scholarly journals Meteorological context of the onset and end of the rainy season in Central Amazonia during the GoAmazon2014/5

2017 ◽  
Vol 17 (12) ◽  
pp. 7671-7681 ◽  
Author(s):  
Jose A. Marengo ◽  
Gilberto F. Fisch ◽  
Lincoln M. Alves ◽  
Natanael V. Sousa ◽  
Rong Fu ◽  
...  
Keyword(s):  
Rainy Season ◽  
Large Scale ◽  
Meteorological Data ◽  
Austral Summer ◽  
Thermodynamic Characteristics ◽  
Weather Conditions ◽  
Madden Julian Oscillation ◽  
Wet Season ◽  
Significant Difference ◽  
Central Amazonia

Abstract. The onset and demise of the rainy season in Amazonia are assessed in this study using meteorological data from the GoAmazon experiment, with a focus on the 2014–2015 rainy season. In addition, global reanalyses are also used to identify changes in circulation leading to the establishment of the rainy season in the region. Our results show that the onset occurred in January 2015, 2–3 pentads later than normal, and the rainy season during the austral summer of 2015 contained several periods with consecutive dry days in both Manacapuru and Manaus, which are not common for the wet season, and resulted in below-normal precipitation. The onset of the rainy season has been strongly associated with changes in large-scale weather conditions in the region due to the effect of the Madden–Julian Oscillation (MJO). Regional thermodynamic indices and the height of the boundary layer did not present a significant difference between the onset and demise of the wet season of 2015. This suggests that local changes, such as those in the regional thermodynamic characteristics, may not have influenced its onset. Thus, variability of the large-scale circulation was responsible for regional convection and rainfall changes in Amazonia during the austral summer of 2014–2015.

scholarly journals Meteorological context of the onset and end of the rainy season in Central Amazonia during the 2014–15 Go-Amazon Experiment

2017 ◽  
Author(s):  
Jose A. Marengo ◽  
Gilberto F. Fisch ◽  
Lincoln M. Alves ◽  
Natanael V. Sousa ◽  
Rong Fu ◽  
...  
Keyword(s):  
Rainy Season ◽  
Large Scale ◽  
Meteorological Data ◽  
Austral Summer ◽  
Thermodynamic Characteristics ◽  
Weather Conditions ◽  
Wet Season ◽  
Significant Difference ◽  
Central Amazonia ◽  
Consecutive Dry Days

Abstract. The onset and demise of the rainy season in Amazonia are assessed in this study using meteorological data from the Go Amazon experiment, with focus is on the 2014–15 rainy season. In addition, global reanalyses are also used to identify changes in circulation leading to the establishment of the rainy season in the region. Our results show that the onset occurred in January 2015, 2–3 pentads later than normal, and the rainy season during austral summer of 2015 exhibited several periods with consecutive dry days in both Manacapuru and Manaus, which are not common for the wet season, and thus determining below normal precipitation. The onset of the rainy season has been strongly associated with changes in large-scale weather conditions in the region due to the effect of the MJO. Regional thermodynamic indices (CAPE, CIN) and the height of the PBL did not present a significant difference between the onset and demise of wet season 2015. This suggests that local changes such the regional thermodynamic characteristics may have not influenced the onset of the rainy season. Variability of the large-scale circulation was responsible for regional convection and rainfall changes in Amazonia during the austral summer of 2014–15.

scholarly journals Influence of the Stratospheric Quasi-Biennial Oscillation on the Madden–Julian Oscillation during Austral Summer

2017 ◽  
Vol 74 (4) ◽  
pp. 1105-1125 ◽  
Author(s):  
Eriko Nishimoto ◽  
Shigeo Yoden
Keyword(s):  
Large Scale ◽  
Statistical Significance ◽  
Austral Summer ◽  
Horizontal Wind ◽  
Convective System ◽  
Madden Julian Oscillation ◽  
Quasi Biennial Oscillation ◽  
Enso Events ◽  
Convective Region ◽  
Biennial Oscillation

