scholarly journals RESPON CURAH HUJAN DIURNAL TERHADAP MADDEN-JULIAN OSCILLATION AKTIF DI BENUA MARITIM BERBASIS GSMAP GAUGE-CALIBRATED V7

2021 ◽  
Vol 22 (1) ◽  
pp. 17-24
Author(s):  
Achmad Fahruddin Rais ◽  
Ahmad Kosasih ◽  
Soenardi ◽  
Yamin Saleh Saidu ◽  
Sanya Gautami ◽  
...  
Keyword(s):  
Phase Shift ◽  
Outgoing Longwave Radiation ◽  
Longwave Radiation ◽  
Madden Julian Oscillation ◽  
Maritime Continent ◽  
June July August ◽  
Diurnal Rainfall ◽  
The Mean ◽  
June July ◽  
Peak Phase

Intisari Keberadaan pergeseran puncak curah hujan diurnal (DR) terhadap Madden-Julian Oscillation (MJO) aktif di Maritime Continent (MC) masih diperdebatkan sehingga studi ini bertujuan untuk menginvestigasi perubahan tersebut. Selain itu, intensitas rata-rata dan amplitudo DR juga dikaji dalam penelitian ini berbasis GSMaP Gauge-Calibrated V7. Komposit anomali intensitas rata-rata (Ra), amplitudo (Rax) DR MJO aktif dan perbandingan fase puncak DR MJO aktif terhadap klimatologinya (Pax-Pm) pada periode Desember-Januari-Februari (DJF), Maret-April-Mei (MAM), Juni-Juli-Agustus (JJA) dan September-Oktober-November (SON) digunakan dalam tulisan ini dengan uji-z 80%. MJO aktif berbasis rekonstruksi outgoing longwave radiation (OLR) dari kedua indeks realtime multivariate MJO (RMM). Hasil memperlihatkan bahwa MJO aktif memodulasi peningkatan intensitas rata-rata dan amplitudo DR di lautan dan mempengaruhi pergeseran puncak DR menjadi lebih cepat 1 jam dari klimatologi musimannya. Abstract The occurrence of peak phase shift of diurnal rainfall (DR) to active Madden-Jullian Oscillation (MJO) has been debatable, so this study is aimed to investigate the change. Moreover, the mean and amplitude intensity of DR were also analyzed in this study based on GSMaP Gauge-Calibrated V7. The composite of the mean (Ra) and amplitude (Rax) intensity anomaly of DR, and the comparison of DR peak phase during the active MJO to its climatology (Pax-Pm) in the period December-January-February (DJF), March-April-May (MAM), June-July-August (JJA), and September-October-November (SON) were used in the study with the z-test of 80%. The active MJO was based on reconstructed outgoing longwave radiation (OLR) of two real-time multivariate MJO (RMM) indexes. The results showed that active MJO modulated the increased mean and amplitude intensity of DR over the ocean and influenced the DR peak phase shift to be faster than its seasonal climatology by one hour.

scholarly journals Significant seasonal variations in the rate of women diagnosed with gestational diabetes: A observational single centre study of 28,128 women

2021 ◽  
Author(s):  
Matthew Cauldwell ◽  
Yolande VanDerI'isle ◽  
Ingrid Watt-Coote ◽  
Philip Steer
Keyword(s):  
Gestational Diabetes ◽  
Glucose Tolerance Test ◽  
Tolerance Test ◽  
Oral Glucose ◽  
Test Design ◽  
Single Centre ◽  
June July August ◽  
Single Centre Study ◽  
The Mean ◽  
June July

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.

scholarly journals Large-Scale Environmental Characteristics of MJOs that Strengthen and Weaken over the Maritime Continent

2018 ◽  
Vol 31 (14) ◽  
pp. 5731-5748 ◽  
Author(s):  
Casey D. Burleyson ◽  
Samson M. Hagos ◽  
Zhe Feng ◽  
Brandon W. J. Kerns ◽  
Daehyun Kim
Keyword(s):  
Seasonal Cycle ◽  
Large Scale ◽  
Longwave Radiation ◽  
Sea Surface ◽  
Madden Julian Oscillation ◽  
Moist Static Energy ◽  
Maritime Continent ◽  
New Finding ◽  
Field Campaigns ◽  
Static Energy

