Dust and Radiation Presenter: Xiaomeng...
Transcript of Dust and Radiation Presenter: Xiaomeng...
![Page 1: Dust and Radiation Presenter: Xiaomeng Jinamfiore/eescG9910_s16_ppts/Radiation_presentation.pdfRadiative effect of dusts: contributing factors (Ch. 11.1) Optical properties Dependent](https://reader033.fdocuments.in/reader033/viewer/2022051921/600dc0435aff871fe61c20f1/html5/thumbnails/1.jpg)
EESC G9910 Dust in the Earth System
Dust and Radiation Presenter: Xiaomeng Jin
![Page 2: Dust and Radiation Presenter: Xiaomeng Jinamfiore/eescG9910_s16_ppts/Radiation_presentation.pdfRadiative effect of dusts: contributing factors (Ch. 11.1) Optical properties Dependent](https://reader033.fdocuments.in/reader033/viewer/2022051921/600dc0435aff871fe61c20f1/html5/thumbnails/2.jpg)
Direct impacts of dust on energy budget
Figure source: Italian Climate Observatory
↑ more SW scattered back
to space
↓ less SW reaching the surface
↑ more SW scattered (or
absorbed) by dust
↑ more LW absorbed by dust
↓ less LW escaping the
TOA
↑ more LW emitted to the
surface
ScatteringAbsorption
![Page 3: Dust and Radiation Presenter: Xiaomeng Jinamfiore/eescG9910_s16_ppts/Radiation_presentation.pdfRadiative effect of dusts: contributing factors (Ch. 11.1) Optical properties Dependent](https://reader033.fdocuments.in/reader033/viewer/2022051921/600dc0435aff871fe61c20f1/html5/thumbnails/3.jpg)
Radiative effect of dusts: contributing factors (Ch. 11.1)
❖ Optical properties
❖ Dependent on size, shape and composition of dust.
❖ Extinction coefficient, single scattering albedo etc.
❖ Function of wavelength.
❖ Vertical profile of dust.
❖ Underlying surface
❖ Large radiative effect of dust over dark ocean.
❖ Small radiative effect over desert.
![Page 4: Dust and Radiation Presenter: Xiaomeng Jinamfiore/eescG9910_s16_ppts/Radiation_presentation.pdfRadiative effect of dusts: contributing factors (Ch. 11.1) Optical properties Dependent](https://reader033.fdocuments.in/reader033/viewer/2022051921/600dc0435aff871fe61c20f1/html5/thumbnails/4.jpg)
Optical Properties (Ch. 11.2)❖ Extinction = absorption+scattering
❖ Refractive index (n: scattering; k: absorption):
❖ Single scattering albedo (SSA):
❖ Aerosol optical depth (AOD):
σ ext (λ) =σ abs (λ)+σ sca (λ)
ω0 =σ sca
σ ext
m = n+ ki
τ = σ ext dz∫
Figure 11.2 and 11.3(b), pp. 273Size Distribution
![Page 5: Dust and Radiation Presenter: Xiaomeng Jinamfiore/eescG9910_s16_ppts/Radiation_presentation.pdfRadiative effect of dusts: contributing factors (Ch. 11.1) Optical properties Dependent](https://reader033.fdocuments.in/reader033/viewer/2022051921/600dc0435aff871fe61c20f1/html5/thumbnails/5.jpg)
Measurements and Estimates of Radiative Effects (Ch. 11.3)
❖ Radiative Effect (RE) = Radiative Flux (with dust) - Radiative Flux (without dust)
❖ Observation:
❖ Satellite observation: CERES (Cloud and the Earth’s Radiant Energy System); OMI; MODIS…
❖ Ground-based and airborne observations: sky radiometer; AERONET sun photometer, lidar…
❖ Model simulation:
❖ An important feedback mechanism to climate change.
❖ Models require specification of scattering and absorption efficiency.
![Page 6: Dust and Radiation Presenter: Xiaomeng Jinamfiore/eescG9910_s16_ppts/Radiation_presentation.pdfRadiative effect of dusts: contributing factors (Ch. 11.1) Optical properties Dependent](https://reader033.fdocuments.in/reader033/viewer/2022051921/600dc0435aff871fe61c20f1/html5/thumbnails/6.jpg)
Surface radiative forcing by soil dust aerosols and the hydrological cycle (Miller et al., 2004)
❖ NASA GISS atmospheric general circulation model (AGCM)
❖ Resolution: 4° x 5°, 12 vertical layers.
