scholarly journals A New Linear Relation for Estimating Surface Broadband Emissivity in Arid Regions Based on FTIR and MODIS Products

2021 ◽  
Vol 13 (9) ◽  
pp. 1686
Author(s):  
Huoqing Li ◽  
Zonghui Liu ◽  
Ali Mamtimin ◽  
Junjian Liu ◽  
Yongqiang Liu ◽  
...  
Keyword(s):  
Land Surface ◽  
Arid Regions ◽  
Mean Squared Error ◽  
Single Channel ◽  
Radiation Budget ◽  
Future Research ◽  
Inhomogeneous Surface ◽  
Imaging Spectrometer ◽  
Area Index ◽  
The Relationship

Broadband emissivity is a crucial parameter for calculating the radiation budget, still, it adopts a constant value in land surface models due to a lack of adequate observations. Arid regions have complex underlying surfaces and estimations of the broadband emissivity in such areas suffer from high spatial variation and uncertainty. Here, we propose a novel method for estimating broadband emissivity in the 8–14 µm range based on Fourier-transform infrared spectroscopy (FTIR) observations, moderate resolution imaging spectrometer (MODIS) emissivity, the leaf area index (LAI) and reflectance products. The proposed method exploits FTIR observations, MODIS single-channel emissivity, reflectance and the LAI to fit a linear regression of the broadband emissivity, so the optimal equation includes emissivity, reflectance and the LAI, with an R2 and root-mean-squared error of 0.942 and 0.08. Then we used the proposed method to generate a broadband emissivity map of Northwest of China, the broadband emissivity estimated by the method showed higher variations and finer distribution in arid areas and sparsely vegetated regions compared to data from the global land surface satellite and land model. An analysis of the relationship between the broadband emissivity, land-use type and soil moisture found an existing but not linear relationship, which indicated that the relationship was complicated under the inhomogeneous surface of wetness and vegetation. In conclusion, our results suggest that the proposed method can accurately estimate the broadband emissivity in arid regions. In future research, we will test the data in a land model.

scholarly journals Complexity of relationship between 2D/3D urban morphology and land surface temperature: A multi-scale perspective

2021 ◽  
Author(s):  
Yu Liu ◽  
Zhipeng Wang ◽  
Xuan Liu ◽  
Baolei Zhang
Keyword(s):  
Surface Temperature ◽  
Land Surface Temperature ◽  
Land Surface ◽  
Urban Morphology ◽  
Grid Size ◽  
Area Index ◽  
Maximum Information ◽  
Building Density ◽  
Multi Scale ◽  
The Relationship

Abstract Urban morphology is a crucial contributor to urban heat island (UHI) effects. However, few studies have explored the complex effect of 2D/3D urban morphology on UHI from a multi-scale perspective. In this study, We chose the central area of Jinan city, which was commonly known as the “furnace”, as the case study area. novel 2D/3D urban morphology indexes-building coverage ratio (BCR)(for assessing the 2D building density), building volume density (BVD)( for assessing the 3D building density), and the frontal area index (FAI)(for assessing 3D ventilation conditions) were calculated and derived to investigated complexity of relationship between 2D/3D urban morphology and land surface temperature(LST) at different scales using the maximum information coefficient (MIC) and geographically weighted regression (GWR). The results indicated that (1) These newly 2D/3D urban morphology indexes as essential factors that are responsible for LST variation, BCR is the most important urban morphology index affecting the LST, followed by BVD and FAI. Importantly, the relationship between the BCR, BVD, and FAI and the LST was an inverse U-shaped curve. (2) The relationship between 2D/3D urban morphology and LST variation showed a significant scale effect. With increased grid size, the correlation between the BCR, BVD, and FAI and the LST strengthened, “inflection point” of inverse U-shaped curve was significantly declined, and their explanation rate to LST first increased and then decreased, with a maximum value at the 700-m scale. Additionally, the FAI exerted a stronger negative effect, while the BCR and BVD generally had stronger positive effects on LST as the grid size increasing. This study extends our scientific understanding of the complexity effect of urban morphology on LST and is of great practical significance for urban thermal environment regulation at multi-scale.

