Interviews of Mongolian herders and high resolution precipitation data reveal an increase in short heavy rains and thunderstorm activity in semi-arid Mongolia
Interviews of Mongolian herders and high resolution precipitation data reveal an increase in short heavy rains and thunderstorm activity in semi-arid Mongolia
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DOI：
10.1007/s10584-016-1614-4
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发表时间：
2016-05-01
期刊：
影响因子：
4.8
通讯作者：
Petraitis, Peter S.
中科院分区：
文献类型：
--
作者：
Goulden, Clyde E.;Mead, Jerry;Petraitis, Peter S.
极端破纪录的每日降水事件的增加伴随着气温变暖，导致世界许多地区的洪水增加，但对于干旱和半干旱地区却没有充分的记录。在半干旱的蒙古，从 1940 年到 2008 年，气温升高超过 2 摄氏度，游牧民描述了他们对炎热天数增加以及从多日小雨转变为持续不到一小时的大雨的担忧，这损害了他们的牧场、动物、蒙古包和人类，这表明从层状雨到对流风暴的转变。短暂的强降雨在气象站通常报告的每日降水数据中是看不到的，这里利用细尺度降雨读数与雷暴活动之间的相关性来预测短暂的强降雨。从2008年到2012年，蒙古霍夫苏古尔湖达尔拜山谷的一个自动气象站每隔5分钟进行一次记录，检测到至少40次亚日夏季降雨，每次持续时间不到40分钟。达尔贝的大雨与雷暴活动相关，Hatgal 气象站（达尔贝西南 80 公里）在过去 24 小时内报告有雷暴的情况下，发生雷暴的可能性是没有报告雷暴时的 2.5 倍。从1960年到2012年，附近气象站记录的每日雷暴频率有所增加，从而支持了牧民的看法，即短时大雨的频率有所增加。如果没有高时间分辨率的降水数据（例如我们在本研究中报告的数据），就不可能检测夏季降雨类型的变化，这在理论和实践中具有许多意义。
Increases in extreme record-breaking daily precipitation events have accompanied warming temperatures causing increased flooding in many areas of the World, but are not well documented for arid and semi-arid regions. In semi-arid Mongolia where warming has been over 2(o) C from 1940 to 2008, nomadic herders described their concerns over an increase in the number of hot days and a shift from multi-day gentle rains to heavy rains lasting less than one hour that damage their pastures, animals, gers and people, suggesting a transition from stratiform rains to convective storms. The brief intense rains are not seen in daily precipitation data typically reported by meteorological stations, and here the correlation between fine-scale rainfall readings and thunderstorm activity were used to hind cast brief heavy rains. From 2008 to 2012, an automated weather station in Dalbay Valley at Lake Hovsgol, Mongolia, recording at 5-min intervals, detected at least 40 heavy sub-daily summer rains each lasting less than 40 min. Heavy rains in Dalbay were correlated with thunderstorm activity and were 2.5 times more likely to occur when thunderstorms were reported within the previous 24 h at the Hatgal meteorological station (80 km to the southwest of Dalbay) than when no thunderstorms were reported. Daily thunderstorm frequency, recorded at nearby meteorological stations from 1960 to 2012, has increased and thus supports herders' perceptions that the frequency of the short heavy rains have increased. Without high temporal resolution data for precipitation, such as those we report in this study, it is impossible detect shifts in summer rain types, which have many implications in theory and practice.