Small Seasonal Variations Research Articles

Near‐surface wind variability in Prydz Bay and Amery Ice Shelf region, East Antarctica: A four‐decade SOM analysis

AbstractNear‐surface wind fields in the Prydz Bay and Amery Ice Shelf region of East Antarctica play a crucial role in the formation and variability of Antarctic Bottom Water, a cold, dense water mass that sinks and spreads across the deep ocean basins influencing ocean circulation and modulating earth's climate system. This study investigates the primary modes of variability of these wind fields using the self‐organizing map (SOM) method and data from the latest version of the European Centre for Medium‐Range Weather Forecasts (ECMWF) ReAnalyses (ERA5), spanning four decades from 1979 to 2020. While the wind field climatology, characterized by small seasonal variation, is dominated by katabatic and large‐scale forcing, the spatial patterns of the primary variability modes are mainly influenced by synoptic system activities. The overall trend in annual wind speed anomalies is positive across the study region, with the exception of the southwestern part and central Prydz Bay. However, significant trends are observed in only two out of nine SOM nodes (nodes 4 and 9), which collectively explain less than 30% of the averaged trends over the region. The interannual variability in the seasonal occurrences of certain nodes is linked to several well‐known climate modes, including the El Niño–Southern Oscillation, the Southern Annular Mode and Zonal Wavenumber 3. Our results provide a reference for forecasting the occurrence frequency of specific patterns, which could help mitigate the impact of extreme wind events through improved forecasting.

Patient result monitoring of HbA1c shows small seasonal variations and steady decrease over more than 10 years.

Internal and external quality assurance materials often use highly processed matrixes. This can render the materials non-commutable. Monitoring laboratory methods with patient medians helps in identifying and correcting systematic errors that may affect diagnostic accuracy. The aim of the present study was to use HbA1c patient results for monitoring of method performance over time. Test HbA1c results from 2010 to 2022 was analyzed (n=722,553) regarding changes over time and seasonal variation. The HbA1c testing was initially performed on a Cobas 501 instrument using immunological detection but in May 2017 the method was replaced by capillary electrophoresis on Capillarys 3 Tera. There was a steady decrease in HbA1c values. From 2011 to 2021 the decrease was for 0.10 percentile 6.6 %, lower quartile 7.9 %, median 10.2 %, mean values 9 %, upper quartile 11.2 %, and 0.90 percentile 9.3 %. No clear shift in HbA1c levels was observed due to the shift in methods. The median HbA1c values per month was approximately 44 mmol/mol (6.2 %, DCCT/NGSP). The only month with a median HbA1c that differed by more than 1 mmol/mol was July with a median value of 42 mmol/mol (6.0 %). The patient data showed a similar decrease as in the National Diabetes Register which indicates that the method is stable over time without any sudden changes and that the seasonal variation is low. The continuous decrease in HbA1c values over time is most likely to a shift towards earlier detection of patient with diabetes and improved treatment.

Application of a multiparameter sonde for real-time monitoring of seawater quality in Durrës Bay in Albania

Abstract Coastal areas are characterized by a high population and a wide range of industrial and agricultural activities, which puts them under high pressure and continuous pollution from anthropogenic activities. This research focuses on the application of HYDROLAB HL7 multiparameter sonde equipped with smart sensors for the measurement of physical–chemical parameters in marine waters in the Durrës Bay. The sonde is part of a transnational repository network that receives, stores, and analyzes data about seawater quality, serving as an early warning system for preventing the diffusion of marine pollution. This sophisticated instrument can thrive in demanding environmental conditions for long-term continuous monitoring. It maximizes deployment lifespan, and provides traceable data for high-quality, reliable monitoring of vital changes in water quality. Low variability on the measured parameters indicates a stable status in the water quality of the Durrës site. Time series revealed small seasonal variations on all parameters, except turbidity and water temperature. Total dissolved solids, salinity, and electrical conductivity revealed similar temporal trends over the monitoring period by indicating strong relationships between them. The obtained data for the physical–chemical parameters in this study align with the recommended values. Ensuring water quality in the Durrës Bay requires advanced monitoring, regulatory measures, and community engagement.

