Earth and its Atmosphere最新文献

{"title":"VARMA-EGARCH Model for Air-Quality Analyses and Application in Southern Taiwan","authors":"E. Wu, Shu‐Lung Kuo","doi":"10.3390/atmos11101096","DOIUrl":"https://doi.org/10.3390/atmos11101096","url":null,"abstract":"This study adopted the Exponential Generalized Autoregressive Conditional Heteroscedasticity (EGARCH) model to analyze seven air pollutants (or the seven variables in this study) from ten air quality monitoring stations in the Kaohsiung–Pingtung Air Pollutant Control Area located in southern Taiwan. Before the verification analysis of the EGARCH model is conducted, the air quality data collected at the ten air quality monitoring stations in the Kaohsiung–Pingtung area are classified into three major factors using the factor analyses in multiple statistical analyses. The factors with the most significance are then selected as the targets for conducting investigations; they are termed “photochemical pollution factors”, or factors related to pollution caused by air pollutants, including particulate matter with particles below 10 microns (PM10), ozone (O3) and nitrogen dioxide (NO2). Then, we applied the Vector Autoregressive Moving Average-EGARCH (VARMA-EGARCH) model under the condition where the standardized residual existed in order to study the relationships among three air pollutants and how their concentration changed in the time series. By simulating the optimal model, namely VARMA (1,1)-EGARCH (1,1), we found that when O3 was the dependent variable, the concentration of O3 was not affected by the concentration of PM10 and NO2 in the same term. In terms of the impact response analysis on the predictive power of the three air pollutants in the time series, we found that the asymmetry effect of NO2 was the most significant, meaning that NO2 influenced the GARCH effect the least when the change of seasons caused the NO2 concentration to fluctuate; it also suggested that the concentration of NO2 produced in this area and the degree of change are lower than those of the other two air pollutants. This research is the first of its kind in the world to adopt a VARMA-EGARCH model to explore the interplay among various air pollutants and reactions triggered by it over time. The results of this study can be referenced by authorities for planning air quality total quantity control, applying and examining various air quality models, simulating the allowable increase in air quality limits, and evaluating the benefit of air quality improvement.","PeriodicalId":283309,"journal":{"name":"Earth and its Atmosphere","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131046567","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lake Nyos, a Multirisk and Vulnerability Appraisal","authors":"M. Tchindjang","doi":"10.3390/GEOSCIENCES8090312","DOIUrl":"https://doi.org/10.3390/GEOSCIENCES8090312","url":null,"abstract":"Situated at the northern flank of the Oku Massif, Lake Nyos crater epitomizes landscape features originating from volcanic explosions during the Quaternary. The Cameroon Volcanic Line (CVL), to which it belongs, constitutes the most active volcanic region in Cameroon. In 1986, an outgas explosion occurred from beneath the lake and killed 1746 people in several neighbouring villages. The event influenced a radial area of 25 to 40 km wide, particularly in eastern and western direction. This was mainly due to: (1) the rugged nature of the landscape (fault fields), which enabled the heavier gas to follow valleys framed by faults corridors without affecting elevated areas; and (2) the seasonal dominating western wind direction, which channeled the gas along tectonic corridors and valleys. This paper assesses the geological risk and vulnerability in the Lake Nyos before and after several proposal to mitigate future outgas events. Remotely sensed data, together with GIS tools (topographic maps, aerial photographs), helped to determine and assess lineaments and associated risks. A critical grid combining severity and frequency analysis was used to assess the vulnerability of the local population. There is evidence that along the main fault directions (SW–NE), anthropogenic activities are most intensive and they may play an aggravating role for disasters. This requires the local population’s consciousness-raising. The results also show that population around Lake Nyos still remains vulnerable to volcanic hazards and floods. However, the area has been safe since the last degassing and jet grouting through multiple procedures and actions proposed in the National Contingency Plan, and equally by the relief organization plan (DROP or ORSEC plan) for the Menchum Division. Another issue