Soil moisture (SM) plays an important role in regulating regional weather and climate. However, the simulations of SM in current land surface models (LSMs) contain large biases and model spreads. One primary reason contributing to such model biases could be the misrepresentation of soil texture in LSMs, since current available large-scale soil texture data are often generated from extrapolation algorithm based on a scarce number of in-situ geological measurements. Fortunately, recent advancements of satellite technology provide a unique opportunity to constrain the soil texture datasets by introducing observed information at large spatial scales. Here, two major soil texture baseline datasets (Global Soil Datasets for Earth system science, GSDE and Harmonized World Soil Data from Food and Agriculture Organization, HWSD) are optimized with satellite-estimated soil hydraulic parameters. The optimized soil maps show increased (decreased) sand (clay) content over arid regions. The soil organic carbon content increases globally especially over regions with dense vegetation cover. The optimized soil texture datasets are then used to run simulations in one example LSM, i.e., Noah LSM with Multiple Parameters. Results show that the simulated SM with satellite-optimized soil texture maps are improved at both grid and in-situ scales. Intercase comparison analyses show the SM improvement differs between simulations using different soil maps and soil hydraulic schemes. Our results highlight the importance of incorporating observation-oriented calibration on soil texture in current LSMs. This study also joins the call for a better soil profile representation in the next generation Earth System Models.

Stable water isotopes in inland Antarctic ice cores are powerful paleoclimate proxies; however, their relationship with dynamical atmospheric circulations remains controversial. Using a water isotope climate model (MIROC5-iso), we assessed the influence of the Last Glacial Maximum (LGM; ~21,000 years ago) sea surface temperatures (SST) and sea ice (SIC) on Antarctic precipitation isotopes (δ18Op) through atmospheric circulation. The results revealed that the synoptic circulation mostly maintained southward moisture transport, reaching inland Antarctica. The steepened meridional SST gradient in the mid-latitudes increased δ18Op in inland Antarctica by enhancing the baroclinic instability and synoptic moisture transport. In contrast, enhanced SIC reduced the atmospheric humidity around Antarctica and lowered δ18Op through extensive surface cooling and transport from the ocean. These findings elucidate the isotopic proxies and enable us to constrain the southern hemisphere atmospheric circulation, including the westerlies, using ice cores during past climates, including the LGM.

Water scarcity is a critical global issue impacting human life. Supply-side solutions alone do not meet the ever-increasing water demands. Economic assessment of water resources can reduce water scarcity risk by managing and prioritizing demand. This study aims to estimate domestic water withdrawal (DWW) and its economic value globally from 1980–2010. To represent the economic value, consumer surplus is calculated by building a demand function for each country, based on the water price at different levels of DWW per capita (DWWC). Global domestic water withdrawal increased by a factor of 2.1 in 2010 compared to 1980, with an average annual growth rate of 2.5%, while the population increased 1.5 times during the same period. In 2010, 93-645 million people, in particular, 93-500 million of the African population, did not have access to the basic water demand. The global average of DWWC’s economic value is estimated as 2,015-4,076 USD in 2010 with a 5-6% increase from 1980 (1,909-3,884 USD). Also, it was found that, because of the low water prices, the economic values of domestic water are relatively low in some regions where water scarcity is one of the major societal problems (e.g., Middle Eastern and North African) compared to developed countries with a similar DWWC level. In such regions, toward sustainable water management, it is suggested to reconsider their policies adjusting water price and access to a fair water demand level. Therefore, the proposed framework would be beneficial for policymakers and international agencies to design sustainable water management systems.