A Physics-Based Method for Retrieving Land Surface Emissivities from FengYun-3D Microwave Radiation Imager Data

The passive microwave land surface emissivity (MLSE) plays a crucial role in retrieving various land surface and atmospheric parameters and in Numerical Weather Prediction models. The retrieval accuracy of MLSE depends on many factors, including the consistency of the input data acquisition time. The FengYun-3D (FY-3D) polar-orbiting meteorological satellite, equipped with passive microwave and infrared bands, offers time-consistent data crucial for MLSE retrieval. This study proposes a physics-based MLSE retrieval algorithm using all the input data from the FY-3D satellite. Based on the retrieved MLSE, the spatial distribution of the MLSE is closely correlated with the land cover types and topography. Lower emissivities prevailed over barren or sparsely vegetated regions, river basins, and coastal areas. Higher emissivities dominated densely vegetated regions and mountainous areas. Moderate emissivities dominated grasslands and croplands. Lower-frequency channels showed larger emissivity differences with different polarizations than those of higher-frequency channels in barren or sparsely vegetated regions. The MLSE across densely vegetated land areas, mountainous areas, and deserts showed small seasonal variations. However, woody savannas, grasslands, croplands, and seasonal snow-covered areas showed noticeable seasonal variations. For most land cover types, the differences between vertically and horizontally polarized emissivities remained relatively constant across seasons. However, certain grasslands in eastern Inner Mongolia and southern Mongolia showed clear seasonal variations. It is very difficult to verify the MLSE on a large scale. Consequently, the possible error sources in the retrieved MLSE were analyzed, including the brightness temperature errors (correlation coefficient ranging from 0.92 to 0.99) and the retrieved land surface temperature errors (Root Mean Square Error was 3.34 K and relation coefficient was 0.958).

Numerical analysis of CH4 concentration distributions over East Asia with a regional chemical transport model

Atmospheric CH4 concentrations have increased rapidly and exhibited large spatiotemporal variations. But their values were generally fixed in regional air quality models, without considering the processes of emissions, transport, and diffusion. In this study, a regional air quality modeling system RAMS-CMAQ was developed by incorporating the emissions, transport, and diffusion processes of CH4 to produce CH4 concentration distributions. The developed model was applied to simulate CH4 concentrations over East Asia in 2020. As a result, the comparisons between the simulated CH4 vertical column densities (VCDS) and the observations derived from GOSAT showed that the developed model can reasonably reflect the crucial features in CH4 concentration variations with the correlation coefficients larger than 0.94. The temporal-spatial patterns of surface CH4 concentrations showed that concentrations were high (≥2.3 ppm) over Sichuan Basin, central-eastern China and South China as well as India, where the highest was in summer because of the largest agricultural emissions, and the lowest was in spring due to less emissions and stronger OH sinks compared to winter. The low surface CH4 concentrations (≤1.9 ppm) appeared over Northwest China with small seasonal variations (high in summer and low in winter and autumn) and less local emissions. The temporal-spatial patterns of CH4 VCDS showed that VCDS were high (3.6–4.5 × 1019 molec/cm2) over eastern China with significant seasonal variations (high in summer and autumn), and low (≤3.0 × 1019 molec/cm2) over Tibet Plateau and western Mongolia with slight variations.

Environmental impacts of shallow water mining in the Baltic Sea

The discovery of rare metal resources in international waters has raised seabed mining claims for large areas of the bottom. There is abundant scientific evidence of major negative consequences for the maritime environment, such as the destruction of natural landforms and the fauna that depend on them, as well as the production of enormous silt plumes that disrupt aquatic life. This study investigated the environmental risks of seabed mining for metal resources in the Baltic Sea using a combination of hydrodynamic, particle-tracking, and sediment-transport models. The models were applied for ten years i.e., 2000-2009 under prevailing conditions to simulate seabed mining operations. The focus was on sediment concentration near the seabed and its spread. The mean background concentrations were low with small seasonal bed-level variations throughout the Baltic Sea Basin. Late summer and early autumn periods were the most active. Seabed mining significantly alters the dynamics of sediment suspensions and bed level variations. The concentrations increase unsustainably to high levels, posing a serious threat to the ecological health of the Baltic Sea. The Gotland basins in the Baltic Sea are the most susceptible to mining. The bed level variations will be ten-fold, exposing the highly contaminated sediments at the seabed to the flow. In less than a year, 30-60% of the total particles released in each basin reached the thermocline layers. This study suggests that seabed mining in the Baltic Sea is not sustainable.

