While the evaporative water loss from global lakes is invisible, the volume is substantial. In recent decades, lake evaporation volume has been significantly increasing due to enhanced evaporation rate, melting lake ice, and expansion of water extent.

We present greater than or similar to 15,000 metal-rich ([Fe/H] > -0.2 dex) A and F stars whose surface abundances deviate strongly from solar abundance ratios and cannot plausibly reflect their birth material composition. These stars are identified by their high [Ba/Fe] abundance ratios ([Ba/Fe] > 1.0 dex) in the LAMOST DR5 spectra analyzed by Xiang et al. They are almost exclusively main-sequence and subgiant stars with T-eff greater than or similar to 6300 K. Their distribution in the Kiel diagram (T-eff-log g) traces a sharp border at low temperatures along a roughly fixed-mass trajectory (around 1.4M(circle dot)) that corresponds to an upper limit in convective envelope mass fraction of around 10(-4). Most of these stars exhibit distinctly enhanced abundances of iron-peak elements (Cr, Mn, Fe, Ni) but depleted abundances of Mg and Ca. Rotational velocity measurements from GALAH DR2 show that the majority of these stars rotate slower than typical stars in an equivalent temperature range. These characteristics suggest that they are related to the so-called Am/Fm stars. Their abundance patterns are qualitatively consistent with the predictions of stellar evolution models that incorporate radiative acceleration, suggesting they are a consequence of stellar internal evolution, particularly involving the competition between gravitational settling and radiative acceleration. These peculiar stars constitute 40% of the whole population of stars with mass above 1.5M(circle dot), affirming that "peculiar" photospheric abundances due to stellar evolution effects are a ubiquitous phenomenon for these intermediate-mass stars. This large sample of Ba-enhanced, chemically peculiar A/F stars with individual element abundances provides the statistics to test more stringently the mechanisms that alter the surface abundances in stars with radiative envelopes.

We report the discovery of a highly eccentric long-period Jovian planet orbiting the hot-Jupiter host HD 83443. By combining radial velocity data from four instruments (AAT/UCLES, Keck/HIRES, HARPS, Minerva-Australis) spanning more than two decades, we find evidence for a planet with m sin i = 1.35(-0.06)(+0.07) M-J, moving on an orbit with a = 8.0 +/- 0.8 au and eccentricity e = 0.76 +/- 0.05. We combine our radial velocity analysis with Gaia eDR3/Hipparcos proper motion anomalies and derive a dynamical mass of 1.5(-0.2)(+0.5)M(Jup). We perform a detailed dynamical simulation that reveals locations of stability within the system that may harbor additional planets, including stable regions within the habitable zone of the host star. HD 83443 is a rare example of a system hosting a hot Jupiter and an exterior planetary companion. The high eccentricity of HD 83443c suggests that a scattering event may have sent the hot Jupiter to its close orbit while leaving the outer planet on a wide and eccentric path.

Recordings of the Bolivian Earthquake of 9 June, 1994 from two portable experiments were analyzed for ScS and sScS reverberations. These stations span the distance range 6 degrees - 22 degrees, sampling the mantle beneath South America along an EW line from the central Andes to the Brasilian Craton. We used the CORE method to obtain path-averaged locations of the Moho and 400 and 660 km discontinuities. The average depth for D-400 is 410km for the BANJO stations and 395km beneath Brazil, and the value for D-660 is 700km for BANJO and 675km for BLSP, while the difference D-660-D-400 = Delta D is 290km and 280km respectively. These values are much larger than the global average (around 245km) and suggest 200 degrees - 300 degrees colder temperatures in the region sampled. This is most plausibly explained by the reduced temperatures in the slab and surrounding region. We also detect a significant discontinuity at 210 km depth, with a shear wave impedance increase of at least 5%. Finally, we observe systematic variations in duration between P, ScS and sScS that can only be attributed to source finiteness. These observations constrain the inclination of an equivalent unilateral rupture velocity vector to be -17 degrees (positive up from horizontal). Our rupture model is consistent with models derived from subevent analysis of the P wave arrivals, and implies a source extent of 72 km.

This paper introduces the motivations, objectives, and scope of a PUB working group to investigate the linkage between orographic precipitation, surface water and groundwater interactions, and their impacts on water resources. The ultimate goal of the working group is to assess the reduction of uncertainties in hydrological predictions for ungauged basins through improvements of two important physical processes of land-atmosphere interactions: orographic precipitation and surface water and groundwater interactions. In particular, we will focus on, in our current work, cold season orographic precipitation, snowmelt recharge to groundwater bodies,and their impacts on water resources. Our objectives are to: (1) improve the prediction of cold season orographic precipitation processes in mountainous regions and estimate their impacts on hydrological predictions and regional climate through land-atmosphere interactions; (2) improve our understanding of snowmelt recharge to groundwater bodies and surface water and groundwater interactions; and (3) improve the management of water resources through improved understanding and predictions of snowpack and surface water and groundwater interactions. Preliminary results are presented based on a regional-scale coupled land-atmosphere model that has been recently developed to address science questions of the working group. The model includes a subgrid parameterization of orographic precipitation and dynamic surface water-groundwater interactions. Simulations with and without the dynamic groundwater component have been compared to investigate the potential impacts of surface water and groundwater interactions.