Abstract Influence of the stratospheric quasi-biennial oscillation (QBO) on the Madden–Julian oscillation (MJO) and its statistical significance are examined for austral summer (DJF) in neutral ENSO events during 1979–2013. The amplitude of the OLR-based MJO index (OMI) is typically larger in the easterly phase of the QBO at 50 hPa (E-QBO phase) than in the westerly (W-QBO) phase. Daily composite analyses are performed by focusing on phase 4 of the OMI, when the active convective system is located over the eastern Indian Ocean through the Maritime Continent. The composite OLR anomaly shows a larger negative value and slower eastward propagation with a prolonged period of active convection in the E-QBO phase than in the W-QBO phase. Statistically significant differences of the MJO activities between the QBO phases also exist with dynamical consistency in the divergence of horizontal wind, the vertical wind, the moisture, the precipitation, and the 100-hPa temperature. A conditional sampling analysis is also performed by focusing on the most active convective region for each day, irrespective of the MJO amplitude and phase. Composite vertical profiles of the conditionally sampled data over the most active convective region reveal lower temperature and static stability around the tropopause in the E-QBO phase than in the W-QBO phase, which indicates more favorable conditions for developing deep convection. This feature is more prominent and extends into lower levels in the upper troposphere over the most active convective region than other tropical regions. Composite longitude–height sections show similar features of the large-scale convective system associated with the MJO, including a vertically propagating Kelvin response.

On the Atmospheric Regulation of the Growth of Moderate to Deep Cumulonimbus in a Tropical Environment

2014 ◽  
Vol 71 (3) ◽  
pp. 1105-1120 ◽  
Author(s):  
Vickal V. Kumar ◽  
Alain Protat ◽  
Christian Jakob ◽  
Peter T. May
Keyword(s):  
Large Scale ◽  
Deep Convection ◽  
Atmospheric Conditions ◽  
Wet Season ◽  
Cumulus Clouds ◽  
Significant Difference ◽  
The Hours ◽  
Using Data ◽  
Cumulus Congestus ◽  
Rain Rates

Abstract Some cumulus clouds with tops between 3 and 7 km (Cu3km–7km) remain in this height region throughout their lifetime (congestus) while others develop into deeper clouds (cumulonimbus). This study describes two techniques to identify the congestus and cumulonimbus cloud types using data from scanning weather radar and identifies the atmospheric conditions that regulate these two modes. A two-wet-season cumulus cloud database of the Darwin C-band polarimetric radar is analyzed and the two modes are identified by examining the 0-dBZ cloud-top height (CTH) of the Cu3km–7km cells over a sequence of radar scans. It is found that ~26% of the classified Cu3km–7km population grow into cumulonimbus clouds. The cumulonimbus cells exhibit reflectivities, rain rates, and drop sizes larger than the congestus cells. The occurrence frequency of cumulonimbus cells peak in the afternoon at ~1500 local time—a few hours after the peak in congestus cells. The analysis of Darwin International Airport radiosonde profiles associated with the two types of cells shows no noticeable difference in the thermal stability rates, but a significant difference in midtropospheric (5–10 km) relative humidity. Moister conditions are found in the hours preceding the cumulonimbus cells when compared with the congestus cells. Using a moisture budget dataset derived for the Darwin region, it is shown that the existence of cumulonimbus cells, and hence deep convection, is mainly determined by the presence of the midtroposphere large-scale upward motion and not merely by the presence of congestus clouds prior to deep convection. This contradicts the thermodynamic viewpoint that the midtroposphere moistening prior to deep convection is solely due to the preceding cumulus congestus cells.

scholarly journals A COMPARISON OF WET MASH AND DRY MASH FEEDING FOR BROILER FINISHER DURING WET SEASON IN TIIE TROPICS

2021 ◽  
Vol 28 (2) ◽  
pp. 143-146
Author(s):  
H. A. AW0JOBI ◽  
O. O. MESHIOYE
Keyword(s):  
Weight Gain ◽  
Feed Intake ◽  
Feed Efficiency ◽  
Rainy Season ◽  
Live Weight ◽  
Weather Conditions ◽  
Abdominal Fat ◽  
Wet Season ◽  
Hot Weather ◽  
The Tropics

