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Chinese Science Bulletin, Volume 64 , Issue 15 : 1637-1650(2019) https://doi.org/10.1360/N972018-01014

The energy mechanism controlling the continuous development of a super-thick atmospheric convective boundary layer during continuous summer sunny periods in an arid area

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  • ReceivedOct 14, 2018
  • AcceptedMar 11, 2019
  • PublishedApr 28, 2019

Abstract

In the arid regions of the world, due to the specific climatic and environmental background, a super-thick convective boundary layer (SCBL) often develops on sunny days in summer, whereas such phenomena rarely occur in other areas. This special boundary layer structure has an important synoptic and climatic significance, but there have been few studies of its development mechanism in arid areas, which greatly restricts the parametric improvement of the SCBL and our understanding of the interaction between weather and climate processes. This study was conducted in Dunhuang, which is located in the hinterland of northwest China. Based on data obtained from land-air interaction experiments and long-term operational sounding observations in this region, the energy mechanism controlling the development of the CBL and the developmental process of the SCBL were systematically analyzed. In arid northwest China, it is possible that the thickness of the CBL can extend to over 3 km for most of the year, except winter. Even in the early summer, when there is little rain and strong solar radiation, the thickness of the CBL may reach an extreme state of 5.4 km. The thickness of the CBL at this time is higher than that observed in midsummer, when there is slightly more precipitation in this area. This is basically consistent with the extreme thickness of the CBL recently discovered in the Sahara Desert in Africa. In the general mechanism that controls the development of the CBL, there is a close relationship between the development of the CBL and the sensible heat flux of the surface. However, the correlation between the thickness of the CBL and the surface sensible heat flux at the same time is not strong, whereas the correlation between the thickness of the CBL and the cumulative surface sensible heat flux is very strong. This indicates that the development of the CBL is the result of the continuous accumulation of the sensible heat flux on the surface, which is consistent with the energy mechanism controlling the CBL. Although the development of the CBL is closely related to the cumulative heating effect of the daytime surface sensible heat flux, the CBL would still continue to increase even if the integral value of the daytime surface sensible heat flux remained unchanged or even weakened during the continuous clear sky period. The energy provided through sensible heat does not fully explain the energy required to develop the CBL. This is mainly because the deep near-neutral residual layer (RL) background plays an important role in the development of the SCBL. The entrainment energy from the deep RL to the CBL is the key energy supply for the continuous development of the CBL. The sum of the entrainment energy and surface sensible heat energy coincides with the energy absorbed by the development of the SCBL. The reason for the occurrence of an SCBL in arid areas is not only the strong sensible heating in summer but also the persistent clear skies in such areas. In each continuous clear sky period, the positive feedback mechanism between the CBL and the RL will become operational. Under this mechanism, the daily maximum thickness of the CBL and the thickness of the RL will increase continuously. The thickness of the SCBL is generally over 3 km, although depths of over 5 km can develop through a cyclic growth mechanism during periods of strong surface heating. Otherwise, the thickness of the CBL can only reach 2–3 km in summer, and it is unlikely that an SCBL will develop. Strong sensible heating is the key trigger of the positive feedback cycle growth mechanism between the CBL and the RL, which explains why the SCBL phenomenon can only occur in dry areas, with intense surface heating in summer.


Funded by

国家自然科学基金重点项目(41630426)

干旱气象科学研究基金(IAM201709)


Acknowledgment

感谢中国气象局兰州干旱气象研究所王胜研究员提供资料.


Supplement

补充材料

图S1 陆-气相互作用综合观测试验期累积地表感热通量与累积地-气温差的对比

图S2 感热加热作用下对流边界层发展的能量示意图

图S3 陆-气相互作用综合观测试验期对流边界层发展所吸收的能量与地表感热通量累积提供的能量对比

图S4 雨天转晴和阴天转晴的持续晴空期日最大对流边界层归一化厚度变化特征

图S5 阴天转晴类型和雨天转晴类型对流边界层发展过程中物理参数对比

图S6 累积地-气温差随对流边界层日最大厚度分布的离散棒和对流边界层日最大厚度区间地-气温差累积值的正态分布图

图S7 几次持续晴空期对流边界层日最大厚度的日增幅与每日残余层夹卷能量及对流边界层日最大厚度与每日总能量之间的相关性比较

本文以上补充材料见网络版csb.scichina.com. 补充材料为作者提供的原始数据, 作者对其学术质量和内容负责.


