K. Cervantes-Martínez, H. Riojas-Rodríguez, C. Díaz-Avalos, H. Moreno-Macías, R. López‐Ridaura, D. Stern, Jorge Octavio Acosta-Montes, J. Texcalac-Sangrador
Epidemiological studies on air pollution in Mexico often use the environmental concentrations of pollutants as measured by monitors closest to the home of participants as exposure proxies, yet this approach does not account for the space gradients of pollutants and ignores intra-city human mobility. This study aimed to develop high-resolution spatial and temporal models for predicting long-term exposure to PM2.5 and NO2 in ~16,500 participants from the Mexican Teachers’ Cohort study. We geocoded the home and work addresses of participants, and used secondary source information on geographical and meteorological variables as well as other pollutants to fit two generalized additive models capable of predicting monthly PM2.5 and NO2 concentrations during the 2004-2019 period. Both models were evaluated through 10-fold cross-validation, and showed high predictive accuracy with out-of-sample data and no overfitting (CV-RMSE=0.102 for PM2.5 and CV-RMSE=4.497 for NO2). Participants were exposed to a monthly average of 24.38 (6.78) mg/m3 of PM2.5 and 28.21 (8.00) ppb of NO2 during the study period. These models offer a promising alternative for estimating PM2.5 and NO2 exposure with high spatio-temporal resolution for epidemiological studies in the Mexico City Metropolitan Area.
{"title":"Geocoding and spatio-temporal modeling of long-term PM2.5 and NO2 exposure: the Mexican Teachers´ Cohort","authors":"K. Cervantes-Martínez, H. Riojas-Rodríguez, C. Díaz-Avalos, H. Moreno-Macías, R. López‐Ridaura, D. Stern, Jorge Octavio Acosta-Montes, J. Texcalac-Sangrador","doi":"10.20937/atm.53110","DOIUrl":"https://doi.org/10.20937/atm.53110","url":null,"abstract":"Epidemiological studies on air pollution in Mexico often use the environmental concentrations of pollutants as measured by monitors closest to the home of participants as exposure proxies, yet this approach does not account for the space gradients of pollutants and ignores intra-city human mobility. This study aimed to develop high-resolution spatial and temporal models for predicting long-term exposure to PM2.5 and NO2 in ~16,500 participants from the Mexican Teachers’ Cohort study. We geocoded the home and work addresses of participants, and used secondary source information on geographical and meteorological variables as well as other pollutants to fit two generalized additive models capable of predicting monthly PM2.5 and NO2 concentrations during the 2004-2019 period. Both models were evaluated through 10-fold cross-validation, and showed high predictive accuracy with out-of-sample data and no overfitting (CV-RMSE=0.102 for PM2.5 and CV-RMSE=4.497 for NO2). Participants were exposed to a monthly average of 24.38 (6.78) mg/m3 of PM2.5 and 28.21 (8.00) ppb of NO2 during the study period. These models offer a promising alternative for estimating PM2.5 and NO2 exposure with high spatio-temporal resolution for epidemiological studies in the Mexico City Metropolitan Area.","PeriodicalId":55576,"journal":{"name":"Atmosfera","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2021-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48903189","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The first direct current observations (with LADCP and surface drifters) in Bahía de La Paz, a bay in the southwestern Gulf of California (GC), concur with previous reports that the main dynamical feature during summer is a closed cyclonic circulation. However, we found that geostrophic calculations overestimate the speed of the orbital velocity: actual speeds (0.20-0.25 m s-1) were ~25-40% lower than those estimated from geostrophic balance (0.25-0.35 m s-1). The reason is that the centrifugal force cannot be neglected in this case. The mean rotation period during ship-borne observations in August 2004 was ~1.4 days, but it varied during the time that surface drifters were inside the bay, from ~1-2 days in June-July to ~2.5-3 days in September-October. The analysis of satellite data (wind velocity, sea surface temperature and chlorophyll) show that from May to September the wind stress curl is strong and cyclonic, and the surface of the bay is cooler and richer than the adjacent Gulf of California waters, which could be attributed to the positive wind stress curl. This positive wind stress curl on the bay is part of a larger-scale positive wind stress curl distribution that surrounds the southern part of the Baja California Peninsula during summer, probably enhanced in the bay by local topography features. Although there is an exchange of water between the bay and the GC, its effect on the dynamics is poorly known.
