Global Assimilation of Loon Stratospheric Balloon Observations
Global Assimilation of Loon Stratospheric Balloon Observations
复制标题
Loon 平流层气球观测的全球同化
DOI：
--
复制
发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Robert W. Carver
中科院分区：
文献类型：
--
作者：
Lawrence Coy;M. Schoeberl;Steven Pawson;Salvatore Candido;Robert W. Carver
平流层风的准确分析对于确定现实的成分输送以及提供更好的平流层诊断研究和预报非常重要。本研究探讨全球气象分析的影响，使用来自Loon超压气球在平流层下部（以下Loon风）作为额外的输入观测到的戈达德地球观测系统（GEOS）数据同化系统。为了充分研究同化Loon风的影响，采取了两个步骤：（1）比较GEOS分析风与Loon风（控制实验）和（2）检查同化Loon风到GEOS数据同化系统中的影响（Loon实验）。选择的时间段是2014年6月至8月，当时发射了150多个Loon气球，主要是在南半球。在中纬度地区，Loon风和控制风吻合得很好（Loon气球纬向风观测减去预报，O-F，均方根（RMS）值约为2.75 m/s），同化Loon风的影响很小（O-F RMS值不变）。在热带地区，Loon观测和控制分析风的差异大于中纬度地区（纬向风O-F RMS ~3.75 m/s），同化Loon风可以使纬向风O-F RMS提高~1 m/s。在选定的Loon观测和控制分析差异很大的情况下（O-F RMS值大于10 m/s），同化Loon风会显着降低纬向风O-F RMS 5 m/s。O-F RMS值的这些下降表明，在Loon气球观测位置的6小时预报有所改善。
Accurate analyses of stratospheric winds are important for determining realistic constituent transport and providing improved diagnostic studies and forecasts of the stratosphere. This study examines impacts on global meteorological analyses resulting from using winds derived from Loon superpressure balloons in the lower stratosphere (hereafter Loon winds) as additional input observations to the Goddard Earth Observing System (GEOS) data assimilation system. To fully investigate the impacts of assimilating the Loon winds, two steps are taken: (1) comparison of the GEOS analysis winds with Loon winds (Control experiment) and (2) examination of the impacts of assimilating the Loon winds into the GEOS data assimilation system (Loon experiment). The time period selected is June–August 2014 when over 150 Loon balloons were launched, mainly in the Southern Hemisphere. In the middle latitudes, the Loon winds and Control winds agree well (Loon balloon zonal wind observation minus forecast, O − F, root‐mean‐square (RMS) values of ~2.75 m/s) and assimilating the Loon winds has a small impact (O − F RMS values unchanged). In the tropics, the Loon observations and Control analysis winds differ more than in middle latitudes (zonal wind O − F RMS ~3.75 m/s) and assimilating the Loon winds improves the zonal wind O − F RMS by ~1 m/s. In selected cases where the Loon observations and Control analysis differ greatly (O − F RMS values greater than 10 m/s), assimilating Loon winds significantly decreases the zonal wind O − F RMS by 5 m/s. These decreases in O − F RMS values show that the 6‐hr forecasts are improved at the Loon balloon observation locations.