scholarly journals An inversion model for estimating the negative air ion concentration using MODIS images of the Daxing’anling region

PLoS ONE ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. e0242554
Author(s):  
Cui Yue ◽  
Zhao Yuxin ◽  
Zhang Nan ◽  
Zhang Dongyou ◽  
Yang Jiangning
Keyword(s):  
Air Quality ◽  
Surface Temperature ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Land Surface Temperature ◽  
Land Surface ◽  
Area Index ◽  
Inversion Model ◽  
Forest Coverage ◽  
The Relationship

The negative air ion (NAI) concentration is an essential indicator of air quality and atmospheric pollution. The NAI concentration can be used to monitor air quality on a regional scale and is commonly determined using field measurements. However, obtaining these measurements is time-consuming. In this paper, the relationship between remotely sensed surface parameters (such as land surface temperature, normalized difference vegetation index (NDVI), and leaf area index) obtained from MODIS data products and the measured NAI concentration using a stepwise regression method was analyzed to estimate the spatial distribution of the NAI concentration and verify the precision. The results indicated that the NAI concentration had a negative correlation with temperature, leaf area index (LAI), and gross primary production while it exhibited a positive correlation with the NDVI. The relationship between land surface temperature and the NAI concentration in the Daxing’anling region is expressed by the regression equation of y = -35.51x1 + 11206.813 (R2 = 0.6123). Additionally, the NAI concentration in northwest regions with high forest coverage was higher than that in southeast regions with low forest coverage, suggesting that forests influence the air quality and reduce the impact of environmental pollution. The proposed inversion model is suitable for evaluating the air quality in Daxing’anling and provides a reference for air quality evaluation in other areas. In the future, we will expand the quantity and distribution range of sampling points, conduct continuous observations of NAI concentrations and environmental parameters in the research areas with different land-use types, and further improve the accuracy of inversion results to analyze the spatiotemporal dynamic changes in NAI concentration and explore the possibility of expanding the application areas of NAI monitoring.

Radiation interception and biomass accumulation in a sugarcane crop grown under irrigated tropical conditions

1994 ◽  
Vol 45 (1) ◽  
pp. 37 ◽  
Author(s):  
RC Muchow ◽  
MF Spillman ◽  
AW Wood ◽  
MR Thomas
Keyword(s):  
Climatic Factors ◽  
Maximum Yield ◽  
Biomass Accumulation ◽  
Cane Yield ◽  
Future Research ◽  
Area Index ◽  
Radiation Interception ◽  
Sugarcane Crop ◽  
Tropical Conditions ◽  
The Relationship

Little quantitative information relating yield accumulation in sugarcane to climatic factors is available to allow the maximum yield in different seasons and locations to be determined. By comparison of actual yield with the climatically determined maximum yield for a given crop, the extent of yield limitation due to management and soil and pest factors can be assessed. This paper analyses the relationship between radiation interception and biomass accumulation for an autumn-planted sugarcane crop grown under irrigated conditions at Ayr, Qld (lat. 19.5� S.). Crop samplings were conducted from 167 to 445 days after planting (DAP). Less than 60% of the seasonal incident solar radiation was intercepted by the crop. A radiation extinction coefficient of 0.38 was estimated from the relationship between green leaf area index and the fraction of the radiation intercepted (fi). A maximum crop radiation (SW, 0.35-2-5 8m) use efficiency (RUE) of 1.75 g MJ-1 was determined. The maximum crop growth rate over a 140 day period was 41.1 g m-2d-1. However, this value is dependent on fi and the incident radiation ( S ) , and accordingly would be expected to vary across locations. In contrast, the RUE value of 1.75 g MJ-1is independent of fi and S, and can be used as a baseline value to assess the extent of yield limitation and the scope for yield improvement at different locations. The maximum biomass production was 72 t ha-1and the maximum fresh cane yield was 201 t ha-1. However, these maximum yields were attained up to 4 months before the final sampling. Future research should examine the wider applicability of this early yield plateau, and focus on the factors responsible for the early cessation in yield accumulation.

