Rising Planetary Boundary Layer Height over the Sahara Desert and Arabian Peninsula in a Warming Climate
Rising Planetary Boundary Layer Height over the Sahara Desert and Arabian Peninsula in a Warming Climate
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DOI：
10.1175/jcli-d-20-0645.1
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发表时间：
2021-02
影响因子：
4.9
通讯作者：
Liming Zhou;Yuhong Tian;Nan Wei;S. Ho;Jing Li
中科院分区：
文献类型：
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作者：
Liming Zhou;Yuhong Tian;Nan Wei;S. Ho;Jing Li
行星边界层（PBL）中的湍流混合控制着地表-大气界面中热量、水分、动量、微量气体和气溶胶的垂直交换。PBL高度（PBLH）代表直接受地球表面影响的自由大气的最大高度。本研究使用多数据合成方法，从无线电探空仪观测，再分析产品和气候模式模拟的多个全球数据集的集合，以研究1979- 2019年期间608 S和608 N之间陆地上长期PBLH趋势的空间格局。通过考虑趋势的符号和统计显著性，我们识别出变化信号稳健且一致的大规模区域，以增加我们对所得结果的信心。尽管在许多地区的PBLH趋势的幅度和迹象的差异，所有的数据集揭示了一个共识，增加PBLH在巨大的和非常干燥的撒哈拉沙漠和阿拉伯半岛（SDAP）和下降的PBLH在印度。在全球范围内，PBLH的变化显着正相关的变化，在地面加热和负相关的变化，在地面水分，与理论和文献中先前的研究结果一致。上升的PBLH是在很好的协议，增加感热和地面温度和相对湿度下降的SDAP与沙漠放大，而下降的PBLH共振以及增加相对湿度和潜热和减少感热和地面变暖在印度。PBLH的变化同意在SDAP无线电探空仪探测，但不能验证印度由于缺乏高质量的无线电探空仪观测。
Turbulent mixing in the planetary boundary layer (PBL) governs the vertical exchange of heat, moisture, momentum, trace gases, and aerosols in the surface–atmosphere interface. The PBL height (PBLH) represents the maximum height of the free atmosphere that is directly influenced by Earth’s surface. This study uses a multidata synthesis approach from an ensemble of multiple global datasets of radiosonde observations, reanalysis products, and climate model simulations to examine the spatial patterns of long-term PBLH trends over land between 608S and 608N for the period 1979– 2019. By considering both the sign and statistical significance of trends, we identify large-scale regions where the change signal is robust and consistent to increase our confidence in the obtained results. Despite differences in the magnitude and sign of PBLH trends over many areas, all datasets reveal a consensus on increasing PBLH over the enormous and very dry Sahara Desert and Arabian Peninsula (SDAP) and declining PBLH in India. At the global scale, the changes in PBLH are significantly correlated positively with the changes in surface heating and negatively with the changes in surface moisture, consistent with theory and previous findings in the literature. The rising PBLH is in good agreement with increasing sensible heat and surface temperature and decreasing relative humidity over the SDAP associated with desert amplification, while the declining PBLH resonates well with increasing relative humidity and latent heat and decreasing sensible heat and surface warming in India. The PBLH changes agree with radiosonde soundings over the SDAPbut cannot be validated over India due to lack of good-quality radiosonde observations.