Mesoscale characteristics of dust storms and mineral dust aerosol's spectral optical depth over Northern China (Invited Paper)

2005 ◽  
Author(s):  
Daren Lu ◽  
Wenxing Zhang ◽  
Hongzhou Li
Keyword(s):  
Optical Depth ◽  
Mineral Dust ◽  
Northern China ◽  
Dust Storms

Mineral Dust Cycle

2016 ◽  
Author(s):  
Irina Sokolik
Keyword(s):  
Atmospheric Aerosols ◽  
Environmental Changes ◽  
Mineral Dust ◽  
Global Climate ◽  
Dust Emission ◽  
Northern China ◽  
Dust Storms ◽  
Atmospheric Composition ◽  
System Response ◽  
Beneficial Effects

There is scientific consensus that human activities have been altering the atmospheric composition and are a key driver of global climate and environmental changes since pre-industrial times (IPCC, 2013). It is a pressing priority to understand the Earth system response to atmospheric aerosol input from diverse sources, which so far remain one of the largest uncertainties in climate studies (Boucher et al., 2014; Forster et al., 2007). As the second most abundant component (in terms of mass) of atmospheric aerosols, mineral dust exerts tremendous impacts on Earth’s climate and environment through various interaction and feedback processes. Dust can also have beneficial effects where it deposits: Central and South American rain forests get most of their mineral nutrients from the Sahara; iron-poor ocean regions get iron; and dust in Hawaii increases plantain growth. In northern China as well as the midwestern United States, ancient dust storm deposits known as loess are highly fertile soils, but they are also a significant source of contemporary dust storms when soil-securing vegetation is disturbed. Accurate assessments of dust emission are of great importance to improvements in quantifying the diverse dust impacts.

The Impact of Dust Storms on Aerosol Optical Depth and Radiative Forcing

2020 ◽  
Vol 16 (1) ◽  
pp. 1-14
Author(s):  
Monim Jiboori ◽  
Nadia Abed ◽  
Mohamed Abdel Wahab
Keyword(s):  
Aerosol Optical Depth ◽  
Optical Depth ◽  
Radiative Forcing ◽  
Dust Storms ◽  
The Impact

scholarly journals Aerosol optical depth retrievals at the Izaña Atmospheric Observatory from 1941 to 2013 by using artificial neural networks

2016 ◽  
Vol 9 (1) ◽  
pp. 53-62 ◽  
Author(s):  
R. D. García ◽  
O. E. García ◽  
E. Cuevas ◽  
V. E. Cachorro ◽  
A. Barreto ◽  
...  
Keyword(s):  
Neural Networks ◽  
Time Series ◽  
Artificial Neural Networks ◽  
Aerosol Optical Depth ◽  
Optical Depth ◽  
Mineral Dust ◽  
Dust Particles ◽  
Filter Radiometer ◽  
Artificial Neural

Abstract. This paper presents the reconstruction of a 73-year time series of the aerosol optical depth (AOD) at 500 nm at the subtropical high-mountain Izaña Atmospheric Observatory (IZO) located in Tenerife (Canary Islands, Spain). For this purpose, we have combined AOD estimates from artificial neural networks (ANNs) from 1941 to 2001 and AOD measurements directly obtained with a Precision Filter Radiometer (PFR) between 2003 and 2013. The analysis is limited to summer months (July–August–September), when the largest aerosol load is observed at IZO (Saharan mineral dust particles). The ANN AOD time series has been comprehensively validated against coincident AOD measurements performed with a solar spectrometer Mark-I (1984–2009) and AERONET (AErosol RObotic NETwork) CIMEL photometers (2004–2009) at IZO, obtaining a rather good agreement on a daily basis: Pearson coefficient, R, of 0.97 between AERONET and ANN AOD, and 0.93 between Mark-I and ANN AOD estimates. In addition, we have analysed the long-term consistency between ANN AOD time series and long-term meteorological records identifying Saharan mineral dust events at IZO (synoptical observations and local wind records). Both analyses provide consistent results, with correlations  >  85 %. Therefore, we can conclude that the reconstructed AOD time series captures well the AOD variations and dust-laden Saharan air mass outbreaks on short-term and long-term timescales and, thus, it is suitable to be used in climate analysis.

