Spatial fields of outgoing longwave radiation (OLR) spectrum variance are analyzed in different time-scales: synoptic, sub-monthly, intra-seasonal, during the 1979-2016 austral summer months in southern Brazil. Variability fields differ both in intensity and location and highlight dominant convection cycles in the study area. The results show that the amplitude of sub-monthly variability is greater than the other scales in the southeastern region of Brazil, while the synoptic scale prevails in the southern region. The above-mentioned scales show higher amplitudes over the western Pacific Ocean where the Madden-Julian Oscillation plays an important role, along the South Pacific Convergence Zone, and over the storm track areas over the South Pacific Ocean. The influence of spectral OLR scale interaction is also analyzed, associated to the occurrence of two intense rainfall events over the southeastern Brazil in the austral summers of 2011 and 2014 when the South Atlantic Convergence Zone was involved in both events. The results obtained suggest that spectral OLR scale interaction takes place in such way that it strengthens the South Atlantic Convergence Zone, since the spatial pattern footprints of the 2 to 8-day timescale (synoptic), 10 to 30-day timescale (sub-monthly) and 30 to 60-day timescale (intra-seasonal) overlap in the study region.
{"title":"Connecting heavy precipitation events to outgoing longwave radiation variability scales: case analysis in Brazil","authors":"G. Muller, Valesca Fernandes","doi":"10.20937/ATM.53028","DOIUrl":"https://doi.org/10.20937/ATM.53028","url":null,"abstract":"Spatial fields of outgoing longwave radiation (OLR) spectrum variance are analyzed in different time-scales: synoptic, sub-monthly, intra-seasonal, during the 1979-2016 austral summer months in southern Brazil. Variability fields differ both in intensity and location and highlight dominant convection cycles in the study area. The results show that the amplitude of sub-monthly variability is greater than the other scales in the southeastern region of Brazil, while the synoptic scale prevails in the southern region. The above-mentioned scales show higher amplitudes over the western Pacific Ocean where the Madden-Julian Oscillation plays an important role, along the South Pacific Convergence Zone, and over the storm track areas over the South Pacific Ocean. The influence of spectral OLR scale interaction is also analyzed, associated to the occurrence of two intense rainfall events over the southeastern Brazil in the austral summers of 2011 and 2014 when the South Atlantic Convergence Zone was involved in both events. The results obtained suggest that spectral OLR scale interaction takes place in such way that it strengthens the South Atlantic Convergence Zone, since the spatial pattern footprints of the 2 to 8-day timescale (synoptic), 10 to 30-day timescale (sub-monthly) and 30 to 60-day timescale (intra-seasonal) overlap in the study region.","PeriodicalId":55576,"journal":{"name":"Atmosfera","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2021-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45487094","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 Split-Window algorithm has been used in the Ilam Dam watershed to determine the relationship between Land Surface Temperature (LST) and types of land use. Landsat satellite images of TM sensor for 1990, 1995, 2000, 2005 and 2010 and Landsat 8 (OLI Sensor) for 2015 and 2018 are used. After geometric and radiometric corrections of satellite images, land use maps are extracted by using Fuzzy ARTMAP method. An accuracy assessment showed that the highest value of the Kappa coefficient was 94% with a total accuracy of 0.95 for 2015, and that the lowest Kappa coefficient value was 87% with a total accuracy of 0.9 for 1990. The high values of these coefficients indicate the acceptable accuracy of using Landsat's remote sensing data for land use detection. The most important land use change is related to dense forest and sparse forest land uses, with a decrease of 20.07 and 17.04 percent, respectively. The minimum LST measures in 1990, 2010, and 2018 in dense forest are 21.27, 30.55 and 33.82 °C respectively. The maximum LST for the sparse forest land use in 1990 and 2010 are 52.48, 56.09, and for the dense forest land use in 2018 is 56.10 °C. As a result, the average LST in agricultural lands was lower than in sparse forest and rangeland; this is mainly due to the high moisture content and the greater evapotranspiration rate. Land Use / Land Cover (LULC) variations from 1990 to 2018 show that all land uses have experienced an increase in LST.
