Poor air quality poses a great threat to human health. Accurate high-resolution satellite remote sensing of atmospheric aerosols would highly benefit satellite-based air quality estimates. We have developed and validated a post-process correction and downscaling approach for satellite remote sensing of aerosols. We use NASA's Moderate Resolution Imaging Spectroradiometer (MODIS) aerosol optical depth (AOD) over Washington D.C. -Baltimore area during the Distributed Regional Aerosol Gridded Observation Networks (DRAGON) campaign in 2011 to evaluate our approach. We derive and evaluate the AOD fields with high 250 meter resolution. The results show that the post-process correction approach is suitable for deriving downscaled, high-resolution AOD estimates and significantly improves the accuracy of the AOD retrievals.

Poor air quality poses a great threat to human health. Accurate high‐resolution satellite remote sensing of atmospheric aerosols would highly benefit satellite‐based air quality estimates. We have developed and validated a post‐process correction and downscaling approach for satellite remote sensing of aerosols. We use NASA's Moderate Resolution Imaging Spectroradiometer aerosol optical depth (AOD) over the Washington D.C.—Baltimore area during the Distributed Regional Aerosol Gridded Observation Networks campaign in 2011 to evaluate our approach. We derive and evaluate the AOD fields at high 250 m resolution. The results show that the post‐process correction approach is suitable for deriving downscaled, high‐resolution AOD estimates and significantly improves the accuracy of the AOD retrievals.

<p>Like the solar wind in general, interplanetary coronal mass ejections (ICMEs) display magnetic field and velocity fluctuations across a wide range of scales. These fluctuations may be interpreted as Alfvénic wave packets propagating parallel or anti-parallel to the local magnetic field direction, with cross helicity, σ<sub>c</sub>, quantifying the difference in power between the counter-propagating fluxes. We have determined σ<sub>c</sub> at inertial range frequencies in a large sample of ICME flux ropes and sheaths observed by the Wind spacecraft at 1 au. The mean σ<sub>c</sub> value was low for both the flux ropes and sheaths, with the balance tipped towards the positive, anti-sunward direction. The low values indicate that Alfvénic fluxes are more balanced in ICMEs than in the solar wind at 1 au, where σ<sub>c</sub> tends to be larger and anti-sunward fluctuations show a greater predominance. Superposed epoch profiles show σ<sub>c</sub> falling sharply in the upstream sheath and being typically close to balance inside the flux rope near the leading edge. More imbalanced, solar wind-like σ<sub>c</sub> values are found towards the trailing edge and further from the rope axis. The presence or absence of an upstream shock also has a significant effect on σ<sub>c</sub>. Coronal and interplanetary origins of low σ<sub>c</sub> in ICMEs are discussed.</p>