Leaf photosynthetic pigment as a predictor of leaf maximum carboxylation rate in a farmland ecosystem.

The leaf maximum rate of carboxylation (Vcmax) is a key parameter of plant photosynthetic capacity. The accurate estimation of Vcmax is crucial for correctly predicting the carbon flux in the terrestrial carbon cycle. Vcmax is correlated with plant traits including leaf nitrogen (Narea) and leaf photosynthetic pigments. Proxies for leaf chlorophyll (Chlarea) and carotenoid contents (Cararea) need to be explored in different ecosystems. In this study, we evaluated the relationship between leaf maximum rate of carboxylation (scaled to 25°C; Vcmax25) and both leaf Narea and photosynthetic pigments (Chlarea and Cararea) in winter wheat in a farmland ecosystem. Our results showed that Vcmax25 followed the same trends as leaf Chlarea. However, leaf Narea showed smaller dynamic changes before the flowering stage, and there were smaller seasonal variations in leaf Cararea. The correlation between leaf Vcmax25 and leaf Chlarea was the strongest, followed by leaf Cararea and leaf Narea (R2=0.69, R2=0.47 and R2=0.36, respectively). The random forest regression analysis also showed that leaf Chlarea and leaf Cararea were more important than leaf Narea for Vcmax25. The correlation between leaf Vcmax25 and Narea can be weaker since nitrogen allocation is dynamic. The estimation accuracy of the Vcmax25 model based on Narea, Chlarea, and Cararea (R2=0.75) was only 0.05 higher than that of the Vcmax25 model based on Chlarea and Cararea (R2=0.70). However, the estimation accuracy of the Vcmax25 model based on Chlarea and Cararea (R2=0.70) was 0.34 higher than that of the Vcmax25 model based on Narea (R2=0.36). These results highlight that leaf photosynthetic pigments can be a predictor for estimating Vcmax25, expanding a new way to estimate spatially continuous Vcmax25 on a regional scale, and to improve model simulation accuracy.

Effects of Season and Daylight Saving Time Shifts on Sleep Symptoms: Canadian Longitudinal Study on Aging.

There has been conflicting evidence regarding the association between seasonal changes and daylight saving time (DST) and sleep disorders. This topic is of particular interest currently because the United States and Canada are considering the elimination of seasonal clock changes. The aim of this study was to compare sleep symptoms among participants who were interviewed in different seasons and before/after the transition into DST and standard time (ST). A total of 30,097 people aged 45-85 years taking part in the Canadian Longitudinal Study on Aging were studied. Participants completed a questionnaire on sleep duration, satisfaction, sleep-onset insomnia, sleep-maintenance insomnia, and hypersomnolence symptoms. Sleep disorders were compared between participants who were interviewed during different seasons and at different times of the year (DST/ST). Data were analyzed using χ2, analysis of variance, binary logistic, and linear regression tests. Among participants interviewed in different seasons, we found no difference in dissatisfaction with sleep, sleep onset, sleep maintenance, and hypersomnolence. Those interviewed in summer had slightly shorter sleep duration compared with those in winter (6.76 ± 1.2 vs 6.84 ± 1.3 hours). Participants interviewed 1 week before vs 1 week after DST transition showed no difference in sleep symptoms, except for a 9-minute decrease in sleep duration a week after transition. However, those who were interviewed a week after transition to ST compared with a week before reported more dissatisfaction with sleep (28% vs 22.6%, adjusted odds ratio [aOR] 1.34, 95% CI 1.02-1.76), higher sleep-onset insomnia (7.1% vs 3.3%, aOR 2.26, 95% CI 1.19-4.27), higher sleep-maintenance insomnia (12.9% vs 8.2%, aOR 1.64, 95% CI 1.02-2.66), and more hypersomnolence with adequate sleep (7.3% vs 3.6%, aOR 2.08, 95% CI 1.14-3.79). We found small seasonal variations in sleep duration but no difference in other sleep symptoms. The transition from DST to ST was associated with a transient increase in sleep disorders.

