scholarly journals An Assessment of Convective Initiation Nowcasting Algorithm within 0-60 Minutes using Himawari-8 Satellite

2021 ◽  
Vol 893 (1) ◽  
pp. 012049
Author(s):  
I F P Perdana ◽  
D Septiadi

Abstract Convective cloud monitoring since its growth stage primarily related to location and time of the first convective cloud initiated, called convective initiation (CI), could be the primary key in providing an earlier heavy rainfall event prediction. This study aimed to assess the accuracy and lead time of CI nowcasting using Satellite Convection Analysis and Tracking (SATCAST) algorithm in predicting the CI event within 0-60 minutes over Surabaya and surrounding area using Himawari-8 satellite during June-July-August (JJA) period in 2018. Three main processes used in this study were cloud masking, cloud object tracking, and CI nowcasting. Twelve interest fields were utilized as predictors based on six bands of Himawari-8 satellite, which represented cloud physics attributes such as cloud-top height, glaciation, or cooling rate. The verification was conducted by comparing CI prediction to CI location and time based on Surabaya weather radar within the next 0-60 minutes. The algorithm resulted that the prediction could achieve 87.3% of accuracy from the 3449 cloud objects. The prediction had POD, FAR, and CSI scores of 57.1%, 52.2%, and 35.2%, respectively. The 32.3 minutes of averaged lead time prediction indicated that CI nowcasting could detect growing cumulus about 30 minutes prior to the CI event.

Atmosphere ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 886
Author(s):  
Abdul Azim Amirudin ◽  
Ester Salimun ◽  
Fredolin Tangang ◽  
Liew Juneng ◽  
Muhamad Zuhairi

This study investigates the individual and combined impacts of El Niño and the positive Indian Ocean Dipole (IOD) on the Southeast Asia (SEA) rainfall variability. Using composite and partial correlation techniques, it is shown that both inter-annual events have individually distinct impacts on the SEA rainfall anomaly distribution. The results showed that the impacts of the co-occurrence of El Niño and IOD events are significant compared to the individual effects of pure El Niño or pure IOD. During June-July-August and September-October-November, the individual impacts of the pure El Niño and IOD events are similar but less significant. Both events caused negative impacts over the southern part of SEA during June-July-August (JJA) and propagated northeastward/eastward during September-October-November (SON). Thus, there are significant negative impacts over the southern part of SEA during the co-occurrence of both events. The differential impacts on the anomalous rainfall patterns are due to the changes in the sea surface temperature (SST) surrounding the region. Additionally, the differences are also related to the anomalous regional atmospheric circulations that interact with the regional SST. The anomalous Walker circulation that connects the Indian Ocean and tropical Pacific Ocean also plays a significant role in determining the regional anomalous rainfall patterns.


Author(s):  
Matthew Cauldwell ◽  
Yolande VanDerI'isle ◽  
Ingrid Watt-Coote ◽  
Philip Steer

Objective To test the hypothesis that there is seasonal variation in the rates of gestational diabetes (GDM) diagnosed using a 2 hour oral glucose tolerance test. Design Monthly assessment of the percentage of women screened from 1st April 2016 to the 31st December 2020 who were diagnosed as having gestational diabetes Setting London Teaching Hospital Population 28,128 women receiving antenatal care between April 1st 2016 and 31 December 2020. Methods Retrospective study of prospectively collected data. Main Outcome Measures Proportion of women screened diagnosed as having gestational diabetes. Results The mean (SD) percentage of women diagnosed with GDM was 14.78 (2.24) in summer (June, July, August) compared with 11.23 (1.62) in winter (p < 0.001), 12.13 (1.94) in spring (p = 0.002), and 11.88 (2.67) in autumn (p = 0.003). There was a highly significant positive correlation of the percentage testing positive for GDM with the mean maximum monthly temperature (R2 = 0.248, p < 0.001). There was a statistically significant 33.8% increase in the proportion of GDM diagnoses from June 2020 onwards, possibly related to a reduction in exercise secondary to the Covid-19 pandemic. Conclusions There is a 23.3% higher rate of GDM diagnoses in the warmer summer months. There has been a 33.8% rise in GDM diagnoses associated with the Covid-19 pandemic.