scholarly journals Land Surface Temperature Retrieval from Landsat 5, 7, and 8 over Rural Areas: Assessment of Different Retrieval Algorithms and Emissivity Models and Toolbox Implementation

2020 ◽  
Vol 12 (2) ◽  
pp. 294 ◽  
Author(s):  
Aliihsan Sekertekin ◽  
Stefania Bonafoni
Keyword(s):  
Surface Temperature ◽  
Land Surface Temperature ◽  
Land Surface ◽  
Single Channel ◽  
Thematic Mapper ◽  
Surface Radiation ◽  
Radiation Budget ◽  
Bias Error ◽  
Landsat 8 ◽  
Retrieval Algorithms

Land Surface Temperature (LST) is an important parameter for many scientific disciplines since it affects the interaction between the land and the atmosphere. Many LST retrieval algorithms based on remotely sensed images have been introduced so far, where the Land Surface Emissivity (LSE) is one of the main factors affecting the accuracy of the LST estimation. The aim of this study is to evaluate the performance of LST retrieval methods using different LSE models and data of old and current Landsat missions. Mono Window Algorithm (MWA), Radiative Transfer Equation (RTE) method, Single Channel Algorithm (SCA) and Split Window Algorithm (SWA) were assessed as LST retrieval methods processing data of Landsat missions (Landsat 5, 7 and 8) over rural pixels. Considering the LSE models introduced in the literature, different Normalized Difference Vegetation Index (NDVI)-based LSE models were investigated in this study. Specifically, three LSE models were considered for the LST estimation from Landsat 5 Thematic Mapper (TM) and seven Enhanced Thematic Mapper Plus (ETM+), and six for Landsat 8. For the accurate evaluation of the estimated LST, in-situ LST data were obtained from the Surface Radiation Budget Network (SURFRAD) stations. In total, forty-five daytime Landsat images; fifteen images for each Landsat mission, acquired in the Spring-Summer-Autumn period in the mid-latitude region in the Northern Hemisphere were acquired over five SURFRAD rural sites. After determining the best LSE model for the study case, firstly, the LST retrieval accuracy was evaluated considering the sensor type: when using Landsat 5 TM, 7 ETM+, and 8 Operational Land Imager (OLI), and Thermal Infrared Sensor (TIRS) data separately, RTE, MWA, and MWA presented the best results, respectively. Then, the performance was evaluated independently of the sensor types. In this case, all LST methods provided satisfying results, with MWA having a slightly better accuracy with a Root Mean Square Error (RMSE) equals to 2.39 K and a lower bias error. In addition, the spatio-temporal and seasonal analyses indicated that RTE and SCA presented similar results regardless of the season, while MWA differed from RTE and SCA for all seasons, especially in summer. To efficiently perform this work, an ArcGIS toolbox, including all the methods and models analyzed here, was implemented and provided as a user facility for the LST retrieval from Landsat data.

scholarly journals Evaluation of Land Surface Temperature Retrieval from Landsat 8/TIRS Images before and after Stray Light Correction Using the SURFRAD Dataset

2020 ◽  
Vol 12 (6) ◽  
pp. 1023 ◽  
Author(s):  
Jinxin Guo ◽  
Huazhong Ren ◽  
Yitong Zheng ◽  
Shangzong Lu ◽  
Jiaji Dong
Keyword(s):  
High Temperature ◽  
Surface Temperature ◽  
Land Surface Temperature ◽  
Land Surface ◽  
Single Channel ◽  
Thermal Infrared ◽  
Stray Light ◽  
Radiation Budget ◽  
Landsat 8 ◽  
Before And After

