A case study on the vertical distribution and characteristics of aerosols using ground-based raman lidar, satellite and model over Western India

The vertical distribution of epiphytic bryophytes in European forests are still relatively poorly understood. The aim of the study was to analyse the diversity and vertical zonation of epiphytic mosses and liverworts on selected tree types (Quercus petraea, Betula pendula and Pinus sylvestris) within windthrow areas in the Kampinoski National Park (Central Poland). The investigations were performed in five parts of the trees: the tree base, lower trunk, upper trunk, lower crown, and upper crown. Deciduous trees have more species than pine trees (13 on Quercus and Betula, 8 on Pinus). The type of phorophyte was crucial for the differences in the species composition from the tree base to the upper crown that was observed. The highest richness of bryophytes was recorded on the tree bases, while the lowest was recorded in the upper parts of the crowns. The variability of the habitat conditions in the vertical gradient on the trunk that affected the patterns of the occurrence of species with different ecological preferences was determined using the Ellenberg indicator values. An increase in the value of the light and acidity indicators from the base of the trunk upwards and decreasing tendency in the case of moisture indicator was noted.

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Wind Erosion at a Saline Playa Environment, Ebinur Lake, Xinjiang, China - A Case Study on the Source of Saline Dust Storm

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.260-261.1003 ◽

2012 ◽

Vol 260-261 ◽

pp. 1003-1008

Author(s):

Dong Wei Liu ◽

Jilili Abuduwaili

Keyword(s):

Vertical Distribution ◽

Wind Erosion ◽

Dust Storms ◽

Aeolian Transport ◽

Near Surface ◽

Erosion Pins ◽

Dry Lake ◽

The Vertical Distribution ◽

Main Factor

In many arid and semiarid lands, dry lake beds (saline playa) represent a tremendous source of unconsolidated salt-rich sediments that are available for aeolian transport. Severe salt-dust storms caused by the erosion of such landforms have become very harmful natural phenomena. Base on texture and appearance characteristic, five principal undisturbed playa surfaces for sampling to investigate the deflation rate and the vertical distribution of material abraded using a wind-tunnel experiment in this study. Two additional field deflation monitoring transect were aslo established to examine vertical deflation by wind from measurements of erosion pins at the Ebinur (dry) Lake. The results indicate that winds greater than 8 m/s is the main factor for inducing the erosion of the playa sediments. Soft salt, aeloian sediment and alluvial deposit are the main sources of the saline dust storms in Ebinur region. The near-surface vertical distribution of material abraded concentrated in 0 -10 cm height. The annual wind erosion rate ranged from 0.48 cm to 5.6 cm in the northwest portion of the lake and from 0.24 cm to 0.96 cm in the southeast portion.

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Long-term variation in aerosol lidar ratio in Shanghai based on Raman lidar measurements

Atmospheric Chemistry and Physics ◽

10.5194/acp-21-5377-2021 ◽

2021 ◽

Vol 21 (7) ◽

pp. 5377-5391

Author(s):

Tongqiang Liu ◽

Qianshan He ◽

Yonghang Chen ◽

Jie Liu ◽

Qiong Liu ◽

...

Keyword(s):

Vertical Distribution ◽

Particle Shape ◽

Strong Dependence ◽

Influence Factors ◽

Raman Lidar ◽

Height Range ◽

Average Value ◽

Variation Characteristics ◽

Lidar Ratio ◽

The Vertical Distribution

Abstract. Accurate lidar ratio (LR) and better understanding of its variation characteristics can not only improve the retrieval accuracy of parameters from elastic lidar, but also play an important role in assessing the impacts of aerosols on climate. Using the observational data of a Raman lidar in Shanghai from 2017 to 2019, LRs at 355 nm were retrieved and their variations and influence factors were analyzed. Within the height range of 0.5–5 km, about 90 % of the LRs were distributed in 10–80 sr with an average value of 41.0 ± 22.5 sr, and the LR decreased with the increase in height. The volume depolarization ratio (δ) was positively correlated with LR, and it also decreased with the increase in height, indicating that the vertical distribution of particle shape was one of the influence factors of the variations in LR with height. LR had a strong dependence on the original source of air masses. Affected by the aerosols transported from the northwest, the average LR was the largest, 44.2 ± 24.7 sr, accompanied by the most irregular particle shape. The vertical distribution of LR was affected by atmospheric turbidity, with the greater gradient of LR under clean conditions. The LR above 1 km could be more than 80 sr, when Shanghai was affected by biomass burning aerosols.

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