Climate Teleconnections and the Biosphere

Abstract:

Teleconnection patterns have been demonstrated to impact many aspects of weather and climate on sub-seasonal to interannual timescales, yet their influence on biophysical systems is under explored. Some teleconnection patterns, like the North Atlantic Oscillation (NAO) and the El Nino Southern Oscillation (ENSO) are well known to ecologists and land surface modelers, while others have remained in the realm of atmospheric science. Because teleconnection patterns influence many different aspects of global climate, their impacts on the biosphere are similarly diverse and in many cases contradictory – if a peak in a teleconnection pattern (e.g. an El Nino year) causes cooler temperatures but more rainfall, whether that leads to more or less plant growth will depend on the broader context of the ecosystem. Understanding where and how teleconnection patterns have influenced the biosphere in the past could both improve our understanding of the Earth system and lead to better models. Here we compare a global thirty year satellite record of Leaf Area Index (LAI3g; Zhu et al 2013) to six different teleconnection patterns: ENSO, NAO, the Antarctic Oscillation, the Atlantic Gradient, the Pacific Decadal Oscillation, and the Indian Ocean Dipole. We found that while ENSO and NAO do have strong influences on vegetation patterns as has been shown previously, the other teleconnection patterns we considered are comparable in their reach and strength of signal. We also suggest that geographical patterns of correlation like those described here could serve as a ‘second tier’ of benchmarking data for Earth system models – climate models should be able to simulate the biophysical impacts of well-organized modes of climate variability, not just their meteorological dynamics.