| 黄土高原半干旱区异常能量闭合率特征分析 |
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| 引用本文： | 朱岩,左洪超,郭阳,武建军.黄土高原半干旱区异常能量闭合率特征分析[J].甘肃气象,2014(5):719-726. |
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| 作者姓名： | 朱岩 左洪超 郭阳 武建军 |
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| 作者单位： | 1. 兰州大学大气科学学院,甘肃 兰州,730000
2. 中国人民解放军93801 部队,陕西 武功,712200 |
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| 基金项目： | 国家重大科学研究计划“973”项目，国家自然科学基金项目 |
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| 摘 要： | 以兰州大学半干旱气候与环境观测站（简称SACOL站）4 a的陆面通量数据为基础,利用普通最小二乘法（OLS）和能量平衡比率（EBR）方法,对能量平衡的异常闭合特征及其与相对垂直湍强（RIw）的关系进行了研究,并进行了能量滞后分析。结果表明,能量过闭合和负闭合现象分别主要发生在白天和夜间,大小遵从正态分布;较大异常闭合产生的原因主要是日出日落时净辐射与地表热通量接近以及降水影响造成湍流通量出现异常大值。一般来说,垂直湍流运动越强,异常闭合越少,闭合度越向1收敛,反之亦然。强湍流或极弱湍流都不利于产生异常闭合,过闭合、负闭合的最适相对垂直湍强RIw约为0.11、0.14。另外,能量支出项的相对滞后也是造成包括负闭合在内的异常闭合的原因之一。剔除湍强较弱的点或将地表热通量G0、感热H、潜热LE相位相对净辐射Rn提前30 min后,异常闭合所占比重减少;月平均EBR法过闭合度降低,OLS法闭合度提高。
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| 关 键 词： | 半干旱区 异常能量闭合率 相对垂直湍强 能量滞后现象 |
Characteristics of Abnormal Energy Balance Ratio in Semi-Arid Region of Loess Plateau |
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| ZHU Yan,ZUO Hongchao,GUO Yang,WU Jianjun.Characteristics of Abnormal Energy Balance Ratio in Semi-Arid Region of Loess Plateau[J].Gansu Meteorology,2014(5):719-726. |
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| Authors: | ZHU Yan ZUO Hongchao GUO Yang WU Jianjun |
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| Institution: | ZHU Yan, ZUO Hongchao , GUO Yang , WU Jianjun (1. College of Atmospheric Sciences, Lanzhou University, Lanzhou 730000, China; 2. Unit of 93801 of the Chinese Peoples＇ s Liberation Army, Wugong 712200, China) |
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| Abstract: | On the basis of 4-year surface layer fluxes data of the Semi-Arid Climate and Environment Observatory of Lanzhou University（SACOL）,the characteristics of abnormal energy balance ratio and its relationship with relative vertical turbulence intensity（RIW） were studied firstly by using ordinary least square（OLS） method and energy balance ratio（EBR） method.Then the phase lag phenomenon of surface energy was analyzed.The results show that abnormal EBRs（EBR 1 and EBR 0） mainly occurred in the daytime and at night,respectively.Great abnormal EBRs were mainly caused by the adjacence of net radiation Rn and surface heat flux G0 around sunrise and sunset as well as the spike points of turbulence fluxes triggered by the influence of precipitation.In general,when the turbulence is stronger,the abnormal EBR is less likely to happen and energy balance ratio converges to 1,vice versa.Thus the most favorable turbulence intensity for the occurrence of abnormal EBR was neither too intense nor extremely weak.The optimum turbulence intensity for EBR 1 and EBR 0 was about 0.14 and 0.11,respectively.Moreover,the phase lag of surface heat flux G0,sensible heat H and latent heat LE against net radiation Rnwas also the reason for abnormal EBRs including EBR 0.After those RIW 0.3 being removed or the phase of G0,H,LE being displaced half hour forward,the proportion of abnormal EBRs decreased.Monthly mean closure of EBR 1 reduced and closure of OLS method increased. |
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| Keywords: | semi-arid region abnormal EBR relative intensity of vertical turbulence phase lag phenomenon of energy |
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