Intensive Observation Research Articles

The effects of methylene blue during and after cardiac arrest in a porcine model; a randomized, blinded, placebo-controlled study

PurposeTo evaluate the effect of methylene blue administered as a bolus on return of spontaneous circulation (ROSC), lactate levels, vasopressor requirements, and markers of neurological injury in a clinically relevant pig model of cardiac arrest. Materials and methods40 anesthetized pigs were subjected to acute myocardial infarction and 7 min of untreated cardiac arrest. Animals were randomized into three groups: one group received saline only (controls), one group received 2 mg/kg methylene blue and saline (MB + saline), and one group received two doses of 2 mg/kg methylene blue (MB + MB). The first intervention was given after the 3rd rhythm analysis, while the second dose was administered one hour after achieving ROSC. Animals underwent intensive care and observation for six hours, followed by cerebral magnetic resonance imaging (MRI). The primary outcome for this study was development in lactate levels after cardiac arrest. Categorical data were compared using Fisher's exact test and pointwise data were analyzed using one-way analysis of variance (ANOVA) or equivalent non-parametric test. Continuous data collected over time were analyzed using a linear mixed effects model. A value of p < .05 was considered statistically significant. ResultsLactate levels increased in all groups after cardiac arrest and resuscitation, however lactate levels in the MB + MB group decreased significantly faster compared with the control group (p = .007) and the MB + saline group (p = .02). The proportion of animals achieving initial ROSC was similar across groups: 11/13 (85%) in the control group, 10/13 (77%) in the MB + saline group, and 12/14 (86%) in the MB + MB group (p = .81). Time to ROSC did not differ between groups (p = .67). There was no significant difference in accumulated norepinephrine dose between groups (p = .15). Cerebral glycerol levels were significantly lower in the MB + MB group after resuscitation compared with control group (p = .03). However, MRI data revealed no difference in apparent diffusion coefficient, cerebral blood flow, or dynamic contrast enhanced MR perfusion between groups. ConclusionTreatment with a bolus of methylene blue during cardiac arrest and after resuscitation did not significantly improve hemodynamic function. A bolus of methylene blue did not yield the neuroprotective effects that have previously been described in animals receiving methylene blue as an infusion.

Main Factors Affected by the Threat of Extinction and Damage to the Betawi Language for Society

The Betawi language, like other languages in the world, is in danger of extinction caused by many things, including the dynamics of civilization. This situation threatens many contexts of indigenous Betawi culture and civilization. Therefore, the maintenance and preservation of the Betawi language is a necessity that must be carried out. The problem is the breadth of the Betawi text and linguistic context. For this reason, it is necessary to formulate an approach strategy that is more focused on what are the main factors that must be studied from the impact of damage and the endangerment of the Betawi language on the Betawi people themselves. This study formulates these factors by conducting research and field testing for more than 1 year of intensive observation 24 hours a day. Sociological qualitative analysis in particular observing the social assessment of society is the most effective method found during this research process. As a result, at least 5 segments were found that must be studied to see the impact of damage and the endangerment of the Betawi language, namely linguistic factors, personal identity, communication between generations, transfer of knowledge and knowledge, and economics.

A New Framework for Evaluating Model Simulated Inland Tropical Cyclone Wind Fields

AbstractThough tropical cyclone (TC) models have been routinely evaluated against track and intensity observations, little work has been performed to validate modeled TC wind fields over land. In this paper, we present a simple framework for evaluating simulated low‐level inland winds with in‐situ observations and existing TC structure theory. The Automated Surface Observing Systems, Florida Coastal Monitoring Program, and best track data are used to generate a theory‐predicted wind profile that reasonably represents the observed radial distribution of TC wind speeds. We quantitatively and qualitatively evaluated the modeled inland TC wind fields, and described the model performance with a set of simple indicators. The framework was used to examine the performance of a high‐resolution two‐way nested Geophysical Fluid Dynamics Laboratory model on recent U.S. landfalling TCs. Results demonstrate the capacity of using this framework to assess the modeled TC low‐level wind field in the absence of dense inland observations.

Lessons learned in implementing the Low Birthweight Infant Feeding Exploration study: A large, multi-site observational study.