❖ Dust is an interactive tracer:The distribution of dust depends on circulation, which is also perturbed by dust radiative forcing.
![Page 7: Dust and Radiation Presenter: Xiaomeng Jinamfiore/eescG9910_s16_ppts/Radiation_presentation.pdfRadiative effect of dusts: contributing factors (Ch. 11.1) Optical properties Dependent](https://reader033.fdocuments.in/reader033/viewer/2022051921/600dc0435aff871fe61c20f1/html5/thumbnails/7.jpg)
Global and regional emissions of soil dust aerosol
Figure 1
Table 1
![Page 8: Dust and Radiation Presenter: Xiaomeng Jinamfiore/eescG9910_s16_ppts/Radiation_presentation.pdfRadiative effect of dusts: contributing factors (Ch. 11.1) Optical properties Dependent](https://reader033.fdocuments.in/reader033/viewer/2022051921/600dc0435aff871fe61c20f1/html5/thumbnails/8.jpg)
Global dust load: size distribution
Clay Silt
Clay < 1 µm 1 µm <Silt < 8 µm
Clay Silt
Figure 2 a) Figure 2 b)
![Page 9: Dust and Radiation Presenter: Xiaomeng Jinamfiore/eescG9910_s16_ppts/Radiation_presentation.pdfRadiative effect of dusts: contributing factors (Ch. 11.1) Optical properties Dependent](https://reader033.fdocuments.in/reader033/viewer/2022051921/600dc0435aff871fe61c20f1/html5/thumbnails/9.jpg)
Radiative forcing within global dust layer: TOA vs. Surface
Figure 5
![Page 10: Dust and Radiation Presenter: Xiaomeng Jinamfiore/eescG9910_s16_ppts/Radiation_presentation.pdfRadiative effect of dusts: contributing factors (Ch. 11.1) Optical properties Dependent](https://reader033.fdocuments.in/reader033/viewer/2022051921/600dc0435aff871fe61c20f1/html5/thumbnails/10.jpg)
Global dust radiative forcing: spatial distribution (Figure 7&8)
![Page 11: Dust and Radiation Presenter: Xiaomeng Jinamfiore/eescG9910_s16_ppts/Radiation_presentation.pdfRadiative effect of dusts: contributing factors (Ch. 11.1) Optical properties Dependent](https://reader033.fdocuments.in/reader033/viewer/2022051921/600dc0435aff871fe61c20f1/html5/thumbnails/11.jpg)
Dust radiative forcing: uncertainty with dust load
![Page 12: Dust and Radiation Presenter: Xiaomeng Jinamfiore/eescG9910_s16_ppts/Radiation_presentation.pdfRadiative effect of dusts: contributing factors (Ch. 11.1) Optical properties Dependent](https://reader033.fdocuments.in/reader033/viewer/2022051921/600dc0435aff871fe61c20f1/html5/thumbnails/12.jpg)
Dust radiative forcing: Uncertainty with optical properties
Figure 10 Figure 11
![Page 13: Dust and Radiation Presenter: Xiaomeng Jinamfiore/eescG9910_s16_ppts/Radiation_presentation.pdfRadiative effect of dusts: contributing factors (Ch. 11.1) Optical properties Dependent](https://reader033.fdocuments.in/reader033/viewer/2022051921/600dc0435aff871fe61c20f1/html5/thumbnails/13.jpg)
Dust radiative forcing: uncertainty with particle size distribution
Figure 12 Figure 13
![Page 14: Dust and Radiation Presenter: Xiaomeng Jinamfiore/eescG9910_s16_ppts/Radiation_presentation.pdfRadiative effect of dusts: contributing factors (Ch. 11.1) Optical properties Dependent](https://reader033.fdocuments.in/reader033/viewer/2022051921/600dc0435aff871fe61c20f1/html5/thumbnails/14.jpg)
Dust forcing of the hydrological cycle: global vs. local effects
![Page 15: Dust and Radiation Presenter: Xiaomeng Jinamfiore/eescG9910_s16_ppts/Radiation_presentation.pdfRadiative effect of dusts: contributing factors (Ch. 11.1) Optical properties Dependent](https://reader033.fdocuments.in/reader033/viewer/2022051921/600dc0435aff871fe61c20f1/html5/thumbnails/15.jpg)
Surface flux anomaly as a result of dust radiative forcing
