Mountain warming through the seasons
mountain melt EDW July 2018 smallA new paper published in the International Journal of Climatology examines seasonal patterns of warming amplification at high elevations worldwide – and finds highly significant temperature trends.

Thanks to research efforts, there is a growing body of evidence that suggests warming rates are amplified by elevation, with high mountain areas experiencing more rapid changes in temperature than lower elevation environments. However, despite the interest in this phenomenon, the global assessment of seasonal signals of EDW has received limited attention. As a result, there is still restricted seasonal evidence of EDW. A new paper published in the International Journal of Climatology attempts to go some way towards bridging this gap.

Using monthly mean temperatures from 2,104 observation stations across the world for the period 1961-2010, researchers explored the seasonal signals of temperature changes at high elevations. First, the temperature trends between the high-elevation stations and their low-elevation counterparts were compared using a method similar to the paired region comparison method. EDW at the high-elevation stations was then examined using the elevation band method, and the relationship between temperature trends and altitude and latitude for the high-elevation stations was explored using a stepwise regression analysis.

Significant temperature trends
The researchers found that the temperature trends are highly significant across all seasons for the high-elevation stations, as well as their low-elevation counterparts over the study period. For the high-elevation stations, the warming was the strongest in winter, followed by autumn, spring, and summer. With the exception of spring, the trends across the three other seasons were clearly higher for the high-elevation stations than their low elevation counterparts. A significant altitudinal amplification trend was also detected for all seasons for the high-elevation stations based on the elevation band method, and the amplification amplitude for autumn and winter was found to be about two times that for spring and summer.

What is more, the stepwise regression analysis revealed that the trends of each season for the high-elevation stations are closely related to altitude and latitude, suggesting that there exists not only an altitudinal amplification trend but also a latitudinal amplification trend on the seasonal scale for the high elevation stations over the past 50 years. It was also found that the warming in each season for the high-elevation stations was linearly related to the temperature lapse rates in altitudinal and latitudinal directions.

Read the full paper: Qixiang, W. et al. ‘Seasonal patterns of warming amplification of high‐elevation stations across the globe.’ International Journal of Climatology, 2018; DOI: 10.1002/joc.5509 

The Mountain Research Initiative is also working to enhance our understanding of elevation dependent warming.
Discover more here.