Being the highest and largest land mass of the earth, the Tibetan Plateau has a strong impact on the Asian climate especially on the Asian monsoon. With high downward solar radiation, the Tibetan Plateau is a climate sensitive region and the main water source for many rivers in South and East Asia. Although many studies have analyzed energy fluxes in the Tibetan Plateau, a long-term detailed spatio-temporal variability of all energy budget parameters is not clear for understanding the dynamics of the regional climate change. In this paper, satellite remote sensing and reanalysis data are used to quantify spatio-temporal trends of energy budget parameters, net radiation, latent heat flux, and sensible heat flux over the Tibetan Plateau from 2001 to 2019. The validity of both data sources is analyzed from in situ ground measurements of the FluxNet micrometeorological tower network, which verifies that both datasets are valid and reliable. It is found that the trend of net radiation shows a slight increase. The latent heat flux increases continuously, while the sensible heat flux decreases continuously throughout the study period over the Tibetan Plateau. Varying energy fluxes in the Tibetan plateau will affect the regional hydrological cycle. Satellite LE product observation is limited to certain land covers. Thus, for larger spatial areas, reanalysis data is a more appropriate choice. Normalized difference vegetation index proves a useful indicator to explain the latent heat flux trend. Despite the reduction of sensible heat, the atmospheric temperature increases continuously resulting in the warming of the Tibetan Plateau. The opposite trend of sensible heat flux and air temperature is an interesting and explainable phenomenon. It is also concluded that the surface evaporative cooling is not the indicator of atmospheric cooling/warming. In the future, more work shall be done to explain the mechanism which involves the complete heat cycle in the Tibetan Plateau.

The Moon-Based Earth Radiation Observatory (MERO) is a new platform, which is expected to advance current Earth radiation budget (ERB) research with better observations. For the instrument design of a MERO system, ascertaining the spatial resolution and sampling scheme is important. However, current knowledge about this is still limited. Here we proposed a simulation method for the MERO-measured Earth top of atmosphere (TOA) outgoing shortwave radiation (OSR) and outgoing longwave radiation (OLR) fluxes and constructed the “true” Earth TOA OSR and OLR fluxes based on the Clouds and Earth’s Radiant Energy System (CERES) data. Then we used them to reveal the effects of spatial resolution and temporal scheme (sampling interval and the temporal sampling sequence) on the measurement error of a MERO. Our results indicate that the spatial sampling error in the unit of percentage reduces linearly as the spatial resolution varies from 1000 km to 100 km; the rate is 2.5%/100 km for the Earth TOA OSR flux, which is higher than that (1%/100 km) of the TOA OLR flux. Besides, this rate becomes larger when the spatial resolution is finer than 40 km. It is also demonstrated that a sampling temporal sequence of starting time of 64 min with a sampling interval of 90 min is the optimal sampling scheme that results in the least temporal sampling error for the MERO system with a 40 km spatial resolution, note that this conclusion depends on the temporal resolution and quality of the data used to construct the “true” Earth TOA OSR and OLR fluxes. The proposed method and derived results in this study could facilitate the ascertainment of the optimal spatial resolution and sampling scheme of a MERO system under certain manufacturing budget and measurement error limit.

This study focuses on the genesis mechanism of thermal anomalies in the southwestern part of the Anan Depression in the Erlian Basin. Based on magnetotelluric 3D inversion data, a high-resolution electrical resistivity structure model was constructed, revealing the spatial configuration of deep heat sources and thermal pathways. The main conclusions are as follows: (1) Magnetotelluric 3D imaging reveals an elliptical low-resistivity anomaly (Anomaly C: 20 km × 16 km × 5 km, 0–5 Ωm) at depths of ~10–15 km. This anomaly is interpreted as a hypersaline fluid (approximately 400 °C, ~1.5% volume fraction, 3–5 wt.% NaCl), acting as the primary heat source. (2) Upward migration along F1/F3 fault conduits (10–40 Ωm) establishes a continuous pathway to mid-depth reservoirs D1/D2 (~5 km, 5–10 Ωm) and shallow crust. An overlying high-resistivity caprock (40–100 Ωm) seals thermal energy, forming a convective “source-conduit-reservoir-cap” system. (3) Integrated seismic data reveal that heat from the Abaga volcanic melt supplements Anomaly C via conduction through these conduits, combining with mantle-derived heat to form a composite source. This research delineates the interacting genesis mechanism of “deep low-resistivity heat source—medium-low resistivity fault conduit—shallow low-resistivity reservoir—relatively high-resistivity cap rock” in the southwestern A’nan Sag, providing a scientific basis for optimizing geothermal exploration targets and assessing resource potential.

Understanding the volcanic SO₂ diffusive characteristics can enhance our knowledge of the impact of volcanic eruptions on climate change. In this study, the SO₂ diffusion features of the Hunga Tonga–Hunga Ha’apai underwater volcano (HTHH) 2022 eruptions are investigated based on the Deep Space Climate Observatory (DSCOVR) Earth Polychromatic Imaging Camera (EPIC) dataset, which could provide longer term, more consistent, and higher temporal sampling rate observations to complement current low-orbit satellite-based research. SO₂ plume major-direction profile analysis indicates that the SO₂ diffusion extent of subaerial eruption initiating at 15:20/13 January 2022 was approximately 1500 km in the Southeast–Northwest major diffusive direction by 20:15/14 January 2022 (about 29 h after the HTHH subaerial eruption). All-direction SO₂ plume analysis shows that the HTHH subaerial eruption-emitted SO₂ plume could diffuse as far as 6242 km by 02:20/15 January 2022. Furthermore, these two analyses in terms of the HTHH major eruption initiating at 04:00/15 January 2022 imply that HTHH major eruption-emitted SO₂ plume could diffuse as far as 8600 km in the Southeast–Northwest major diffusive direction by 02:24/18 January 2022 (about 70 h after the HTHH major eruption). It is also implied that HTHH major eruption-emitted SO₂ plume could extend to approximately 14,729 km away from the crater by 13:12/18 January 2022. We believe that these findings could provide certain guidance for volcanic gas estimations, thus helping to deepen our understanding of volcanic impacts on climate change.

The Moon-based Earth Radiation Observatory (MERO) has the potential to complement current Earth Radiation Budget (ERB) missions by providing higher temporal resolution data, especially for the Earth polar regions. Regarding the MERO mission design, quantifying its mixed-pixel-induced uncertainty is crucial, which occupies an important part in the MERO inherent systematic errors. However, current knowledge about this MERO mixed-pixel-induced uncertainty is still limited. In this study, we proposed a MERO 2-endmember-mixed-pixel error quantification method and explored such errors in the land-snow, land-waterbody and waterbody-snow mixing scenarios. Results indicate that the land-snow mixing leads to the biggest measurement errors, which are as large as 4.02% and 7.98 % for the Earth top of the atmosphere (TOA) outgoing solar-reflected shortwave radiation (OSR) and outgoing thermally-emitted longwave radiation (OLR) fluxes respectively. The waterbody-snow mixing caused the secondly largest measurement error with TOA OSR maximum of 3.01% and TOA OLR maximum of 7.08 %. The land-waterbody mixing results in the least measurement error with TOA OSR maximum of 0.79% and TOA OLR maximum of 0.41 %.

A Moon-based Earth radiation observatory (MERO) could contribute to the better understanding of the Earth radiation budget by providing data with less nonsimultaneous sampling uncertainty and higher temporal resolution as well as better Earth polar region spatial-temporal coverage. Assessing the gap-sunlight-intrusion risk is a crucial step in the MERO protection unit design and operation planning. In this study, we proposed a new method to estimate such a risk taking into account the Earth atmosphere radiative refraction and attenuation as well as the entrance pupil irradiance of the MERO, which could find the new refracted-type risky events and eliminated the included “fake” risky incidents compared to current method solely based on Sun-Earth-Moon geometric analysis. As 18.6-years evaluation from Jan. 2021 to Sep. 2039 shows that gap-sunlight-intrusion risk annual duration ranges from 10 to 29 h. MERO-location-effect assessment exhibits that MERO location latitudinal change [from (0°E, 81°N) to (0°E, 81°S)] would result in an annual risky duration difference ranging from 0 to 5 h, and that induced by longitudinal MERO location change [from (80°E, 0°N) to (80°W, 0°S)] varied between 0 and 3 h. Total risky time occupies 0.23% in the 18.6-years evaluation period (Jan. 2021 to Sep. 2039), which is about 2.56 times larger than that of the study only with consideration of the Sun-Earth-Moon geometry.