Use case Comparison of snow-off dates (in Northern Europe)
An impact researcher would like to estimate the timing of the peak flying date of a spring-flying insect species (a moth) that has started to cause damages in forests in recent years in Northern Europe. This information is required for planning of appropriate pest protection measuresmeasures
In climate policy, measures are technologies, processes, and practices that contribute to mitigation, for example renewable energy technologies, waste minimization processes and public transport commuting practices.. He knows that the peak flying date of the moth species is related to the timing of snow melt.
The CLIPC portal provides two datasets for the snow-off date from remote sensing observations that could be used in his analysis. The snow-off date is there defined as the first day when no snow is observed after the snow season. To decide which dataset to use, he will examine the differences between the two datasets with the CLIPC tools.
The analysis comprises two tasks:
- Display the two CLIPC indicators in the comparison tool for visual comparison
- Compute their difference in the combination tool
- Pan-European snow-off date 2001-2015 (SYKE snow-off) derived from time series of daily Fractional Snow Cover (FSC) from the CryoLand Copernicus Service Snow and Land Ice (http://www.cryoland.eu/)
- Northern Hemisphere snow-off date 1979-2012 (Ophidia snow-off) calculated with the Ophidia processing system (http://ophidia.cmcc.it) from time series of daily GlobSnow Snow Water Equivalent (SWE) observations
CLIP-C tools featured
Compare tool, combine tool
Kristin Böttcher, SYKE
Alessandro D’Anca, CMCC
Analytical steps in detail
- Select the 'Precipitation and floods' theme on the left side of the compare tool.
- Load indicator ‘Snow melt-off date’.
- Select the following dataset: snowoff MATLAB-8-1 SYKE CryoLand FSC yr 20010101-20151231.
- Load indicator ‘Snow melt-off date’ in the right side of the combine tool.
- Select the following dataset: snowoff ophidia-0-10-1 CMCC GlobSnow- SWE L3A yr 19790701-20120630.
- Select for both datasets the same timestamp (year 2004) and zoom with the mouse to the Finnish area.
- For a quantitative analysis of the differences between the two datasets for a given year in Finland go to the combine tool.
- Select the same datasets as in steps 3 and 5 above. Zoom to the Finnish area and select year 2004 as timestamp.
- Select Normalization: None and Process: Subtract, you can change the output filename and press Execute.
- Compute the average difference in days for the Finnish area: press the ‘NUTS0’ button below the resulting map.
The resulting map shows the difference in days between the datasets. For the Finnish area (NUTSid: FI) the average difference is -4 days, indicating a later Ophidia snow-off compared to SYKE snow-off in 2004. As can be seen from the map, there are larger differences in coastal areas and in areas near lakes for which the Ophidia snow-off shows very early snow melt.