在加利福尼亚湾(GC)西南部的一个海湾Bahía de La Paz进行的第一次直流电观测(LADCP和地面漂移)与以前的报道一致，即夏季的主要动力特征是一个封闭的气旋环流。然而，我们发现地转计算高估了轨道速度的速度:实际速度(0.20-0.25 m s-1)比地转平衡估计的速度(0.25-0.35 m s-1)低~25-40%。原因是在这种情况下离心力是不可忽视的。2004年8月船载观测的平均轮候为~1.4 d，但随着海面漂船在湾内的时间变化，轮候从6 ~ 7月的~1 ~2 d到9 ~ 10月的~2.5 ~ 3 d不等。卫星数据(风速、海表温度和叶绿素)分析表明，5 - 9月湾内风应力旋度强，呈气旋性，且湾表面比相邻的加利福尼亚湾水域更冷、更富，这可能归因于正风应力旋度。海湾上的这种正风应力旋度是夏季包围下加利福尼亚半岛南部的更大规模的正风应力旋度分布的一部分，可能是当地地形特征在海湾中增强的。虽然海湾和环流之间有水的交换，但其对动力学的影响却鲜为人知。
{"title":"Cyclonic circulation and climatology of SST, CHL and wind stress curl in a semi-enclosed bay (Bahía de La Paz, Gulf of California)","authors":"E. Beier, R. Castro, V. M. Godínez","doi":"10.20937/atm.53093","DOIUrl":"https://doi.org/10.20937/atm.53093","url":null,"abstract":"The first direct current observations (with LADCP and surface drifters) in Bahía de La Paz, a bay in the southwestern Gulf of California (GC), concur with previous reports that the main dynamical feature during summer is a closed cyclonic circulation. However, we found that geostrophic calculations overestimate the speed of the orbital velocity: actual speeds (0.20-0.25 m s-1) were ~25-40% lower than those estimated from geostrophic balance (0.25-0.35 m s-1). The reason is that the centrifugal force cannot be neglected in this case. The mean rotation period during ship-borne observations in August 2004 was ~1.4 days, but it varied during the time that surface drifters were inside the bay, from ~1-2 days in June-July to ~2.5-3 days in September-October. The analysis of satellite data (wind velocity, sea surface temperature and chlorophyll) show that from May to September the wind stress curl is strong and cyclonic, and the surface of the bay is cooler and richer than the adjacent Gulf of California waters, which could be attributed to the positive wind stress curl. This positive wind stress curl on the bay is part of a larger-scale positive wind stress curl distribution that surrounds the southern part of the Baja California Peninsula during summer, probably enhanced in the bay by local topography features. Although there is an exchange of water between the bay and the GC, its effect on the dynamics is poorly known.","PeriodicalId":55576,"journal":{"name":"Atmosfera","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2021-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45177053","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Luiza Maria Marcos Cerqueira Mendes, V. S. B. Carvalho, Fabrina Bolzan Martins, Taciana Toledo de Almeida Albuquerque
Air pollution from human and industrial activities has been a major concern in recent years. Among the various pollutants found in the atmosphere, particulate matter (PM) and ozone (O3) show significant occurrences, with high concentrations in several urban centers frequently associated with environmental and public health problems. Therefore, this study uses the Analysis of Variance (ANOVA) technique and Tukey's test to investigate the patterns related to the variability of maximum daily concentrations of O3 and mean daily concentrations of particulate matter with a diameter inferior to 10 μm (PM10), registered between 2007 and 2012 through six sites in the Metropolitan Area of Belo Horizonte (MABH), Brazil. To this end, the data were analyzed using ANOVA arranged in a factorial scheme (6 x 4 x 2) with four repetitions per treatment, followed by Tukey’s test. In the ANOVA and Tukey's test, the first factor (A) represents the six air quality monitoring stations, the second (B) represents the seasons, and the third (C) the measurements carried out during working days and weekends. Seasonal variability patterns show higher concentrations of O3 in the Spring and PM10 in the Winter. The mean values for working days and weekends showed different patterns for the two pollutants. For PM10, the concentrations were higher during the working days when compared to the weekends. For O3, the weekend effect was found only in one of the stations. The profiles of vehicular and industrial emissions have been identified as a potential factor that led to these results.
