scholarly journals Investigating the assimilation of CALIPSO global aerosol vertical observations using Four-Dimensional Ensemble Kalman Filter

2019 ◽  
Author(s):  
Yueming Cheng ◽  
Tie Dai ◽  
Daisuke Goto ◽  
Nick A. J. Schutgens ◽  
Guangyu Shi ◽  
...  
Keyword(s):  
Kalman Filter ◽  
Transport Model ◽  
Radiation Transport ◽  
Satellite Observation ◽  
Atmospheric Model ◽  
Orthogonal Polarization ◽  
Spectral Radiation ◽  
Extinction Coefficients ◽  
Model Simulations ◽  
Radiation Transport Model

Abstract. The aerosol vertical information is critical to quantify the influences of the aerosol on the climate and environment, however large uncertainties still persist in model simulations. In this study, the vertical aerosol extinction coefficients from Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) onboard Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) are assimilated to optimize the hourly aerosol fields of the Non‐hydrostatic ICosahedral Atmospheric Model (NICAM) online coupled with the Spectral Radiation Transport Model for Aerosol Species (SPRINTARS) using the four-dimensional Local Ensemble Transform Kalman Filter (4D-LETKF). Additionally, a parallel assimilation experiment using the bias-corrected Aerosol Optical Thicknesses (AOTs) from the Moderate Resolution Imaging Spectroradiometer (MODIS) is conducted to investigate the effects of assimilating the observations whether including the vertical information on the model performances. The assimilation experiments are successfully performed for a one-month long, making it possible to evaluate the results in a statistical sense. The hourly analyses are validated via both the CALIOP observed aerosol vertical extinction coefficients and the AOT observations from the MODIS and AErosol RObotic NETwork (AERONET). Our results reveal both the CALIOP and MODIS assimilations can improve the model simulations. The CALIOP assimilation is superior to the MODIS assimilation in modifying the incorrect aerosol vertical distributions and reproducing the real magnitudes and variations. However, the MODIS assimilation can better reproduce the AOT distributions than the CALIOP assimilation. This is probably due to the nadir-viewing CALIOP has much sparser coverages than the MODIS. The assimilation efficiencies of CALIOP decrease with the increasing distances of the overpass time, indicating that more aerosol vertical observation platforms are required to fill the sensor-specific observation gaps and hence improve the aerosol vertical data assimilation.

scholarly journals Investigating the assimilation of CALIPSO global aerosol vertical observations using a four-dimensional ensemble Kalman filter

2019 ◽  
Vol 19 (21) ◽  
pp. 13445-13467 ◽  
Author(s):  
Yueming Cheng ◽  
Tie Dai ◽  
Daisuke Goto ◽  
Nick A. J. Schutgens ◽  
Guangyu Shi ◽  
...  
Keyword(s):  
Kalman Filter ◽  
Transport Model ◽  
Radiation Transport ◽  
Satellite Observation ◽  
Atmospheric Model ◽  
Orthogonal Polarization ◽  
Spectral Radiation ◽  
Extinction Coefficients ◽  
Model Simulations ◽  
Radiation Transport Model

Abstract. Aerosol vertical information is critical to quantify the influences of aerosol on the climate and environment; however, large uncertainties still persist in model simulations. In this study, the vertical aerosol extinction coefficients from the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) onboard the Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) are assimilated to optimize the hourly aerosol fields of the Non-hydrostatic ICosahedral Atmospheric Model (NICAM) online coupled with the Spectral Radiation Transport Model for Aerosol Species (SPRINTARS) using a four-dimensional local ensemble transform Kalman filter (4-D LETKF). A parallel assimilation experiment using bias-corrected aerosol optical thicknesses (AOTs) from the Moderate Resolution Imaging Spectroradiometer (MODIS) is conducted to investigate the effects of assimilating the observations (and whether to include vertical information) on the model performances. Additionally, an experiment simultaneously assimilating both CALIOP and MODIS observations is conducted. The assimilation experiments are successfully performed for 1 month, making it possible to evaluate the results in a statistical sense. The hourly analyses are validated via both the CALIOP-observed aerosol vertical extinction coefficients and the AOT observations from MODIS and the AErosol RObotic NETwork (AERONET). Our results reveal that both the CALIOP and MODIS assimilations can improve the model simulations. The CALIOP assimilation is superior to the MODIS assimilation in modifying the incorrect aerosol vertical distributions and reproducing the real magnitudes and variations, and the joint CALIOP and MODIS assimilation can further improve the simulated aerosol vertical distribution. However, the MODIS assimilation can better reproduce the AOT distributions than the CALIOP assimilation, and the inclusion of the CALIOP observations has an insignificant impact on the AOT analysis. This is probably due to the nadir-viewing CALIOP having much sparser coverage than MODIS. The assimilation efficiencies of CALIOP decrease with increasing distances of the overpass time, indicating that more aerosol vertical observation platforms are required to fill the sensor-specific observation gaps and hence improve the aerosol vertical data assimilation.

scholarly journals Chemical Source Inversion Using Assimilated Constituent Observations in an Idealized Two-Dimensional System