An experiment was conducted to compare wet mash and conventional dry mash feeding for finisher broilers. Feed intake, live-weight gain, feed efficiency and weights of heart, crop, and abdominal fat deposit were significantly (P<0.05) higher in broilers receiving the wet mash. Water intake and gizzard weight were significantly (P<0.05) higher in birds fed dry mash. No significant (P<0.05) differences were observed in dressing percentage, weights of liver, intestine and the proventriculus. The results of this experiment demonstrated that wet feeding is not deleterious to the performance of broilers in the tropics. It also concluded that wet feeding is desirable not under hot weather conditions alone, but also during the rainy season.

scholarly journals Influence of Subseasonal Variability on the Diurnal Cycle of Precipitation on a Mountainous Island: The Case of New Caledonia

2019 ◽  
Vol 148 (1) ◽  
pp. 333-351 ◽  
Author(s):  
Damien Specq ◽  
Gilles Bellon ◽  
Alexandre Peltier ◽  
Jérôme Lefèvre ◽  
Christophe Menkes
Keyword(s):  
Diurnal Cycle ◽  
Large Scale ◽  
New Caledonia ◽  
Austral Summer ◽  
Mountain Range ◽  
Wet Season ◽  
Diurnal Variability ◽  
Synoptic Wind ◽  
Diurnal Cycle Of Precipitation ◽  
Wind Regimes

Abstract The relationship between the large-scale intraseasonal variability, synoptic wind regimes, and the local daily variability of precipitation over the main island of New Caledonia (southwest tropical Pacific) is investigated with a focus on the austral summer wet season (November–April). The average diurnal cycle of precipitation over the island is characterized by a sharp afternoon maximum around 1600 local time, with significant differences between the windward east coast, the leeward west coast, and the mountain range. The afternoon peak is related to the afternoon sea-breeze circulation and to the diurnal cycle of convection over land. In general, its magnitude follows the same evolution as the daily mean. In agreement with past studies, a clear modulation of the Madden–Julian oscillation (MJO) on both the diurnal cycle of precipitation and the probability of occurrence of four robust wind regimes can be identified in the New Caledonia region during the wet season. From the evidence that there is a qualitative correspondence between the effects of both the MJO phases and the wind regimes on features in the diurnal cycle of precipitation, a simple model is proposed to inspect the MJO forcing mediated by wind regimes on the diurnal variability of rain. The complete decomposition of the MJO impact shows that the modulation of diurnal cycle by the MJO relies on complex interactions between the MJO and synoptic winds that involve both large-scale MJO convective anomalies and MJO-induced modification of wind patterns.

scholarly journals Remote Sensing Based Estimation of Evapo-Transpiration Using Selected Algorithms: The Case of Wonji Shoa Sugar Cane Estate, Ethiopia

2016 ◽  
Author(s):  
Mulugeta Genanu ◽  
Tena Alamirew ◽  
Gabriel Senay ◽  
Mekonnen Gebremichael
Keyword(s):  
Remote Sensing ◽  
Energy Balance ◽  
Surface Energy ◽  
Large Scale ◽  
Surface Energy Balance ◽  
Meteorological Data ◽  
Wet Season ◽  
Spatially Distributed ◽  
Spatio Temporal ◽  
Water Surplus

