Search Results

You are looking at 1 - 5 of 5 items for :

  • Author or Editor: Qiang Zhao x
  • Bulletin of the American Meteorological Society x
  • Refine by Access: All Content x
Clear All Modify Search
Kun Zhao
,
Qing Lin
,
Wen-Chau Lee
,
Y. Qiang Sun
, and
Fuqing Zhang

Abstract

Strong tropical cyclones often undergo eyewall replacement cycles that are accompanied by concentric eyewalls and/or rapid intensity changes while the secondary eyewall contracts radially inward and eventually replaces the inner eyewall. To the best of our knowledge, the only documented partial/incomplete tertiary eyewall has been mostly inferred from two-dimensional satellite images or one-dimensional aircraft flight-level measurements that can be regarded as indirect and tangential. This study presents the first high spatial and temporal resolution Doppler radar observations of a tertiary eyewall formation event in Typhoon Usagi (2013) over a 14-h time period before it makes landfall. The primary (tangential) and secondary (radial) circulations of Usagi deduced from the Ground-Based Velocity Track Display (GBVTD) methodology clearly portrayed three distinct axisymmetric maxima of radar reflectivity, tangential wind, vertical velocity, and vertical vorticity. Usagi’s central pressure steadily deepened during the contraction of the secondary and tertiary eyewalls until the tertiary eyewall hit the coast of southeast China, which erminated the intensification of the storm.

Full access
Shunlin Liang
,
Jie Cheng
,
Kun Jia
,
Bo Jiang
,
Qiang Liu
,
Zhiqiang Xiao
,
Yunjun Yao
,
Wenping Yuan
,
Xiaotong Zhang
,
Xiang Zhao
, and
Ji Zhou

Abstract:

The Global Land Surface Satellite (GLASS) product suite currently contains 12 products, including leaf area index, fraction of absorbed photosynthetically active radiation, fraction of green vegetation coverage, gross primary production, broadband albedo, broadband longwave emissivity, downward shortwave radiation and photosynthetically active radiation, land surface temperature, downward and upwelling thermal radiation, all-wave net radiation, and evapotranspiration. These products are generated from the Advanced Very High Resolution Radiometer and Moderate Resolution Imaging Spectroradiometer satellite data. Their unique features include long-term temporal coverage (many from 1981 to the present), high spatial resolutions of the surface radiation products (1 km and 0.05°), spatial continuities without missing pixels, and high quality and accuracy based on extensive validation using in situ measurements and intercomparisons with other existing satellite products. Moreover, the GLASS products are based on robust algorithms that have been published in peer-reviewed literature. Herein, we provide an overview of the algorithm development, product characteristics, and some preliminary applications of these products. We also describe the next steps, such as improving the existing GLASS products, generating more climate data records (CDRs), broadening product dissemination, and fostering their wider utilization. The GLASS products are freely available to the public.

Full access
Xuhui Lee
,
Zhiqiu Gao
,
Chaolin Zhang
,
Fei Chen
,
Yinqiao Hu
,
Weimei Jiang
,
Shuhua Liu
,
Longhua Lu
,
Jielun Sun
,
Jiemin Wang
,
Zhihua Zeng
,
Qiang Zhang
,
Ming Zhao
, and
Mingyu Zhou
Full access
Ping Zhao
,
Xiangde Xu
,
Fei Chen
,
Xueliang Guo
,
Xiangdong Zheng
,
Liping Liu
,
Yang Hong
,
Yueqing Li
,
Zuo La
,
Hao Peng
,
Linzhi Zhong
,
Yaoming Ma
,
Shihao Tang
,
Yimin Liu
,
Huizhi Liu
,
Yaohui Li
,
Qiang Zhang
,
Zeyong Hu
,
Jihua Sun
,
Shengjun Zhang
,
Lixin Dong
,
Hezhen Zhang
,
Yang Zhao
,
Xiaolu Yan
,
An Xiao
,
Wei Wan
,
Yu Liu
,
Junming Chen
,
Ge Liu
,
Yangzong Zhaxi
, and
Xiuji Zhou