Inferring parental areas of juvenile mussels using hydrodynamic modelling

Mussel aquaculture is heavily reliant on wild mussel populations that supply juveniles (spat) for seeding farms. However, little is often known about parent populations, representing a risk for the sustainability of the industry. We used hydrodynamic back-tracking models to identify potential parental areas that provision green-lipped mussel (Perna canaliculus) spat across a range of settlement sites in New Zealand's largest aquaculture area. Median parental area varied considerably between 19 km2 for sites located in enclosed bays and a maximum of >1150 km2 for sites located in open bays. Median distance to parent populations ranged between 1.8 and 21.4 km, with a maximum larval dispersal estimated to be ca. 100 km. Small seasonal variations in parental area and dispersal distance were detected in some regions, whereas inter-annual variability was relatively minor. Regional connectivity between settlement and parental regions ranged between a minimum of 45% of larvae originating in the same parental region, to maximum retention rates of 99.9% for sites in enclosed bays, implying a considerable regional variation in the potential for self-seeding and exporting mussel larvae other areas. Our results also delineate areas that support spatfall by identifying likely locations for wild or farmed parental populations, and by establishing the spatial extent where mussel reproduction and larval development through to settlement take place. These dispersal and connectivity patterns are crucial to support management decisions for the conservation and restoration of parental populations, and other environmental constraints, such as water quality, which are necessary to ensure the sustainability of spat catching operations that enable shellfish farming.

Design and Analysis of a Solar-Powered DC Irrigation System: A Case Study of a Shrimp Pond

In this paper, a new approach for supplying water to shrimp production ponds in Purworejo, Indonesia, is proposed. The paper covers the design of a solar-powered DC water pump system (SWPS), system performance analysis, and economic analysis by comparing it with the existing fossil-fuel-powered pumps. The mathematical approach for the designing process is shown and Lorents Compass alternative tool is introduced. By taking into consideration the daily water demand of 50 m3/day, the annual-averaged local solar irradiation of 4.7 kWh/m2 per day, and the available components in the market, an SWPS in Purworejo would comprise a 1200 Wp PV panel and a 600 W DC pump submerged in a borehole in the seashore. The SWPS would be able to meet the daily water demand with small seasonal variations. The financial analysis shows high feasibility to install SWPS in Purworejo with a 1,6 years simple payback period, which is very short. The SWPS would provide more than 20 years of free energy for the farmers to draw seawater to the pond each day when the sun shines. It can provide not only environmental and social benefits but also significant economic advantages, both at the farm and the national levels.

A Comparison of RSOC-Battery Hybrid Energy Storage for Microgrids in the Netherlands and India

The importance of energy storage is steadily rising as electricity grids around the world become more reliant on intermittent renewable power sources such as solar PV and wind turbines. Apart from pumped hydro storage, which forms the bulk of existing energy storage, several other technologies are in development, such as batteries, super-capacitors, flywheels and synthetic e-fuels. Li-ion batteries are highly efficient and dynamic, while e-fuels have many advantages for large-scale seasonal storage. Reversible solid oxide cells (rSOC) are efficient electrochemical devices, which can play an important role in energy storage in the form of e-fuels in the near future. This paper seeks to show the advantages of rSOC systems in long-term energy storage. In particular, it seeks to compare the capital cost of a hybrid system to a purely Li-ion battery system.This paper focuses on the design of energy storage for isolated sustainable micro-grids. A hybrid system is designed, using Li-ion batteries for instantaneous grid balancing, and rSOC system for long-term storage in the form of hydrogen. The paper also focuses on the effect of the wind-solar energy mix and climate. For temperate and cloudy climates, Groningen in the Netherlands is used as an example. The Netherlands has a renewable energy mix of around 70% wind and 30% solar. For sunny tropical climates, Jodhpur in India is used, and India has a renewable energy mix of around 55% wind and 45% solar. Using hourly local data for solar irradiation and wind velocities, a simple algorithm is developed for system sizing. The generation as well as storage systems are sized for a constant consumption load of 20 kW (a constant load is considered to be a reasonable assumption for industrial loads, for example). The capital cost calculation includes the wind turbine(s), solar panels, battery bank, rSOC stack, and compressed hydrogen tank.The results show that the use of an rSOC-hydrogen module in a hybrid-energy storage system leads to significant capital cost reduction compared to a purely Li-ion battery-based system. As expected, this reduction is a result of the fact that power and energy-storage capacities are decoupled in an rSOC/e-fuel system, which means that a small rSOC stack can be used with a large tank, which is suitable for long-term seasonal storage. Hydrogen tanks also cost significantly less than batteries for the same energy capacity. The cost reduction for Jodhpur is more significant than for Groningen.The study also shows the significant effect of the local energy mix on the design of energy storage systems. Naturally, Jodhpur has more solar radiation and less seasonal variation in solar energy. But contrary to initial expectations, tropical Jodhpur requires larger energy seasonal storage facilities than temperate Groningen. This is because the small seasonal solar variation in Jodhpur is further compounded by the seasonal wind pattern, where the wind is strong in summer and weak in winter. On the other hand, the wind patterns are much more stable in Groningen, which largely neutralises the solar variation, especially since wind makes up 70% of the energy mix in Groningen. Figure 1