Globally, early and optimal feeding practices and strategies for small and vulnerable infants are limited. We aim to share the challenges faced and implementation lessons learned from a complex, mixed methods research study on infant feeding. A formative, multi-site, observational cohort study using convergent parallel, mixed-methods design. Twelve tertiary/secondary, public/private hospitals in India, Malawi and Tanzania. Moderately low birthweight infants (MLBW; 1.50-2.49 kg). We assessed infant feeding and care practices through: (1) assessment of in-facility documentation of 603 MLBW patient charts; (2) intensive observation of 148 MLBW infants during facility admission; and (3) prospective 1-year follow-up of 1114 MLBW infants. Focus group discussions and in-depth interviews gathered perspectives on infant feeding among clinicians, families, and key stakeholders. The outcomes of the primary study were: (1) To understand the current practices and standard of care for feeding LBW infants; (2) To define and document the key outcomes (including growth, morbidity, and lack of success on mother's own milk) for LBW infants under current practices; (3) To assess the acceptability and feasibility of a system-level Infant and Young Child Feeding (IYCF) intervention and the proposed infant feeding options for LBW infants. Hospital-level guidelines and provision of care for MLBW infants varied across and within countries. In all, 89% of charts had missing data on time to first feed and 56% lacked discharge weights. Among 148 infants observed in-facility, 18.5% were discharged prior to meeting stated weight goals. Despite challenges during COVID, 90% of the prospective cohort was followed until 12 months of age. Enrolment and follow-up of this vulnerable population required additional effort from researchers and the community. Using a mixed-methods exploratory study allowed for a comprehensive understanding of MLBW health and evidence-based planning of targeted large-scale interventions. Multi-site partnerships in global health research, which require active and equal engagement, are instrumental in avoiding duplication and building a stronger, generalisable evidence base.

Uncertainties in Intensity-Based Earthquake Magnitude Estimates

Abstract Estimating the magnitude of historical earthquakes is crucial for assessing seismic hazard. Magnitudes of early-instrumental earthquakes can be inferred using a combination of instrumental records, field observations, and the observed distribution of shaking intensity determined from macroseismic observations. For earthquakes before 1900, shaking intensity distributions often provide the only information to constrain earthquake magnitude. Considerable effort has been made to develop methods to estimate the magnitude of moderate-to-large historical earthquakes using shaking intensities derived from macroseismic data. In this study, we consider earthquakes in California with known instrumental magnitudes to explore uncertainties in estimating the magnitude of historical earthquakes from intensity information alone. We use three California-specific intensity prediction equations (IPEs) and an IPE based on a global ground-motion model (GMM) to determine optimum intensity-based magnitudes for 33 moderate-to-large California earthquakes between 1979 and 2021. Intensity-based magnitudes are close to instrumental magnitudes on average. However, intensity-based magnitudes for individual events differ by as much as 2.2 magnitude units from instrumental magnitudes. This result reflects the weak dependence of ground motions and shaking intensities on moment magnitude and their strong dependence on stress drop. Considering the intensity distributions of the 1906 San Francisco and 1989 Loma Prieta earthquakes, we show that information that could constrain rupture length is discarded when considering only the 2D decay of intensity with distance. We also show that ground-motion intensity conversion equations used in a GMM-based approach may cause a systematic overestimation of large historical earthquake magnitudes. This study underscores both the reducible and potentially irreducible uncertainties associated with using intensity data to estimate magnitudes of historical earthquakes using IPEs and highlights the value of using additional information to constrain rupture dimensions. Using intensity observations alone, moment magnitude uncertainties are typically on the order of a full unit.

Muslim Pakistan Amerika pada Film Pendek American Eid: Simbolisme Religius dan Harmoni Budaya

Films often present cultural expressions, religiosity, as well as social criticisms of realities. In fact, films have played a relatively effective role in doing all of the mentioned aspects even in cross socio-cultural situations. Through films, people in Indonesia can observe the reflection of the lives of Muslims in America and vice versa. American Eid depicts the life of a Pakistani American Muslim immigrant family and challenges they face as a minority celebrating their first Eid al-Fitr in America. This article attempts to examine some of the symbolisms that emphasize the religious identity of the main characters of the film and the cultural harmony that exists between Pakistani Muslim traditions and American society. To collect data, I made intensive observations by watching the movie, reading the relevant sources to get the theories, and conducting the analysis through a qualitative method. The results of the study show that there are several religious symbolisms depicted through material and non-material elements as well as the harmony of Pakistani Muslim culture and American society in the context of school life.