{"title":"Spatial and temporal changes of land uses and its relationship with surface temperature in western Iran","authors":"N. Rostami, H. Fathizad","doi":"10.20937/ATM.52985","DOIUrl":"https://doi.org/10.20937/ATM.52985","url":null,"abstract":"A Split-Window algorithm has been used in the Ilam Dam watershed to determine the relationship between Land Surface Temperature (LST) and types of land use. Landsat satellite images of TM sensor for 1990, 1995, 2000, 2005 and 2010 and Landsat 8 (OLI Sensor) for 2015 and 2018 are used. After geometric and radiometric corrections of satellite images, land use maps are extracted by using Fuzzy ARTMAP method. An accuracy assessment showed that the highest value of the Kappa coefficient was 94% with a total accuracy of 0.95 for 2015, and that the lowest Kappa coefficient value was 87% with a total accuracy of 0.9 for 1990. The high values of these coefficients indicate the acceptable accuracy of using Landsat's remote sensing data for land use detection. The most important land use change is related to dense forest and sparse forest land uses, with a decrease of 20.07 and 17.04 percent, respectively. The minimum LST measures in 1990, 2010, and 2018 in dense forest are 21.27, 30.55 and 33.82 °C respectively. The maximum LST for the sparse forest land use in 1990 and 2010 are 52.48, 56.09, and for the dense forest land use in 2018 is 56.10 °C. As a result, the average LST in agricultural lands was lower than in sparse forest and rangeland; this is mainly due to the high moisture content and the greater evapotranspiration rate. Land Use / Land Cover (LULC) variations from 1990 to 2018 show that all land uses have experienced an increase in LST.","PeriodicalId":55576,"journal":{"name":"Atmosfera","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2021-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42538570","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}
B. Figueroa‐Espinoza, Z. Sanchez‐Mejia, J. Uuh-Sonda, P. Salles, L. Méndez-Barroso, H. Gutiérrez‐Jurado
Friction velocity (u*) is an important velocity scale used in the study of engineering and geophysical flows. The widespread use of 2D sonic anemometers in modern meteorological stations makes the estimation of u* from just the horizontal components of the velocity a very attractive possibility. The presence of different wind regimes (such as sea breezes in or near coastal zones) cause the turbulent parameters to be dependent on the wind direction. Additionally, u* depends on atmospheric stability. This makes the estimation of u* from 2D measurements very difficult. A simple expression is proposed, and then tested with data from six independent experiments located in coastal zones. The results show that it is possible to estimate friction velocity from 2D measurements using the turbulence Intensity as a proxy for u*, reducing substantially the sensitivity to the wind direction or atmospheric stability, with small root mean squared errors (0.06
{"title":"Friction Velocity estimation using a 2D Sonic Anemometer in Coastal Zones","authors":"B. Figueroa‐Espinoza, Z. Sanchez‐Mejia, J. Uuh-Sonda, P. Salles, L. Méndez-Barroso, H. Gutiérrez‐Jurado","doi":"10.20937/ATM.52960","DOIUrl":"https://doi.org/10.20937/ATM.52960","url":null,"abstract":"Friction velocity (u*) is an important velocity scale used in the study of engineering and geophysical flows. The widespread use of 2D sonic anemometers in modern meteorological stations makes the estimation of u* from just the horizontal components of the velocity a very attractive possibility. The presence of different wind regimes (such as sea breezes in or near coastal zones) cause the turbulent parameters to be dependent on the wind direction. Additionally, u* depends on atmospheric stability. This makes the estimation of u* from 2D measurements very difficult. A simple expression is proposed, and then tested with data from six independent experiments located in coastal zones. The results show that it is possible to estimate friction velocity from 2D measurements using the turbulence Intensity as a proxy for u*, reducing substantially the sensitivity to the wind direction or atmospheric stability, with small root mean squared errors (0.06","PeriodicalId":55576,"journal":{"name":"Atmosfera","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2021-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45242102","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. C. Freitas, R. Belardi, Henrique de Melo Jorge Barbosa
Itabira has in its territory the largest complex of opencast mining in the world, which is located close to residential areas of the city. The air quality-monitoring network installed in the city is the main source of particulate matter emission data. However, these air quality stations only cover the areas near the mines and does not measure fine particulate matter. Thus, a first field campaign was carried out to characterize the particulate matter in the city and to compare the Hi-Vol data from air quality stations with the dichotomous air sampler data. Results of trajectories cluster analysis showed a long-range transport of aerosols during the sampling days from northeast (84% of the trajectories), east-southeast (12%) and south-southwest (3%) directions. Regarding to the meteorological conditions during the sampling days, negative correlations were seen between coarse particulate matter from mostly air quality stations and all meteorological parameters (but temperature). Results of the X-ray fluorescence and principal component analyses showed that the main trace elements in the coarse and fine modes are Iron and Sulfur, associated with emissions from mining activities, air mass transport from regional iron and steelmaking industry activities, vehicle emissions, local and regional biomass burning and natural biogenic emissions. This work represents the first assessment of source apportionment done in the city. Comparisons with other studies for some Brazilian larger cities showed that Itabira has comparable contributions of sulfur, iron and elements, such as copper, selenium, chromium, nickel, vanadium and lead.
