Subjects: Geosciences >> Atmospheric Sciences submitted time 2023-02-27 Cooperative journals: 《干旱区地理》
Abstract： Previous studies have shown that the Emanuel scheme performs relatively well in simulating temperature and precipitation in East Asia. However, the user’s guide of RegCM4.6 points out that the Emanuel scheme tends to produce excessive precipitation over lands, especially in some intense individual precipitation events. In contrast, the Grell scheme tends to produce weak precipitation over tropical oceans. Therefore, the new version of the regional climate model RegCM4.6 has incorporated the Mix cumulus convective parameterization scheme, which means that the Emanuel scheme can be used over oceans and the Grell scheme over land, to compensate for the deficiencies of a single scheme. Previous validation studies have mainly focused on temperature and precipitation, and few studies have been conducted on the Mix scheme. The MODIS product from January 1st , 2016, to December 31st , 2016, was used as a reference to evaluate the simulation results of cloud fraction (CF), ice water path (IWP), and liquid water path (LWP) in East Asia from the Emanuel and Mix schemes in RegCM4.6 at various time scales. Some statistical parameters were calculated, such as the correlation coefficient (r), mean absolute error (MAE), mean bias error (MBE), and root mean square error (RMSE). The results were as follows. (1) The simulated CF were slightly overestimated in the northwest and mainly underestimated in the southeast roughly bounded by the Hu Huanyong line. The performance of the two schemes in simulating CF was the best in summer and the worst in winter. In the four seasons, the absolute values of MAE, MBE, and RMSE of the Mix scheme were generally lower than those of the Emanuel scheme. (2) The systematic deviations of IWP were negative in the whole of East Asia. Except in summer, the IWP from the two simulations and MODIS was significantly negatively correlated in the other three seasons, indicating that it was a challenge to accurately simulate physical processes related to ice particles in the cloud. (3) The LWP was underestimated by the two schemes in the Qinghai Tibet Plateau and Eastern Ocean and was overestimated in southern, central, and northern China, but the annual MBE of the Mix scheme were closer to 0. The performances of the two schemes were similar in winter. In the other three seasons, the absolute values of MAE, MBE, and RMSE of the Mix scheme were less than those of the Emanuel scheme, and the differences in MAE for the two schemes were 21-39 g·m-2 . In conclusion, the Mix scheme is more suitable to simulate cloud water resources in East Asia. This study will contribute to the exploitation of cloud water resources in East Asia and provide a reference for the selection and improvement of the cumulus convection parameterization scheme in a regional climate model.