A path to precision cosmology: synergy between four promising late-universe cosmological probes

In the next decades, it is necessary to forge new late-universe cosmological probes to precisely measure the Hubble constant and the equation of state of dark energy simultaneously. In this work, we show that the four novel late-universe cosmological probes, 21 cm intensity mapping (IM), fast radio burst (FRB), gravitational wave (GW) standard siren, and strong gravitational lensing (SGL), are expected to be forged into useful tools in solving the Hubble tension and exploring dark energy. We propose that the synergy of them is rather important in cosmology. We simulate the 21 cm IM, FRB, GW, and SGL data based on the hypothetical observations of the Hydrogen Intensity and Real-time Analysis eXperiment, the Square Kilometre Array, the Einstein Telescope, and the Large Synoptic Survey Telescope, respectively. We find that the four probes have different parameter dependencies in cosmological constraints, so any combination of them can break the degeneracies and thus significantly improve the constraint precision. The joint 21 cm IM+FRB+GW+SGL data can provide the constraint errors of σ(Ωm) = 0.0022 and σ(H 0) = 0.16 km s-1 Mpc-1 in the ΛCDM model, which meet the standard of precision cosmology, i.e., the constraint precision of parameters is better than 1%. In addition, the joint data give σ(w) = 0.020 in the wCDM model, and σ(w 0) = 0.066 and σ(wa ) = 0.25 in the w 0 wa CDM model, which are better than the constraints obtained by the CMB+BAO+SN data. We show that the synergy between the four late-universe cosmological probes has magnificent prospects.

Strongly Intensive Observables as a Tool for Studying Clusters of Quark–Gluon Strings in Relativistic Hadron Interactions

Strongly Intensive Observables as a Tool for Studying Clusters of Quark–Gluon Strings in Relativistic Hadron Interactions

Apocenter pileup and arcs: A narrow dust ring around HD 129590

Context. Observations of debris disks have significantly improved over the past decades, both in terms of sensitivity and spatial resolution. At near-infrared wavelengths, new observing strategies and post-processing algorithms allow us to drastically improve the final images and reveal faint structures in the disks. These structures inform us about the properties and spatial distribution of the small dust particles. Aims. We present new H-band observations of the disk around the solar-type star HD 129590, which display an intriguing arc-like structure in total intensity observations but not in total polarimetry, and we propose an explanation for the origin of this arc. Methods. Assuming geometric parameters for the birth ring of planetesimals, our model provides the positions of millions of particles of different sizes to compute scattered light images. The code can either produce images over the full size distribution or over several smaller intervals of grain sizes. Results. We demonstrate that if the grain size distribution is truncated or strongly peaks at a size larger than the radiation pressure blow-out size, we are able to produce an arc quite similar to the one detected in the observations. If the birth ring is radially narrow, given that particles of a given size have similar eccentricities, they will have their apocenters at the same distance from the star. Since this is where the particles spend most of their time, an “apocenter pileup” occurs that can look like a ring. Due to more efficient forward scattering, this arc only appears in total intensity observations and remains undetected in polarimetric data, which is in good agreement with our observations. Conclusions. For the secondary ring to be detected, sharp variations either in the grain size distribution or for the scattering efficiencies Qsca (or a combination of both) are required. We show that a wavy size distribution and a size-dependent phase function can strengthen the apocenter pileup. Overall, such arcs are rarely detected in other systems, which can mainly be explained by the fact that most parent belts are usually broad.