{"title":"Characterization of particulate matter in iron ore mining region of Itabira, Minas Gerais, Brazil","authors":"A. C. Freitas, R. Belardi, Henrique de Melo Jorge Barbosa","doi":"10.20937/ATM.52987","DOIUrl":"https://doi.org/10.20937/ATM.52987","url":null,"abstract":"Itabira has in its territory the largest complex of opencast mining in the world, which is located close to residential areas of the city. The air quality-monitoring network installed in the city is the main source of particulate matter emission data. However, these air quality stations only cover the areas near the mines and does not measure fine particulate matter. Thus, a first field campaign was carried out to characterize the particulate matter in the city and to compare the Hi-Vol data from air quality stations with the dichotomous air sampler data. Results of trajectories cluster analysis showed a long-range transport of aerosols during the sampling days from northeast (84% of the trajectories), east-southeast (12%) and south-southwest (3%) directions. Regarding to the meteorological conditions during the sampling days, negative correlations were seen between coarse particulate matter from mostly air quality stations and all meteorological parameters (but temperature). Results of the X-ray fluorescence and principal component analyses showed that the main trace elements in the coarse and fine modes are Iron and Sulfur, associated with emissions from mining activities, air mass transport from regional iron and steelmaking industry activities, vehicle emissions, local and regional biomass burning and natural biogenic emissions. This work represents the first assessment of source apportionment done in the city. Comparisons with other studies for some Brazilian larger cities showed that Itabira has comparable contributions of sulfur, iron and elements, such as copper, selenium, chromium, nickel, vanadium and lead.","PeriodicalId":55576,"journal":{"name":"Atmosfera","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2021-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45771557","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}
S. Mishra, Shreyas Pandit, A. Mittal, Velampudi Sudarshan Srinivas
Time and intensity specific very short-term forecasting or nowcasting is the biggest challenge faced by an Aviation Meteorologist. Ground-based Microwave Radiometer (MWR) has been used for nowcasting convective activity and it was established that there is a good comparison between thermodynamic parameters derived from MWR and GPS radiosonde observations, indicating that MWR observations can be used to develop techniques for nowcasting severe convective activity. In this study, efforts have been made to bring out the efficacy of MWR in nowcasting thunderstorms and fog. Firstly, the observations of MWR located at Palam, New Delhi, India have been compared with the nearest radiosonde (RS) data to ascertain the variation in respective profiles. Large differences were found in Relative Humidity (RH) whereas temperatures from MWR were found to be close to RS observed temperature upto 3.5 Km. Subsequently, the scattered plots and correlation coefficient of thermodynamic indices / parameters indicated that most of the parameters are either not correlated or have moderate correlation only for 1200 UTC profiles. The superepoch technique of lagged composite for various thermodynamic indices / parameters to obtain a combined picture of all the thunderstorm and dense fog cases on the time series could not determine any pattern to predict thunderstorm and dense fog with lead time of 2-4 hours. MWR profile for a case of occurrence of thunderstorm was analyzed. No significant variation was observed in most of the indices (as calculated from MWR observed parameters) prior to the occurrence of thunderstorm. RH at freezing level and between 950 and 700 hPa levels were the only parameters which increased four hours prior to the occurrence.