Abstract The characteristics of Madden–Julian oscillation (MJO) events that strengthen and weaken over the Maritime Continent (MC) are examined. The real-time multivariate MJO (RMM) index is used to assess changes in global MJO amplitude over the MC. The MJO weakens at least twice as often as it strengthens over the MC, with weakening MJOs being twice as likely during El Niño compared to La Niña years and the reverse for strengthening events. MJO weakening shows a pronounced seasonal cycle that has not been previously documented. During the Northern Hemisphere (NH) summer and fall the RMM index can strengthen over the MC. MJOs that approach the MC during the NH winter typically weaken according to the RMM index. This seasonal cycle corresponds to whether the MJO crosses the MC primarily north or south of the equator. Because of the seasonal cycle, weakening MJOs are characterized by positive sea surface temperature and moist-static energy anomalies in the Southern Hemisphere (SH) of the MC compared to strengthening events. Analysis of the outgoing longwave radiation (OLR) MJO index (OMI) shows that MJO precipitation weakens when it crosses the MC along the equator. A possible explanation of this based on previous results is that the MJO encounters more landmasses and taller mountains when crossing along the equator or in the SH. The new finding of a seasonal cycle in MJO weakening over the MC highlights the importance of sampling MJOs throughout the year in future field campaigns designed to study MJO–MC interactions.

scholarly journals An Evaluation of Northern Australian Wet Season Rainfall Bursts in CMIP5 Models

2018 ◽  
Vol 31 (19) ◽  
pp. 7789-7802 ◽  
Author(s):  
Sugata Narsey ◽  
Michael J. Reeder ◽  
Christian Jakob ◽  
Duncan Ackerley
Keyword(s):  
Outgoing Longwave Radiation ◽  
Climate Models ◽  
Longwave Radiation ◽  
Cmip5 Models ◽  
Madden Julian Oscillation ◽  
Wet Season ◽  
The North ◽  
Coupled Climate Models ◽  
The Tropics ◽  
The Relationship

The simulation of northern Australian wet season rainfall bursts by coupled climate models is evaluated. Individual models produce vastly different amounts of precipitation over the north of Australia during the wet season, and this is found to be related to the number of bursts they produce. The seasonal cycle of bursts is found to be poor in most of the models evaluated. It is known that northern Australian wet season bursts are often associated with midlatitude Rossby wave packets and their surface signature as they are refracted toward the tropics. The relationship between midlatitude waves and the initiation of wet season bursts is simulated well by the models evaluated. Another well-documented influence on the initiation of northern Australian wet season bursts is the Madden–Julian oscillation (MJO). No model adequately simulated the tropical outgoing longwave radiation temporal–spatial patterns seen in the reanalysis-derived OLR. This result suggests that the connection between the MJO and the initiation of northern Australian wet season bursts in models is poor.

scholarly journals PENGEMBANGAN MODEL PREDIKSI MADDEN JULIAN OSCILLATION (MJO) BERBASIS PADA HASIL ANALISIS DATA REAL TIME MULTIVARIATE MJO (RMM1 DAN RMM2) (PREDICTION MODEL DEVELOPMENT MADDEN JULIAN OSCILLATION (MJO) BASED ON THE RESULTS OF DATA ANALYSIS ...