A Deep-Learning Scheme for Hydrometeor Type Classification Using Passive Microwave Observations

This paper proposes a novel approach for hydrometeor classification using passive microwave observations. The use of passive measurements for this purpose has not been extensively explored, despite being available for over four decades. We utilize the Micro-Wave Humidity Sounder-2 (MWHS-2) to relate microwave brightness temperatures to hydrometeor types derived from the global precipitation measurement’s (GPM) dual-frequency precipitation radar (DPR), which are classified into liquid, mixed, and ice phases. To achieve this, we utilize a convolutional neural network model with an attention mechanism that learns feature representations of MWHS-2 observations from spatial and temporal dimensions. The proposed algorithm classified hydrometeors with 84.7% accuracy using testing data and captured the geographical characteristics of hydrometeor types well in most areas, especially for frozen precipitation. We then evaluated our results by comparing predictions from a different year against DPR retrievals seasonally and globally. Our global annual cycles of precipitation occurrences largely agreed with DPR retrievals with biases being 8.4%, −11.8%, and 3.4%, respectively. Our approach provides a promising direction for utilizing passive microwave observations and deep-learning techniques in hydrometeor classification, with potential applications in the time-resolved observations of precipitation structure and storm intensity with a constellation of smallsats (TROPICS) algorithm development.

P182 A STRANGE ELECTROCARDIOGRAM RECORDED AFTER A FALL TO THE GROUND

Abstract An 84–year–old man was found unconscious on the ground by his daughter. The patient had a medical history of arterial hypertension, dyslipidemia and type II diabetes mellitus complicated by peripheral neuropathy and has been experiencing frequent falls. The emergency services were alerted, and the man was taken to the emergency room. In the ER, an abnormal electrocardiogram was recorded, and an urgent cardiological consultation was requested. Upon reading the ECG, the cardiologist ordered the patient‘s body temperature to be measured, which was found to be 29.7°C. The recorded ECG showed signs of severe hypothermia, including an advanced atrioventricular block (in this case, III–degree AV block), a widening of the QRS complex with the appearance of the Osborn wave, and a prolonged QT interval. The Osborn wave is a positive deflection visible at the J point and it is an uncommon electrocardiographic finding that immediately suggests hypothermia, although it is not pathognomonic (it can also be found in acute myocardial ischemia, hypercalcemia, sepsis, and other non–hypothermic conditions). The electrophysiological basis of the Osborn wave lies in the Ito current, a transient current caused by the release of potassium ions from the ventricular myocardiocyte, which is responsible for a brief partial repolarization during phase 1 of the action potential. Hypothermia increases the amplitude and width of the action potential notch due to the Ito current in the epicardium much more than in the endocardium, creating a transmural voltage gradient that manifests on the surface ECG as the Osborn wave. The Osborn wave is initially more evident in the inferolateral leads; as the body temperature decreases, the wave gradually becomes visible in all 12 leads and, when the body temperature returns to normal, the wave progressively disappears. This potential difference also correlates with possible proarrhythmic effects and, when linked to acute myocardial ischemia, the Osborn wave is an adverse prognostic factor as it is associated with a higher risk of ventricular fibrillation. In this case, the patient had fallen during the night and remained on the ground for hours. He was hospitalized for short intensive observation, warmed up, and hydrated, with a rapid and complete resolution of the clinical and electrocardiographic abnormalities

Irrigation Optimization via Crop Water Use in Saline Coastal Areas-A Field Data Analysis in China's Yellow River Delta.

Freshwater resources are becoming increasingly scarce in coastal areas, limiting crop productivity in coastal farmlands. Although the characteristic of crop water use is an important factor for water conservation in coastal farmlands, it has not been studied extensively. This study aimed to depict the water use process of soil-plant systems under saline stress in coastal ecosystems and optimize water management. An intensive observation experiment was performed within China's Yellow River Delta to identify the water use processes and crop coefficients (KC) and also quantify the impacts of salt stress on crop water use. The results show that shallow groundwater did not contribute to soil water in the whole rotation; KC values for wheat-maize, wheat-sorghum, and wheat-soybean rotation systems were 45.0, 58.4, and 57% less, respectively, than the FAO values. The water use efficiency of the maize (8.70) and sorghum (9.00) in coastal farmlands was higher than that of the soybean (4.37). By identifying the critical periods of water and salt stress, this paper provides suggestions for water-saving and salinity control in coastal farmlands. Our findings can inform the sustainable development of coastal farmlands and provide new insights to cope with aspects of the global food crisis.