{"title":"Application of Ground based Microwave Radiometer in Aviation Weather Forecasting in Indian Air Force","authors":"S. Mishra, Shreyas Pandit, A. Mittal, Velampudi Sudarshan Srinivas","doi":"10.20937/ATM.52982","DOIUrl":"https://doi.org/10.20937/ATM.52982","url":null,"abstract":"Time and intensity specific very short-term forecasting or nowcasting is the biggest challenge faced by an Aviation Meteorologist. Ground-based Microwave Radiometer (MWR) has been used for nowcasting convective activity and it was established that there is a good comparison between thermodynamic parameters derived from MWR and GPS radiosonde observations, indicating that MWR observations can be used to develop techniques for nowcasting severe convective activity. In this study, efforts have been made to bring out the efficacy of MWR in nowcasting thunderstorms and fog. Firstly, the observations of MWR located at Palam, New Delhi, India have been compared with the nearest radiosonde (RS) data to ascertain the variation in respective profiles. Large differences were found in Relative Humidity (RH) whereas temperatures from MWR were found to be close to RS observed temperature upto 3.5 Km. Subsequently, the scattered plots and correlation coefficient of thermodynamic indices / parameters indicated that most of the parameters are either not correlated or have moderate correlation only for 1200 UTC profiles. The superepoch technique of lagged composite for various thermodynamic indices / parameters to obtain a combined picture of all the thunderstorm and dense fog cases on the time series could not determine any pattern to predict thunderstorm and dense fog with lead time of 2-4 hours. MWR profile for a case of occurrence of thunderstorm was analyzed. No significant variation was observed in most of the indices (as calculated from MWR observed parameters) prior to the occurrence of thunderstorm. RH at freezing level and between 950 and 700 hPa levels were the only parameters which increased four hours prior to the occurrence.","PeriodicalId":55576,"journal":{"name":"Atmosfera","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2021-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45075751","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}
Y. Kitagawa, E. G. S. Nascimento, Noéle Bissoli Perini Souza, P. Zucatelli, Prashant Kumar, T. Albuquerque, M. R. Moraes, D. Moreira
This study simulates an unusual extreme rainfall event that occurred in Salvador City, Bahia, Brazil, on December 9, 2017, which was the subtropical storm Guará and had precipitation of approximately 24 mm within less than 1 h. Numerical simulations were conducted using the weather research and forecasting (WRF) model over three domains with horizontal resolutions of 9, 3, and 1 km. Different combinations of seven microphysics, three cumulus, and three planetary boundary layer schemes were evaluated based on their ability to simulate the hourly precipitation during this rainfall event. The results were compared with the data measured at the Brazilian National Institute of Meteorology (INMET) meteorological stations. The best configuration for the planetary boundary layer, cumulus, and microphysics schemes were Mellor-Yamada-Janjić, Grell-Devenyi, and Lin, respectively. The WRF model could depict the daily variations on the hourly parameters well, along with the spatial and temporal evolution of the extreme event.
