Mesoscale Characteristics and Structures of Stratiform Precipitation on the Tibetan Plateau.

Shuji Shimizu; Ken’ichi Ueno; Hideyuki Fujii; Hiroyuki Yamada; Ryuichi Shirooka; Liping Liu

doi:10.2151/jmsj.79.435

Mesoscale structures of stratiform precipitation on the Tibetan Plateau using an X-band Doppler radar and TRMM PR

10.1117/12.410617 ◽

2000 ◽

Author(s):

Shuji Shimizu

Keyword(s):

Tibetan Plateau ◽

Doppler Radar ◽

The Tibetan Plateau ◽

Mesoscale Structures ◽

X Band ◽

Trmm Pr ◽

Stratiform Precipitation

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Combined Space and Ground Radars for Improving Quantitative Precipitation Estimations in the Eastern Downstream Region of the Tibetan Plateau. Part I: Variability in the Vertical Structure of Precipitation in ChuanYu Analyzed from Long-Term Spaceborne Observations by TRMM PR

Journal of Applied Meteorology and Climatology ◽

10.1175/jamc-d-16-0382.1 ◽

2017 ◽

Vol 56 (8) ◽

pp. 2259-2274 ◽

Cited By ~ 1

Author(s):

Lingzhi Zhong ◽

Rongfang Yang ◽

Lin Chen ◽

Yixin Wen ◽

Ruiyi Li ◽

...

Keyword(s):

Tibetan Plateau ◽

Vertical Structure ◽

Tropical Rainfall Measuring Mission ◽

Convective Precipitation ◽

The Tibetan Plateau ◽

Surface Precipitation ◽

Freezing Level ◽

Maximum Reflectivity ◽

Downstream Region ◽

Stratiform Precipitation

AbstractThis study presents a statistical analysis of the variability of the vertical structure of precipitation in the eastern downstream region of the Tibetan Plateau as measured by the Precipitation Radar (PR) on the National Aeronautics and Space Administration Tropical Rainfall Measuring Mission (TRMM) satellite. Data were analyzed over an 11-yr time span (January 2004–December 2014). The results show the seasonal and spatial variability of the storm height, freezing level, and bright band for different types of precipitation as well as the characteristics of intensity-related and type-related vertical profiles of reflectivity (VPR). Major findings were as follows: About 90% of the brightband peak reflectivity of stratiform precipitation was less than 32 dBZ, and 40% of the maximum reflectivity of convective precipitation exceeded 35 dBZ. The intensity of surface rainfall rates also depended on the shapes of VPRs. For stratiform precipitation, ice–snow aggregation was faster during moderate and heavy rainfall than it was in light rainfall. Since both the moisture and temperature are lower in winter, the transformation efficiency of hydrometeors becomes slower. Typical Ku-band representative climatological VPRs (CPRs) for stratiform precipitation have been created on the basis of the integration of normalized VPR shape for the given area and the rainfall intensity. All of the findings indicate that the developed CPRs can be used to improve surface precipitation estimates in regions with complex terrain where the ground-based radar net has limited visibility at low levels.

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A Comparative Study on the Vertical Structures and Microphysical Properties of Stratiform Precipitation over South China and the Tibetan Plateau

Remote Sensing ◽

10.3390/rs13152897 ◽

2021 ◽

Vol 13 (15) ◽

pp. 2897

Author(s):

Jingshu He ◽

Jiafeng Zheng ◽

Zhengmao Zeng ◽

Yuzhang Che ◽

Min Zheng ◽

...

Keyword(s):

Tibetan Plateau ◽

South China ◽

Sample Selection ◽

Doppler Velocity ◽

The Tibetan Plateau ◽

Atmospheric Conditions ◽

Melting Layer ◽

Microphysical Properties ◽

Raindrop Size Distribution ◽

Stratiform Precipitation

Under different water vapor and dynamic conditions, and the influence of topographies and atmospheric environments, stratiform precipitation over South China and the Tibetan Plateau can produce different features. In this study, stratiform precipitation vertical characteristics, bright-band (BB) microstructures, and the vertical variations of the raindrop size distribution (DSD) over a low-altitude site (Longmen site, 86 m) in South China and a high-altitude site (Nagqu site, 4507 m) on the Tibetan Plateau were comprehensively investigated and compared using measurements from a Ka-band millimeter-wave cloud radar (CR), a K-band microrain radar (MRR), and a Parsivel disdrometer (disdrometer). A reliable BB identification scheme was proposed on the basis of CR variables and used for stratiform precipitation sample selection and further statistics and analysis. Results indicate that melting layers over the Longmen are much higher and slightly thicker than those over the Nagqu due to significant differences in atmospheric conditions. For stratiform precipitation, vertical air motions and radar variables over the two sites show different variation trends from cloud top to the ground. Vertical air motions are very weak in the stratiform precipitation over the Longmen, whereas updrafts are more active over the Nagqu. Above the melting layer, radar equivalent reflectivity factor Ze (mean Doppler velocity VM) gradually increases (decreases) as height decreases over the two sites, but the aggregation rate for ice particles over the Longmen can be faster. In the melting layer, Ze (VM) at the BB bottom/center over the Longmen is larger (smaller) than those over the Nagqu for the reason that melted raindrops in the melting layers over the Longmen are larger than those over the Nagqu. Below the melting layer, profiles of radar variables and DSDs show completely different behaviors over the two sites, which reflects that the collision, coalescence, evaporation, and breakup processes of raindrops are different between the two sites. Over the Longmen, collision and coalescence dominate the precipitation properties; in particular, from 2.0–2.8 km, the breakup process competes with collision–coalescence processes but later is overpowered. In contrast, due to the lower BB heights over the Nagqu, collision and coalescence dominate raindrop properties. Comparisons of raindrop spectra suggest that the concentration of small (medium-to-large) raindrops over the Nagqu is much higher (slightly lower) than that over the Longmen. Therefore, the mass-weighted mean diameter Dm (the generalized intercept parameter Nw) over the Nagqu is smaller (larger) than that over the Longmen.

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