References

[1] Zhang Q, Zhao Y D, Wang S, et al. A study on atmospheric thermal boundary layer structure in extremely arid desert and gobi region on the clear day in summer (in Chinese). Adv Earth Sci, 2007, 22: 1150−1159 [张强, 赵映东, 王胜, 等. 极端干旱荒漠区典型晴天大气热力边界层结构分析. 地球科学进展, 2007, 22: 1150−1159]. Google Scholar

[2] Zhang Q. Study on depth of atmospheric thermal boundary layer in extreme arid desert regions (in Chinese). J Desert Res, 2007, 27: 614−620 [张强. 极端干旱荒漠地区大气热力边界层厚度研究. 中国沙漠, 2007, 27: 614−620]. Google Scholar

[3] Liu H Z, Fen J W, Wang L, et al. Overview of recent studies on atmospheric boundary layer physics at LAPC (in Chinese). Chin J Atmos Sci, 2013, 37: 467−476 [刘辉志, 冯健武, 王雷, 等. 大气边界层物理研究进展. 大气科学, 2013, 37: 467−476]. Google Scholar

[4] Huang R H, Zhou D G, Chen W, et al. Recent progress in studies of air-land interaction over the arid area of northwest China and its impact on climate (in Chinese). Chin J Atmos Sci, 2013, 37: 189−210 [黄荣辉, 周德刚, 陈文, 等. 关于中国西北干旱区陆-气相互作用及其对气候影响研究的最近进展. 大气科学, 2013, 37: 189−210]. Google Scholar

[5] Zhang Q, Wang S. On physical characteristics of heavy dust storm and its climatic effect (in Chinese). J Desert Res, 2005, 25: 675−681 [张强, 王胜. 论特强沙尘暴(黑风)的物理特征及其气候效应. 中国沙漠, 2005, 25: 675−681]. Google Scholar

[6] Cai X N, Shou S W, Zhong Q. Impact of different boundary layer parameterization schemes on the numerical simulation for a rainstorm (in Chinese). Trans Atmos Sci, 2006, 29: 364−370 [蔡芗宁, 寿绍文, 钟青. 边界层参数化方案对暴雨数值模拟的影响. 大气科学学报, 2006, 29: 364−370]. Google Scholar

[7] Angevine W M, White A B, Avery S K. Boundary-layer depth and entrainment zone characterization with a boundary-layer profiler. Bound-Layer Meteorol, 2007, 68: 375-385 CrossRef Google Scholar

[8] Garratt J R. The Atmospheric Boundary Layer. Combridge: Cambridge University Press, 1992. 316. Google Scholar

[9] Sheng P X, Mao J T, Li J G, et al. Atmospheric Physics (in Chinese). Beijing: Peking University Press, 2003. 239−272 [盛裴轩, 毛洁泰, 李建国, 等. 大气物理学. 北京: 北京大学出版社, 2003. 239−272]. Google Scholar

[10] Kaimal J C, Finnigan J J. Atmospheric Boundary Layer Flows. Oxford: Oxford University Press, 1994. 391−420. Google Scholar

[11] Raman S, Templeman B, Templeman S, et al. Structure of the Indian southwesterly pre-monsoon and monsoon boundary layers: Observations and numerical simulation. Atmos Environ Part A General Top, 1990, 24: 723-734 CrossRef ADS Google Scholar

[12] Gamo M, Goyal P, Kumari M, et al. Mixed-layer characteristics as related to the monsoon climate of New Delhi, India. Bound-Layer Meteorol, 1994, 67: 213-227 CrossRef Google Scholar

[13] Gamo M. Thickness of the dry convection and large-scale subsidence above deserts. Bound-Layer Meteorol, 1996, 79: 265-278 CrossRef ADS Google Scholar

[14] Li M S, Ma Y M, Ma W Q, et al. Structural difference of atmospheric boundary layer between dry and rainy seasons over the central Tibetan Plateau (in Chinese). J Glaciol Geocryol, 2011, 33: 72−79 [李茂善, 马耀明, 马伟强, 等. 藏北高原地区干、雨季大气边界层结构的不同特征. 冰川冻土, 2011, 33: 72−79]. Google Scholar

[15] Chen X, Škerlak B, Rotach M W, et al. Reasons for the extremely high-ranging planetary boundary layer over the Western Tibetan Plateau in winter. J Atmos Sci, 2016, 73: 2021-2038 CrossRef ADS Google Scholar

[16] Chen X, Añel J A, Su Z, et al. The deep atmospheric boundary layer and its significance to the stratosphere and troposphere exchange over the Tibetan Plateau. PLoS One, 2013, 8: e56909 CrossRef PubMed ADS Google Scholar