ADMM and spectral proximity operators in hyperspectral broadband phase retrieval for quantitative phase imaging

The hyperspectral broadband phase retrieval is developed for a scenario where both object and modulation phase masks are spectrally varying. The proposed iterative algorithm is based on a complex domain version of the alternating direction method of multipliers (ADMM) and the novel Spectral Proximity Operators derived for Gaussian and Poissonian multiple intensity observations. These proximity operators solve two problems. First, the complex-domain spectral components of the object are extracted from the total intensity observations calculated as the sums of the spectral intensities of diffractive patterns. Second, noisy observations are filtered, compromising noisy intensity observations and their predicted counterparts. The simulation and physical tests confirm that the broadband hyperspectral phase retrieval in the proposed formulation can be successfully resolved.

On the propagation of gravity waves in the lower solar atmosphere in different magnetic configurations

Gravity waves are generated by turbulent subsurface convection overshooting or penetrating locally into a stably stratified medium. While propagating energy upwards, their characteristic negative phase shift over height is a well-recognized observational signature. Since their first detailed observational detection and estimates of energy content, a number of studies have explored their propagation characteristics and interaction with magnetic fields and other waves modes in the solar atmosphere. Here, we present a study of the atmospheric gravity wave dispersion diagrams utilizing intensity observations that cover photospheric to chromospheric heights over different magnetic configurations of quiet-Sun (magnetic network regions), a plage, and a sunspot as well as velocity observations within the photospheric layer over a quiet and a sunspot region. In order to investigate the propagation characteristics, we construct two–height intensity - intensity and velocity- velocity cross-spectra and study phase and coherence signals in the wavenumber - frequency dispersion diagrams and their association with background magnetic fields. We find signatures of association between magnetic fields and much reduced coherence and phase shifts over height from intensity-intensity and velocity-velocity phase and coherence diagrams, both indicating suppression/scattering of gravity waves by the magnetic fields. Our results are consistent with the earlier numerical simulations, which indicate that gravity waves are suppressed or scattered and reflected back into the lower solar atmosphere in the presence of magnetic fields.

Study of fluorescent nanodiamonds concentrations in aqueous solutions for biological applications

Commercial fluorescent nanodiamonds constitute a new class of nanoprobes with excellent perspectives for biomedical applications. They produce a broad emission spectrum partially matching the biological window for high tissue penetration, which can be excited in the visible region (380–780 nm) and in the biological window (1000–2500 nm) using two-photon excitation processes, giving a chance for high-resolution multi-photon fluorescence imaging at a sub-cellular resolution scale. Because of their carbon-based structure, nanodiamonds are highly biocompatible and display low toxicity if adequately coated. The nanodiamonds fluorescence spectrum arises due to the so-called Nitrogen-Vacancy (NV) color centers, which are highly photostable and are formed by local charge density compensating defects because of the typical nitrogen presence impurity ions in the host nanocrystals. In this work, a study of different nanodiamonds’ concentrations in terms of their fluorescent activity was investigated in the range of 0.1–10 mg/mL by means of fluorescence spectroscopy with the purpose of determining which concentration of nanodiamonds suspended in milliQ water achieves the maximum intensity, in which it was found that the 5 mg/mL was the most intense in our experimental observations. Additionally, a non-linear fit of the experimental observations of intensity was performed to predict the fluorescence intensity following an expression of a fourth order polynomial with respect to concentration, with a figure of merit, FOM = 0.03–0.04 (3–4%). Based on this effect, the optimal nanodiamonds/aqueous media solution has been determined by means of cell viability assays, finding that concentrations ≤0.1 mg/mL are as biocompatible as milliQ water.

