Arctic climate change & seasonal timing

Context

Arctic birds depend on a short snow-free season to breed and raise chicks. Small shifts in timing can change whether that season is favourable or difficult.

The project focused on how temperature, snow cover, and rainfall affect this breeding window, and how those conditions are changing across the Arctic.

Approach

I combined ERA5 reanalysis, CMIP6 climate-model output, and long EC-Earth simulations to study present and future Arctic conditions.

The analysis tracked snowmelt, snow return, warming, and rainfall extremes across regions that are important for Arctic-breeding birds.

Key components

• Snow cover: when snow clears, breeding areas become available.
• Snow return: early return can shorten the useful season.
• Temperature: warmer conditions change the pace of seasonal development.
• Rainfall extremes: heavy rain can create difficult breeding conditions even in a longer season.

Results

The snow-free season tends to become longer because snow melts earlier and returns later.

At the same time, rainfall extremes become more frequent and stronger. This means that a longer season does not automatically mean a better season.

Why it matters

Birds do not respond only to average warming. They also have to cope with unreliable conditions and more extreme weather during breeding.

This project helps identify where climate change may open opportunities and where it may create new risks for Arctic-breeding species.

Tools

Python, xarray, climate model data (CMIP6), ERA5 reanalysis, satellite data (NDVI).