Identifying dominant environmental predictors of freshwater wetland methane fluxes across diurnal to seasonal time scales.

While wetlands are the largest natural source of methane (CH4 ) to the atmosphere, they represent a large source of uncertainty in the global CH4 budget due to the complex biogeochemical controls on CH4 dynamics. Here we present, to our knowledge, the first multi-site synthesis of how predictors of CH4 fluxes (FCH4) in freshwater wetlands vary across wetland types at diel, multiday (synoptic), and seasonal time scales. We used several statistical approaches (correlation analysis, generalized additive modeling, mutual information, and random forests) in a wavelet-based multi-resolution framework to assess the importance of environmental predictors, nonlinearities and lags on FCH4 across 23 eddy covariance sites. Seasonally, soil and air temperature were dominant predictors of FCH4 at sites with smaller seasonal variation in water table depth (WTD). In contrast, WTD was the dominant predictor for wetlands with smaller variations in temperature (e.g., seasonal tropical/subtropical wetlands). Changes in seasonal FCH4 lagged fluctuations in WTD by ~17±11days, and lagged air and soil temperature by median values of 8±16 and 5±15days, respectively. Temperature and WTD were also dominant predictors at the multiday scale. Atmospheric pressure (PA) was another important multiday scale predictor for peat-dominated sites, with drops in PA coinciding with synchronous releases of CH4 . At the diel scale, synchronous relationships with latent heat flux and vapor pressure deficit suggest that physical processes controlling evaporation and boundary layer mixing exert similar controls on CH4 volatilization, and suggest the influence of pressurized ventilation in aerenchymatous vegetation. In addition, 1- to 4-h lagged relationships with ecosystem photosynthesis indicate recent carbon substrates, such as root exudates, may also control FCH4. By addressing issues of scale, asynchrony, and nonlinearity, this work improves understanding of the predictors and timing of wetland FCH4 that can inform future studies and models, and help constrain wetland CH4 emissions.

Convective Cloud Regimes From a Classification of Object‐Based CloudSat Observations Over Asian‐Australian Monsoon Areas

AbstractThe present study objectively classified the convective cloud objects detected by the space‐borne CloudSat radar over the Asian‐Australian monsoon region using the hierarchical agglomerative clustering algorithm. Based on key properties representing the morphological features and convective intensity of the systems, five distinct convective cloud regimes were derived. The unique Coastal‐Intense (CI) regime exhibits the most expansive horizontal scales (>1,000 km), high convective strength, the strongest cloud radiative effects, the highest probability of extreme rainfall, and a significant coupling with the sharp onset of the Asian summer monsoon circulation. Second, the Coastal regime illustrates smaller but also highly organized coastal convections, with the strongest convective strength. Less than 10% of the systems in the CI and Coastal regimes overlap with the tropical cyclones. The rest three regimes mark the less organized convection at various life cycle stages mainly over the land areas, with small seasonal variation in their occurrence.