近年来，人类和工业活动造成的空气污染一直是一个主要问题。在大气中发现的各种污染物中，颗粒物（PM）和臭氧（O3）显著存在，几个城市中心的高浓度经常与环境和公共卫生问题有关。因此，本研究使用方差分析（ANOVA）技术和Tukey检验来调查与2007年至2012年间在巴西贝洛奥里藏特大都会区（MABH）的六个地点登记的O3最大日浓度和直径小于10μm的颗粒物（PM10）平均日浓度变化相关的模式。为此，使用因子分析法（6 x 4 x 2）对数据进行分析，每次治疗重复四次，然后进行Tukey检验。在方差分析和Tukey检验中，第一个因素（A）代表六个空气质量监测站，第二个因素（B）代表季节，第三个因素（C）代表在工作日和周末进行的测量。季节变化模式显示，春季O3浓度较高，冬季PM10浓度较高。工作日和周末的平均值显示出两种污染物的不同模式。对于PM10，与周末相比，工作日的浓度更高。对于O3，仅在其中一个站点中发现了周末效应。车辆和工业排放情况已被确定为导致这些结果的潜在因素。
{"title":"Patterns related to the pollutant concentration data in the Metropolitan Area of Belo Horizonte, Brasil","authors":"Luiza Maria Marcos Cerqueira Mendes, V. S. B. Carvalho, Fabrina Bolzan Martins, Taciana Toledo de Almeida Albuquerque","doi":"10.20937/atm.53056","DOIUrl":"https://doi.org/10.20937/atm.53056","url":null,"abstract":"Air pollution from human and industrial activities has been a major concern in recent years. Among the various pollutants found in the atmosphere, particulate matter (PM) and ozone (O3) show significant occurrences, with high concentrations in several urban centers frequently associated with environmental and public health problems. Therefore, this study uses the Analysis of Variance (ANOVA) technique and Tukey's test to investigate the patterns related to the variability of maximum daily concentrations of O3 and mean daily concentrations of particulate matter with a diameter inferior to 10 μm (PM10), registered between 2007 and 2012 through six sites in the Metropolitan Area of Belo Horizonte (MABH), Brazil. To this end, the data were analyzed using ANOVA arranged in a factorial scheme (6 x 4 x 2) with four repetitions per treatment, followed by Tukey’s test. In the ANOVA and Tukey's test, the first factor (A) represents the six air quality monitoring stations, the second (B) represents the seasons, and the third (C) the measurements carried out during working days and weekends. Seasonal variability patterns show higher concentrations of O3 in the Spring and PM10 in the Winter. The mean values for working days and weekends showed different patterns for the two pollutants. For PM10, the concentrations were higher during the working days when compared to the weekends. For O3, the weekend effect was found only in one of the stations. The profiles of vehicular and industrial emissions have been identified as a potential factor that led to these results.","PeriodicalId":55576,"journal":{"name":"Atmosfera","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2021-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42912059","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wind energy power plants are vulnerable, among others, to abrupt weather changes caused especially by thunderstorms associated with lightning activity and the accompanying severe wind gusts and rapid wind direction changes. Due to a range of damages such phenomena may cause, the knowledge of the relationship between the storm systems and the produced wind field is essential to establish a wind power plant during the construction and operation phase as well. In first part of this study, the relationship of severe wind gusts in regard to lightning activity in a wind farm in a hilly region of western Greece is investigated. Wind data come from wind turbines covering a period of three years (2012-2014), while the corresponding lightning data from the ZEUS lighting detection network. The analysis shows that wind gusts are well correlated to lightning strikes. Furthermore, correlation maximizes during winter when well organized weather systems affect the area and minimum in summer as a result of local storms due to thermal instability. In the second part the study focuses on the development of an ANN model in order to forecast these two parameters in a horizon of 1-h ahead by using except for the wind data, four variables namely CAPE, TTI, wind speed at the 500 hPa isobaric level and the 0-6 km vertical wind shear. The results revealed that proposed model could be considered as a promising tool in simulating the occurrence both of wind gusts and lightning flashes providing a relatively good evidence of the possibility of occurrence of such events.