{"title":"Evaluation of the WRF-ARW model during an extreme rainfall event: subtropical storm Guará","authors":"Y. Kitagawa, E. G. S. Nascimento, Noéle Bissoli Perini Souza, P. Zucatelli, Prashant Kumar, T. Albuquerque, M. R. Moraes, D. Moreira","doi":"10.20937/ATM.52977","DOIUrl":"https://doi.org/10.20937/ATM.52977","url":null,"abstract":"This study simulates an unusual extreme rainfall event that occurred in Salvador City, Bahia, Brazil, on December 9, 2017, which was the subtropical storm Guará and had precipitation of approximately 24 mm within less than 1 h. Numerical simulations were conducted using the weather research and forecasting (WRF) model over three domains with horizontal resolutions of 9, 3, and 1 km. Different combinations of seven microphysics, three cumulus, and three planetary boundary layer schemes were evaluated based on their ability to simulate the hourly precipitation during this rainfall event. The results were compared with the data measured at the Brazilian National Institute of Meteorology (INMET) meteorological stations. The best configuration for the planetary boundary layer, cumulus, and microphysics schemes were Mellor-Yamada-Janjić, Grell-Devenyi, and Lin, respectively. The WRF model could depict the daily variations on the hourly parameters well, along with the spatial and temporal evolution of the extreme event.","PeriodicalId":55576,"journal":{"name":"Atmosfera","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2021-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42449939","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}
J. Vaquero, V. Carrasco, Javier Vaquero Martínez, M. C. Gallego
{"title":"Attitudes of university students from Mérida (Spain) to the challenge of climate change","authors":"J. Vaquero, V. Carrasco, Javier Vaquero Martínez, M. C. Gallego","doi":"10.20937/ATM.53045","DOIUrl":"https://doi.org/10.20937/ATM.53045","url":null,"abstract":"","PeriodicalId":55576,"journal":{"name":"Atmosfera","volume":"25 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2021-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81302458","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}
J. R. Ávila-Carrasco, G. Herrera, Hugo E. Junez-Ferrerira, Arturo Valdés-Manzanilla
Weather radar calibration is a topic of great current interest because it is useful for various hydrological applications. Several methods have been developed for adjusting the relation between reflectivity data Z and rainfall intensity R (Z/R) because droplet size distributions in different storm events are unknown and highly variable in time and space. The present study developed and tested a new space and time window-based procedure for optimal local calibration of weather radar using Z/R relations and applying it to convective and stratiform storms in the lower Grijalva river basin in Mexico. Improving rain estimates from the Sabancuy, Campeche radar is essential because it monitors this basin, which is prone to floods. The resulting estimates of the optimal power-law (Z = ARb) window-based procedure (OP) are compared with those of the default Marshall and Palmer (MP) relation using the observed rain gauge records. The appropriate window was selected using a criterion that considers factors affecting the free fall of raindrops. For most of the storms tested, metrics for the OP models showed better values than those calculated for the MP ones. The best MP performance is when using smooth calibration data, achieving similar metric results to that of the OP. The proposed observed calibration method could be useful to improve the default MP model estimates at any weather radar with similar characteristics to the ones analyzed in this work. The resulting Z/R relations could improve precipitation radar estimates for hydrologic model inputs.
{"title":"New approach for local C-band weather radar precipitation calibration","authors":"J. R. Ávila-Carrasco, G. Herrera, Hugo E. Junez-Ferrerira, Arturo Valdés-Manzanilla","doi":"10.20937/ATM.52763","DOIUrl":"https://doi.org/10.20937/ATM.52763","url":null,"abstract":"Weather radar calibration is a topic of great current interest because it is useful for various hydrological applications. Several methods have been developed for adjusting the relation between reflectivity data Z and rainfall intensity R (Z/R) because droplet size distributions in different storm events are unknown and highly variable in time and space. The present study developed and tested a new space and time window-based procedure for optimal local calibration of weather radar using Z/R relations and applying it to convective and stratiform storms in the lower Grijalva river basin in Mexico. Improving rain estimates from the Sabancuy, Campeche radar is essential because it monitors this basin, which is prone to floods. The resulting estimates of the optimal power-law (Z = ARb) window-based procedure (OP) are compared with those of the default Marshall and Palmer (MP) relation using the observed rain gauge records. The appropriate window was selected using a criterion that considers factors affecting the free fall of raindrops. For most of the storms tested, metrics for the OP models showed better values than those calculated for the MP ones. The best MP performance is when using smooth calibration data, achieving similar metric results to that of the OP. The proposed observed calibration method could be useful to improve the default MP model estimates at any weather radar with similar characteristics to the ones analyzed in this work. The resulting Z/R relations could improve precipitation radar estimates for hydrologic model inputs.","PeriodicalId":55576,"journal":{"name":"Atmosfera","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2021-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49332915","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}
Changes to the eastern North Pacific tropical intraseasonal oscillation (ISO) at the end of the 21st Century and implications for tropical cyclone (TC) genesis are examined in the Shared Socioeconomic Pathways (SSP585) scenario of the Coupled Model Intercomparison Project phase 6 (CMIP6) data set. Multimodel mean composite low-level wind and precipitation anomalies associated with the leading intraseasonal mode indicate that precipitation amplitude increases while wind amplitude weakens under global warming, consistent with previous studies for the Indo-Pacific warm pool. The eastern North Pacific intraseasonal precipitation/wind pattern also tends to shift southwestward in a warmer climate, associated with weaker positive precipitation anomalies near the coast of Mexico and Central America during the enhanced convection/westerly wind phase. Implications for the modulation of TC genesis by the leading intraseasonal mode are then explored using an empirical genesis potential index (GPI). In the historical simulation, GPI shows positive anomalies in the eastern North Pacific in the convectively enhanced phase of the ISO. The ISO’s modulation of GPI weakens near the coast of Mexico and Central America with warming, associated with a southward shift of GPI anomalies. Further examination of the contribution from individual environmental variables that enter the GPI shows that relative humidity and vorticity changes during ISO events weaken positive GPI anomalies near the Mexican coast with warming and make genesis more favorable to the southwest. The impact of vertical shear anomaly changes is also to favor genesis away from the coast. These results suggest a weaker modulation of TCs near the Mexican Coast by the ISO in a warmer climate.
