Quantitative Detection of Dust Storms with the Millimeter Wave Radar in the Taklimakan Desert

Abstract

In order to conduct real-time quantitative monitoring of dust storms, Ka-band millimeter wave radar (MMWR) was utilized for the consecutive detection of dust storms over the Taklimakan Desert from April to June 2018. The retrievals of the reflectivity factor, dust spectrum distribution and dust mass concentration were carried out with the power spectrum data detected by MMWR for three dust storm processes. The analysis shows that: The probability density distribution of dust conforms to the lognormal distribution. During the dust storm processes, the effective detection height of the reflectivity factor was within 2000 m and the range of the reflectivity factors was between −25 dBZ and 25 dBZ. During the floating dust period, the effective height of the dust spectrum distribution was lower than 300 m and the values of dust mass concentration were less than 31.62 µg·m −3 , at a height of 200 m. Furthermore, during the blowing sand stage, the effective height of the dust spectrum distribution was normally lower than 600 m and the values of dust mass concentration were mainly less than 316.23 µg·m −3 , at a height of 200 m. During the dust storm period, the effective height of the dust spectrum distribution exceeded 1000 m; when the height was 100 m, the values of dust mass concentration were between 1220 µg·m −3 and 42, 146 µg·m −3 and the average mass concentration was 9287 µg·m −3 ; whereas, the values of dust mass concentration were between 2 µg·m −3 and 820 µg·m −3 when the height was 1200 m and the average mass concentration was 24 µg·m −3 . The relationship between the reflectivity factor Z and the dust mass concentration M is defined as Z = 651.6M 0.796 . Compared with the observational data from Grimm180 particle detector, the data of the retrieved dust mass concentration are basically accurate and this retrieved method proves to be feasible. Thus, the MMWR cans be used as a new device for quantitative monitoring of dust storms.

Visibility Parameter in Sand/Dust Storms’ Radio Wave Attenuation Equations: An Approach for Reliable Visibility Estimation Based on Existing Empirical Equations to Minimize Potential Biases in Calculations

“…Wei et al's [30] results confer greater credibility on the results obtained from Equation (13). Therefore, for evaluation purposes, the values may be adopted conveniently, considering that the observation height for Mujlid's [26] environment conditions could not have exceeded 1.7 m, which is the average human height [31].…”

“…By substituting the reported wind speeds (and estimated errors) in the order mentioned in the earlier paragraphs into Equation ( 13 [29] was superficially mentioned without elaborating on its employability restrictions. However, assuming the same study environment as in [29], a recently published work [30] indicated that variation in SDS particle concentrations are not only limited to changing wind speeds but can be observed in their vertical distribution as well. Wei et al's [30] real-time measurements revealed that during the SDS period for heights less than 100 m, the concentrations ranged between 1220 µg/m 3 and 42,146 µg/m 3 .…”

“…However, assuming the same study environment as in [29], a recently published work [30] indicated that variation in SDS particle concentrations are not only limited to changing wind speeds but can be observed in their vertical distribution as well. Wei et al's [30] real-time measurements revealed that during the SDS period for heights less than 100 m, the concentrations ranged between 1220 µg/m 3 and 42,146 µg/m 3 . Meanwhile, the lowest measured concentration in the same event at its initial meteorological conditions leading up to the storm was an average of 31.62 µg/m 3 at heights less than 200 m.…”

Impact of Dust Storm on the Atmospheric Boundary Layer over Ahmedabad, a Western Indian Region .

“…Wang et al (2013) have used wind pro ling radar to study the dust storm over Taklimakan desert in detail. Ming et al (2019) have used a groundbased multimeter wave radar to detect dust storm in the same desert region, where re ectivity factors of dust storms were better estimated in real time in comparison with satellite remote sensing. However, the spatial movement of the dust storm cannot be comprehended by ground based instruments.…”

A scheme to detect sand/dust weather applying meteorological radars

“…On the other hand, as we all know, microwave radar is widely distributed in monitoring stations all over the world, and it is an important means of meteorological monitoring, and plays a very important role in sudden and disastrous monitoring, forecasting and alarm. Recent field measurements have found that effective echoes have been received when using microwave radar to measure sandstorms, which provides an idea for using microwave radar to detect sandy dust weather (Wang et al, 2017;Ming et al, 2019). In addition, some studies have found that dust particles carry a large amount of net charge (Zheng et al, 2003;Bo et al, 2014;Zhang and Zhou, 2020), and the charge carried by particles will enhance the backscattering of radar waves and the attenuation of radar waves on the back-and-forth path.…”