{"title":"Analyzing and Forecasting Lightning Flashes and the Related Wind Gusts at a Wind Energy Power Plant in a Hilly Region of Western Greece","authors":"A. Argiriou, Constaninos Kolokythas, V. Kotroni","doi":"10.20937/atm.53043","DOIUrl":"https://doi.org/10.20937/atm.53043","url":null,"abstract":"Wind energy power plants are vulnerable, among others, to abrupt weather changes caused especially by thunderstorms associated with lightning activity and the accompanying severe wind gusts and rapid wind direction changes. Due to a range of damages such phenomena may cause, the knowledge of the relationship between the storm systems and the produced wind field is essential to establish a wind power plant during the construction and operation phase as well. In first part of this study, the relationship of severe wind gusts in regard to lightning activity in a wind farm in a hilly region of western Greece is investigated. Wind data come from wind turbines covering a period of three years (2012-2014), while the corresponding lightning data from the ZEUS lighting detection network. The analysis shows that wind gusts are well correlated to lightning strikes. Furthermore, correlation maximizes during winter when well organized weather systems affect the area and minimum in summer as a result of local storms due to thermal instability. In the second part the study focuses on the development of an ANN model in order to forecast these two parameters in a horizon of 1-h ahead by using except for the wind data, four variables namely CAPE, TTI, wind speed at the 500 hPa isobaric level and the 0-6 km vertical wind shear. The results revealed that proposed model could be considered as a promising tool in simulating the occurrence both of wind gusts and lightning flashes providing a relatively good evidence of the possibility of occurrence of such events.","PeriodicalId":55576,"journal":{"name":"Atmosfera","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2021-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49621221","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Currently the drinking water supply service system of the Metropolitan Area of Mexico City (ZMCM) faces serious problems in its operation, which generate highly negative impacts on the environmental, social and provider sectors of this system. Given the presence of climate change, we consider the possible scenario in which a decrease in average annual precipitation is generated in the area. To evaluate its impact on each of the sectors, the fuzzy cognitive map (FCM) associated with each of them was constructed. This framework allowed the study of a system that, in addition to being highly complex, the available information presented large ranges of uncertainty. Based on the resuls obtained, we present a mitigation measure for each sector, in order to provide efficient actions to decisions makers.
{"title":"Fuzzy cognitive maps to explore the repercussions of less precipitation on the water supply service of the Metropolitan Area of Mexico City","authors":"Norma Elizabeth Olvera Fuentes, C. Gay García","doi":"10.20937/atm.53037","DOIUrl":"https://doi.org/10.20937/atm.53037","url":null,"abstract":"Currently the drinking water supply service system of the Metropolitan Area of Mexico City (ZMCM) faces serious problems in its operation, which generate highly negative impacts on the environmental, social and provider sectors of this system. Given the presence of climate change, we consider the possible scenario in which a decrease in average annual precipitation is generated in the area. To evaluate its impact on each of the sectors, the fuzzy cognitive map (FCM) associated with each of them was constructed. This framework allowed the study of a system that, in addition to being highly complex, the available information presented large ranges of uncertainty. Based on the resuls obtained, we present a mitigation measure for each sector, in order to provide efficient actions to decisions makers.","PeriodicalId":55576,"journal":{"name":"Atmosfera","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2021-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48647192","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A flow climatology was established for the Metropolitan Area of Queretaro (MAQ), in central Mexico, by analyzing four years (2014-2017) of back-trajectories generated using the HYSPLIT Model. Two flow regimes were found: one from June until September (rainy regime); the other from December to May (dry regime). October and November were considered transition months. Northeasterly flows were present throughout the year; in contrast, trajectories from the southwest were much less frequent and observed mainly during the dry regime. An analysis of the wind fields from the NARR database for a longer period of time (1979 – 2019), suggests that these results are representative of the average conditions of the atmosphere at the study site. Some of the northeasterly trajectories observed originate within a desertic region of the state of Queretaro, where several limestone mines are located. During the dry regime and transition months some clusters originate at the industrial area in Guanajuato, which includes the Salamanca refinery. As air transport of pollutants follow these paths, this analysis could be useful for identifying regional sources that affect the MAQ and possibly increase its air pollution load. In fact, the variability of criteria pollutants concentrations matched the flow regimes described above.