Subjects: Geosciences >> Atmospheric Sciences submitted time 2022-10-21 Cooperative journals: 《干旱区地理》
Abstract：利用2019年冬季吐鲁番和2020年冬季若羌共14次完整机载探测气溶胶资料，结合宏观天 气资料及大气污染数据，研究飞机爬升或降落阶段两地上空气溶胶粒子数浓度、粒子平均粒径的 垂直变化规律，分析不同高度的粒子谱分布特征。结果表明：（1）两地冬季气溶胶粒子数浓度及粒 子直径存在明显差异。在无明显天气过程下，若羌气溶胶粒子数浓度均值（5354cm-3）明显高于吐 鲁番（3948cm-3）；粒子平均粒径来看，均值差异不大，但吐鲁番出现大直径粒子（0.16 m）数量高 于若羌（0.13 m）。2019年12月15日大风后最为明显，粒子直径最大值达到0.21 m ，这与沙尘 气溶胶多有关联。从垂直变化情况来看，两地气溶胶粒子数浓度均随高度增加而升高，若羌各层 普遍高于吐鲁番，但吐鲁番近地面粒子直径随高度增加有明显下降，若羌整层变化很小。（2）吐鲁 番、若羌气溶胶粒子数浓度和粒子平均粒径受大风、降水等天气过程以及逆温层的影响十分明 显。两地高层均主要为输入型气溶胶，低层差异主要是由于吐鲁番地区人为源气溶胶粒子的排放 导致的大气环境污染。（3）吐鲁番、若羌两地粒子谱分布在0.10~3.00 m 范围内变化趋势大体一 致，主要以小粒径为主，谱分布受天气过程影响变化较为明显。（4）从三模态粒径相似度对比可以 得出，无论是吐鲁番还是若羌，在第一模态中数谱分布差异不大，若羌平均相似度为50.330%，略 高于吐鲁番46.770%。有明显天气过程时，吐鲁番气溶胶数谱在二、三模态相似度（小于0.020%） 急剧下降，而若羌第二模态相似度仍满足置信度95%，但第三模态中变化凸显，相似度不足 0.020%。
Subjects: Geosciences >> Geography submitted time 2021-04-23 Cooperative journals: 《干旱区研究》
Abstract：利用2000—2019年新疆升温融雪（冰）型洪水灾情资料，分析了近20 a融雪（冰）型洪水频次的时空分布和地域差异性，结果表明：北疆融雪型洪水频次占全疆的75%，主汛期在春季，集中出现在北疆西部北部区域，伊犁哈萨克自治州最多（新源县最多）；南疆主汛期在夏季，融雪（冰）型洪水主要出现于昆仑山北坡，3月和7月是北疆融雪和南疆融雪（冰）型洪水的高发月份。20 a来南北疆春季融雪型洪水频次均呈增多趋势，后10 a融雪（冰）型洪水频次较前10 a均增多，增幅30%左右。阐明了新疆融雪（冰）型洪水的天气学分型，分析了伊朗副高东扩型、西太副高西伸型和新疆脊发展型三类大气环流形势，给出新疆升温融雪（冰）型洪水的高低空环流形势及天气系统配置。得出融雪（冰）型洪水发生前，100 hPa南亚高压呈单体型，100～700 hPa新疆受深厚高压脊控制，高空0 ℃层高度明显偏高，前期山区降水明显偏多。北疆需重点防范春季伊犁州的中低山体季节融雪型洪水，南疆则应密切关注夏季高山冰湖溃决型和积雪、冰川融水型两类融雪（冰）型洪水。
Subjects: Environmental Sciences, Resource Sciences >> Basic Disciplines of Environmental Science and Technology submitted time 2019-03-07 Cooperative journals: 《干旱区地理》
Abstract：利用NASA发布的2008—2015年CloudSat卫星的2B-CWC-RO、2B-CLDCLASS、2C-SNOW-PROFILE和地面气象站的观测资料，对北疆沿天山及其周边区域内21次强降雪天气降雪前和降雪期间卫星过境时云宏微观特征进行了对比分析。本文将研究区域分为了北疆沿天山西部和中部地区，分析结果表明：（1）降雪前和降雪期间的云类型以层云、积云、高层云和深对流云为主。（2）降雪前冰粒子等效半径均值分布在58.65~67.29 μm之间，冰粒子数浓度的均值在41.2~76.5 L-1之间，冰水含量的均值在25.4~135.1 mg·m-3之间，雪水含量均值在28.0~88.0 mg·m-3之间，降雪强度均值在0.08~0.36 mm·h-1之间。（3）降雪前冰粒子等效半径、冰粒子数浓度、冰水含量、雪水含量和降雪强度均值分别比降雪期间大2.9 %、6.2 %、34.4 %、36.4 %和18.7 %，且高值区主要集中在北疆沿天山西部地区。
Subjects: Geosciences >> Geography submitted time 2019-01-11 Cooperative journals: 《干旱区地理》
Abstract：利用美国宇航局（NASA）发布的2003年1月～2015年12月的AIRS Standard Physical Retrieval Edition 6.0中的level2的反演数据，对新疆及其周边地区--特别是三大山区近13 a的可降水量的时空分布特征进行了研究。结果表明，从空间分布看，可降水量高值区主要集中在盆地地区，尤其在塔里木盆地、准最低值达1.92 mm；新疆及其周边地区可降水量所有格点13 a平均值来看，总体上，夏季最高，冬季最低。从时间分布看，对新疆及其周边地区、天山、昆仑山和阿尔泰山四个研究区域分别进行区域平均，发现以个区域年变化呈单峰型，从1～7月的可降水量逐渐增加，8～12月份的可降水量逐月减少；可降水量的整体年际变化趋势是一致的，2003—2010年呈上升趋势，2010—2015年呈下降趋势。
Subjects: Geosciences >> Atmospheric Sciences submitted time 2018-10-23 Cooperative journals: 《干旱区地理》
Abstract： 本文利用2008－2017年5～8月天山南侧喀什地区气象台站观测记录、人工防雹作业点记录、灾害调查等资料，喀什探空站08时、20时探空资料，喀什雷达探测资料及其基数据反演产品，对冰雹的年分布、月分布及日变化特征进行了分析，归纳出冰雹云的雷达回波特征及移动路径，依据百分位数方法确定了以0 ℃层高度、-20 ℃层高度、冻结层厚度、全总指数、杰弗逊指数、K指数、沙氏指数为代表的冰雹预报指标，以及以回波顶高及其与当日0 ℃层高度差、40～50 dBZ回波高度及其与当日0 ℃层高度差、组合反射率、垂直积分液态水含量为代表的雷达特征预警指标。
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