Next Article in Journal
Evaluation of Meteorological Drought and Flood Scenarios over Kenya, East Africa
Previous Article in Journal
Gaseous Emissions from a Seagoing Ship under Different Operating Conditions in the Coastal Region of China
Open AccessArticle

Spatiotemporal Trends of Aerosols over Urban Regions in Pakistan and Their Possible Links to Meteorological Parameters

1
Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters (CIC-FEMD), Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration, School of Atmospheric SciencesNanjing University of Information Science and Technology, Nanjing 210044, China
2
Pakistan Meteorological Department, Sector H-8/2, Islamabad 44000, Pakistan
3
Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters (CIC-FEMD), School of Geographical Sciences, Nanjing University of Information Science and Technology, Nanjing 210044, China
4
Key Laboratory of Meteorological Disaster, Ministry of Education (KLME), Joint International Research Laboratory of Climate and Environmental Change (ILCEC), Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters (CIC-FEMD), Earth System Modeling Center, Nanjing University of Information Science and Technology (NUIST), Nanjing 210044, China
5
Qinghai Provincial Meteorological Observatory, Xining 810001, China
6
Beijing Meteorological Observation Center, Beijing 100089, China
7
Golmud Meteorological Bureau of Qinghai Province, Golmud, Qinghai 816099, China
*
Authors to whom correspondence should be addressed.
Atmosphere 2020, 11(3), 306; https://doi.org/10.3390/atmos11030306
Received: 5 March 2020 / Revised: 17 March 2020 / Accepted: 18 March 2020 / Published: 21 March 2020
(This article belongs to the Section Aerosols)
Aerosol optical depth (AOD) has become one of the most crucial parameters for climate change assessment on regional and global scales. The present study investigates trends in AOD using long-term data derived from moderate resolution imaging spectro-radiometer (MODIS) over twelve regions in Pakistan. Different statistical tests are used to assess the annual and seasonal trends in AOD. Results reveal increasing AOD trends over most of the selected regions with an obvious increase over the north and northeastern parts of the study area. Annually, increasing trends (0.0002–0.0047 year−1) were observed over seven regions, with three being statistically significant. All the selected regions experience increasing AOD trends during the winter season with six being statistically significant while during the summer season seven regions experience increasing AOD trends and the remaining five exhibit the converse with two being statistically significant. The changes in the sign and magnitude of AOD trends have been attributed to prevailing meteorological conditions. The decreasing rainfall and increasing temperature trends mostly support the increasing AOD trend over the selected regions. The high/low AOD phases during the study period may be ascribed to the anomalies in mid-tropospheric relative humidity and wind fields. The summer season is generally characterized by high AOD with peak values observed over the regions located in central plains, which can be attributed to the dense population and enhanced concentration of industrial and vehicular emissions over this part of the study area. The results derived from the present study give an insight into aerosol trends and could form the basis for aerosol-induced climate change assessment over the study area. View Full-Text
Keywords: AOD trends; modified Mann–Kendall test; MODIS; Pakistan AOD trends; modified Mann–Kendall test; MODIS; Pakistan
Show Figures

Figure 1

MDPI and ACS Style

Ali, G.; Bao, Y.; Ullah, W.; Ullah, S.; Guan, Q.; Liu, X.; Li, L.; Lei, Y.; Li, G.; Ma, J. Spatiotemporal Trends of Aerosols over Urban Regions in Pakistan and Their Possible Links to Meteorological Parameters. Atmosphere 2020, 11, 306.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop