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Land surface temperature (LST) and soil moisture (SM) are two important parameters in land surface ecosystem at regional and global scale. The accurate acquisition of LST and SM can benefit various fields, including agriculture and climate which are closely related to human life. This study proposed a simultaneous retrieval method of LST and SM based on the approximate and correction of passive microwave radiation transfer equation. Compared to LST and SM in simulated database, the accuracy of retrieved LST is approximately 1.63 K and the accuracy of retrieved SM is about 0.063 m3/m3.

Passive microwave data are much less affected by clouds than TIR data for the retrieval of land surface temperature (LST), providing its unique advantages in global mapping of LST. In this study, a physically-based algorithm for LST retrieval was applied to AMSR2 global brightness temperature data. The performances of this algorithm applied on different land cover types were further evaluated against nighttime MYD11A1 thermal infrared LST products. The results showed that (i) the overall accuracy of the algorithm is about 5.42 K by root mean square error (RMSE) and 2.99 K by bias against MODIS LST during nighttime; (ii) the algorithm overestimates the LST over all land types. The overestimation is most evident over barren/sparsely vegetated surfaces. The algorithm shows that the algorithm has a robust performance comparing with MODIS LST and could be applied to estimate LST effectively.

The change of global thermal environment plays an important role in land surface processes. In this study, global thermal environment was analyzed using the vertically polarized brightness temperature at 36.5 GHz. The daily brightness temperature from 2003 to 2010 were decomposed using the annual temperature cycle (ATC) model, and the annual cycle parameters (ACPs) were obtained. The results show that the brightness temperature decreases with the increasing latitudes respectively for the northern hemisphere and the southern hemisphere. The land covered by vegetation is colder than the desert and barren. Some plateaus lead to lower brightness temperature than surrounding areas. In addition, the atmospheric and ocean circulation also affect global brightness temperature. The ACPs from brightness temperature can generally characterize the global thermal environment.

Evapotranspiration (ET) plays a key role for energy transfer and water circulation in the biosphere, lithosphere, hydrosphere, cryosphere and atmosphere. In present study, spatially complete ET over the Heihe river basin, Northwest of China, was estimated from the synergistic use of MODIS (MODerate-resolution Imaging Spectroradiometer) data and CLDAS (China Meteorological Administration Land Data Assimilation) gridded meteorological data from June 1 to September 15 in 2012. For the estimation of ET over clear-sky pixels, a pixel-to-pixel pattern of land surface temperature (LST)-vegetation index (VI) feature space was developed where meteorological data were used to determine the dry and wet edges for each pixel; whereas the traditional Penman-Monteith equation was implemented to obtain ET over clouds pixels. Finally, ground ET measurements collected at two sites (corn and orchard) were used to evaluate the estimated results, root mean square error (RMSE) of 77.2W/m2 and 74.9W/m2 can be obtained for the two sites, respectively, indicating that spatially complete ET can be derived from currently available satellite images and meteorological data.

As a new remote sensing monitoring information, sun-induced chlorophyll fluorescence (SIF) has been widely used in the detection of changes in vegetation state at global and regional scales in recent years. SIF study in agricultural field has quickly become a research hotspot. TanSat is a global scientific experiment satellite for carbon dioxide monitoring launched in December 2016 with SIF monitoring capability. This paper aims to retrieve SIF based on a simplified physical model using TanSat data. The KI Fraunhofer Line at 770.1 nm was selected, which is less affected by the atmosphere. L1B-level data of TanSat was used to extract SIF of southeast China in July 2017. We used cloud mask products from MODIS data at the same period to eliminate cloud-affected areas and obtain SIF under clear sky conditions. The SIF value of our retrieval result is between −2 mW.m−2. sr−1. nm−1 and 5 mW. m−2. sr−1. nm−1. Comparing the result with SIF products showed that there is an encouraging consistency between them. This indicated that the inversion algorithm based on the simplified physical model can be used to retrieve SIF from TanSat data.

Accurate characterization of land surface evaporation is essential for understanding climate dynamics and the terrestrial ecosystem productivity because it is closely related to energy transfer processes. A practical all-weather method for estimating the annual daily averaged evapotranspiration (ET) was proposed using the passive microwave brightness temperature (22 and 37 GHz) and latitude, and a favorable accuracy with RMSE = 0.27 mm/day was obtained. Moreover, the annual daily averaged ET across China from 1996 to 2015 was calculated using the proposed method. The results showed that annual daily averaged ET decreases from southeast to northwest China. The annual ET over all of China ranges from 128 to 1223mm/yr. The interannual variability of ET showed a slightly increase from 1996 to 2007, a sudden decrease in 2008 and a relatively increase from 2008 to 2015. The mean annual ET over all of China ranges from 340 to 400 mm/yr.

Soil moisture plays an important role in the process of energy exchange and water cycle. Soil moisture also provides critical information in agriculture, including crop growth and drought. In this study, the comparison between NASA AMSR-E soil moisture product and ground-based measurement are performed in terms of (1) measurement depths of soil moisture, and (2) satellite overpass times. The results show that the NASA AMSR-E soil moisture product can be used to monitor time-series variation in soil moisture. Compared to the AMSR-E product from descending overpasses, the AMSR-E product from ascending overpasses has better ability in monitoring soil moisture variation. Also the AMSR-E product has better ability in monitoring soil moisture at the depth of 0–10 cm than 10–20 cm.

This paper is about safety assessment for the pre-hydrogenation reactor with a surface crack. The pre-hydrogenation reactor contains a weld-crack defect. Safety assessment of in-service pressure vessel is based on the principle of "fit-for-service". The author has safety assessment in accordance with Chinese national standard Safety Assessment for In-service Pressure Vessels Containing Defects (GB/T 19624-2004 ). The pre-hydrogenation reactor with crack defect is in the margin of safety through the safty assessment and result analysis.