{"title":"Regional flow climatology for central Mexico (Queretaro): a first case study","authors":"Daniel Rozanes-Valenzuela, A. Magaldi, D. Salcedo","doi":"10.20937/atm.53038","DOIUrl":"https://doi.org/10.20937/atm.53038","url":null,"abstract":"A flow climatology was established for the Metropolitan Area of Queretaro (MAQ), in central Mexico, by analyzing four years (2014-2017) of back-trajectories generated using the HYSPLIT Model. Two flow regimes were found: one from June until September (rainy regime); the other from December to May (dry regime). October and November were considered transition months. Northeasterly flows were present throughout the year; in contrast, trajectories from the southwest were much less frequent and observed mainly during the dry regime. An analysis of the wind fields from the NARR database for a longer period of time (1979 – 2019), suggests that these results are representative of the average conditions of the atmosphere at the study site. Some of the northeasterly trajectories observed originate within a desertic region of the state of Queretaro, where several limestone mines are located. During the dry regime and transition months some clusters originate at the industrial area in Guanajuato, which includes the Salamanca refinery. As air transport of pollutants follow these paths, this analysis could be useful for identifying regional sources that affect the MAQ and possibly increase its air pollution load. In fact, the variability of criteria pollutants concentrations matched the flow regimes described above.","PeriodicalId":55576,"journal":{"name":"Atmosfera","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2021-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47192864","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Julio César Morales Hernández, Clara Rosalía Ávila, Luis Felipe Lastras, A. Lastras, D. Flores, Abraham Cárdenas, Marcos Algara
Nitrogen dioxide (NO2) was remotely measured in the urban area of San Luis Potosí (México) using the differential optical absorption spectroscopy (DOAS) technique. Measurements were taken from July to August 2015. In this technique, light scattered by the sun through the atmosphere is focused by a telescope onto a linear array-based spectrometer at ground level. During the measurement period, the maximum NO2 levels (2.3 x 1016 molecules/cm2) were found at around 11:00 h, whereas NO2 levels fell on days with wind speeds lower than 1.5 m/s. The NO2 levels were compared and explained with the behavior of meteorological data such as wind speed, relative humidity, and surface temperature obtained from the Weather Research and Forecasting Model (WRF).
利用差分光学吸收光谱(DOAS)技术，在美国圣路易斯Potosí (m录影带西科)市区进行了二氧化氮(NO2)的远程测量。测量于2015年7月至8月进行。在这项技术中，太阳通过大气散射的光被望远镜聚焦到地面上基于线性阵列的光谱仪上。在测量期间，NO2水平在11:00左右达到最大值(2.3 x 1016分子/cm2)，而风速低于1.5 m/s的天NO2水平下降。利用气象研究与预报模式(WRF)的风速、相对湿度和地表温度等气象资料对NO2水平的变化进行了比较和解释。
{"title":"Remote sensing of atmospheric nitrogen dioxide in an urban area in central northern Mexico","authors":"Julio César Morales Hernández, Clara Rosalía Ávila, Luis Felipe Lastras, A. Lastras, D. Flores, Abraham Cárdenas, Marcos Algara","doi":"10.20937/atm.53032","DOIUrl":"https://doi.org/10.20937/atm.53032","url":null,"abstract":"Nitrogen dioxide (NO2) was remotely measured in the urban area of San Luis Potosí (México) using the differential optical absorption spectroscopy (DOAS) technique. Measurements were taken from July to August 2015. In this technique, light scattered by the sun through the atmosphere is focused by a telescope onto a linear array-based spectrometer at ground level. During the measurement period, the maximum NO2 levels (2.3 x 1016 molecules/cm2) were found at around 11:00 h, whereas NO2 levels fell on days with wind speeds lower than 1.5 m/s. The NO2 levels were compared and explained with the behavior of meteorological data such as wind speed, relative humidity, and surface temperature obtained from the Weather Research and Forecasting Model (WRF).","PeriodicalId":55576,"journal":{"name":"Atmosfera","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2021-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45204277","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Noéle Bissoli Perini Souza, E. G. S. Nascimento, D. Moreira
In this study, the performance of the mesoscale Weather Research and Forecasting (WRF) model is evaluated using combinations of three Planetary Boundary Layer (PBL) and three Land Surface Model (LSM) schemes, in order to identify the optimal parameters for the determination of wind speed in a tropical region. The state of Bahia in Brazil is selected as the location for the case study and simulations are performed over a period of eight months between 2015 and 2016. This is done to ensure that the dry and rainy seasons at the three different experimental sites—Esplanada, Mucuri, and Mucugê—are well separated from each other. The results of the simulations are compared with the observational data obtained from three towers equipped with anemometers at heights of 80, 100, 120 and 150 m, strategically placed at each site. Overestimation of wind speed is observed in the simulations, despite similarities between the simulated and observed wind directions. In addition, the accuracies of simulations corresponding to sites that are closer to the ocean are observed to be lower—the most accurate wind speed estimates are obtained corresponding to Mucugê, which is located farthest from the ocean. Finally, analysis of the results obtained from each tower accounting for periods with higher and lower precipitation reveals that the combination of the PBL-YSU scheme with the LSM-RUC scheme yields the best results.