is that the local population is concerned with the idea of returning to the affected areas in order to stay close to their ancestors or the deceased. Therefore, even after jet grouting and degassing, the problem of risk minimization for local residents remains.","PeriodicalId":283309,"journal":{"name":"Earth and its Atmosphere","volume":"178 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131588719","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The SeaSWIR dataset","authors":"E. Knaeps, D. Doxaran, A. Dogliotti, B. Nechad, K. Ruddick, D. Raymaekers, S. Sterckx","doi":"10.5194/ESSD-10-1439-2018","DOIUrl":"https://doi.org/10.5194/ESSD-10-1439-2018","url":null,"abstract":"Abstract. The SeaSWIR dataset consists of 137 ASD (Analytical Spectral Devices, Inc.)\u0000marine reflectances, 137 total suspended matter (TSM) measurements and 97\u0000turbidity measurements gathered at three turbid estuarine sites (Gironde, La\u0000Plata, Scheldt). The dataset is valuable because of the high-quality\u0000measurements of the marine reflectance in the Short Wave InfraRed I region\u0000(SWIR-I: 1000–1200 nm) and SWIR-II (1200–1300 nm) and\u0000because of the wide range of TSM concentrations from 48 up to\u00001400 mg L−1. The ASD measurements were gathered using a detailed\u0000measurement protocol and were subjected to a strict quality control. The\u0000SeaSWIR marine reflectance is characterized by low reflectance at short\u0000wavelengths (<450 nm), peak reflectance values between 600 and\u0000720 nm and significant contributions in the near-infrared (NIR) and\u0000SWIR-I parts of the spectrum. Comparison of the ASD water reflectance with\u0000simultaneously acquired reflectance from a three-radiometer system revealed a\u0000correlation of 0.98 for short wavelengths (412, 490 and 555 nm) and\u00000.93 for long wavelengths (686, 780 and 865 nm). The relationship\u0000between TSM and turbidity (for all sites) is linear, with a correlation\u0000coefficient of 0.96. The SeaSWIR dataset has been made publicly available\u0000(https://doi.org/10.1594/PANGAEA.886287).\u0000","PeriodicalId":283309,"journal":{"name":"Earth and its Atmosphere","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127937137","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparison of Global Observations and Trends of Total Precipitable Water Derived from Microwave Radiometers and COSMIC Radio Occultation from 2006 to 2013","authors":"S. Ho, Liang Peng, C. Mears, R. Anthes","doi":"10.5194/ACP-18-259-2018","DOIUrl":"https://doi.org/10.5194/ACP-18-259-2018","url":null,"abstract":"Abstract. We compare atmospheric total precipitable water (TPW) derived from\u0000the\u0000SSM/I (Special Sensor Microwave Imager) and SSMIS (Special Sensor Microwave\u0000Imager/Sounder) radiometers and WindSat to collocated TPW estimates derived\u0000from COSMIC (Constellation System for Meteorology, Ionosphere, and Climate)\u0000radio occultation (RO) under clear and cloudy conditions over the oceans from\u0000June 2006 to December 2013. Results show that the mean microwave (MW)\u0000radiometer – COSMIC TPW differences range from 0.06 to 0.18 mm for clear\u0000skies, from\u00000.79 to 0.96 mm for cloudy skies, from 0.46 to 0.49 mm for cloudy but non-precipitating\u0000conditions, and from 1.64 to 1.88 mm for precipitating conditions. Because RO\u0000measurements are not significantly affected by clouds and precipitation, the\u0000biases mainly result from MW retrieval uncertainties under cloudy and\u0000precipitating conditions. All COSMIC and MW radiometers detect a positive TPW\u0000trend over these 8 years. The trend using all COSMIC observations\u0000collocated with MW pixels for this data set is 1.79 mm decade −1 , with a 95 %\u0000confidence interval of (0.96, 2.63), which is in close agreement with the\u0000trend estimated by the collocated MW observations (1.78 mm decade −1 with a\u000095 % confidence interval of 0.94, 2.62). The sample of MW and RO pairs used\u0000in this study is highly biased toward middle latitudes (40–60 ∘  N and 40–65 ∘  S), and thus these trends are\u0000not representative of global average trends. However, they are representative\u0000of the latitudes of extratropical storm tracks and the trend values are\u0000approximately 4 to 6 times the global average trends, which are\u0000approximately 0.3 mm decade −1 . In addition, the close agreement of these two\u0000trends from independent observations, which represent an increase in TPW in\u0000our data set of about 6.9 %, are a strong indication of the positive water\u0000vapor–temperature feedback on a warming planet in regions where precipitation\u0000from extratropical storms is already