2009 ◽  
Vol 137 (9) ◽  
pp. 3013-3025
Author(s):  
Andrew Tangborn ◽  
Robert Cooper ◽  
Steven Pawson ◽  
Zhibin Sun
Keyword(s):  
Kalman Filter ◽  
Green’S Function ◽  
Green's Function ◽  
Transport Model ◽  
Chemical Constituents ◽  
Gaussian Model ◽  
Satellite Observation ◽  
Dimensional System ◽  
Two Dimensional ◽  
Source Inversion

Abstract A source inversion technique for chemical constituents is presented that uses assimilated constituent observations rather than directly using the observations. The method is tested with a simple model problem, which is a two-dimensional Fourier–Galerkin transport model combined with a Kalman filter for data assimilation. Inversion is carried out using a Green’s function method and observations are simulated from a true state with added Gaussian noise. The forecast state uses the same spectral model but differs by an unbiased Gaussian model error and emissions models with constant errors. The numerical experiments employ both simulated in situ and satellite observation networks. Source inversion was carried out either by directly using synthetically generated observations with added noise or by first assimilating the observations and using the analyses to extract observations. Twenty identical twin experiments were conducted for each set of source and observation configurations, and it was found that in the limiting cases of a very few localized observations or an extremely large observation network there is little advantage to carrying out assimilation first. For intermediate observation densities, the source inversion error standard deviation is decreased by 50% to 90% when the observations are assimilated with the Kalman filter before carrying out the Green’s function inversion.

scholarly journals Radiation transport model for ablation hollows on snowfields

2006 ◽  
Vol 111 (F2) ◽  
Author(s):  
T. Tiedje ◽  
Kevin A. Mitchell ◽  
Bayo Lau ◽  
A. Ballestad ◽  
E. Nodwell
Keyword(s):  
Transport Model ◽  
Radiation Transport ◽  
Radiation Transport Model

scholarly journals Climatology of the aerosol optical depth by components from the Multiangle Imaging SpectroRadiometer (MISR) and a high-resolution chemistry transport model

2015 ◽  
Vol 15 (23) ◽  
pp. 33897-33929 ◽  
Author(s):  
H. Lee ◽  
O. V. Kalashnikova ◽  
K. Suzuki ◽  
A. Braverman ◽  
M. J. Garay ◽  
...  
Keyword(s):  
Aerosol Optical Depth ◽  
Optical Depth ◽  
Transport Model ◽  
Radiation Transport ◽  
Spectral Radiation ◽  
Chemistry Transport Model ◽  
Source Regions ◽  
Level 3 ◽  
Level 2 ◽  
Aerosol Type

Abstract. The Multi-angle Imaging SpectroRadiometer (MISR) Joint Aerosol (JOINT_AS) Level 3 product provides a global, descriptive summary of MISR Level 2 aerosol optical depth (AOD) and aerosol type information for each month between March 2000 and the present. Using Version 1 of JOINT_AS, which is based on the operational (Version 22) MISR Level 2 aerosol product, this study analyzes, for the first time, characteristics of observed and simulated distributions of AOD for three broad classes of aerosols: non-absorbing, absorbing, and non-spherical – near or downwind of their major source regions. The statistical moments (means, standard deviations, and skewnesses) and distributions of AOD by components derived from the JOINT_AS are compared with results from the SPectral RadIatioN-TrAnSport (SPRINTARS) model, a chemistry transport model (CTM) with very high spatial and temporal resolution. Overall, the AOD distributions of combined MISR aerosol types show good agreement with those from SPRINTARS. Marginal distributions of AOD for each aerosol type in both MISR and SPRINTARS show considerable high positive skewness, which indicates the importance of including extreme AOD events when comparing satellite retrievals with models. The MISR JOINT_AS product will greatly facilitate comparisons between satellite observations and model simulations of aerosols by type.

scholarly journals Химический анализ зоопланктона методом лазерно-искровой эмиссионной спектроскопии без использования образцов сравнения

2020 ◽  
Vol 128 (9) ◽  
pp. 1231
Author(s):  
Н.И. Сушков ◽  
Н.В. Лобус ◽  
И.В. Селиверстова ◽  
Т.А. Лабутин
Keyword(s):  
Inductively Coupled Plasma ◽  
Transport Model ◽  
Radiation Transport ◽  
Atomic Emission ◽  
Stark Broadening ◽  
Inductively Coupled ◽  
Breakdown Spectroscopy ◽  
Atomic Lines ◽  
Radiation Transport Model

This study deals with the determination of ratios of light metals (Li, Na, K, Mg, and Ca) in zooplankton (Calanus spp.) by calibration free laser-induced breakdown spectroscopy, assuming local thermodynamic equilibrium. The temperature of laser-induced plasma of zooplankton was derived from rotation-vibration bands of CN, and the electron density was calculated by Stark broadening of Mg I 383.23 nm, Li I 610.37 nm, and Ca II 396.85 nm lines. The synthetic spectra calculated with a radiation transport model for the experimental values of T and Ne were used for a selection of analytical atomic lines free from self-absorption. We compared the obtained data with the results of atomic emission and mass spectrometry with inductively coupled plasma. We also discussed the influence of ionization equilibrium on the accuracy of the results. We propose the presented method for direct semi-quantitative determination of Li, Mg, and Ca ratios in zooplankton.

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