石家庄极端冷暖天气气候事件及其与气候变暖

用石家庄市1955～2002年逐日气温资料，取其第95个和第5个百分位值作为确定极端高(低)温日的阈值来检测极端冷暖事件。对发生在2002年的极端冷暖事件进行检测分析证明，上述方法能比较有效地检测极端冷暖事件的发生。计算气温趋势变率表明，石家庄气候有明显的增暖趋势，随气候变暖夏季持续性强高温和破记录高温事件的出现频次增加；寒冷期趋于缩短；极端冷日趋于减少，极端暖日趋于增加。用季极端冷(暖)日数与气温求取相关的方法，分析各季极端冷暖事件与气候变暖的联系发现，气候变暖对冬季极端冷日减少的影响最甚。城市化效应使城市变暖趋势速率高于郊区，尤以最低气温表现明显；暖事件增多、冷事件减少的趋势速率也是城市高于郊区，且冷事件减少速率高于暖事件增多速率。在气候变暖背景下应特别重视冬季冷事件减少给人类带来的潜在影响。

Cold and Warm Extreme Events in Shijiazhuang and Climate Warming

Using daily air temperature data of Shijiazhuang from 1955 to 2002,the thresholds of extrema are estimated in terms of the 95th and the 5th percentiles,and the temperature extrema are identified. Analysis of cold and warm extreme events occurred in 2002 in Shijiazhuang shows that the above-mentioned schemes can effectively identify temperature extrema. The calculated temperature trend rates show that the climate in Shijiazhuang had obviously warming trends. With the climate warming,the continual and record-broken high temperature events increased;the cold period tended to shorten,cold days to decrease and warm days to increase. The relation of temperature extreme events and climate warming in Shijiazhuang is studied by using the correlative analysis method. The decrease of extreme cold days was most obvious. The urbanization effect enhanced climate-warming rates in the urban area,and especially the variation of the daily lowest temperature was most evident. The increasing/decreasing of warm/cold events was quicker in the urban area than in suburb. Under the background of climate warming,the decrease of cold events in winter and their potential impacts on human being must be paid special attention.