{"title":"Changes to Tropical Eastern North Pacific Intraseasonal Variability under Global Warming – Implications for Tropical Cyclogenesis","authors":"E. Maloney, Hien X. Bui","doi":"10.20937/ATM.53021","DOIUrl":"https://doi.org/10.20937/ATM.53021","url":null,"abstract":"Changes to the eastern North Pacific tropical intraseasonal oscillation (ISO) at the end of the 21st Century and implications for tropical cyclone (TC) genesis are examined in the Shared Socioeconomic Pathways (SSP585) scenario of the Coupled Model Intercomparison Project phase 6 (CMIP6) data set. Multimodel mean composite low-level wind and precipitation anomalies associated with the leading intraseasonal mode indicate that precipitation amplitude increases while wind amplitude weakens under global warming, consistent with previous studies for the Indo-Pacific warm pool. The eastern North Pacific intraseasonal precipitation/wind pattern also tends to shift southwestward in a warmer climate, associated with weaker positive precipitation anomalies near the coast of Mexico and Central America during the enhanced convection/westerly wind phase. Implications for the modulation of TC genesis by the leading intraseasonal mode are then explored using an empirical genesis potential index (GPI). In the historical simulation, GPI shows positive anomalies in the eastern North Pacific in the convectively enhanced phase of the ISO. The ISO’s modulation of GPI weakens near the coast of Mexico and Central America with warming, associated with a southward shift of GPI anomalies. Further examination of the contribution from individual environmental variables that enter the GPI shows that relative humidity and vorticity changes during ISO events weaken positive GPI anomalies near the Mexican coast with warming and make genesis more favorable to the southwest. The impact of vertical shear anomaly changes is also to favor genesis away from the coast. These results suggest a weaker modulation of TCs near the Mexican Coast by the ISO in a warmer climate.","PeriodicalId":55576,"journal":{"name":"Atmosfera","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2021-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45732548","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 city of Eskişehir is located in the Central Anatolia Region of Turkey, where harsh continental climatic characteristics are prevalent i.e. cold winters and hot summers. Quality and quantity of research studies on bioclimatic comfort or outdoor thermal environment as a subject have long been increasing all over the world and in Turkey in recent years (for nearly 20 years). Outdoor bioclimatic comfort conditions, which are counted to be among the human quality of life indicators in an urban environment together with other physical, social and economic ones such as air quality, GDP, social activity possibilities, help cities make urban spaces more livable and are now used as a concrete value instead of mean values of some climatic elements in order to give an idea about the climatic conditions of a city. It was aimed in the present research study to determine 1) hourly bioclimatic comfort conditions in Eskişehir city center during sultry summer days considering bioclimatic comfort values calculated according to the 12-year data obtained between 2007 and 2018 from the meteorological stations representing urban (U; Regional Meteorology Administration Station surrounded by a densely structured area), semiurban (SU; Anadolu University Meteorology Station) and rural (R; Eskişehir Airport Meteorology Station) areas using physiological equivalent temperature index (PET) and RayMan software in the hottest months of the year (between May and September; 5 months), 2) spatial distribution of these comfort values in decades (ten – day intervals) using Geographic Information Systems (GIS; ArcGIS 10.1 software program and raster maps taking into consideration elevation and land use and 3) what urban design and planning principles might be adopted against the adverse thermal comfort conditions triggered by urban heat island (UHI) effect. It was seen as a result of the study that the poorest comfort conditions are provided in urban area (U; the sultriest area) while the rural area (R) is the most advantageous one for the comfort conditions. New bioclimate – sensitive urban design principles were taken into consideration to create bioclimatically more comfortable areas i.e. out of heat stress, windier and less humid sites open to prevalent wind direction.
