Effects of the diurnal cycle in solar radiation on the tropical Indian Ocean mixed layer variability during wintertime Madden-Julian Oscillations

The effects of solar radiation diurnal cycle on intraseasonal mixed layer variability in the tropical Indian Ocean during boreal wintertime Madden-Julian Oscillation (MJO) events are examined using the HYbrid Coordinate Ocean Model. Two parallel experiments, the main run and the experimental run, are performed for the period of 2005–2011 with daily atmospheric forcing except that an idealized hourly shortwave radiation diurnal cycle is included in the main run. The results show that the diurnal cycle of solar radiation generally warms the Indian Ocean sea surface temperature (SST) north of 10 °S, particularly during the calm phase of the MJO when sea surface wind is weak, mixed layer is thin, and the SST diurnal cycle amplitude (dSST) is large. The diurnal cycle enhances the MJO-forced intraseasonal SST variability by about 20% in key regions like the Seychelles-Chagos Thermocline Ridge (SCTR; 55° –70° E, 12° –4 °S) and the central equatorial Indian Ocean (CEIO; 65° –95° E, 3° S–3° N) primarily through nonlinear rectification. The model also well reproduced the upper-ocean variations monitored by the CINDY/DYNAMO field campaign between September-November 2011. During this period, dSST reaches 0.7° C in the CEIO region, and intraseasonal SST variability is significantly amplified. In the SCTR region where mean easterly winds are strong during this period, diurnal SST variation and its impact on intraseasonal ocean variability are much weaker. In both regions, the diurnal cycle also has a large impact on the upward surface turbulent heat flux Q[Subscript T] and induces diurnal variation of Q[subscript T] with a peak-to-peak difference of O(10 W m⁻ ²).Keywords: Sea surface temperature, CINDY/DYNAMO, Madden-Julian Oscillation, Diurnal cycl

Heat transport into the interior ocean induced by water-mass subduction

The subduction of oceanic water masses provides a crucial pathway for anthropogenic heat to enter the subsurface ocean, thereby shaping deep-reaching warming signatures. Analyzing data from eight ocean and atmosphere reanalysis datasets, we show that the average annual subduction rate of the global ocean (excluding 10° S–10° N) is 312.4 ± 27.9 Sv, resulting in a mean heat transport of 20.2 ± 2.1 PW towards the subsurface ocean. This subduction-driven heat transport has exhibited an increase of 0.09 ± 0.08 PW/decade since 1970. The increase predominantly stems from the overall enhancement of subduction within the latitudes of 30° S–50° S, dictated by intensified westerly winds that lead to the deepening of the local mixed layer depth. Our findings underscore the essence of wind-driven changes in the Southern Ocean subduction, which wield considerable influence over the global climate by regulating the vertical transport of heat and carbon from the sea surface to the deep waters

Processing and Prebiotics Characteristics of β-Glucan Extract from Highland Barley

β-glucan extract (GE) was obtained from highland barley bran using alkaline–acid–alcohol extraction method. The stability, solubility, foaming ability, and prebiotics characteristics of GE were assessed consecutively. GE demonstrated excellent heat stability (hardly degraded at 220 °C) and pH stability, especially at neutral or alkaline condition, and its solubility was significantly influenced by temperature instead of pH or NaCl, achieving 0.91 g/100 g at 100 °C. Good foaming ability and foam stability of GE were observed during low temperatures (≤40 °C), neutral or alkaline condition. GE indicated a strong anti-digestibility capacity of resisting the hydrolysis of α-amylase and simulated human gastric acid. Interestingly, GE could effectively promote the growth of Lactobacillus bulgaricus and Bifidobacterium adolescentis, which was close to fructooligosaccharide. The results of this study could offer valuable information for the application of β-glucan from highland barley as prebiotics in promoting human intestinal health metabolism