Aerosol Radiative Forcing and Forcing Efficiency in the UVB for Regions Affected by Saharan and Asian Mineral Dust

2009 ◽  
Vol 66 (4) ◽  
pp. 1033-1040 ◽  
Author(s):  
O. E. García ◽  
A. M. Díaz ◽  
F. J. Expósito ◽  
J. P. Díaz ◽  
A. Redondas ◽  
...  
Keyword(s):  
Aerosol Optical Depth ◽  
Optical Depth ◽  
Radiative Forcing ◽  
Climate Model ◽  
Mineral Dust ◽  
Global Climate ◽  
Global Climate Model ◽  
Aerosol Radiative Forcing ◽  
Benchmark Database ◽  
Aerosol Radiative

Abstract The influence of mineral dust on ultraviolet energy transfer is studied for two different mineralogical origins. The aerosol radiative forcing ΔF and the forcing efficiency at the surface ΔFeff in the range 290–325 nm were estimated in ground-based stations affected by the Saharan and Asian deserts during the dusty seasons. UVB solar measurements were taken from the World Ozone and Ultraviolet Data Center (WOUDC) for four Asian stations (2000–04) and from the Santa Cruz Observatory, Canary Islands (2002–03), under Gobi and Sahara Desert influences, respectively. The Moderate Resolution Imaging Spectroradiometer (MODIS) aerosol optical depth at 550 nm was used to characterize the aerosol load τ, whereas the aerosol index provided by the Total Ozone Mapping Spectrometer (TOMS) sensor was employed to identify the mineral dust events. The ΔF is strongly affected by the aerosol load, the values found being comparable in both regions during the dusty seasons. Under those conditions, ΔF values as large as −1.29 ± 0.53 W m−2 (τ550 = 0.48 ± 0.24) and −1.43 ± 0.38 W m−2 (τ550 = 0.54 ± 0.26) were reached under Saharan and Asian dust conditions, respectively. Nevertheless, significant differences have been observed in the aerosol radiative forcing per unit of aerosol optical depth in the slant path, τS. The maximum ΔFeff values associated with dust influences were −1.55 ± 0.20 W m−2 τS550−1 for the Saharan region and −0.95 ± 0.11 W m−2 τS550−1 in the Asian area. These results may be used as a benchmark database for establishing aerosol corrections in UV satellite products or in global climate model estimations.

scholarly journals Measurement of aerosol optical depth and sub-visual cloud detection using the optical depth sensor (ODS)

2016 ◽  
Vol 9 (2) ◽  
pp. 455-467 ◽  
Author(s):  
D. Toledo ◽  
P. Rannou ◽  
J.-P. Pommereau ◽  
A. Sarkissian ◽  
T. Foujols
Keyword(s):  
Aerosol Optical Depth ◽  
Optical Depth ◽  
Diffuse Radiation ◽  
Dust Storms ◽  
Saharan Dust ◽  
Cloud Detection ◽  
Depth Sensor ◽  
Data Set ◽  
Good Agreement

Abstract. A small and sophisticated optical depth sensor (ODS) has been designed to work in the atmosphere of Mars. The instrument measures alternatively the diffuse radiation from the sky and the attenuated direct radiation from the Sun on the surface. The principal goals of ODS are to retrieve the daily mean aerosol optical depth (AOD) and to detect very high and optically thin clouds, crucial parameters in understanding the Martian meteorology and climatology. The detection of clouds is undertaken at twilight, allowing the detection and characterization of clouds with opacities below 0.03 (sub-visual clouds). In addition, ODS is capable to retrieve the aerosol optical depth during nighttime from moonlight measurements. Recently, ODS has been selected at the METEO meteorological station on board the ExoMars 2018 Lander. In order to study the performance of ODS under Mars-like conditions as well as to evaluate the retrieval algorithms for terrestrial measurements, ODS was deployed in Ouagadougou (Africa) between November 2004 and October 2005, a Sahelian region characterized by its high dust aerosol load and the frequent occurrence of Saharan dust storms. The daily average AOD values retrieved by ODS were compared with those provided by a CIMEL sunphotometer of the AERONET (Aerosol Robotic NETwork) network localized at the same location. Results represent a good agreement between both ground-based instruments, with a correlation coefficient of 0.77 for the whole data set and 0.94 considering only the cloud-free days. From the whole data set, a total of 71 sub-visual cirrus (SVC) were detected at twilight with opacities as thin as 1.10−3 and with a maximum of occurrence at altitudes between 14 and 20 km. Although further optimizations and comparisons of ODS terrestrial measurements are required, results indicate the potential of these measurements to retrieve the AOD and detect sub-visual clouds.

scholarly journals Desertification Control Practices in China

2020 ◽  
Vol 12 (8) ◽  
pp. 3258
Author(s):  
Yanli Lyu ◽  
Peijun Shi ◽  
Guoyi Han ◽  
Lianyou Liu ◽  
Lanlan Guo ◽  
...  
Keyword(s):  
Water Conservation ◽  
Anthropogenic Activities ◽  
Northern China ◽  
Global Scale ◽  
Lessons Learned ◽  
Dust Storms ◽  
Arid Ecosystems ◽  
Desertification Control ◽  
The Impact ◽  
Semi Arid