From the experiences learned in three decades of exoplanet search, wide-field transit surveys have proven to be one of the most effective ways to detect exoplanets. Wide field of view, however, suffers from high false-positive rates caused by blended eclipsing binaries. The chromaticity in eclipse depth is an effective feature to distinguish low-depth eclipsing binaries from transiting exoplanets, making multiple-band photometry follow-up advantageous before a target is passed onto more expensive spectroscopic follow-up. Moreover, a multiple-band photometric survey is itself a powerful method to find and vet planetary candidates and narrow down the candidate list of high-priority targets. In this work, we report the first results of a dual-band (Sloan-g and -i) wide-field photometry survey-the Chinese Small Telescope ARray II (CSTAR-II), an updated version of the original CSTAR. As a key component of the Chinese Exoplanet Searching Program from Antarctica, CSTAR-II has been tested thoroughly at a remote arctic site near Mohe during the winter of 2014. In total, 13,531 light curves with the best overall photometric precision of similar to 3 mmag were extracted from 7721 stars in the Sloan-g and -i bands. Using a robust method, we have detected 63 variables, of which 48 are newly discovered. The dual-band photometric results as well as the stellar properties of the detected sources are provided in this work.

The CHinense Exoplanet Searching Program from Antarctica is a ground-based wide-field photometric survey using the AST3 and CSTAR telescopes located at Dome A, Antarctica. Blessed with the unparalleled observing conditions on the highest point of the Antarctic plateau, three remotely controlled, fully automatic telescopes (AST3-I, AST3-II, and CSTAR-II) carried out continuous high-precision photometric surveys through the polar nights of 2016 and 2017. During the observing seasons of 2016, a total of 26,578 light curves were obtained for stars within the area of the southern continuous viewing zone of TESS, covering an i-band magnitude range from 7.5 to 15. At m(i) = 10, photometric precision reaches similar to 2 mmag, allowing possible discoveries of sub-Jupiter-size exoplanets. Here we report 20 stellar flares with i-band energies larger than 10(34) erg detected in the 2016 data set of AST3-II, all from different sources. We model the stellar flares and calculate the durations, amplitudes, energies, and skewnesses. The flare properties and the stellar properties of their sources are presented in this work.

Luminous z Luminous z >= 7 quasars provide direct probes of the evolution of supermassive black holes (SMBHs) and the intergalactic medium (IGM) during the epoch of reionization (EoR). The Ly alpha damping wing absorption imprinted by neutral hydrogen in the IGM can be detected in a single EoR quasar spectrum, allowing the measurement of the IGM neutral fraction toward that line of sight. However, damping wing features have only been detected in two z > 7 quasars in previous studies. In this paper, we present new high-quality optical and near-infrared spectroscopy of the z = 7.00 quasar DES J025216.64-050331.8 obtained with Keck/Near-Infrared Echellette Spectrometer and Gemini/GMOS. By using the Mg II single-epoch virial method, we find that it hosts a (1.39 +/- 0.16) x 10(9) M-circle dot SMBH accreting at an Eddington ratio of lambda(Edd) = 0.7 +/- 0.1, consistent with the values seen in other luminous z similar to 7 quasars. Furthermore, the Lya region of the spectrum exhibits a strong damping wing absorption feature. The lack of associated metal absorption in the quasar spectrum indicates that this absorption is imprinted by a neutral IGM. Using a state-of-the-art model developed by Davies et al., we measure a volumeaveraged neutral hydrogen fraction at z = 7 of < x(H I)> = 0.70(-0.23)(+0.20)

X-ray emission from quasars has been detected up to redshift z = 7.5, although only limited to a few objects at z > 6.5. In this work, we present new Chandra observations of five z > 6.5 quasars. By combining with archival Chandra observations of six additional z > 6.5 quasars, we perform a systematic analysis on the X-ray properties of these earliest accreting supermassive black holes (SMBHs). We measure the black hole masses, bolometric luminosities (L-bol), Eddington ratios (lambda(Edd)), emission line properties, and infrared luminosities (L-IR) of these quasars using infrared and submillimeter observations. Correlation analysis indicates that the X-ray bolometric correction (the factor that converts from X-ray luminosity to bolometric luminosity) decreases with increasing L-bol, and that the UV/optical-to-X-ray ratio, alpha(ox), strongly correlates with L-2500 A, and moderately correlates with lambda(Edd) and blueshift of C iv emission lines. These correlations are consistent with those found in lower-z quasars, indicating quasar accretion physics does not evolve with redshift. We also find that L-IR does not correlate with L2-10 keV in these luminous distant quasars, suggesting that the ratio of the SMBH growth rate and their host galaxy growth rate in these early luminous quasars are different from those of local galaxies. A joint spectral analysis of the X-ray detected z > 6.5 quasars yields an average X-ray photon index of Gamma = 2.32(-0.30)(+0.31), steeper than that of low-z quasars. By comparing it with the Gamma - lambda(Edd) relation, we conclude that the steepening of Gamma for quasars at z > 6.5 is mainly driven by their higher Eddington ratios.

Carbohydrates (sugars) are an essential energy-source for all life forms. They take a significant share of our daily consumption and are used for biofuel production as well. However, sugarcane and sugar beet are the only two crop plants which are used to produce sugar in significant amounts. Here, we have discovered and fine-tuned a phenomenon in rice which leads them to produce sugary-grain. We knocked-out GCS1 genes in rice by using CRISPR technology, which led to fertilization failure and pollen tube-dependent ovule enlargement morphology (POEM) phenomenon. Apparently, the POEMed-like rice ovule ('endosperm-focused') can grow near-normal seed-size unlike earlier observations in Arabidopsis in which gcs1 ovules ('embryo-focused') were aborted quite early. The POEMed-like rice ovules contained 10-20% sugar, with extremely high sucrose content (98%). Trancriptomic analysis revealed that the osgcs1 ovules had downregulation of starch biosynthetic genes, which would otherwise have converted sucrose to starch. Overall, this study shows that pollen tube content release is sufficient to trigger sucrose unloading at rice ovules. However, successful fertilization is indispensable to trigger sucrose-starch conversion. These findings are expected to pave the way for developing novel sugar producing crops suited for diverse climatic regions.