{"title":"Performance evaluation of the WRF model in a tropical region: wind speed analysis at different sites","authors":"Noéle Bissoli Perini Souza, E. G. S. Nascimento, D. Moreira","doi":"10.20937/atm.52968","DOIUrl":"https://doi.org/10.20937/atm.52968","url":null,"abstract":"In this study, the performance of the mesoscale Weather Research and Forecasting (WRF) model is evaluated using combinations of three Planetary Boundary Layer (PBL) and three Land Surface Model (LSM) schemes, in order to identify the optimal parameters for the determination of wind speed in a tropical region. The state of Bahia in Brazil is selected as the location for the case study and simulations are performed over a period of eight months between 2015 and 2016. This is done to ensure that the dry and rainy seasons at the three different experimental sites—Esplanada, Mucuri, and Mucugê—are well separated from each other. The results of the simulations are compared with the observational data obtained from three towers equipped with anemometers at heights of 80, 100, 120 and 150 m, strategically placed at each site. Overestimation of wind speed is observed in the simulations, despite similarities between the simulated and observed wind directions. In addition, the accuracies of simulations corresponding to sites that are closer to the ocean are observed to be lower—the most accurate wind speed estimates are obtained corresponding to Mucugê, which is located farthest from the ocean. Finally, analysis of the results obtained from each tower accounting for periods with higher and lower precipitation reveals that the combination of the PBL-YSU scheme with the LSM-RUC scheme yields the best results.","PeriodicalId":55576,"journal":{"name":"Atmosfera","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2021-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48674636","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Alejandro Casallas, D. Hernandez-Deckers, H. Mora-Páez
We investigate convective storms over the Sabana de Bogotá, a high-altitude and densely populated area in the Colombian tropical Andes. Convective events are identified using infrared satellite images and in-situ precipitation data. As expected, convection shows a strong early-afternoon peak during the two rainy seasons. Previous studies hypothesize that early-afternoon westerly winds and their moisture advection from the warmer Magdalena Valley are the main explanatory mechanism for intense storms. We find that early-afternoon westerlies are present in 78% of the rainy season days, but convective events develop in only 26% of the days. Thus, although westerlies seem necessary for convection due to the convergence they generate, they only occasionally generate storms, and are therefore not a good predictor. Furthermore, reanalysis data indicate that precipitable water vapor (PWV) at the Magdalena Valley is anomalously low during convective days, suggesting that moisture converges locally instead of being advected from the west. Based on composites of surface wind speed, air temperature, pressure and GPS-derived PWV, we identify the most prominent signals associated to deep convection: a weaker than average wind speed throughout the morning, higher than normal values of surface air temperature towards noon, followed by an anomalous steep increase of PWV and wind speed. These features indicate that convection results from a strong diurnal forcing facilitated by convergence of westerly winds, combined with sufficient water vapor convergence, with a timescale of about 3 hours. This highlights the relevance of high temporal resolution monitoring of PWV offered by Global Navigational Satellite System stations.