[17] Zhang Q, Wei G A, Hou P. Observation studies of atmosphere boundary layer characteristic over Dunhuang gobi in early summer (in Chinese). Plateau Meteorol, 2004, 23: 587−597 [张强, 卫国安, 侯平. 初夏敦煌荒漠戈壁大气边界结构特征的一次观测研究. 高原气象, 2004, 23: 587−597]. Google Scholar

[18] Takemi T, Satomura T. Numerical experiments on the mechanisms for the development and maintenance of long-lived squall lines in dry environments. J Atmos Sci, 2000, 57: 1718-1740 CrossRef Google Scholar

[19] Yang Y, Liu X Y, Lu Z H, et al. Study on depth of atmospheric boundary layer in gobi desert regions of the Bosten lake basin (in Chinese). Acta Sci Nat Univ Pek, 2016, 52: 829−836 [杨洋, 刘晓阳, 陆征辉, 等. 博斯腾湖流域戈壁地区大气边界层高度特征研究. 北京大学学报(自然科学版), 2016, 52: 829−836]. Google Scholar

[20] Ma M, Pu Z, Wang S, et al. Characteristics and numerical simulations of extremely large atmospheric boundary-layer heights over an arid region in North-west China. Bound-Layer Meteorol, 2011, 140: 163-176 CrossRef ADS Google Scholar

[21] Zhao C L, Lü S H, Li Z G, et al. Numerical simulation of influence of land surface thermal condition on Badain Jaran Desert atmospheric boundary layer height in summer (in Chinese). Plateau Meteorol, 2014, 33: 1526−1533 [赵采玲, 吕世华, 李照国, 等. 夏季巴丹吉林沙漠陆面热状况对边界层高度影响的模拟实验. 高原气象, 2014, 33: 1526−1533]. Google Scholar

[22] Messager C, Parker D J, Reitebuch O, et al. Structure and dynamics of the Saharan atmospheric boundary layer during the West African monsoon onset: Observations and analyses from the research flights of 14 and 17 July 2006. Quart J Roy Meteorol Soc, 2006, 136: 107-124 CrossRef ADS Google Scholar

[23] Parker D J, Thorncroft C D, Burton R R, et al. Analysis of the African easterly jet, using aircraft observations from the JET2000 experiment. Quart J Roy Meteorol Soc, 2000, 131: 1461-1482 CrossRef ADS Google Scholar

[24] Marsham J H, Parker D J, Grams C M, et al. Observations of mesoscale and boundary-layer circulations affecting dust uplift and transport in the Saharan boundary layer. Atmos Chem Phys Discuss, 2008, 8: 8817-8846 CrossRef Google Scholar

[25] Cuesta J, Edouart D, Mimouni M, et al. Multiplatform observations of the seasonal evolution of the Saharan atmospheric boundary layer in Tamanrasset, Algeria, in the framework of the African monsoon multidisciplinary analysis field campaign conducted in 2006. J Geophys Res Atmos, 2008, 113: 596−598. Google Scholar

[26] Cuesta J, Marsham J H, Parker D J, et al. Dynamical mechanisms controlling the vertical redistribution of dust and the thermodynamic structure of the West Saharan atmospheric boundary layer during summer. Atmos Sci Lett, 2010, 10: 34-42 CrossRef ADS Google Scholar

[27] Zhang Q, Wang S. On physical characteristics of heavy dust storm and its climatic effect (in Chinese). J Desert Res, 2005, 25: 675–681 [张强, 王胜. 论特强沙尘暴(黑风)的物理特征及其气候效应. 中国沙漠, 2005, 25: 675−681]. Google Scholar

[28] Zhang Q, Wang S, Sun Z X. A study of atmospheric boundary layer structure during a clear day in the arid region of Northwest China. Acta Meteorol Sin, 2009, 23: 327−337. Google Scholar

[29] Zhang Q, Wang S, Zhang J, et al. The progress on land surface processes and atmospheric boundary layer in arid regions (in Chinese). Adv Earth Sci, 2009, 24: 1185−1194 [张强, 王胜, 张杰, 等. 干旱区陆面过程和大气边界层研究进展. 地球科学进展, 2009, 24: 1185−1194]. Google Scholar

[30] Zhang Q, Zhang J, Qiao J, et al. Relationship of atmospheric boundary layer depth with thermodynamic processes at the land surface in arid regions of China. Sci China Earth Sci, 2012, 54: 1585−1594. Google Scholar

[31] Zhang Q, Wang S, Li Y Y. The study of physical mechanism of influence on atmospheric boundary layer depth in arid regions of Northwest China. Acta Meteorol Sin, 2006, 20: 1−12. Google Scholar