eski ehir市位于土耳其安纳托利亚中部地区，那里普遍存在严酷的大陆性气候特征，即冬季寒冷，夏季炎热。生物气候舒适或室外热环境作为一门学科的研究质量和数量在世界各地和土耳其近年来(近20年)一直在增加。室外生物气候舒适条件与其他物理、社会和经济指标(如空气质量、GDP、社会活动可能性)一起被视为城市环境中人类生活质量指标之一，有助于城市使城市空间更宜居，现在被用作一些气候要素的具体值，而不是平均值，以便给出一个关于城市气候条件的想法。本研究的目的是确定1)根据2007 - 2018年代表城市(U)气象站的12年数据计算的生物气候舒适值，在闷热的夏季，爱斯基基市中心每小时的生物气候舒适条件;区域气象站周围有结构密集的区域)、半城市(SU;阿纳多卢大学气象站)和农村(R;eski机场气象站)在一年中最热的月份(5月至9月;2)利用地理信息系统(GIS)研究这些舒适值在几十年(10天间隔)内的空间分布;考虑高程和土地利用的ArcGIS 10.1软件程序和栅格图;3)针对城市热岛效应引发的不利热舒适条件，可以采用哪些城市设计和规划原则。这项研究的结果是，城市地区提供的舒适条件最差(U;(最闷热的地区)，而农村地区(R)是舒适条件最有利的地区。新的生物气候敏感型城市设计原则被考虑在内，以创造生物气候上更舒适的区域，即摆脱热压力，多风和较少潮湿的场地向流行风向开放。
{"title":"Assessment of bioclimatic sensitive spatial planning in a Turkish city, Eskisehir","authors":"S. Toy, Savaş Çağlak, A. Esringü","doi":"10.20937/ATM.52963","DOIUrl":"https://doi.org/10.20937/ATM.52963","url":null,"abstract":"The city of Eskişehir is located in the Central Anatolia Region of Turkey, where harsh continental climatic characteristics are prevalent i.e. cold winters and hot summers. Quality and quantity of research studies on bioclimatic comfort or outdoor thermal environment as a subject have long been increasing all over the world and in Turkey in recent years (for nearly 20 years). Outdoor bioclimatic comfort conditions, which are counted to be among the human quality of life indicators in an urban environment together with other physical, social and economic ones such as air quality, GDP, social activity possibilities, help cities make urban spaces more livable and are now used as a concrete value instead of mean values of some climatic elements in order to give an idea about the climatic conditions of a city. It was aimed in the present research study to determine 1) hourly bioclimatic comfort conditions in Eskişehir city center during sultry summer days considering bioclimatic comfort values calculated according to the 12-year data obtained between 2007 and 2018 from the meteorological stations representing urban (U; Regional Meteorology Administration Station surrounded by a densely structured area), semiurban (SU; Anadolu University Meteorology Station) and rural (R; Eskişehir Airport Meteorology Station) areas using physiological equivalent temperature index (PET) and RayMan software in the hottest months of the year (between May and September; 5 months), 2) spatial distribution of these comfort values in decades (ten – day intervals) using Geographic Information Systems (GIS; ArcGIS 10.1 software program and raster maps taking into consideration elevation and land use and 3) what urban design and planning principles might be adopted against the adverse thermal comfort conditions triggered by urban heat island (UHI) effect. It was seen as a result of the study that the poorest comfort conditions are provided in urban area (U; the sultriest area) while the rural area (R) is the most advantageous one for the comfort conditions. New bioclimate – sensitive urban design principles were taken into consideration to create bioclimatically more comfortable areas i.e. out of heat stress, windier and less humid sites open to prevalent wind direction.","PeriodicalId":55576,"journal":{"name":"Atmosfera","volume":"1 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2021-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41377682","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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