Researchers, funded in part by CPO’s Climate Observation and Monitoring (COM) program, used climate indicators—simplified metrics that help us monitor and understand the rapidly changing Earth system—to study the trends and changes in Arctic tundra vegetation from 1982 to 2019. Their work, available as an early online release from Environmental Research Letters, identifies important climate drivers affecting tundra vegetation productivity and points to potential methods of predicting vegetation a season or two ahead of time.
This study focused on the pan-Arctic and continental scale relationships between key indicators and tundra vegetation. The authors looked at two different measures of vegetation, both based on Normalized Difference Vegetation Index (NDVI) provided by NOAA satellite data. NDVI is commonly used to monitor vegetation greenness and is used there to observe enhanced greening in the Arctic. As vegetation cover increases, so too does NDVI. Indicators included two measures of sea ice, two temperature data datasets, precipitation, seasonal representation, and two teleconnection indices.
Over almost a 40-year period, the authors found significant decreasing trends in spring sea-ice and increasing trends in summer open water and temperature indicators consistently linked to increasing maximum Arctic vegetation throughout Eurasia and North America. However, they found that the initially strong upward trends in NDVI are weakening and becoming more varied over space and time, especially in the Canadian High Arctic and southwest Alaska. Their findings suggest other processes, such as winter teleconnections, are changing how sea ice impacts tundra vegetation.
Regional climate anomalies seem to have competing effects on tundra vegetation and further study is needed to examine climate drivers at a regional scale. At any scale, a better understanding of the climate drivers of tundra vegetation is needed to anticipate future water and carbon budgets.
Read the study »