Research Highlights

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  • Earth & environment

Published online: 3 September 2008 | doi:10.1038/nchina.2008.206

Climate change: Holding back hail

Tim Reid

Introduction

© (2008) istockphoto.com/Dominic Ryan

Most parts of China experience hail, apart from some areas in the south and east. These balls or lumps of ice are produced when the atmosphere is unstable, and are important for understanding climate changes on a regional basis. Now Qinghong Zhang at Peking University and co-workers¹ have shown that hail is becoming less common in China.

The researchers analysed data recorded by the National Meteorological Information Center at 523 monitoring stations across China over the period 1960 to 2005. The data from about a quarter of the stations, mainly those in the northeast and northwest, showed significant downward trends in hail since 1980, whereas only one station in the whole country showed an increase in hail. Overall, the mean number of 'hail days' in China had almost halved.

By examining further data from atmospheric sounding, the researchers showed that the freezing level (the height at which the temperature goes below zero) is now about 200 metres higher than it was in the 1970s. This trend makes it harder for hail to form, and is almost certainly caused by increased surface temperatures.

Recent studies have shown that hail is also decreasing in the United States. Therefore the pattern could be a global phenomenon linked to climate change.

The authors of this work are from:
Department of Atmospheric Science, School of Physics, Peking University, Beijing, China; Department of Meteorology and International Pacific Research Center, University of Hawaii at Manoa, Honolulu, Hawaii, USA.

Reference

1. Xie, B., Zhang, Q. & Wang, Y. Trends in hail in China during 1960–2005. Geophys. Res. Lett. doi: 10.1029/2008GL034067 (2008). | Article |