In general, total organic carbon (TOC) is directly used as a proxy for paleoproductivity, however, it is not only affected by paleoproductivity, but also controlled by redox conditions and terrigenous detrital matter influx. Major and trace elements were analysed with the purpose of investigating the redox potential and paleoproductivity during deposition of the Hongshuizhuang Formation. In the present study, C-S relationship, V/Cr ratio and Mo concentration indicate that the dolomites were deposited in oxic environments, however, most of the black shales were accumulated in euxinic environments. P/Ti values in the Hongshuizhuang samples can be compared with those in the Japanese Ubara Permian-Triassic section which were regarded to be deposited under a moderate to high paleoproductivity. Ba/Al values are slightly lower than that of the laminated sediments from the continental margins of Central California (CCAL) which were thought to be accumulated under a high paleoproductivity. These results indicate that the paleoproductivity was moderate to high during deposition of the Hongshuizhuang Formation. Burial organic carbon shows positive correlations with V/Cr and Mo, but shows only weakly or no correlation with P/Ti and Ba/Al, respectively, suggesting that although the paleoproductivity was moderate to high during deposition of the Hongshuizhuang Formation, its organic-rich sediments were predominantly controlled by redox conditions and had no direct relationship with paleoproductivity.

Attributed to its unique advantage of cloud vertical resolving, Cloud Profiling Radar (CPR) measurements have been used as the primary component in synthetic cloud data for relevant studies. However, due to surface clutter and sensitivity limitation, considerable warm clouds over global oceans are missed by CPR, which causes severe sampling biases and problematic statistics of cloud properties. By using independent cloud mask data jointly from Moderate Resolution Imaging Spectroradiometer and Cloud‐Aerosol Lidar with Orthogonal Polarization measurements, this study gives an evaluation on these issues and focuses on single‐layer clouds. By excluding effects from CPR's spatial resolution, the CPR detection failures are found to be frequent over global oceans, with an overall miss rate at ~0.39. For each cloud type, altocumulus, stratus, stratocumulus, and cumulus, its miss rate decreases monotonically with height, and it is only at 2.5–3.0 km altitude that the miss rate is negligible for the ensemble of oceanic single‐layer warm clouds. The miss rates are different among cloud types, which are attributed to their distinct microphysical properties. Clouds with droplet effective radius below 12 µm or cloud optical depth below 4 are very likely to be missed by CPR, resulting the globally averaged overestimation of 10–24% and 24–36%, respectively. The miss rate has a strong negative correlation with cloud water path (CWP) and decreases below 0.1 only for CWP exceeding 200 g m−2. The resulting overestimation on globally averaged CWP is 36.6 g m−2 (44.3%). Throughout the globe, the biases are mostly positive and have notable regional variations. Especially in the typical oceans that have abundant warm clouds, the CWP is overestimated by 20%–80%.

The Lower Permian Shanxi Formation in the Eastern Ordos Basin is a set of transitional facies shale, and it is also a key target for shale gas exploration in China. Based on lithofacies classification by X-ray diffraction and kerogen type identification, nanoscale reservoir space, pore volume, pore size distribution, surface area, and fractal characterization were studied using comprehensive methods including N2 and CO2 adsorption, mercury injection capillary pressure, field emission-scanning electron microscopy (FE-SEM), and nuclear magnetic resonance. The results indicate that Shanxi Formation shale can be subdivided into five types of lithofacies: clayey shale (lithofacies I), siliceous clayey shale (lithofacies II), siliceous shale (lithofacies IV), calcareous siliceous shale (lithofacies V), and siliceous calcareous shale (lithofacies VI). Lithofacies V and lithofacies VI are the best lithofacies in terms of organic pore morphology, connectivity, and development degree, followed by lithofacies II. Inorganic pores and microfractures are well developed in all lithofacies. The majority of pores in lithofacies I comprise organic mesopores, but pore volume is contributed by a few inorganic macropores. The pore types and pore volume contributors of lithofacies II are organic macropores. The pore size distribution of lithofacies IV is very similar to that of lithofacies I. The pore size distribution of lithofacies V shows typical bimodal characteristics. It is suggested that the inorganic pores of lithofacies V are mainly macropores, which have the greatest contribution to pore volume, followed by organic mesopores. Total organic carbon (TOC) and thermal maturity do not present obvious controls on pore structure. Vitrinite is the main kerogen type in lithofacies II and IV, and this is associated with disfavored morphology, low connectivity, and poor development degree of organic pores. In contrast, sapropelinite is observed in other shale lithofacies, and it is suggested to be an effective kerogen type that contributes to better development of organic pores.

C 31-to C 35 MS) analysis to exist as double isomers in most samples of the Aershan Formation and members 1 and 2 of the Tenggeer Formation from well SH3. Comprehensive organic geochemistry and organic petrology study indicates that algae and bacteria are the main biological source of lower Cretaceous sediments in the Saihantala Sag, and this is in accordance with the existence of hop-17(21)-enes. The similar distributions of hop-17(21)-enes and hopanes of these samples indicate that hop-17(21)-enes were transformed into hopanes through hydrogenation during diagenesis processes. The existence of hop-17(21)-enes means that not only the formation of organic matter is related to an anoxic environment and a biological source of algae and bacteria, but also hop-17(21)-enes are direct indicators of hydrocarbon rock at an immature to low-maturity stage. High hydrocarbon conversion ratio, algae and bacteria source and a high abundance of organic matter suggest that the Saihantala Sag has the potential to generate immature to low-maturity