001–2012 for the period April-July, depending on the location, in average 34%-73% of daily observations were missing. NDWI time series with gaps longer than two weeks during the spring vegetation development were discarded. Böttcher, K., Markkanen, T., Thum, T., Aalto, T., Aurela, M., Reick, C., Kolari, P., Arslan, A., & Pulliainen, J. (2016). Evaluating biosphere model estimates of the start of the vegetation active season in boreal forests by satellite observations. Remote Sensing, 8, 580. 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://monimet.fmi.fi/index.php?style=warm&page=Deliverables&p=2 (accessed 27.07.2017); http://dx.doi.org/10.3390/rs8070580

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 of deciduous vegetation.
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., Markkanen, T., Thum, T., Aalto, T., Aurela, M., Reick, C., Kolari, P., Arslan, A., & Pulliainen, J. (2016). Evaluating biosphere model estimates of the start of the vegetation active season in boreal forests by satellite observations. Remote Sensing, 8, 580, http://dx.doi.org/10.3390/rs8070580.

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=%7B45D3F820-DA63-47FE-8ABA-53047CDCEF37%7D