44 research outputs found
Investigation of the aerosol–cloud–rainfall association over the Indian summer monsoon region
Monsoonal rainfall is the
primary source of surface water in India. Using 12Â years of in situ and
satellite observations, we examined the association of aerosol loading with
cloud fraction, cloud top pressure, cloud top temperature, and daily surface
rainfall over the Indian summer monsoon region (ISMR). Our results showed
positive correlations between aerosol loading and cloud properties as well as
rainfall. A decrease in outgoing longwave radiation and an increase in
reflected shortwave radiation at the top of the atmosphere with an increase
in aerosol loading further indicates a possible seminal role of aerosols in
the deepening of cloud systems. Significant perturbation in liquid- and
ice-phase microphysics was also evident over the ISMR. For the polluted
cases, delay in the onset of collision–coalescence processes and an
enhancement in the condensation efficiency allows for more condensate mass to
be lifted up to the mixed colder phases. This results in the higher mass
concentration of larger-sized ice-phase hydrometeors and, therefore, implies
that the delayed rain processes eventually lead to more surface rainfall. A
numerical simulation of a typical rainfall event case over the ISMR using a
spectral bin microphysical scheme coupled with the Weather Research
Forecasting (WRF-SBM) model was also performed. Simulated microphysics also
illustrated that the initial suppression of warm rain coupled with an
increase in updraft velocity under high aerosol loading leads to enhanced
super-cooled liquid droplets above freezing level and ice-phase hydrometeors,
resulting in increased accumulated surface rainfall. Thus, both observational
and numerical analysis suggest that high aerosol loading may induce cloud
invigoration, thereby increasing surface rainfall over the ISMR. While the
meteorological variability influences the strength of the observed positive
association, our results suggest that the persistent aerosol-associated
deepening of cloud systems and an intensification of surface rain amounts was
applicable to all the meteorological sub-regimes over the ISMR. Hence, we
believe that these results provide a step forward in our ability to address
aerosol–cloud–rainfall associations based on satellite observations over
the ISMR
Ranichauri Data
DMPS aerosol size distribution and BC archived data
Rain drop size distribution
Rain drop size distribution measurements from a tropical site, Pune, India (JJAS, 2013-2015)
Ranichauri Data
DMPS aerosol size distribution and BC archived data
nCNC_SMPS_Hyd
Nano Condensation Nucleus Counter and Scanning Mobility Particle Sizer raw datatsets from 1 April to 25 June 202
COVID-19 PSM and SMPS
PSM inverted EM-algorithm, SMPS AIM software exported text file, trace gases and meteorological datasets for the years 2019 and 2020 during 15 April - 31 May
Quantitative assessment of AOD from 17 CMIP5 models based on satellite-derived AOD over India
Aerosol optical depth (AOD) values from 17Â CMIP5 models are compared with
Moderate Resolution Imaging Spectroradiometer (MODIS) and Multiangle Imaging
Spectroradiometer (MISR) derived AODs over India. The objective is to
identify the cases of successful AOD simulation by CMIP5 models, considering
satellite-derived AOD as a benchmark. Six years of AOD data (2000–2005) from
MISR and MODIS are processed to create quality-assured gridded AOD maps over
India, which are compared with corresponding maps of 17Â CMIP5 models at the
same grid resolution. Intercomparison of model and satellite data shows that
model-AOD is better correlated with MISR-derived AOD than MODIS. The
correlation between model-AOD and MISR-AOD is used to segregate the models
into three categories identifying their performance in simulating the AOD
over India. Maps of correlation between model-AOD and MISR-/MODIS-AOD are
generated to provide quantitative information about the intercomparison. The
two sets of data are examined for different seasons and years to examine the
seasonal and interannual variation in the correlation coefficients.
Latitudinal and longitudinal variations in AOD as simulated by models are
also examined and compared with corresponding variations observed by
satellites
Rain drop size distribution
Rain drop size distribution measurements from a tropical site, Pune, India (JJAS, 2013-2015)