Striking seasonal pattern of primary production in the river-dominated ocean margin of the northern South China Sea (NSCS-RiOMar) revealed by new field and remotely sensed data

Seasonal patterns of phytoplankton biomass and primary production (PP) are important features characterizing a marine ecosystem. The South China Sea (SCS) has been arbitrarily illustrated as an ecosystem with low PP in summer and high PP in winter. However, there is an emerging consensus about a lack of unity of PP seasonality in the SCS even in the northern SCS shelf-sea. Through analysis of the distributions of the remotely sensed colored dissolved organic matter absorption coefficient, a river-dominated ocean margin in the northern SCS (NSCS-RiOMar) with the 50 m isobath as its southeastern boundary has been defined. The difference in PP seasonality between the NSCS-RiOMar and the whole shelf-sea was evaluated by both the measured and the remotely sensed depth-integrated primary production (ΣPP). A diagnostic analysis found that euphotic depth and a function of the half-saturation light intensity accounted for the seasonal variation of ΣPP in the NSCS-RiOMar. Accordingly, the Platt and Sathyendranath (1993) model plus the nearest neighbor method and the semi-analytical estimates of euphotic depth were used to compute the remotely sensed ΣPP. The average ΣPP in the NSCS-RiOMar were 1146.4, 1604.7, 979.5, and 891.3 mg C m−2 d−1 in spring, summer, autumn, and winter, respectively, contrasted with small seasonal variations in the whole shelf-sea. The unimodal ΣPP peak was in June-July in accordance with the peak of Pearl River discharge. This result was striking because previous remote sensing studies all showed the reversed seasonal pattern of ΣPP in both the NSCS-RiOMar and the whole shelf-sea. The annual PP was estimated to be 33.5 ± 2.3 Mt C yr−1 and 56.2 ± 3.2 Mt C yr−1 in the NSCS-RiOMar and the whole shelf-sea, respectively. The nutrients inputted by the China Coastal Current might account for 4–23% of ΣPP in the NSCS-RiOMar between December and February.

Seasonal and fortnightly variability of the hydrodynamic regime at Babitonga Bay, Southern of Brazil

This paper provides the first comprehensive observational results of the seasonal variability of hydrography and currents in Babitonga Bay, a microtidal subtropical estuary, and one of the largest estuaries in Brazil with economic and ecological importance. Measurement campaigns were performed during the higher and lower rain conditions in austral summer and winter, respectively. Time series of current velocity and salinity–temperature were obtained near the bottom at the head estuary for each season. Along-estuary hydrographic sections and tidal-cycle cross-estuary transect surveys of current velocity and hydrographic profiles at the mouth were performed in the spring and neap tides. The M2 is the main harmonic constituent. The third-diurnal principal lunar (M3) suffers the highest amplification (∼115%), followed by the shallow water overtides of principal lunar (M4) with ∼82%. The tide mainly controls the variability of salinity, density, and longitudinal currents with no variation between the two seasons. The water temperature presents irregular daily variations associated with daytime heating (summer) and nighttime cooling (summer and winter). The along-estuary salinity distribution characterizes a weakly stratified estuary with small intratidal, fortnightly, and seasonal variations. At the mouth, the flood currents start to inflow laterally in the shallow flank of the estuary, in both spring and neap tides. The maximum velocities measured along-channel are similar for neap and spring tides for both summer and winter seasons. The density induced exchange flow pattern is vertically and horizontally sheared in the spring tides and vertically sheared in the neap with no seasonal variation. The intratidal and the spring–neap cycle are more important than the seasonal scale in governing the hydrodynamic at Babitonga Bay.

Chemical weathering in the upstream and midstream reaches of the Yarlung Tsangpo basin, southern Tibetan Plateau