Remote sensing datasets are increasingly being used to provide spatially explicit large scale evapotranspiration (ET) estimates. The focus of this study was to estimate and thematically map pixel-by-pixel basis, and compare the actual evapotranspiration (ETa) of the Wonji Shoa Sugarcane Estate using Surface Energy Balance Algorithm for Land (SEBAL), Simplified Surface Energy Balance (SSEB) and Operational Simplified Surface Energy Balance (SSEBop) algorithms on Landsat7 ETM+ images acquired on four days in 2002. The algorithms were based on image processing which uses spatially distributed spectral satellite data and ground meteorological data to derive the surface energy balance components. The results obtained revealed that the ranges of the daily ETa estimated on January 25, February 26, September 06 and October 08, 2002 using SEBAL were 0.0&ndash;6.85, 0.0&ndash;9.36, 0.0&ndash;3.61, 0.0&ndash;6.83 mm/day; using SSEB 0.0&ndash;6.78, 0.0&ndash;7.81, 0.0&ndash;3.65, 0.0&ndash;6.46 mm/day, and SSEBop were 0.05&ndash;8.25, 0.0&ndash;8.82, 0.2&ndash;4.0, 0.0&ndash;7.40 mm/day, respectively. The Root Mean Square Error (RMSE) values between SSEB and SEBAL, SSEBop and SEBAL, and SSEB and SSEBop were 0.548, 0.548, and 0.99 for January 25, 2002; 0.739, 0.753, and 0.994 for February 26, 2002;0.847, 0.846, and 0.999 for September 06, 2002; 0.573, 0.573, and 1.00 for October 08, 2002, respectively. The standard deviation of ETa over the sugarcane estate showed high spatio-temporal variability perhaps due to soil moisture variability and surface cover. The three algorithm results showed that well watered sugarcane fields in the mid-season growing stage of the crop and water storage areas had higher ETa values compared with the other dry agricultural fields confirming that they consumptively use more water. Generally during the dry season ETa is limited to water surplus areas only and in wet season, ETa was high throughout the entire sugarcane estate. The evaporation fraction (ETrF) results also followed the same pattern as the daily ETa over the sugarcane estate. The total crop and irrigation water requirement and effective rainfall estimated using the Cropwat model were 2468.8, 2061.6 and 423.8 mm/yr for January 2001 planted and 2281.9, 1851.0 and 437.8 mm/yr for March 2001 planted sugarcanes, respectively. The mean annual ETa estimated for the whole estate were 107 Mm3, 140 Mm3, and 178 Mm3 using SEBAL, SSEB, and SSEBop, respectively. Even though the algorithms should be validated through field observation, they have potential to be used for effective estimation of ET in the sugarcane estate.

Weather Influence on the Prevalence of Carbon Monoxide Intoxications

1989 ◽  
Vol 8 (5) ◽  
pp. 355-358 ◽  
Author(s):  
F.P. Gijsenbergh ◽  
M. Vispoel ◽  
H. Poppel ◽  
H. Delooz
Keyword(s):  
Emergency Department ◽  
Carbon Monoxide ◽  
Retrospective Study ◽  
Meteorological Data ◽  
Weather Conditions ◽  
Significant Difference ◽  
Co Intoxication ◽  
The Media

In a retrospective study over 7 years, data from patients admitted to the Emergency Department with CO intoxication, together with meteorological data were analysed. A statistically significant difference in weather conditions was noticed between CO-intoxication days and reference days. Different weather conditions were found to be present, according to the source of CO, i.e. gas boiler or coal stove. If these data are confirmed, a major role in the prevention of CO intoxication or its sequellae can be played by the media through weather broadcasting. Warning can raise the index of suspicion of physicians and warn the population for vague, collectively appearing sensations of ill feeling.

scholarly journals Change of the Rainfall Seasonality Over Central Peruvian Andes: Onset, End, Duration and Its Relationship With Large-Scale Atmospheric Circulation

Climate ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 23 ◽  
Author(s):  
Lucy Giráldez ◽  
Yamina Silva ◽  
Ricardo Zubieta ◽  
Juan Sulca
Keyword(s):  
Rainy Season ◽  
Large Scale ◽  
Amazon Basin ◽  
Late Onset ◽  
Caribbean Region ◽  
Equatorial Atlantic ◽  
Tropical Andes ◽  
The South ◽  
Wet Season ◽  
Peruvian Andes

Changes of the onset dates, end dates, and duration of the rainy season over central Peruvian Andes (Mantaro river basin, MRB) could severely affect water resources management and the main economic activities (e.g., rainfed agriculture, raising cattle, among others). Nonetheless, these changes have not been documented for the Tropical Andes. To asses that, we used daily datasets of observed rainfall during the 1965–2013 period. For this period, the average onset (end) date of the rainy season over the MRB occurs in the pentad 17 (19–23 September) [pentad 57 (7–11 April)]. The duration of the rainy season mainly is modulated by the onset dates due to it has higher variability than end dates. There is a reduction of 3 days/decade in the duration of wet season over the MRB for the last four decades due to the delay of the onset days. Furthermore, El Niño favors late-onset and early end of the rainy season, while La Niña favors early onset and late end of the rainy season in the MRB. Onset dates are related to the propagation of the convective region of the South American Monsoon System (SAMS), from the Caribbean region toward the central Amazon basin. Early (late)-onset days are associated with a southward (northward) shift of the South Atlantic Convergence Zone (SACZ) and weak (strong) convection over equatorial Atlantic that induces the southernmost propagation (eastward shift) of the SAMS.

