PhD Proposal: Qianqian Song
Friday, May 4, 2018 · 10 AM - 12 PM
ADVISOR: Dr. Zhibo Zhang
TITLE: Are Dust Aerosols Cooling or Warming Our Planet?A Study of the Net Direct Radiative Effects of Dust Aerosols
ABSTRACT: Mineral dust aerosols play an important role in modulating the Earth atmospheric energy budget through their interactions with both solar and thermal infrared radiations. The net direct radiative effect (DRE) of dust, which is the summation of shortwave (SW) and longwave (LW) effect, is dependent on dust microphysical and optical properties, among which dust particle size is an important one as it influences both DRESW and DRELW. Recent studies suggest that the dust particle size from the current satellite remote sensing techniques and the climate models are likely biased too small. As a result, the DRESW is biased too strong and the DRELW is biased too weak. Motivated by these recent studies and the fact that the DRELW of dust is relatively less studied and poorly understood, this research aims to quantify the DRELW of dust, as well as DRESW and DRE net, using satellite observations, in situ measurements and radiative transfer simulation. We have developed an observation-based method to estimate net dust direct radiative effect (DREnet) over Atlantic Ocean dust outflow region. This method is constrained by CERES observation in terms of flux. As the first part of the research, we propose to apply the same method to other dust active regions to ultimately obtain the dust DREnet globally.
The second part of this research is to perform a radiative closure experiment using collocated MODIS and CALIPSO observations. More specifically, the aerosol properties from the MODIS Dark Target product and the aerosol vertical profile observation from CALIPSO will be used to drive radiative transfer models to simulate the MODIS radiance observations which will be compared with the real MODIS observations. The objective of this experiment is to examine whether the retrieved dust properties, usually based on shortwave bands (i.e., 0.5 ~ 2.1 µm) could explain the dust radiative signatures in both shortwave and longwave (i.e., 8µm, 11 µm and 12 µm) regions.
TITLE: Are Dust Aerosols Cooling or Warming Our Planet?A Study of the Net Direct Radiative Effects of Dust Aerosols
ABSTRACT: Mineral dust aerosols play an important role in modulating the Earth atmospheric energy budget through their interactions with both solar and thermal infrared radiations. The net direct radiative effect (DRE) of dust, which is the summation of shortwave (SW) and longwave (LW) effect, is dependent on dust microphysical and optical properties, among which dust particle size is an important one as it influences both DRESW and DRELW. Recent studies suggest that the dust particle size from the current satellite remote sensing techniques and the climate models are likely biased too small. As a result, the DRESW is biased too strong and the DRELW is biased too weak. Motivated by these recent studies and the fact that the DRELW of dust is relatively less studied and poorly understood, this research aims to quantify the DRELW of dust, as well as DRESW and DRE net, using satellite observations, in situ measurements and radiative transfer simulation. We have developed an observation-based method to estimate net dust direct radiative effect (DREnet) over Atlantic Ocean dust outflow region. This method is constrained by CERES observation in terms of flux. As the first part of the research, we propose to apply the same method to other dust active regions to ultimately obtain the dust DREnet globally.
The second part of this research is to perform a radiative closure experiment using collocated MODIS and CALIPSO observations. More specifically, the aerosol properties from the MODIS Dark Target product and the aerosol vertical profile observation from CALIPSO will be used to drive radiative transfer models to simulate the MODIS radiance observations which will be compared with the real MODIS observations. The objective of this experiment is to examine whether the retrieved dust properties, usually based on shortwave bands (i.e., 0.5 ~ 2.1 µm) could explain the dust radiative signatures in both shortwave and longwave (i.e., 8µm, 11 µm and 12 µm) regions.