The Tibetan Plateau (TP) is a focus of chemical weathering research worldwide. However, scant studies on the northern flank of the Himalayas and the vast inland region of the TP hinders understanding of the role the TP has played in the global carbon cycle. The upstream and midstream of the Yarlung Tsangpo (UMRYT) is the longest river in Tibet with the highest elevation in the world. Two sampling campaigns were conducted in December 2012 and August 2013 to estimate the intensity of chemical weathering, CO2 consumption rates, and their controlling factors in the UMRYT basin. Results show that the total dissolved cations and anions have a broad range of changes with an average of 199 mg/L (46–637 mg/L) in December and 196 mg/L (43–523 mg/L) in August. This parameter displays small seasonal variations for most sampling sites; these are just slightly diluted in August even though runoff is 6–12 times higher than that in December. The evidence from TZ+⁎/HCO3−⁎ (⁎indicates after deduction from atmospheric inputs) demonstrates the proportion of rock weathering caused by H2SO4 is surprisingly high in the sub-basins to the extent that it is generally above 50% in both seasons. Dogxung Tsangpo, Nianchu River, and the small tributaries at the southern bank are severely affected by rock weathering involving sulfuric acid (above 90%). The chemical budget shows that the average proportion of TZ+ in river water derives from atmospheric inputs, weathering of silicate, carbonate, and evaporite are 9%, 19%, 50%, and 22%, respectively. The contribution of carbonate dissolution to TZ+ is 8–16% higher during the monsoon season. In contrast, the proportions of silicate weathering and evaporite dissolution are 4–16% and 1–8% larger in the non-monsoon period, respectively. Chemical weathering intensity shows significant spatial differences. Carbonate weathering rates (CWR) and silicate weathering rates (SWR) in the main tributaries vary from 12.6 ± 4.8 to 20.0 ± 5.8 t/km2/y and from 2.9 to 5.6 t/km2/y, respectively. Lithology exerts a profound influence on the spatial heterogeneity of CWR in basins of the main tributaries of the UMRYT, while the spatial distribution of SWR is mainly governed by runoff. The CWR and SWR in the whole basin are 13.2 ± 4.0 t/km2/y and 3.9 t/km2/y, respectively, indicating the chemical weathering intensity and its CO2 sequestration are much lower than most large rivers draining the Tibetan Plateau and other orogenic belts around the world.

P71 Nutrition Education with Incentive at NYC Farmers Markets May Contribute to Longer-Term Increases in Produce Consumption

<h3>Background</h3> Farmers' markets (FMs) present opportunities for health promotion. In New York City (NYC), the Just Say Yes to Fruits and Vegetables Stellar FM Program (Stellar) provides free nutrition and cooking demonstrations for adults from July-November at select FMs coupled with distribution of one $2 Health Bucks (HB) coupon, redeemable toward fresh produce at all NYC FMs. <h3>Objective</h3> Evaluate the relative impact of Stellar and HB distribution on initial and longer-term changes in produce consumption. <h3>Study Design, Setting, Participants</h3> This quasi-experimental, longitudinal evaluation recruited the following groups from NYC FMs located in neighborhoods with low incomes from July-August 2016: Stellar (n = 110): Stellar attendees from 2 FMs; HB (n = 330): shoppers at 2 non-Stellar FMs who received $6 HB at recruitment, and $6 HB/month for 3 months; Controls (n = 325): shoppers at 2 other non-Stellar FMs. Baseline surveys were conducted at recruitment. Phone/mail follow-up surveys were conducted from August-September 2016 (Wave 2) and February-April 2017 (Wave 3). Participant retention at Waves 2 and 3, respectively, were: Stellar 67%/49%; HB 37%/33%; Controls 38%/37%. <h3>Measurable Outcome/Analysis</h3> Daily fruit and vegetable (FV) consumption were measured using the NHANES Dietary Screener Questionnaire. Linear regression models accounting for participant-level clustering and fixed effects for wave, group, wave*group, education, race/ethnicity, and income-assessed adjusted average intake and within-group changes from baseline (α = 0.05). <h3>Results</h3> Baseline total FV intake averaged 2.81 times/day (Controls), 2.80 (HB), and 2.63 (Stellar). At Wave 2, all groups had non-significant increases (Controls: 0.04, <i>P</i> = .734; HB: 0.22, <i>P</i> = .088; Stellar: 0.28, <i>P</i> = .114). At Wave 3, Controls and HB had non-significant changes from baseline by −0.22 (<i>P</i> = .131) and −0.27 (<i>P</i> = .054), respectively, while Stellar significantly increased by 0.41 times/day (<i>P</i> = .041). <h3>Conclusions</h3> These findings indicate that Stellar programming, which includes HB, may support sustained increased FV consumption more than HB distribution alone. This study is limited by unexpectedly small sample sizes and seasonal variation between survey waves.