Fireflies ◽  
2017 ◽  
pp. 59-92
Author(s):  
David P. Owen
Keyword(s):  

Author(s):  
Vaidotas Vaišis ◽  
Tomas Januševičius

The problem of noise is topical not only in Lithuania but the world over as well. The northern part of Klaipeda city is distinct for its industry and heavy traffic in the streets. Noise research was carried out in 17 selected measurement locations in the northern part of Klaipeda city. Noise measurements were taken in May, June, July, August, September, October and November. The measurements were made three times during the day: in the day time from 6 a.m. till 6 p.m., in the evening from 6 p.m. till 10 p.m. and at night from 10 p.m. till 6 a.m. The locations of the measurements are marked on the map. In order to distinguish the source of bigger noise between industry and transport, the northern part was divided into two belts. Industry is prevalent in the first belt, whereas the main troublemakers in the second belt are motor vehicles. The measured noise level is compared with permissible standards in measurement locations, where noise level is usually exceeded, and the analysis of noise levels is presented. In order to show the spread of noise in Klaipeda at all three times of the day more vividly, maps of isolines were compiled. Santrauka Triukšmas - ne tik Lietuvoje, bet ir visame pasaulyje aktuali problema. Klaipedos miesto šiaurine dalis yra išskirtine savo pramone ir intensyviu eismu gatvese. Triukšmo tyrimai atlikti šiaurineje Klaipedos miesto dalyje, 17‐oje pasirinktu matavimo vietu. Triukšmas matuotas gegužes, birželio, liepos, rugpjūčio, rugsejo, spalio ir lapkričio menesiais. Matavimai atlikti trimis paros laikais: diena nuo 6–18 valandos, vakare nuo 18–22 valandos ir nakti nuo 22–6 valandos. Matavimo vietos pateiktos žemelapyje. Siekiant nustatyti, kas kelia didesni triukšma ‐ pramone ar transportas, šiaurine miesto dalis suskirstyta i dvi zonas. Pirmojoje zonoje vyrauja pramone, o antrojoje zonoje pagrindinis triukšmo šaltinis automobiliai. Išmatuotas triukšmo lygis palygintas su leistinosiomis normomis. Pateikta matavimo vietu, kuriose dažniausiai viršijamas triukšmo lygis, triukšmo lygiu analize. Siekiant aiškiau parodyti, kaip triukšmas pasiskirsto Klaipedos mieste visais trimis paros laikais, sudaryti izoliniju žemelapiai. Резюме Шум является актуальной проблемой не только в Литве, но и во всем мире. Северная часть города Клайпеды является промышленным районом с интенсивным транспортным движением. Для исследования шума в этой части города было выбрано 17 мест замера. Шум измерялся с мая по ноябрь. Измерения проводились 3 раза в разное время суток: днем в 6–18 ч, вечером в 18–22 ч и ночью в 22–6 ч. Места замеров показаны на карте. С целью установить, что является бóльшим источником шума – промышленные предприятия или транспортные средства, северная часть города была поделена на две зоны. В первой зоне преобладали промышленные предприятия, а во второй – транспорт. Измеренный уровень шума сравнивался с разрешенным нормами. Для мест замеров, в которых чаще всего уровень шума превышал норму, предлагался анализ уровня шума. Для лучшего представления о распределении шума в городе Клайпеде в разное время суток были созданы карты изолиний.


2021 ◽  
Vol 15 (2) ◽  
pp. 36-41
Author(s):  
I. I. Tsepilova ◽  
N. V. Esaulova ◽  
S. A. Shemyakova

The purpose of the research is studying seasonal dynamics of gastrointestinal strongylatosis in bison in the Central Region of the Russian Federation.Materials and methods. The bison of different age and sex was studied in the Prioksko-Terrasny Nature Reserve, the Moscow Region. Fresh feces collected near feed troughs in enclosures in different seasons for three years were examined according to generally accepted methods. To analyze the infection rate of gastrointestinal strongylates in the European bison by months throughout the year, we took average monthly temperature and humidity values for 2018, 2019, and 2020 into account.Results and discussion. The maximum number of positive samples was diagnosed in the warm season of the year, namely, in summer and in the first months of autumn: August, September and October 2018 (79.3, 83.3 and 82.9%), August, October, November and December 2019 (73.7, 76.9, 77.1 and 77.8%), and June, July, August and October 2020 (85.6, 87.2, 88.0 and 86.3%). Ambient temperatures and precipitations affect significantly on the time of larvae development in the environment, which can be clearly seen in 2019. 


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