Increasing inhomogeneity of the global ocean

Author Posting. © American Geophysical Union, 2022. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 49(12), (2022): e2021GL097598, https://doi.org/10.1029/2021GL097598.The ocean is inhomogeneous in hydrographic properties with diverse water masses. Yet, how this inhomogeneity has evolved in a rapidly changing climate has not been investigated. Using multiple observational and reanalysis datasets, we show that the spatial standard deviation (SSD) of the global ocean has increased by 1.4 ± 0.1% in temperature and 1.5 ± 0.1% in salinity since 1960. A newly defined thermohaline inhomogeneity index, a holistic measure of both temperature and salinity changes, has increased by 2.4 ± 0.1%. Climate model simulations suggest that the observed ocean inhomogeneity increase is dominated by anthropogenic forcing and projected to accelerate by 200%–300% during 2015–2100. Geographically, the rapid upper-ocean warming at mid-to-low latitudes dominates the temperature inhomogeneity increase, while the increasing salinity inhomogeneity is mainly due to the amplified salinity contrast between the subtropical and subpolar latitudes.This work is supported by the Strategic Priority Research Program of Chinese Academy of Sciences (grant XDB42000000 and XDB40000000), the National Key R&D Program of China (2017YFA0603200), and the Shandong Provincial Natural Science Foundation (ZR2020JQ17), and the U.S. National Science Foundation Physical Oceanography Program (OCE- 2048336).2022-12-2

A closed-loop process for recycling LiNixCoyMn(1âxây)O2 from mixed cathode materials of lithium-ion batteries

With the rapid development of consumer electronics and electric vehicles (EV), a large number of spent lithium-ion batteries (LIBs) have been generated worldwide. Thus, effective recycling technologies to recapture a significant amount of valuable metals contained in spent LIBs are highly desirable to prevent the environmental pollution and resource depletion. In this work, a novel recycling technology to regenerate a LiNi1/3Co1/3Mn1/3O2 cathode material from spent LIBs with different cathode chemistries has been developed. By dismantling, crushing, leaching and impurity removing, the LiNi1/3Co1/3Mn1/3O2 (selected as an example of LiNixCoyMn(1âxây)O2) powder can be directly prepared from the purified leaching solution via co-precipitation followed by solid-state synthesis. For comparison purposes, a fresh-synthesized sample with the same composition has also been prepared using the commercial raw materials via the same method. X-ray diffraction (XRD), scanning electron microscopy (SEM) and electrochemical measurements have been carried out to characterize these samples. The electrochemical test result suggests that the re-synthesized sample delivers cycle performance and low rate capability which are comparable to those of the fresh-synthesized sample. This novel recycling technique can be of great value to the regeneration of a pure and marketable LiNixCoyMn(1âxây)O2 cathode material with low secondary pollution. Keywords: Spent lithium-ion battery, Cathode material recycling, Acid leaching, Purification, Co-precipitatio

Tb 3+-nucleic acid probe-based label-free and rapid detection of mercury pollution in food

Mercury is a threatening pollutant in food, herein, we developed a Tb3+-nucleic acid probe-based label-free assay for mix-and-read, rapid detection of mercury pollution. The assay utilized the feature of light-up fluorescence of terbium ions (Tb3+) via binding with single-strand DNA. Mercury ion, Hg2+ induced thymine (T)-rich DNA strand to form a double-strand structure (T-Hg2+-T), thus leading to fluorescence reduction. Based on the principle, Hg2+ can be quantified based on the fluorescence of Tb3+, the limit of detection was 0.0689 μmol/L and the linear range was 0.1 - 6 μmol/L. Due to the specificity of T-Hg2+-T artificial base pair, the assay could distinguish Hg2+ from other metal ions. The recovery rate was ranged in 98.71% -101.34% for detecting mercury pollution in three food samples. The assay is low-cost, separation-free and mix-to-read, thus was a competitive tool for detection of mercury pollution to ensure food safety

Primer-engineered transferase enzyme for one-pot and amplified detection of cobalt pollution and peptide remover screening

Extensive consumption of cobalt in the chemical field such as for battery materials, alloy, pigments, and dyes has aggravated the pollution of cobalt both in food and the environment, and assays for its on-site monitoring are urgently demanded. Herein, we utilized enzyme dependence on metal cofactors to develop terminal transferase (TdT) as a recognition element, achieving a one-pot sensitive and specific assay for detecting cobalt pollution. We engineered a 3′-OH terminus primer to improve the discrimination capacity of TdT for Co2+ from other bivalent cations. The TdT extension reaction amplified the recognition of Co2+ and yielded a limit of detection of 0.99 μM for Co2+ detection. Then, the TdT-based assay was designed to precisely detect cobalt in food and agricultural soil samples. By end-measurement of fluorescence using a microplate reader, the multiplexing assay enabled the rapid screening of the peptide remover for cobalt pollution. The TdT-based assay can be a promising tool for cobalt pollution monitoring and control