Phytoplankton Phenology in the North Atlantic: Insights From Profiling Float Measurements

Phytoplankton division rate (µ), loss rate (l), and specific accumulation rate (r) were calculated using Chlorophyll-a (Chl) and phytoplankton carbon (Cphyto) derived from bio-optical measurements on 12 Argo profiling floats in a north-south section of the western North Atlantic Ocean (40° N to 60° N). The float results were used to quantify the seasonal phytoplankton phenology and bloom dynamics for the region. Latitudinally varying phytoplankton dynamics were observed. In the north, the CPhyto peak was higher, occurred later, and was accompanied by higher total annual CPhyto accumulation. In contrast, in the south, stronger μ-r decoupling occurred despite smaller seasonal variations in mixed layer depth (suggesting the possibility of other ecological forcing), and was accompanied by an increasing portion of winter to total annual production, consistent with relief of nutrient limitation. The float observations of phytoplankton phenology for the mixed layer were compared to ocean color satellite remote sensing observations and found to be similar. A similar comparison to an eddy-resolving ocean simulation found the model only reproduced some of aspects of the observed phytoplankton phenology, indicating possible biases in the simulated physical forcing, turbulent dynamics, and bio-physical interactions. In addition to seasonal patterns in the mixed layer, the float measurements provided information on the vertical distribution of physical and biogeochemical quantities and therefore are complementary to the remote sensing measurements. Seasonal phenology patterns arise from interactions between “bottom-up” (e.g., resources for growth) and “top-down” (e.g., grazing, mortality) factors that involve both biological and physical drivers. The Argo float data are consistent with the disturbance recovery hypothesis over the full, annual seasonal cycle; for the late winter/early spring transition, the float data are also consistent with other bloom hypotheses (e.g. critical photosynthesis, critical division rate, and meso/sub-mesoscale physics) that highlight the importance of brief, episodic boundary layer shoaling for decoupling of division and grazing rates.

Seasonal variation in aragonite saturation states and the controlling factors in the southeastern Yellow Sea.

The aragonite saturation state (Ωarag) was determined to assess its seasonal variations and the major controlling factors in the southeastern Yellow Sea (YS) over four seasons. Ωarag showed large seasonal variation in the surface waters, with dissolved inorganic carbon (DIC) as a major factor controlling the seasonal variation. In the bottom waters, Ωarag exhibited only small seasonal variation compared with the surface waters; DIC and total alkalinity were the main factors contributing to the variation. The bottom water of the southeastern YS was undersaturated with aragonite during the fall, even though the southeastern YS was not typically associated with upwelling, freshwater discharge, or eutrophication processes. Aragonite undersaturation was most likely due to ocean dumping of organic materials. Therefore, ocean pumping should be prohibited in shallow marginal seas to prevent aragonite undersaturation.

Seasonal characterisation of municipal solid waste from Astana city, Kazakhstan: Composition and thermal properties of combustible fraction.

This study presents the results of a seasonal municipal solid waste composition campaign, that took place over the period of September 2017 to June 2018 in the capital city of Kazakhstan, Astana. Four sampling campaigns were conducted in order to identify the seasonal variation of municipal solid waste composition, recyclables and energy potential materials, such as combustible fraction, useful for the evaluation of waste-to-energy potential. The combustible fraction was analysed for thermal fuel properties, such as proximate and elemental analyses and gross calorific value. The results over the four different seasons showed that the average recyclable fraction of municipal solid waste on a wet basis of 33.3 wt.% and combustibles fraction was 8.3 wt.%. The largest fraction was the organics (47.2 wt.%), followed by plastic (15.4 wt.%) and paper (12.5 wt.%). Small seasonal variations were observed for organics, paper, plastic and glass fractions. The highest values were found in summer for the organic waste, in spring for paper and plastic and autumn for glass. The recyclables fraction showed an absolute seasonal variation of 5.7% with a peak in the winter season (35.4%) and the combustibles fraction showed a seasonal variation between 8.3 wt.% to 9.4 wt.%. Finally, the average calorific value of the combustible fraction was estimated to be 21.6 MJ kg-1 on a dry basis.