![Page 16: Dust and Radiation Presenter: Xiaomeng Jinamfiore/eescG9910_s16_ppts/Radiation_presentation.pdfRadiative effect of dusts: contributing factors (Ch. 11.1) Optical properties Dependent](https://reader033.fdocuments.in/reader033/viewer/2022051921/600dc0435aff871fe61c20f1/html5/thumbnails/16.jpg)
Effects of dust radiative forcing on hydrological cycle
![Page 17: Dust and Radiation Presenter: Xiaomeng Jinamfiore/eescG9910_s16_ppts/Radiation_presentation.pdfRadiative effect of dusts: contributing factors (Ch. 11.1) Optical properties Dependent](https://reader033.fdocuments.in/reader033/viewer/2022051921/600dc0435aff871fe61c20f1/html5/thumbnails/17.jpg)
Dust radiative forcing: positive feedback to dust burden
![Page 18: Dust and Radiation Presenter: Xiaomeng Jinamfiore/eescG9910_s16_ppts/Radiation_presentation.pdfRadiative effect of dusts: contributing factors (Ch. 11.1) Optical properties Dependent](https://reader033.fdocuments.in/reader033/viewer/2022051921/600dc0435aff871fe61c20f1/html5/thumbnails/18.jpg)
Conclusions❖ The radiative forcing of dust represents radiative heating
displaced from surface into the dust layer.
❖ The forcing estimate is most sensitive to uncertainty in dust burden and assumptions with optical properties, while the uncertainty with size distribution is of less significance.
❖ Dust radiative forcing alters the hydrological cycle: globally decreasing precipitation vs. locally increasing precipitation.
![Page 19: Dust and Radiation Presenter: Xiaomeng Jinamfiore/eescG9910_s16_ppts/Radiation_presentation.pdfRadiative effect of dusts: contributing factors (Ch. 11.1) Optical properties Dependent](https://reader033.fdocuments.in/reader033/viewer/2022051921/600dc0435aff871fe61c20f1/html5/thumbnails/19.jpg)
Global Energy Budget of the Earth
All fluxes are in Wm-2; solar in yellow, infrared in pink
Stephens et al., Nat. Geosci., 2012
![Page 20: Dust and Radiation Presenter: Xiaomeng Jinamfiore/eescG9910_s16_ppts/Radiation_presentation.pdfRadiative effect of dusts: contributing factors (Ch. 11.1) Optical properties Dependent](https://reader033.fdocuments.in/reader033/viewer/2022051921/600dc0435aff871fe61c20f1/html5/thumbnails/20.jpg)
Contrasting dust volume size distribution
Optical properties
![Page 21: Dust and Radiation Presenter: Xiaomeng Jinamfiore/eescG9910_s16_ppts/Radiation_presentation.pdfRadiative effect of dusts: contributing factors (Ch. 11.1) Optical properties Dependent](https://reader033.fdocuments.in/reader033/viewer/2022051921/600dc0435aff871fe61c20f1/html5/thumbnails/21.jpg)
Global dust load: spatial distribution
![Page 22: Dust and Radiation Presenter: Xiaomeng Jinamfiore/eescG9910_s16_ppts/Radiation_presentation.pdfRadiative effect of dusts: contributing factors (Ch. 11.1) Optical properties Dependent](https://reader033.fdocuments.in/reader033/viewer/2022051921/600dc0435aff871fe61c20f1/html5/thumbnails/22.jpg)
![Page 23: Dust and Radiation Presenter: Xiaomeng Jinamfiore/eescG9910_s16_ppts/Radiation_presentation.pdfRadiative effect of dusts: contributing factors (Ch. 11.1) Optical properties Dependent](https://reader033.fdocuments.in/reader033/viewer/2022051921/600dc0435aff871fe61c20f1/html5/thumbnails/23.jpg)
![Page 24: Dust and Radiation Presenter: Xiaomeng Jinamfiore/eescG9910_s16_ppts/Radiation_presentation.pdfRadiative effect of dusts: contributing factors (Ch. 11.1) Optical properties Dependent](https://reader033.fdocuments.in/reader033/viewer/2022051921/600dc0435aff871fe61c20f1/html5/thumbnails/24.jpg)