[32] Zhao C L, Lü S H, Han B, et al. Relationship between the convective boundary layer and residual layer over Badain Jaran Desert in summer (in Chinese). Plateau Meteorol, 2016, 35: 1004−1014 [赵采玲, 吕世华, 韩博, 等. 夏季巴丹吉林沙漠残余层与深厚对流边界层的关系研究. 高原气象, 2016, 35: 1004−1014]. Google Scholar

[33] Zhao J H, Zhang Q, Wang S. A simulative study of the thermal mechanism for development of the convective boundary layer in the arid zone of northwest China (in Chinese). Acta Meteorol Sin, 2011, 69: 1029−1037 [赵建华, 张强, 王胜. 西北干旱区对流边界层发展的热力机制模拟研究. 气象学报, 2011, 69: 1029−1037]. Google Scholar

[34] Zhang L G, Wang R Z, Huang X M, et al. Introduction of L band wind finding radar electronic radiosonde system (in Chinese). J Arid Meteorol, 2002, 4: 30−32 [张立功, 王汝忠, 黄小明, 等. L波段测风雷达-电子探空仪系统简介. 甘肃气象, 2002, 4: 30−32]. Google Scholar

[35] Yu W P, Zhang C C. L band (1) High Altitude Meteorological Detection System Business Operation Manual (in Chinese). Beijing: Meteorological Press, 2005. 12−18 [俞卫平, 章澄昌. L波段(1型)高空气象探测系统业务操作手册. 北京: 气象出版社, 2005. 12−18]. Google Scholar

[36] Li Y Y, Zhang Q, Xue X L, et al. Relationship between atmosphere boundary layer characteristics and sand-dust weather climatology in Minqin (in Chinese). J Desert Res, 2011, 31: 757−764 [李岩瑛, 张强, 薛新玲, 等. 民勤大气边界层特征与沙尘天气的气候学关系研究. 中国沙漠, 2011, 31: 757−764]. Google Scholar

[37] Holzworth G C. Estimates of mean maximum mixing depths in the contiguous United States. Month Weather Rev, 1964, 12: 235−242. Google Scholar

[38] Hyun Y K, Kim K E, Ha K J. A comparison of methods to estimate the height of stable boundary layer over a temperate grassland. Agric For Meteor, 2005, 132: 132-142 CrossRef ADS Google Scholar

[39] Seibert P, Beyrich F, Gryning S E, et al. Review and intercomparison of operational methods for the determination of the mixing height. Atmos Environ, 2000, 34: 1001-1027 CrossRef ADS Google Scholar

[40] Holzworth G C. Mixing depths, wind speeds and air pollution potential for selected locations in the United States. J Appl Meteor, 1967, 6: 1039-1044 CrossRef Google Scholar

[41] Stull. Introduction to Boundary Layer Meteorology (in Chinese). Qingdao: Qingdao Ocean University Press, 1991. 493−494 [斯塔尔. 边界层气象学导论. 青岛: 青岛海洋大学出版社, 1991. 493−494]. Google Scholar

  • Figure 1

    Comparison of the thickness of the CBL determined by the method of potential temperature profile and dry adiabatic curve

  • Figure 2

    Annual cycle characteristics of maximum daily thickness of CBL in Dunhuang in 2006−2016

  • Figure 3

    Correlation of CBL thickness with real-time sensible heat flux (a) and cumulative sensible heat flux (b) in the period of comprehensive observation of land-air interaction

  • Figure 4

    Correlation between CBL thickness and sensible heat flux integral value (a) and variation trend of diurnal maximum CBL thickness and sensible heat flux integral value (b) in July 8–11, 2006

  • Figure 5

    Schematic diagram of entrainment energy in RL energy development to CBL development. The AB line is the inverted potential temperature profile without RL

  • Figure 6

    Comparison of the correlation between the energy absorbed by the development of the CBL, and the sum of the surface sensible heat flux and the entrainment energy of the RL in the period of comprehensive observation of land-air interaction

  • Figure 7

    Variation trend of maximum daily CBL thickness, RL thickness, the sum of sources energy and RL entrainment energy during persistent sunny days in 8−11 July, 2006

  • Figure 8

    Schematic diagram of positive feedback growth mechanism between super thick CBL and RL

  • Table 1   Statistical comparison of physical parameters in the development of CBL during cloudy day turn to sunny day type and rainy day turn to sunny day type

    转晴首日残

    余层厚度(m)

    日均地-气温差

    累积值(°C)

    对流边界层厚度

    日均增长值(m)

    停止增长

    时间(d)

    对流边界层厚度最大值(m)

    雨天转晴

    0

    145.2

    727

    4.5

    4224

    阴天转晴

    1806

    167.8

    1631

    2.5

    4333

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