large.","PeriodicalId":283309,"journal":{"name":"Earth and its Atmosphere","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125916316","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Motivated for Action and Collaboration: The Abrahamic Religions and Climate Change","authors":"J. Schaefer","doi":"10.3390/GEOSCIENCES6030031","DOIUrl":"https://doi.org/10.3390/GEOSCIENCES6030031","url":null,"abstract":"Leaders of Judaism, Christianity, and Islam have publicly advocated action to mitigate the adverse effects of human-forced climate change. Particularly prominent prior to, during, and after the 21st Conference of the Parties of the United Nations Framework Convention on Climate Change were Rabbi Arthur Waskow, Pope Francis, and Patriarch Bartholomew. Also prominent was a group of Islamic clerics, leaders of organizations, and scholars who collaborated in issuing a declaration on climate change three months prior to COP 21. Informed by the Earth sciences, these leaders shared their faith-based rationales for acting locally to internationally as indicated in the documents explored in this article. Examples of organizations motivated by their leaders’ faith perspectives demonstrate their readiness to act informed by scientists. To work effectively, these religious leaders and activist groups require well-substantiated conclusions from data collected to counter unsubstantiated claims by climate skeptics. Earth scientists will find among the religious leaders and groups allies in the quest for a flourishing planet.","PeriodicalId":283309,"journal":{"name":"Earth and its Atmosphere","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129220366","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Annual Climatology of the Diurnal Cycle on the Canadian Prairies","authors":"A. Betts, A. Tawfik","doi":"10.3389/feart.2016.00001","DOIUrl":"https://doi.org/10.3389/feart.2016.00001","url":null,"abstract":"We show the annual climatology of the diurnal cycle, stratified by opaque cloud, using the full hourly resolution of the Canadian Prairie data. The opaque cloud field itself has distinct cold and warm season diurnal climatologies; with a near-sunrise peak of cloud in the cold season and an early afternoon peak in the warm season. There are two primary climate states on the Canadian Prairies, separated by the freezing point of water, because a reflective surface snow cover acts as a climate switch. Both cold and warm season climatologies can be seen in the transition months of November, March and April with a large difference in mean temperature. In the cold season with snow, the diurnal ranges of temperature and relative humidity increase quasi-linearly with decreasing cloud, and increase from December to March with increased solar forcing. The warm season months, April to September, show a homogeneous coupling to the cloud cover, and a diurnal cycle of temperature and humidity that depends only on net longwave. Our improved representation of the diurnal cycle shows that the warm season coupling between diurnal temperature range and net longwave is weakly quadratic through the origin, rather than the linear coupling shown in earlier papers. We calculate the conceptually important 24-h imbalances of temperature and relative humidity (and other thermodynamic variables) as a function of opaque cloud cover. In the warm season under nearly clear skies, there is a warming of +2oC and a drying of -6% over the 24-h cycle, which is about 12% of their diurnal ranges. We summarize results on conserved variable diagrams and explore the impact of surface windspeed on the diurnal cycle in the cold and warm seasons. In all months, the fall in minimum temperature is reduced with increasing windspeed, which reduces the diurnal temperature range. In July and August, there is an increase of afternoon maximum temperature and humidity at low windspeeds, and a corresponding rise in equivalent potential temperature of 4.4K that appears coupled to increased precipitation. However overcast skies are associated with the major rain events and higher windspeeds.","PeriodicalId":283309,"journal":{"name":"Earth and its Atmosphere","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121656648","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Generation and Propagation of Atmospheric InternalWaves Caused by Volcanic Eruptions","authors":"Peter G Baines, S. Sacks","doi":"10.37247/ea.1.2020.3","DOIUrl":"https://doi.org/10.37247/ea.1.2020.3","url":null,"abstract":"","PeriodicalId":283309,"journal":{"name":"Earth and its Atmosphere","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123358796","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}