The higher concentration of PM_(10) and PM_(2.5) in the lower atmosphere is severely harmful for human health and it also makes visibility diminution along with weather and climate modifications.The main objective is ...The higher concentration of PM_(10) and PM_(2.5) in the lower atmosphere is severely harmful for human health and it also makes visibility diminution along with weather and climate modifications.The main objective is to find out the spatiotemporal variation and dispersal of PM_(10) and PM_(2.5) along with COVID-19 infection in the dusty city Kolkata.The consecutive two years PM_(10) and PM_(2.5) data of different stations have been obtained from State Pollution Control Board,Govt.of West Bengal.Forward trajectory analysis has been done through HYSPLIT(Hybrid Single Particle Lagrangian Integrated Trajectory)model to find the path and direction of air particles.The result showed that the various meteorological or environmental factors(such as temperature,relative humidity,wind,wind speed,pressure and gusty wind)and geographical location regulate the spatiotemporal variation of PM_(10) and PM_(2.5).These factors like high temperature with relative humidity and strong wind influence to disperse the particulate matters from north to south direction from city to outside during summer in Kolkata metropolitan city.During summer(both pre and lockdown years),the height of particles is extended up to 1000 m owing to active atmospheric ventilation whereas in winter it is confined within 100 m.The HYSPLIT model clearly specified that the particles dispersed from south,south-west to north and north east direction due to strong wind.The constant magnification of PM_(10) and PM_(2.5) in the lower atmosphere leads to greater frequency of COVID-19 infections and deaths.In Kolkata,the one of the crucial reasons of high infection and deaths(COVID-19)is co-morbidity of people.展开更多
Using NCEP reanalysis data and an airflow trajectory model based on the Lagrangian method, theHybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model, the daily backward trajectorieson the height of 85...Using NCEP reanalysis data and an airflow trajectory model based on the Lagrangian method, theHybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model, the daily backward trajectorieson the height of 850 hPa above the South China Sea (SCS) area are simulated from April to June. The onsetdate of the SCS summer monsoon from 1948 to 2009 is determined according to the simulated source ofairflow in the monitored area of the SCS. By analyzing the SCS monsoon onset dates over the 62 years, wefound that the number of years in which the SCS monsoon onset is earlier accounts for 13%, and the lateryears 14%, the normal years 73%, of all the 62 years. Analyses with the Lagrangian method, done incomparison with the other two methods which combine wind and potential pseudo-equivalent temperature,were performed to determine the onset dates of the SCS summer monsoon. In some years, the source of thesouthwest airflow in the monitored area of the SCS is in the subtropical region before the onset of the SCSmonsoon, so the airflow from the subtropics can be distinguished with the airflow from the tropics by usingthe Lagrangian method. The simulation by the trajectory model indicated that in some years, after the onsetof SCS summer monsoon, the SCS will be controlled by the southeast wind instead of the southwesterlyusually expected.展开更多
文摘The higher concentration of PM_(10) and PM_(2.5) in the lower atmosphere is severely harmful for human health and it also makes visibility diminution along with weather and climate modifications.The main objective is to find out the spatiotemporal variation and dispersal of PM_(10) and PM_(2.5) along with COVID-19 infection in the dusty city Kolkata.The consecutive two years PM_(10) and PM_(2.5) data of different stations have been obtained from State Pollution Control Board,Govt.of West Bengal.Forward trajectory analysis has been done through HYSPLIT(Hybrid Single Particle Lagrangian Integrated Trajectory)model to find the path and direction of air particles.The result showed that the various meteorological or environmental factors(such as temperature,relative humidity,wind,wind speed,pressure and gusty wind)and geographical location regulate the spatiotemporal variation of PM_(10) and PM_(2.5).These factors like high temperature with relative humidity and strong wind influence to disperse the particulate matters from north to south direction from city to outside during summer in Kolkata metropolitan city.During summer(both pre and lockdown years),the height of particles is extended up to 1000 m owing to active atmospheric ventilation whereas in winter it is confined within 100 m.The HYSPLIT model clearly specified that the particles dispersed from south,south-west to north and north east direction due to strong wind.The constant magnification of PM_(10) and PM_(2.5) in the lower atmosphere leads to greater frequency of COVID-19 infections and deaths.In Kolkata,the one of the crucial reasons of high infection and deaths(COVID-19)is co-morbidity of people.
基金Special Research Program for Public Welfare(Meteorology)of China(GYHY200906016)National Key Technology Support Program(2009BAC51B01)
文摘Using NCEP reanalysis data and an airflow trajectory model based on the Lagrangian method, theHybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model, the daily backward trajectorieson the height of 850 hPa above the South China Sea (SCS) area are simulated from April to June. The onsetdate of the SCS summer monsoon from 1948 to 2009 is determined according to the simulated source ofairflow in the monitored area of the SCS. By analyzing the SCS monsoon onset dates over the 62 years, wefound that the number of years in which the SCS monsoon onset is earlier accounts for 13%, and the lateryears 14%, the normal years 73%, of all the 62 years. Analyses with the Lagrangian method, done incomparison with the other two methods which combine wind and potential pseudo-equivalent temperature,were performed to determine the onset dates of the SCS summer monsoon. In some years, the source of thesouthwest airflow in the monitored area of the SCS is in the subtropical region before the onset of the SCSmonsoon, so the airflow from the subtropics can be distinguished with the airflow from the tropics by usingthe Lagrangian method. The simulation by the trajectory model indicated that in some years, after the onsetof SCS summer monsoon, the SCS will be controlled by the southeast wind instead of the southwesterlyusually expected.