Agromet ◽  
2008 ◽  
Vol 22 (2) ◽  
pp. 144 ◽  
Author(s):  
Lisa Evana ◽  
Sobri Effendy ◽  
Eddy Hermawan
Keyword(s):  
Prediction Model ◽  
Real Time ◽  
Outgoing Longwave Radiation ◽  
Time Series Data ◽  
Longwave Radiation ◽  
Empirical Orthogonal Functions ◽  
Wave Radiation ◽  
Series Data ◽  
Madden Julian Oscillation ◽  
Coverage Area

Background of this research is the importance of study on the Madden Julian Oscillation, the dominant oscillation in the equator area. MJO cycle showed by cloud cluster growing in the Indian Ocean then moved to the east and form a cycle with a range of 40-50 days and the coverage area from 10N-10S. Method that used to predict RMM is Box-Jenkins based on ARIMA (Autoregressive Integrated Moving Average) statistical analysis. The data used RMM daily data period 1 Maret 1979–1 Maret 2009 (30 years). RMM1 and RMM2 is an index for monitoring MJO. This is based on two empirical orthogonal functions (EOFs) from the combined average zonal 850hPa wind, 200hPa zonal wind, and satellite-observed Outgoing Longwave Radiation (OLR) data. The results in form of the Power Spectral Density (PSD) graph Real Time Multivariate MJO (RMM) and long wave radiation (OLR = Outgoing Longwave Radiation) at the position 100° BT, 120° BT, and 140°BT that show the wave pattern (spectrum pattern) and clearly shows the oscillation periods. There is a close relation between RMM1 with OLR at the position 100oBT that characterized the PSD value about 45 day. Through Box-Jenkins method, the prediction model that close to time series data of RMM1 and RMM2 is ARIMA (2,1,2), that mean the forecasts of RMM data for the future depending on one time previously and the error one time before. Prediction model for Zt = Zt = 1,681 Zt-1 – 0,722 Zt-2 - 0,02 at-1 - 0,05 at-2.. Prediction model for RMM2 is Zt = 1,714 Zt-1 – 0,764 Zt-2 - 0,109 at-1 - 0,05 at-2.. The flood case in Jakarta January-February 1996 and 2002 are one of real evidence that made the MJO prediction important. MJO with active phase dominant cover almost the entire Indonesia west area at that moment.

FREQUENCY OF RENAL COLIC DUE TO RENAL STONE ASSOCIATED WITH CHANGE IN CLIMATE DURING DIFFERENT MONTHS OF THE YEAR

1969 ◽  
Vol 3 (2) ◽  
pp. 383-388
Author(s):  
MUHAMMAD NAEEM ◽  
HAZRATULLAH ◽  
MUHAMMAD KAMRAN KHAN ◽  
RIAZ AHMAD KHAN ◽  
IZHAR AHMAD ◽  
...  
Keyword(s):  
Prospective Study ◽  
Ambient Temperature ◽  
Renal Stone ◽  
Renal Colic ◽  
Kidney Diseases ◽  
June July August ◽  
The Mean ◽  
June July

OBJECTIVE: To study the incidence of renal colic attacks due to renal stone and its relationship withclimate during different months of the year.MATERIAL AND MONTHS: This prospective study was conducted on patients with renal colicsecondary to stones, who were admitted in the Institute of Kidney Diseases Hayatabad Peshawar betweenOctober 2010 & September 2013.RESULTS: This study included 980 patients, 765 (78.06%) were male and 215 (21.93%) were female.Themean age of the patients was ( 33.1± 9.8years). Majority of the patients 807(82.4%) were under 40 years ofage. Renal colic was more common in summer months like June 118 (12%), July 111 (11.3%) August 109(11.1%) and September 88 (9%) respectively. The lowest no of admission was in February 40 (4.1%),January43 (4.4%), and March 45 (4.6%). It shows that the mean admission of the year due to renal colicsecondary to stone was significantly different from mean admission of the warmer months 578 patients(59%) in comparison to winter month 402 patients (41%). It shows that there was 18% increased incidenceof renal colic visits in the warmer months of June, July and august compared with the colder months ofDecember,January and February.CONCLUSION: The renal colic visit was more in the summer and highest in the month of June, July,August and declining start from September onward and lowest in February. We found a strong positivecorrelation between ambient temperature and renal colic visits.

scholarly journals The Madden–Julian Oscillation in ECHAM6 and the Introduction of an Objective MJO Metric

