EFSO at different geographical locations verified with observing-system experiments
EFSO at different geographical locations verified with observing-system experiments
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通过观测系统实验验证了不同地理位置的 EFSO
DOI：
10.1175/waf-d-20-0152.1
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发表时间：
2021
影响因子：
2.9
通讯作者：
and Nobumasa Komori
中科院分区：
文献类型：
--
作者：
Akira Yamazaki;Takemasa Miyoshi;Jun Inoue;Takeshi Enomoto;and Nobumasa Komori
在大气环流模式-集合卡尔曼滤波资料同化系统中实施了基于集合的预报观测敏感性诊断，以估计准业务全球观测系统的特定观测对每周短期预报的影响。审查了EFSO是否合理地近似了来自特定地理位置的观测子集对6小时预报的影响，以及6小时观测影响在7天预报期间可以保留多久。这些预报的参考数据来自12次数据否认试验，其中每一次都排除了从一个地理位置发射的三个无线电探空仪观测的一个子集。这12个地点是从北半球2015/16年冬季北半球四个北极地区、四个北半球中纬度地区和四个热带地区的三个纬度带中挑选出来的。估计的冬季平均EFSO观测影响与数据否认获得的6小时观测影响很好地对应，EFSO可以合理地估计数据拒绝对短期(6小时至2天)预报的观测影响。此外，在中期(4-7天)预报中发现，北极观测往往产生最广泛的影响，其短期观测影响可能对北极和北美洲中纬度地区产生有利影响。中纬度地区位于从北极向中纬度动力传播的下游。通过重复的北极数据否认实验获得的结果被发现与那些不重复的实验结果通常是相同的。
An ensemble-based forecast sensitivity to observations (EFSO) diagnosis has been implemented in an atmospheric general circulation model–ensemble Kalman filter data assimilation system to estimate the impacts of specific observations from the quasi-operational global observing system on weekly short-range forecasts. It was examined whether EFSO reasonably approximates the impacts of a subset of observations from specific geographical locations for 6-h forecasts, and how long the 6-h observation impacts can be retained during the 7-day forecast period. The reference for these forecasts was obtained from 12 data-denial experiments in each of which a subset of three radiosonde observations launched from a geographical location was excluded. The 12 locations were selected from three latitudinal bands comprising (i) four Arctic regions, (ii) four midlatitude regions in the Northern Hemisphere, and (iii) four tropical regions during the Northern Hemisphere winter of 2015/16. The estimated winter-averaged EFSO-derived observation impacts well corresponded to the 6-h observation impacts obtained by the data denials and EFSO could reasonably estimate the observation impacts by the data denials on short-range (from 6 h to 2 day) forecasts. Furthermore, during the medium-range (4–7 day) forecasts, it was found that the Arctic observations tend to seed the broadest impacts and their short-range observation impacts could be projected to beneficial impacts in Arctic and midlatitude North American areas. The midlatitude area was located just downstream of dynamical propagation from the Arctic toward the midlatitudes. Results obtained by repeated Arctic data-denial experiments were found to be generally common to those from the non-repeated experiments.