Simple Biosphere Model version 4.2 (SiB4) technical description

The Simple Biosphere Model (SiB4) is a mechanistic, prognostic land surface model that integrates heterogeneous land cover, environmentally responsive prognostic phenology, dynamic carbon allocation, and cascading carbon pools from live biomass to surface litter to soil organic matter. By combining biogeochemical, biophysical, and phenological processes, SiB4 predicts vegetation and soil moisture states, land surface energy and water budgets, and the terrestrial carbon cycle. Rather than relying on satellite data, SiB4 fully simulates the terrestrial carbon cycle by using the carbon fluxes to determine the above and belowground biomass, which in turn feeds back to impact carbon assimilation and respiration. Every 10-minute time-step, SiB4 computes the albedo, radiation budget, hydrological cycle, layered temperatures, and soil moisture, as well as the resulting energy exchanges, moisture fluxes, carbon fluxes, and carbon pool transfers. Photosynthesis depends directly on environmental factors (humidity, moisture, and temperature) and aboveground biomass; and carbon uptake is determined using enzyme kinetics and stomatal physiology. Carbon release and pool transfers depend on assimilation rate, day length, moisture, phenology, temperature, and pool size. Once daily the net assimilated carbon is allocated to the live pools depending on phenology, soil moisture, and temperature; all live and dead pools are updated, including any necessary carbon transfers between pools; and the land surface state and related properties are revised. The new LAI and pools are then used for sub-hourly assimilation and respiration, completing the carbon cycle and providing self-consistent predicted vegetation states, soil hydrology, carbon pools, and land-atmosphere exchanges

Thirty years of change in a benthic macroinvertebrate community of southwestern Lake Ontario after invasion by four Ponto-Caspian species

Beginning in the mid-1980s, the Laurentian Great Lakes underwent successive invasions by PontoCaspian species. We quantified major changes in the diversity and relative abundance of pre-invasion benthic macroinvertebrates at the same study site in southwestern Lake Ontario from 1983–2014. The zebra mussel Dreissena polymorpha Pallas arrived at the study site before 1991, the quagga mussel Dreissena rostriformis bugensis Andrusov and the amphipod Echinogammarus ischnus Stebbing arrived before 1999, and the Round Goby Neogobius melanostomus Pallas arrived about 2004. The macroinvertebrate community in 2014 was very different from 3 earlier communities in 1983, 1991, and 1999. In 2014, pulmonate and prosobranch snails and sphaeriid bivalves were absent, D. r. bugensis replaced D. polymorpha, E. ischnus replaced Gammarus fasciatus Say as the dominant amphipod, and a previously diverse community of benthic fish was replaced by abundant N. melanostomus. From 1983 to 1999, the relative abundance of prosobranchs and pulmonates declined 10-fold and rose 2-fold, respectively. From 1991 to 2014, the relative abundance of oligochaetes and chironomids increased 32- and 78-fold, respectively. The shifts we report probably are attributable to nutrient enrichment of the nearshore of Lake Ontario during the 1990s leading to a thick carpet of macroalgae, a change in the base of the benthic food web from dressenid feces and pseudofeces to macroalgal detritus, and predation by N. melanostomus on snails

Effect of Sleep on the Attentiveness of Elementary School Students

Sleep is known to be important in the development of children and their cognitive functioning. This study worked to establish correlation between amount of sleep and attentiveness in schoolaged children. This study surveyed the parents of 10 third graders on their child’s sleep habits. The children were read a story in class and asked to answer questions based on details in the story. The data obtained from this quiz and the parent’s survey responses were then compared to see if there was a relation. The results of this study were inconclusive. When genders were separated, it was found that males slept the most but females got more answers correct on the quiz. However, when the data was organized based on the recommended sleep amount for this age, it was found that children who met the recommendation answered more questions correctly compared to those who did not

Detection of an Optical Counterpart to the ALFALFA Ultra-compact High Velocity Cloud AGC 249525

We report on the detection at $>$98% confidence of an optical counterpart to AGC 249525, an Ultra-Compact High Velocity Cloud (UCHVC) discovered by the ALFALFA blind neutral hydrogen survey. UCHVCs are compact, isolated HI clouds with properties consistent with their being nearby low-mass galaxies, but without identified counterparts in extant optical surveys. Analysis of the resolved stellar sources in deep $g$- and $i$-band imaging from the WIYN pODI camera reveals a clustering of possible Red Giant Branch stars associated with AGC 249525 at a distance of 1.64$\pm$0.45 Mpc. Matching our optical detection with the HI synthesis map of AGC 249525 from Adams et al. (2016) shows that the stellar overdensity is exactly coincident with the highest-density HI contour from that study. Combining our optical photometry and the HI properties of this object yields an absolute magnitude of $-7.1 \leq M_V \leq -4.5$, a stellar mass between $2.2\pm0.6\times10^4 M_{\odot}$ and $3.6\pm1.0\times10^5 M_{\odot}$, and an HI to stellar mass ratio between 9 and 144. This object has stellar properties within the observed range of gas-poor Ultra-Faint Dwarfs in the Local Group, but is gas-dominated.Comment: 9 pages, 4 figures; accepted to ApJ