Desertification is a form of land degradation principally in semi-arid and arid areas influenced by climatic and human factors. As a country plagued by extensive sandy desertification and frequent sandstorms and dust storms, China has been trying to find ways to achieve the sustainable management of desertified lands. This paper reviewed the impact of climate change and anthropogenic activities on desertified areas, and the effort, outcome, and lessons learned from desertification control in China. Although drying and warming trends and growing population pressures exist in those areas, the expanding trend of desertified land achieved an overall reversal. In the past six decades, many efforts, including government policies, forestry, and desertification control programs, combined with eco-industrialization development, have been integrated to control the desertification in northern China. Positive human intervention including afforestation, and the rehabilitation of mobile sandy land, and water conservation have facilitated the return of arid and semi-arid ecosystems to a more balanced state. China’s practices in desertification control could provide valuable knowledge for sustainable desertified land management on a global scale.

scholarly journals <i>A Tale of Two Dust Storms</i>: analysis of a complex dust event in the Middle East

2019 ◽  
Vol 12 (9) ◽  
pp. 5101-5118 ◽  
Author(s):  
Steven D. Miller ◽  
Louie D. Grasso ◽  
Qijing Bian ◽  
Sonia M. Kreidenweis ◽  
Jack F. Dostalek ◽  
...  
Keyword(s):  
Water Vapor ◽  
Mineral Dust ◽  
Weather Prediction ◽  
Detection Threshold ◽  
Dust Storms ◽  
Moist Air ◽  
Air Mass ◽  
Dry Air ◽  
Environmental Controls ◽  
Dust Detection

Abstract. Lofted mineral dust over data-sparse regions presents considerable challenges to satellite-based remote sensing methods and numerical weather prediction alike. The southwest Asia domain is replete with such examples, with its diverse array of dust sources, dust mineralogy, and meteorologically driven lofting mechanisms on multiple spatial and temporal scales. A microcosm of these challenges occurred over 3–4 August 2016 when two dust plumes, one lofted within an inland dry air mass and another embedded within a moist air mass, met over the southern Arabian Peninsula. Whereas conventional infrared-based techniques readily detected the dry air mass dust plume, they experienced marked difficulties in detecting the moist air mass dust plume, becoming apparent when visible reflectance revealed the plume crossing over an adjacent dark water background. In combining information from numerical modeling, multi-satellite and multi-sensor observations of lofted dust and moisture profiles, and idealized radiative transfer simulations, we develop a better understanding of the environmental controls of this event, characterizing the sensitivity of infrared-based dust detection to column water vapor, dust vertical extent, and dust optical properties. Differences in assumptions of dust complex refractive index translate to variations in the sign and magnitude of the split-window brightness temperature difference commonly used for detecting mineral dust. A multi-sensor technique for mitigating the radiative masking effects of water vapor via modulation of the split-window dust-detection threshold, predicated on idealized simulations tied to these driving factors, is proposed and demonstrated. The new technique, indexed to an independent description of the surface-to-500 hPa atmospheric column moisture, reveals parts of the missing dust plume embedded in the moist air mass, with the best performance realized over land surfaces.

scholarly journals Dust Storms in Northern China: Long-Term Spatiotemporal Characteristics and Climate Controls

2017 ◽  
Vol 30 (17) ◽  
pp. 6683-6700 ◽  
Author(s):  
Qingyu Guan ◽  
Xiazhong Sun ◽  
Jing Yang ◽  
Baotian Pan ◽  
Shilei Zhao ◽  
...  
Keyword(s):  
Wind Speed ◽  
Dust Storm ◽  
Northern China ◽  
Dust Storms ◽  
Effect Of Temperature ◽  
Mean Annual Precipitation ◽  
Mean Annual Temperature ◽  
Spatiotemporal Characteristics ◽  
Dust Generation ◽  
The Mean

Airborne dust derived from desertification in northern China can be transported to East Asia and other regions, impairing human health and affecting the global climate. This study of northern China dust provides an understanding of the mechanism of dust generation and transportation. The authors used dust storm and climatological data from 129 sites and normalized difference vegetation index (NDVI) datasets in northern China to analyze spatiotemporal characteristics and determine the main factors controlling dust storms occurring during 1960–2007. Dust storm–prone areas are consistent with the spatial distribution of northern China deserts where the average wind speed (AWS) is more than 2 m s−1, the mean annual temperature (MAT) ranges from 5° to 10°C, and the mean annual precipitation (MAP) is less than 450 mm. Dust storms commonly occur on spring afternoons in a 3- to 6-h pattern. The three predominant factors that can affect DSF are the maximum wind speed, AWS, and MAT. During 1960–2007, dust storm frequency (DSF) in most regions of northern China fluctuated but had a decreasing trend; this was mainly caused by a gradual reduction in wind speed. The effect of temperature on DSF is complex, as positive and negative correlations exist simultaneously. Temperatures can affect source material (dust, sand, etc.), cyclone activity, and vegetation growth status, which influence the generation of dust storms. NDVI and precipitation are negatively correlated with DSF, but the effect is weak. Vegetation can protect the topsoil environment and prevent dust storm creation but is affected by the primary decisive influence of precipitation.

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