Seasonal Variations of Hyperglycemic Crises in Diabetic Patients at a National Hospital Center, Benin: a Cross Sectional Study

2021 ◽  
Vol 5 (6) ◽  
pp. 01-06
Author(s):  
Comlan Jules GNINKOUN ◽  
Finagnon Armand WANVOEGBE ◽  
Joseph Soglo FANOU ◽  
Calice Sèdodé TOFFOHOSSOU ◽  
François DJROLO
Keyword(s):  
Rainy Season ◽  
Meteorological Data ◽  
Cross Sectional Study ◽  
Diabetic Patients ◽  
Adherence To Treatment ◽  
Precipitating Factors ◽  
Cross Sectional ◽  
Seasonal Characteristics ◽  
Significant Difference ◽  
Hyperglycemic Hyperosmolar Syndrome

Aim : To study the seasonal characteristics of hyperglycemic decompensations in the endocrinology department of the CNHU-HKM of Cotonou. Materials and methods :It was a cross-sectional, descriptive, and study of diabetic patients hospitalized from January 1, 2010 to December 31, 2019. Diabetic patients hospitalized for ketosis decompensation and/or hyperglycemic hyperosmolar syndrome were included in this study. The meteorological data used were obtained from the climate observation network of the Direction de la Météorologie Nationale (DMN) du Bénin. We have considered the means of rainfall and temperature per month and per year. Results : A total of 613 patients were included during the study period. The mean age of the patients was 46.77±15.84 years. The frequency of hyperglycemic hyperosmolar syndrome and ketoacidosis was 14.7% and 69.5% respectively. Hyperglycemic crises were more frequent during the rainy season and periods of low temperature. The main precipitating factors were infections and non-adherence to treatment. The main infectious sites involved in hyperglycemic crises were pulmonary (19%), urogenital (21.3%) and malaria (26.8%). The frequency of these different infections was higher during the rainy season with a statistically significant difference (p=0.02) for malaria. Conclusion : The frequency of hyperglycemic crises was high and had a seasonal distribution. The most frequent precipitating factors were infections and non-adherence to treatment. Those factors were more frequent in the rainy season.

scholarly journals Schneefernerhaus as a mountain research station for clouds and turbulence – Part 1: Flow conditions and large-scale turbulence

2015 ◽  
Vol 8 (1) ◽  
pp. 541-568 ◽  
Author(s):  
S. Risius ◽  
H. Xu ◽  
F. Di Lorenzo ◽  
H. Xi ◽  
H. Siebert ◽  
...  
Keyword(s):  
Large Scale ◽  
Velocity Structure ◽  
Meteorological Data ◽  
Weather Conditions ◽  
Reynolds Numbers ◽  
Research Station ◽  
Air Turbulence ◽  
Complementary Role ◽  
Scale Turbulence ◽  
Summer Time

Abstract. Cloud measurements are usually carried out with airborne campaigns, which are expensive and are limited by temporal duration and weather conditions. Ground based measurements at high-altitude research stations therefore play a complementary role in cloud study. Using the meteorological data (wind speed, direction, temperature, humidity, visibility, etc.) collected by the German Weather Service (DWD) from 2000 to 2012 and turbulence measurements recorded by multiple ultrasonic sensors (sampled at 10 Hz) in 2010, we show that the Umweltforschungsstation Schneefernerhaus (UFS) located just below the peak of Zugspitze in the German Alps, at a height of 2650 m, is a well-suited station for cloud-turbulence research. The wind at UFS is dominantly in the east–west direction and nearly horizontal. During the summer time (July and August) the UFS is immersed in warm clouds about 25% of the time. The clouds are either from convection originating in the valley in the east, or associated with synoptic-scale weather systems typically advected from the west. Air turbulence, as measured from the second and third order velocity structure functions that exhibit well-developed inertial ranges, possesses Taylor microscale Reynolds numbers up to 104, with the most probable value at ~ 3000. In spite of the complex topography, the turbulence appears to be nearly as isotropic as many laboratory flows when evaluated on the so called "Lumley-triangle".

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