Landsat 8/thermal infrared sensor (TIRS) is suffering from the problem of stray light that makes an inaccurate radiance for two thermal infrared (TIR) bands and the latest correction was conducted in 2017. This paper focused on evaluation of land surface temperature (LST) retrieval from Landsat 8 before and after the correction using ground-measured LST from five surface radiation budget network (SURFRAD) sites. Results indicated that the correction increased the band radiance at the top of the atmosphere for low temperature but decreased such radiance for high temperature. The root-mean-square error (RMSE) of LST retrieval decreased by 0.27 K for Band 10 and 0.78 K for Band 11 using the single-channel algorithm. For the site with high temperature, the LST retrieval RMSE of the single-channel algorithm for Band 11 even reduced by 1.4 K. However, the accuracy of two of three split-window algorithms adopted in this paper decreased. After correction, the single-channel algorithm for Band 10 and the linear split-window algorithm had the least RMSE (approximately 2.5 K) among five adopted algorithms. Moreover, besides SURFRAD sites, it is necessary to validate using more robust and homogeneous ground-measured datasets to help solely clarify the effect of the correction on LST retrieval.

Symptoms of Alcohol Dependence Predict Suicide Ideation Among Alaskan Undergraduates

Crisis ◽  
2016 ◽  
Vol 37 (3) ◽  
pp. 232-235 ◽  
Author(s):  
Christopher R. DeCou ◽  
Monica C. Skewes
Keyword(s):  
Depressive Symptoms ◽  
Alcohol Consumption ◽  
Alcohol Dependence ◽  
Suicide Ideation ◽  
Alcohol Problems ◽  
Future Research ◽  
Causal Mechanism ◽  
Students At Risk ◽  
The Relationship ◽  
Alcohol Related Problems

Abstract. Background: Previous research has demonstrated an association between alcohol-related problems and suicidal ideation (SI). Aims: The present study evaluated, simultaneously, alcohol consequences and symptoms of alcohol dependence as predictors of SI after adjusting for depressive symptoms and alcohol consumption. Method: A sample of 298 Alaskan undergraduates completed survey measures, including the Young Adult Alcohol Consequences Questionnaire, the Short Alcohol Dependence Data Questionnaire, and the Beck Depression Inventory – II. The association between alcohol problems and SI status was evaluated using sequential logistic regression. Results: Symptoms of alcohol dependence (OR = 1.88, p < .05), but not alcohol-related consequences (OR = 1.01, p = .95), emerged as an independent predictor of SI status above and beyond depressive symptoms (OR = 2.39, p < .001) and alcohol consumption (OR = 1.08, p = .39). Conclusion: Alcohol dependence symptoms represented a unique risk for SI relative to alcohol-related consequences and alcohol consumption. Future research should examine the causal mechanism behind the relationship between alcohol dependence and suicidality among university students. Assessing the presence of dependence symptoms may improve the accuracy of identifying students at risk of SI.

The Relationship Between Interoception and Metacognition

2016 ◽  
Vol 30 (2) ◽  
pp. 76-86 ◽  
Author(s):  
Judith Meessen ◽  
Verena Mainz ◽  
Siegfried Gauggel ◽  
Eftychia Volz-Sidiropoulou ◽  
Stefan Sütterlin ◽  
...  
Keyword(s):  
Memory Performance ◽  
Memory Task ◽  
Demographic Characteristics ◽  
Metacognitive Awareness ◽  
Interoceptive Awareness ◽  
Future Research ◽  
Heartbeat Perception ◽  
Interoceptive Accuracy ◽  
The Relationship

Abstract. Recently, Garfinkel and Critchley (2013) proposed to distinguish between three facets of interoception: interoceptive sensibility, interoceptive accuracy, and interoceptive awareness. This pilot study investigated how these facets interrelate to each other and whether interoceptive awareness is related to the metacognitive awareness of memory performance. A sample of 24 healthy students completed a heartbeat perception task (HPT) and a memory task. Judgments of confidence were requested for each task. Participants filled in questionnaires assessing interoceptive sensibility, depression, anxiety, and socio-demographic characteristics. The three facets of interoception were found to be uncorrelated and interoceptive awareness was not related to metacognitive awareness of memory performance. Whereas memory performance was significantly related to metamemory awareness, interoceptive accuracy (HPT) and interoceptive awareness were not correlated. Results suggest that future research on interoception should assess all facets of interoception in order to capture the multifaceted quality of the construct.