2013 ◽  
Vol 26 (10) ◽  
pp. 3241-3257 ◽  
Author(s):  
Traute Crueger ◽  
Bjorn Stevens ◽  
Renate Brokopf
Keyword(s):  
Outgoing Longwave Radiation ◽  
Longwave Radiation ◽  
Circulation System ◽  
Madden Julian Oscillation ◽  
Multivariate Approach ◽  
Convection Scheme ◽  
Convective Rainfall ◽  
Zonal Winds ◽  
Basic Features ◽  
Dynamic Signature

Abstract This study presents a quantitative evaluation of the simulated Madden–Julian oscillation (MJO) in an ensemble of 42 experiments performed with ECHAM6 and previous ECHAM versions. The ECHAM6 experiments differ in their parameter settings, resolution, and whether the atmosphere is coupled to an ocean or not. The analysis concentrates on a few basic features of the MJO, namely, the signatures of convection/precipitation coupled with the circulation system and the eastward propagation strength of outgoing longwave radiation (OLR) and 850- and 200-hPa zonal winds within the MJO-related frequency–wavenumber range. It also examines whether precipitation and OLR show similar signatures in the MJO as simulated by ECHAM. The experiments reveal an MJO, however, to different degrees and in different aspects, so that a sound assessment requires a multivariate approach. In particular, the convective rainfall signatures are decoupled from the dynamic signature of the MJO in the simulations herein, which eventually leads to the introduction of a new MJO diagram and metric that incorporate OLR and the zonal winds in 850 and 200 hPa. The analysis here confirms the importance of the convection scheme: only with the Nordeng modifications to the Tiedtke scheme can realistic MJO features be simulated. High-resolution coupled experiments better represent the MJO as compared to low-resolution AMIP experiments. This is shown to follow from two more general findings, namely, that 1) air–sea interaction mainly increases the convective signature and 2) increased resolution enhances eastward propagation.

scholarly journals Diagnosing the average spatio-temporal impact of convective systems – Part 1: A methodology for evaluating climate models

2013 ◽  
Vol 13 (23) ◽  
pp. 12043-12058 ◽  
Author(s):  
M. S. Johnston ◽  
S. Eliasson ◽  
P. Eriksson ◽  
R. M. Forbes ◽  
K. Wyser ◽  
...  
Keyword(s):  
Water Content ◽  
Outgoing Longwave Radiation ◽  
Longwave Radiation ◽  
Cloud Fraction ◽  
Convective Systems ◽  
Ice Water Content ◽  
The Mean ◽  
Spatio Temporal ◽  
Cloud Ice ◽  
Ice Water

Abstract. An earlier method to determine the mean response of upper-tropospheric water to localised deep convective systems (DC systems) is improved and applied to the EC-Earth climate model. Following Zelinka and Hartmann (2009), several fields related to moist processes and radiation from various satellites are composited with respect to the local maxima in rain rate to determine their spatio-temporal evolution with deep convection in the central Pacific Ocean. Major improvements to the earlier study are the isolation of DC systems in time so as to prevent multiple sampling of the same event, and a revised definition of the mean background state that allows for better characterisation of the DC-system-induced anomalies. The observed DC systems in this study propagate westward at ~4 m s−1. Both the upper-tropospheric relative humidity and the outgoing longwave radiation are substantially perturbed over a broad horizontal extent and for periods >30 h. The cloud fraction anomaly is fairly constant with height but small maximum can be seen around 200 hPa. The cloud ice water content anomaly is mostly confined to pressures greater than 150 hPa and reaches its maximum around 450 hPa, a few hours after the peak convection. Consistent with the large increase in upper-tropospheric cloud ice water content, albedo increases dramatically and persists about 30 h after peak convection. Applying the compositing technique to EC-Earth allows an assessment of the model representation of DC systems. The model captures the large-scale responses, most notably for outgoing longwave radiation, but there are a number of important differences. DC systems appear to propagate eastward in the model, suggesting a strong link to Kelvin waves instead of equatorial Rossby waves. The diurnal cycle in the model is more pronounced and appears to trigger new convection further to the west each time. Finally, the modelled ice water content anomaly peaks at pressures greater than 500 hPa and in the upper troposphere between 250 hPa and 500 hPa, there is less ice than the observations and it does not persist as long after peak convection. The modelled upper-tropospheric cloud fraction anomaly, however, is of a comparable magnitude and exhibits a similar longevity as the observations.

