In this webinar, we will download and process in the SNAP software Sentinel-3 products to map the snow cover evolution in the Sierra Nevada, California from February to May 2021.
Snow cover is the land area blanketed in snow at any given time. Air temperature is one of the main factor that determines the amount of precipitation that falls on land as snow and its melting rate. In many regions of the world, warming trends are inducing fewer snow falls and earlier snow melt.
While snow cover in winter has remained fairly steady and has increased in the fall since 1972 in North America, the United States Environmental Protection Agency (EPA) has found that spring and summer snow cover have been plummeting. In fact, the U.S snow season has shortened by more than two weeks in roughly 50 years, the last day of snow now being 19 days earlier than it was in 1972.
In particular, climate change has made California dryer and hotter which means that more rain than snow is now falling. Since much of the rainfalls is evaporating, spring and summer snowpack constitutes the main water source to fill up reservoirs that fuel human activities such as agriculture or hydropower generation.
The decreasing snow cover and the shift in snow season are contributing factors to the megadrought California has been experiencing since the year 2000. These past 22 years have been the driest years in at least 1200 years based on tree ring records. This has now major impacts on human lives and food production in this American State. For the first time, the federal government is thinking about cutting water supplies by 25%.
Hence monitoring snow cover is of prime importance to determine the amount of available water in California. With their high spatial and temporal resolution and coverage, earth observation satellites constitute key tools to assess the snow cover on a regular basis. In particular, it is possible to compute the Normalized Difference Snow Index (NDSI) from the data collected by the Ocean and Land Colour Instrument (OLCI) on board Sentinel-3A and Sentinel-3B. The NDSI is a key indicator on the presence of snow
Attendees must be in possession of their own computer with an internet connexion.
Cost & Participation
Attendance to the training course is free of charge.
Audience & Selection
Everyone is welcome to attend ! Do not hesitate, register now !
Application opening – closing
Monday 6th of September 2021 – Monday 4th of October 2021
Previous RUS webinar on snow cover mapping
Feel free to check the previous RUS webinar on Sentinel-2 data processing to map snow cover!