The new BELUGA setup for collocated turbulence and radiation measurements using a tethered balloon: first applications in the cloudy Arctic boundary layer
The new BELUGA setup for collocated turbulence and radiation measurements using a tethered balloon: first applications in the cloudy Arctic boundary layer
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DOI：
10.5194/amt-12-4019-2019
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发表时间：
2019-07-22
影响因子：
3.8
通讯作者：
Wendisch, Manfred
中科院分区：
文献类型：
--
作者：
Egerer, Ulrike;Gottschalk, Matthias;Wendisch, Manfred
介绍了一种新的BELUGA系留气球系统。它结合了一套测量湍流和辐射参数以及能量通量的仪器。BELUGA可以在恒定高度或高达1.5公里的垂直剖面上进行共址测量。特别是，BELUGA的仪器有效载荷包括三个模块化仪器包，用于高分辨率气象、风矢量和宽带辐射测量。并置数据采集允许在不同高度的能量平衡中估计驾驶参数。加热率和净辐照度可以与湍流通量和局部湍流参数（如耗散率）相关。本文介绍了BELUGA的技术装备、仪器性能和测量策略。此外，由于上升速度慢，垂直分辨率高，这是系留气球观测的一个主要优点。本文介绍了三个首次在北极大气边界层应用BELUGA的典型案例研究。作为第一个例子，单层层积云的测量进行了讨论。它们显示了一个明显的云顶辐射冷却高达6 Kh（-1）。为了把这一背景下，第二个案例阐述了各自的测量与贝鲁加在一个无云的情况。在第三个例子中，探测了多层层积云，发现湍流减少，低云层的云顶辐射冷却可以忽略不计。在这三种情况下，净辐射通量都远高于湍流通量。总而言之，BELUGA已经证明了其在北极大气边界层多云条件下的强大性能。
The new BELUGA (Balloon-bornE moduLar Utility for profilinG the lower Atmosphere) tethered balloon system is introduced. It combines a set of instruments to measure turbulent and radiative parameters and energy fluxes. BELUGA enables collocated measurements either at a constant altitude or as vertical profiles up to 1.5 km in height. In particular, the instrument payload of BELUGA comprises three modular instrument packages for high-resolution meteorological, wind vector and broadband radiation measurements. Collocated data acquisition allows for estimates of the driving parameters in the energy balance at various heights. Heating rates and net irradiances can be related to turbulent fluxes and local turbulence parameters such as dissipation rates. In this paper the technical setup, the instrument performance, and the measurement strategy of BELUGA are explained. Furthermore, the high vertical resolution due to the slow ascent speed is highlighted as a major advantage of tethered balloon-borne observations. Three illustrative case studies of the first application of BELUGA in the Arctic atmospheric boundary layer are presented. As a first example, measurements of a single-layer stratocumulus are discussed. They show a pronounced cloud top radiative cooling of up to 6Kh(-1). To put this into context, a second case elaborates respective measurements with BELUGA in a cloudless situation. In a third example, a multilayer stratocumulus was probed, revealing reduced turbulence and negligible cloud top radiative cooling for the lower cloud layer. In all three cases the net radiative fluxes are much higher than turbulent fluxes. Altogether, BELUGA has proven its robust performance in cloudy conditions of the Arctic atmospheric boundary layer.