Abstract

This paper presents the background, scientific objectives, experimental design, and preliminary achievements of the Third Tibetan Plateau (TP) Atmospheric Scientific Experiment (TIPEX-III) for 8–10 years. It began in 2013 and has expanded plateau-scale observation networks by adding observation stations in data-scarce areas; executed integrated observation missions for the land surface, planetary boundary layer, cloud–precipitation, and troposphere–stratosphere exchange processes by coordinating ground-based, air-based, and satellite facilities; and achieved noticeable progress in data applications. A new estimation gives a smaller bulk transfer coefficient of surface sensible heat over the TP, which results in a reduction of the possibly overestimated heat intensity found in previous studies. Summer cloud–precipitation microphysical characteristics and cloud radiative effects over the TP are distinguished from those over the downstream plains. Warm rain processes play important roles in the development of cloud and precipitation over the TP. The lower-tropospheric ozone maximum over the northeastern TP is attributed to the regional photochemistry and long-range ozone transports, and the heterogeneous chemical processes of depleting ozone near the tropopause might not be a dominant mechanism for the summer upper-tropospheric–lower-stratospheric ozone valley over the southeastern TP. The TP thermodynamic function not only affects the local atmospheric water maintenance and the downstream precipitation and haze events but also modifies extratropical atmospheric teleconnections like the Asia–Pacific Oscillation, subtropical anticyclones over the North Pacific and Atlantic, and temperature and precipitation over Africa, Asia, and North America. These findings provide new insights into understanding land–atmosphere coupled processes over the TP and their effects, improving model parameterization schemes, and enhancing weather and climate forecast skills.

Open access
Yaohui Li
,
Xing Yuan
,
Hongsheng Zhang
,
Runyuan Wang
,
Chenghai Wang
,
Xianhong Meng
,
Zhiqiang Zhang
,
Shanshan Wang
,
Yang Yang
,
Bo Han
,
Kai Zhang
,
Xiaoping Wang
,
Hong Zhao
,
Guangsheng Zhou
,
Qiang Zhang
,
Qing He
,
Ni Guo
,
Wei Hou
,
Cunjie Zhang
,
Guoju Xiao
,
Xuying Sun
,
Ping Yue
,
Sha Sha
,
Heling Wang
,
Tiejun Zhang
,
Jinsong Wang
, and
Yubi Yao

Abstract

A major experimental drought research project entitled “Mechanisms and Early Warning of Drought Disasters over Northern China” (DroughtEX_China) was launched by the Ministry of Science and Technology of China in 2015. The objective of DroughtEX_China is to investigate drought disaster mechanisms and provide early-warning information via multisource observations and multiscale modeling. Since the implementation of DroughtEX_China, a comprehensive V-shape in situ observation network has been established to integrate different observational experiment systems for different landscapes, including crops in northern China. In this article, we introduce the experimental area, observational network configuration, ground- and air-based observing/testing facilities, implementation scheme, and data management procedures and sharing policy. The preliminary observational and numerical experimental results show that the following are important processes for understanding and modeling drought disasters over arid and semiarid regions: 1) the soil water vapor–heat interactions that affect surface soil moisture variability, 2) the effect of intermittent turbulence on boundary layer energy exchange, 3) the drought–albedo feedback, and 4) the transition from stomatal to nonstomatal control of plant photosynthesis with increasing drought severity. A prototype of a drought monitoring and forecasting system developed from coupled hydroclimate prediction models and an integrated multisource drought information platform is also briefly introduced. DroughtEX_China lasted for four years (i.e., 2015–18) and its implementation now provides regional drought monitoring and forecasting, risk assessment information, and a multisource data-sharing platform for drought adaptation over northern China, contributing to the global drought information system (GDIS).

Full access