The impact of emission reduction policies on the results of PM2.5 emission sources during the 2016 G20 summit: Insights from carbon and nitrogen isotopic signatures

Intensive field observations were conducted on the PM2.5, gaseous pollutants, δ13C, and δ15N values to evaluate the efficacy of much stricter air quality measures and emergency response strategies implemented in Hangzhou and Ningbo during the 2016 G20 Summit. Our data showed that δ13C values of PM2.5 samples collected in two cities varied from −30.8‰ to −24.2‰, with an average of −25.8‰ ± 1.1‰ during sampling periods. Similar δ13C values observed in the two cities indicated that there is no pronounced differences of carbon sources between the Hangzhou and Ningbo. Based on the Bayesian model, results indicated that C3 plant combustion contributed 47.8% and 47.2% to carbon sources of PM2.5 in Hangzhou and Ningbo, respectively. δ15N values of PM2.5 ranged from 2.0‰ to 13.7‰, with a mean value of 8.5‰ ± 2.5‰ during the whole campaign. Notably, more effective results were observed in reducing NH3 compared to NOx in Hangzhou and Ningbo. Additionally, a more reliable source apportionment approach using isotope fractionation effects and a Bayesian model was applied (improved Bayesian model), which reduced the uncertainty in the apportionment of nitrogen sources. The estimated fractionation effects from NH3 to NH4+ averaged at 16.19‰ ± 3.49‰, and from NOx to NO3− averaged at 12.94‰ ± 2.60‰, respectively. Compared to the results of the Bayesian model, the contributions of NOx from coal combustion (13.8%) and vehicle exhausts (11.6%), and NH3 from coal combustion (12.1%) and vehicle exhausts (12.5%) by improved Bayesian model were more consistent with the emission inventory. Collective evidence of multiple isotopes indicated that pollution emissions were sensitive in response to strict control measures. Our results also revealed that fossil fuel combustion reduction and regional control policies should be synergistically implemented for better air quality.

Comparative analysis of two impact systems in a snowstorm in Dalian

In this study, the two influence systems in a snowstorm that occurred in January 2021 are analyzed using conventional observation, intensive snowfall observation data and NCEP-FNL 0.25°×0.25° analysis data. The results show that, first, the westerly trough combined with the surface convergence line and the sub cold front produces strong snowfall in the southern part of the Liaodong Peninsula, then the strong cold air moves southward into the cold flow snowfall. When the westerly trough system has a large water vapor flux, deep wet layer and strong ascending motion, the surface is accompanied by the obvious warm tongue in southwest Dalian and cold pad in the inland, and there is obvious frontogenesis process, with heavy snowfall. The intensity of cold advection is closely related to the amount of snowfall: the stronger the cold advections, the greater the snowfall will be. The combination of mid-upper-level divergence with negative vorticity and convergence with positive vorticity near the ground is also an advantage for heavy snowfall. Cold flow snowfall exhibits strong local characteristics. Compared with the westerly trough system, the cold flow snowfall has a smaller influence area and intensity. The combination of strong ascending motion and wet area is also one of the focuses of cold flow snowfall forecast in Dalian.

Variation of Atmospheric Boundary Layer Height Over the Northern, Central, and Southern Parts of the Tibetan Plateau During Three Monsoon Seasons

AbstractThe atmospheric boundary layer (ABL) over the Tibetan Plateau (TP) is important to the study of the interactions between the underlying surface and the atmosphere. Radiosondes were released during three intensive ABL experimental periods (monsoon‐onset, monsoon, and post‐monsoon) in 2014 and 2019. Using these observational data, this study explored the features of the ABL height (ABLH) in the northern, central, and southern parts of the TP during the three periods and their possible association with the westerlies. Measurements showed that the ABLH over the northern part of the TP in the monsoon season was the highest (average 3 km above ground level [AGL]) among the three intensive observation periods. Meanwhile, the southern part of the TP had the highest ABLH (almost 3.5 km AGL) in post‐monsoon. Using ERA5, we discovered that the ABLH over the TP was not only affected by the surface sensible heat flux but also was influenced by the seasonal north‐south movement of the westerlies. The westerlies correspond to an upper‐level high potential vorticity (PV) center that is associated with the weak atmospheric stability below the westerlies and is conducive to the development of the ABL. When the westerlies are located above the southern TP in winter, they provide conditions that favor ABL increase. Westerlies are above the north TP in summer, and this provides favorable conditions for ABL increase in the northern TP. The role of westerlies in the ABLH explains why the northern and southern parts of the TP have different seasonal variation patterns.