{"title":"Understanding convective storms in a tropical, high-altitude location with in-situ meteorological observations and GPS-derived water vapor","authors":"Alejandro Casallas, D. Hernandez-Deckers, H. Mora-Páez","doi":"10.20937/atm.53051","DOIUrl":"https://doi.org/10.20937/atm.53051","url":null,"abstract":"We investigate convective storms over the Sabana de Bogotá, a high-altitude and densely populated area in the Colombian tropical Andes. Convective events are identified using infrared satellite images and in-situ precipitation data. As expected, convection shows a strong early-afternoon peak during the two rainy seasons. Previous studies hypothesize that early-afternoon westerly winds and their moisture advection from the warmer Magdalena Valley are the main explanatory mechanism for intense storms. We find that early-afternoon westerlies are present in 78% of the rainy season days, but convective events develop in only 26% of the days. Thus, although westerlies seem necessary for convection due to the convergence they generate, they only occasionally generate storms, and are therefore not a good predictor. Furthermore, reanalysis data indicate that precipitable water vapor (PWV) at the Magdalena Valley is anomalously low during convective days, suggesting that moisture converges locally instead of being advected from the west. Based on composites of surface wind speed, air temperature, pressure and GPS-derived PWV, we identify the most prominent signals associated to deep convection: a weaker than average wind speed throughout the morning, higher than normal values of surface air temperature towards noon, followed by an anomalous steep increase of PWV and wind speed. These features indicate that convection results from a strong diurnal forcing facilitated by convergence of westerly winds, combined with sufficient water vapor convergence, with a timescale of about 3 hours. This highlights the relevance of high temporal resolution monitoring of PWV offered by Global Navigational Satellite System stations.","PeriodicalId":55576,"journal":{"name":"Atmosfera","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2021-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42956303","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Sousa, J. Morales, M. Aguilar-Alba, L. García-Barrón
This study estimates the pluviometric evolution between the 13th and 19th centuries on the southwestern Iberian Peninsula based on the historic records of the impacts of the Guadalquivir River flooding on the city of Seville (Spain). The main documentary source was “Critical history of the floods of the Guadalquivir in Seville”, published in 1878, which compiles news from different observers, who were contemporaries of each event. Regarding the methodology, it was necessary to transfer the information from different documentary sources to ordinal indices, which required developing allocation criteria per flood impact. From the annual assigned flood index, an interannual series was generated. Moreover, for the last decades of the 21st century, quantifying the flooding levels in the records allowed us to relate them directly to instrumental records of rainfall and establish a relationship between these two phenomena. Through interannual weighing of the flooding indices, it was possible to deduce the durations and intensities of sequences of rainy periods between 1250 and 1850. This allowed us to reconstruct the pluviometric evolution. Of the ten floods classified as most destructive during the five centuries analysed, i.e., from 1280 to 1880, five occurred during little more than a century (1598-1701). The obtained results contribute to knowledge on regional rainfall, as well as to historical climatology and hydrology, over multiple centuries.
{"title":"Classification of the flood severity of the Guadalquivir River in the Southwest of the Iberian Peninsula during the 13th to 19th centuries","authors":"A. Sousa, J. Morales, M. Aguilar-Alba, L. García-Barrón","doi":"10.20937/atm.52953","DOIUrl":"https://doi.org/10.20937/atm.52953","url":null,"abstract":"This study estimates the pluviometric evolution between the 13th and 19th centuries on the southwestern Iberian Peninsula based on the historic records of the impacts of the Guadalquivir River flooding on the city of Seville (Spain). The main documentary source was “Critical history of the floods of the Guadalquivir in Seville”, published in 1878, which compiles news from different observers, who were contemporaries of each event. Regarding the methodology, it was necessary to transfer the information from different documentary sources to ordinal indices, which required developing allocation criteria per flood impact. From the annual assigned flood index, an interannual series was generated. Moreover, for the last decades of the 21st century, quantifying the flooding levels in the records allowed us to relate them directly to instrumental records of rainfall and establish a relationship between these two phenomena. Through interannual weighing of the flooding indices, it was possible to deduce the durations and intensities of sequences of rainy periods between 1250 and 1850. This allowed us to reconstruct the pluviometric evolution. Of the ten floods classified as most destructive during the five centuries analysed, i.e., from 1280 to 1880, five occurred during little more than a century (1598-1701). The obtained results contribute to knowledge on regional rainfall, as well as to historical climatology and hydrology, over multiple centuries.","PeriodicalId":55576,"journal":{"name":"Atmosfera","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2021-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42866012","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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