The Relationship Between Leader–Member Exchange and Employees’ Proactive Behaviors

2019 ◽  
Vol 18 (2) ◽  
pp. 106-111
Author(s):  
Fong-Yi Lai ◽  
Szu-Chi Lu ◽  
Cheng-Chen Lin ◽  
Yu-Chin Lee
Keyword(s):  
Hierarchical Linear Modeling ◽  
Future Research ◽  
Leader Member Exchange ◽  
Voice Behavior ◽  
Linear Modeling ◽  
Team Members ◽  
Member Exchange ◽  
Multi Temporal ◽  
The Relationship ◽  
Practical Implications

Abstract. The present study proposed that, unlike prior leader–member exchange (LMX) research which often implicitly assumed that each leader develops equal-quality relationships with their supervisors (leader’s LMX; LLX), every leader develops different relationships with their supervisors and, in turn, receive different amounts of resources. Moreover, these differentiated relationships with superiors will influence how leader–member relationship quality affects team members’ voice and creativity. We adopted a multi-temporal (three wave) and multi-source (leaders and employees) research design. Hypotheses were tested on a sample of 227 bank employees working in 52 departments. Results of the hierarchical linear modeling (HLM) analysis showed that LLX moderates the relationship between LMX and team members’ voice behavior and creative performance. Strengths, limitations, practical implications, and directions for future research are discussed.

Coping Humor as a Mediator Between Emotional Intelligence and Job Satisfaction

2017 ◽  
Vol 16 (3) ◽  
pp. 155-159 ◽  
Author(s):  
Peizhen Sun ◽  
Jennifer J. Chen ◽  
Hongyan Jiang
Keyword(s):  
Job Satisfaction ◽  
Emotional Intelligence ◽  
Future Research ◽  
Satisfaction Scale ◽  
Primary School Teachers ◽  
Mediating Role ◽  
Regulation Of Emotion ◽  
The Relationship ◽  
Overall Job Satisfaction

Abstract. This study investigated the mediating role of coping humor in the relationship between emotional intelligence (EI) and job satisfaction. Participants were 398 primary school teachers in China, who completed the Wong Law Emotional Intelligence Scale, Coping Humor Scale, and Overall Job Satisfaction Scale. Results showed that coping humor was a significant mediator between EI and job satisfaction. A further examination revealed, however, that coping humor only mediated two sub-dimensions of EI (use of emotion and regulation of emotion) and job satisfaction. Implications for future research and limitations of the study are discussed.

Workplace Ostracism and Its Negative Outcomes

2016 ◽  
Vol 15 (4) ◽  
pp. 143-151 ◽  
Author(s):  
Xiaoming Zheng ◽  
Jun Yang ◽  
Hang-Yue Ngo ◽  
Xiao-Yu Liu ◽  
Wengjuan Jiao
Keyword(s):  
Affective Commitment ◽  
Psychological Capital ◽  
Intention To Leave ◽  
Future Research ◽  
Conservation Of Resources ◽  
Negative Consequences ◽  
Negative Outcomes ◽  
Workplace Ostracism ◽  
Using Data ◽  
The Relationship

Abstract. Workplace ostracism, conceived as to being ignored or excluded by others, has attracted the attention of researchers in recent years. One essential topic in this area is how to reduce or even eliminate the negative consequences of workplace ostracism. Based on conservation of resources (COR) theory, the current study assesses the relationship between workplace ostracism and its negative outcomes, as well as the moderating role played by psychological capital, using data collected from 256 employees in three companies in the northern part of China. The study yields two important findings: (1) workplace ostracism is positively related to intention to leave and (2) psychological capital moderates the effect of workplace ostracism on affective commitment and intention to leave. This paper concludes by discussing the implications of these findings for organizations and employees, along with recommendations for future research.

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