Populasi dan Intensitas Serangan Larva Spodoptera litura F. pada Tanaman Sawi Hijau (Brassica juncea L.)

Green mustard farmers in the Beba area experienced a decrease in crop yields due to attacks by armyworm larvae. A study needs to be conducted to determine the average population and intensity of the attack by larvae of S. litura F. on mustard greens aged 6 DAP, 8 DAP, 10 DAP, and 12 DAP in the determined plots. The study was conducted in the Beba area, Oelami Village, South Bikomi District, from December 2021 to January 2022. The total observation sub-plots were 16 and the size of each sub-plot is 60 x 60 cm. The collection of S. litura F. and attack intensity observation were carried out starting from 6 DAP – 12 DAP at 06.00-08.00 am. The mean population of S. litura F. larvae obtained from mustard greens aged 6 DAP; 8 DAP, 10 DAP, and 12 DAP was respectively 0.029 DAP/clump; 0.154 head/clump, 0.632 head/clump, and 0.688 head/clump. The percentage of attack intensity on plants aged 6 DAP, 8 DAP, 10 DAP, and 12 DAP were respectively 0.041%; 0.097%; 0.23%, and 0.246%. The attack intensity category is still in the mild category. The highest average population of S. litura F. larvae and the highest percentage of attack intensity was at the age of 12 DAP.

Spatial reconstruction of long-term (2003–2020) sea surface pCO2 in the South China Sea using a machine-learning-based regression method aided by empirical orthogonal function analysis

Abstract. The South China Sea (SCS) is the largest marginal sea of the North Pacific Ocean, where intensive field observations, including mappings of the sea surface partial pressure of CO2 (pCO2), have been conducted over the last 2 decades. It is one of the most studied marginal seas in terms of carbon cycling and could thus be a model system for marginal sea carbon research. However, the cruise-based sea surface pCO2 datasets are still temporally and spatially sparse. Using a machine-learning-based method facilitated by empirical orthogonal function (EOF) analysis, this study provides a reconstructed dataset of the monthly sea surface pCO2 in the SCS with a reasonably high spatial resolution (0.05∘ × 0.05∘) and temporal coverage between 2003 and 2020. The data input to our model includes remote-sensing-derived sea surface salinity, sea surface temperature, and chlorophyll, the spatial pattern of pCO2 constrained by EOF, atmospheric pCO2, and time labels (month). We validated our reconstruction with three independent testing datasets that are not involved in the model training. Among them, Test 1 includes 10 % of our in situ data, Test 2 contains four independent in situ datasets corresponding to the four seasons, and Test 3 is an in situ monthly dataset available from 2003–2019 at the South East Asia Time-series Study (SEATs) station located in the northern basin of the SCS. Our Test 1 validation demonstrated that the reconstructed pCO2 field successfully simulated the spatial and temporal patterns of sea surface pCO2 observations. The root mean square error (RMSE) between our reconstructed data and in situ data in Test 1 averaged ∼10 µatm, which is much smaller (by ∼50 %) than that between the remote-sensing-derived data and in situ data. Test 2 verified the accuracy of our retrieval algorithm in months lacking observations, showing a relatively small bias (RMSE of ∼8 µatm). Test 3 evaluated the accuracy of the reconstructed long-term trend, showing that, at the SEATs station, the difference between the reconstructed pCO2 and in situ data ranged from −10 to 4 µatm (−2.5 % to 1 %). In addition to the typical machine learning performance metrics, we assessed the uncertainty resulting from reconstruction bias and its feature sensitivity. These validations and uncertainty analyses strongly suggest that our reconstruction effectively captures the main spatial and temporal features of sea surface pCO2 distributions in the SCS. Using the reconstructed dataset, we show the long-term trends of sea surface pCO2 in five subregions of the SCS with differing physicobiogeochemical characteristics. We show that mesoscale processes such as the Pearl River plume and China coastal currents significantly impact sea surface pCO2 in the SCS during different seasons. While the SCS is overall a weak source of atmospheric CO2, the northern SCS acts as a sink, showing a trend of increasing strength over the past 2 decades. The data used in this article are available at https://doi.org/10.57760/sciencedb.02050 (Wang and Dai, 2022).