Heavy air pollution suppresses summer thunderstorms in central China

نویسندگان

  • Xin Yang
  • Zhanyu Yao
  • Zhanqing Li
  • Tianyi Fan
چکیده

Time series of rainfall, thunderstorms, temperatures, winds and aerosols of 50 years have been analyzed at the Xian valley (1951–2005, rain rates data are only available for the period of 1961–2000 for Xian) and the nearby Mount Hua (1951–2005) in central China, for assessing the impact of the increasing air pollution on convective precipitation. Adding aerosols to pristine air initially increases convective rainfall. However, aerosol amounts in the Xian valley (represented by large AOT and significant decreasing trend in visibility in the study area) have been shown to be sufficiently high so that added aerosols suppress convection and precipitation, by both radiative and microphysical effects, even at the starting of the analysis period in the 1950s. It was found that the aerosol’s negative radiative forcing stabilized the lowest troposphere. The stabilization resulted in less vertical exchanges of air, which caused reduction in the lowland (Xian) surface winds and increase in the highland (Mount Hua) wind speeds. The decreased instability caused a decrease in the frequency of the thunderstorm normalized by rainfall amount in the lowland due to the thick aerosol layer above, but not at the highland, above which the aerosol layer was much thinner. The indicated decreasing trend of highland precipitation was associated with a similar size decreasing trend in thunderstorm frequency. This decrease was contributed by light and moderate (o25 mmday ) rainy days. These patterns of rainfall changes at the highland are consistent with the microphysical suppressive effects of aerosols. Despite the dramatic relative decrease in the already originally scarce thunderstorm activity in the Xian valley, the rainfall amount there appears to have little diurnal cycle, and shows little trend with the increasing aerosol amounts. Because only small fraction of the rainfall in Xian is generated by local instability, as indicated by the flat diurnal cycle, it appears to be a condition which is unsuitable for quantifying the impact of heavy aerosols on rainfall amounts. However, the dramatic relative decrease of the scarce thunderstorms in Xian suggests that aerosol’s radiative effect can be substantial. Such study should be extended to other areas where local surface heating dominates rainfall amount. & 2013 Elsevier Ltd. All rights reserved.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Increases in thunderstorm activity and relationships with air pollution in southeast China

This study analyzes 15 years of Tropical Rainfall Measuring Mission (TRMM) satellite data, together with surface observations of thunderstorms and visibility, to study trends and relationships between aerosols and thunderstorms in southeast China. TRMM data used are from the lightning imaging sensor (LIS) and the precipitation radar (PR). Surface data are human-observed thunderstormoccurrence a...

متن کامل

Impact of East Asian summer monsoon on the air quality over China: View from space

[1] Tropospheric O3 columns retrieved fromOzoneMonitoring Instrument andMicrowave Limb Sounder measurements, CO columns retrieved from Measurements of Pollution in the Troposphere, and tropospheric O3 and CO concentrations retrieved from the Tropospheric Emission Spectrometer from May to August in 2006 are analyzed using the Regional Chemical and Transport Model to investigate the impact of the...

متن کامل

بررسی تغییرات زمانی و تحلیل فضایی رخداد توفان‌های تندری و ارتباط آن با انسو مورد: استان سیستان و بلوچستان

Thunderstorms are one of the most important, abundant and severe atmospheric hazards. In addition to destroying a large amount of agricultural products and construction projects, cause many human casualties are annually in different parts of the world (Iran Pour and et al, 2015). This phenomenon is associated with severe storms, showery precipitation, hail (Puranik and Karekar, 2004), and thund...

متن کامل

Steady decline of east Asian monsoon winds, 1969–2000: Evidence from direct ground measurements of wind speed

[1] It is commonly believed that greenhouse-gas-induced global warming can weaken the east Asian winter monsoon but strengthen the summer monsoon, because of stronger warming over high-latitude land as compared to low-latitude oceans. In this study, we show that the surface wind speed associated with the east Asian monsoon has significantly weakened in both winter and summer in the recent three...

متن کامل

Heavy air pollution in Beijing

Heavy air pollution episodes in Beijing during January 2013: inorganic ion chemistry and source analysis using Highly Time-Resolved Measurements in an urban site B. Han, R. Zhang, W. Yang, Z. Bai, Z. Ma, and W. Zhang State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, China Beijing Municipal Research Institute of Envir...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2013