什么原因导致了气温的上升呢？
杭城的气温，昨日一下子蹿升。[{'character': '杭', 'pinyin': 'hang2', 'highest pitch': 10.89, 'lowest pitch': 8.7, 'duration': 0.25, 'prosody hierarchy': 'null'}, {'character': '城', 'pinyin': 'cheng2', 'highest pitch': 10.69, 'lowest pitch': 7.93, 'duration': 0.18, 'prosody hierarchy': 'null'}, {'character': '的', 'pinyin': 'de5', 'highest pitch': 9.03, 'lowest pitch': 7.93, 'duration': 0.1, 'prosody hierarchy': '#1'}, {'character': '气', 'pinyin': 'qi4', 'highest pitch': 9.27, 'lowest pitch': 8.16, 'duration': 0.2, 'prosody hierarchy': 'null'}, {'character': '温', 'pinyin': 'uen1', 'highest pitch': 9.59, 'lowest pitch': 8.16, 'duration': 0.3, 'prosody hierarchy': '#3'}, {'character': '昨', 'pinyin': 'zuo2', 'highest pitch': 7.02, 'lowest pitch': 6.59, 'duration': 0.22, 'prosody hierarchy': 'null'}, {'character': '日', 'pinyin': 'riii4', 'highest pitch': 7.68, 'lowest pitch': 6.43, 'duration': 0.2, 'prosody hierarchy': '#1'}, {'character': '一', 'pinyin': 'i2', 'highest pitch': 7.08, 'lowest pitch': 5.9, 'duration': 0.17, 'prosody hierarchy': 'null'}, {'character': '下', 'pinyin': 'xia4', 'highest pitch': 10.76, 'lowest pitch': 8.63, 'duration': 0.2, 'prosody hierarchy': 'null'}, {'character': '子', 'pinyin': 'zii5', 'highest pitch': 8.63, 'lowest pitch': 6.45, 'duration': 0.11, 'prosody hierarchy': '#1'}, {'character': '蹿', 'pinyin': 'cuan1', 'highest pitch': 8.17, 'lowest pitch': 6.45, 'duration': 0.23, 'prosody hierarchy': 'null'}, {'character': '升', 'pinyin': 'sheng1', 'highest pitch': 8.97, 'lowest pitch': 7.43, 'duration': 0.32, 'prosody hierarchy': '#4'}]