scholarly journals Propagating and Nonpropagating MJO Events over Maritime Continent*

2015 ◽  
Vol 28 (21) ◽  
pp. 8430-8449 ◽  
Author(s):  
Jing Feng ◽  
Tim Li ◽  
Weijun Zhu
Keyword(s):  
Rossby Wave ◽  
Longwave Radiation ◽  
Meridional Wind ◽  
Specific Humidity ◽  
Maritime Continent ◽  
Budget Analysis ◽  
Positive Tendency ◽  
Moisture Advection ◽  
Longitudinal Zone ◽  
The Mean

Abstract The observed outgoing longwave radiation (OLR) and ERA-Interim data during 1979–2008 (from November to April) were analyzed to reveal fundamental differences between eastward-propagating (EP) and nonpropagating (NP) MJO events across the Maritime Continent (MC). It was found that when the maximum MJO convection arrives near 120°E, a positive moisture tendency lies in a longitudinal zone (10°S–10°N, 130°–170°E) for the EP cases, whereas a negative tendency appears in the same region for the NP cases. In the latter cases, there are clearly detectable westward-propagating Rossby wave–type dry signals over the equatorial central-western Pacific. The dry Rossby-wave signal may hinder the development of new convection to the east of the MJO convective center, preventing the eastward propagation of the MJO. A moisture budget analysis shows that the positive tendency of specific humidity in the EP composite is mainly attributed to the advection of the mean moisture by an intraseasonal ascending motion anomaly, whereas the negative tendency in the NP composite arises from the advection of anomalous dry air by the mean easterly and the advection of the mean moisture by the anomalous easterly. The EP cases were further separated into two groups: a group with, and a group without, a clear suppressed convective phase of OLR to the east of the MJO convection. In the former (latter), the column-integrated moisture anomaly is negative (positive) to the east of the convection. Nevertheless, MJO crosses the MC in both of the groups, in which anomalous moisture tendency is always positive to the east of the MJO convection. Such positive tendencies are caused by different processes. In the former, anomalous horizontal advections associated with eddy moisture transport and mean moisture advection by intraseasonal meridional wind play an important role. In the latter, it is mainly attributed to mean moisture advection by anomalous vertical velocity.

scholarly journals Evidence of Tropical Forcing of the 6.5-Day Wave from Lightning Observations over Africa

2007 ◽  
Vol 64 (10) ◽  
pp. 3717-3721 ◽  
Author(s):  
Themis G. Chronis ◽  
Earle Williams ◽  
Emmanouil N. Anagnostou
Keyword(s):  
Spectral Analysis ◽  
Outgoing Longwave Radiation ◽  
Amazon Basin ◽  
Longwave Radiation ◽  
Reanalysis Data ◽  
Maritime Continent ◽  
Surface Level ◽  
Tropical Forcing ◽  
Equatorial Africa ◽  
Lightning Detection

Abstract A study employing observations and climatic reanalysis data is concerned with links between convection and the well-documented 6.5-day stratospheric global wave. Observations from a long-range lightning detection network, known as ZEUS, reveal an in-phase behavior between the maximization of daily lightning activity over Africa and the intensification of the wave. To extend the observations on a climatological basis, the authors make use of the outgoing longwave radiation (OLR) as proxy for convection and the surface level pressure (SLP) as an indicator of atmospheric column forcing. Cross-spectral analysis shows significant peaks in coherency between OLR and SLP, apparent only over equatorial Africa and South America (Amazon basin), while strong coherency in this frequency band is absent over the Maritime Continent.

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