scholarly journals Early Morning Peaks in the Diurnal Cycle of Precipitation over the Northern Coast of West Java and Possible Influencing Factors

2020 ◽  
Author(s):  
Erma Yulihastin ◽  
Tri Hadi ◽  
Sari Ningsih Nining ◽  
Muhammad Syahputra
Keyword(s):  
Influencing Factors ◽  
Diurnal Cycle ◽  
Early Morning ◽  
Northern Coast ◽  
West Java ◽  
Diurnal Cycle Of Precipitation

scholarly journals Early morning peaks in the diurnal cycle of precipitation over the northern coast of West Java and possible influencing factors

2020 ◽  
Vol 38 (1) ◽  
pp. 231-242 ◽  
Author(s):  
Erma Yulihastin ◽  
Tri Wahyu Hadi ◽  
Nining Sari Ningsih ◽  
Muhammad Ridho Syahputra
Keyword(s):  
South China Sea ◽  
Influencing Factors ◽  
South China ◽  
Phase Distribution ◽  
Early Morning ◽  
The South China Sea ◽  
Northern Coast ◽  
West Java ◽  
China Sea ◽  
Precipitation Events

Abstract. The diurnal cycles of precipitation over the northern coast of West Java have been studied using the Tropical Rainfall Measuring Mission (TRMM) Real Time Multi-satellite Precipitation Analyses (TMPA-RT) products with records spanning from 2000 to 2016, with emphasis on the occurrences of early morning precipitation peaks. Diurnal precipitation over the study area during November to March is basically characterized by precipitation peaks that occur in the afternoon to evening time (15:00–21:00 LT), but secondary peaks in the night to morning time (01:00–07:00 LT) are also pronounced in January and February. The harmonic analysis method was then applied to data of January and February to objectively determine the diurnal phase and classify the timing of precipitation for each day into three categories, i.e. afternoon-to-evening precipitation (AEP), early morning precipitation (EMP), and late morning precipitation (LMP) with peaks that occur in the time windows of 13:00–24:00, 01:00–04:00, and 05:00–12:00 LT, respectively. In terms of frequency of occurrence, AEP, EMP, and LMP constitute 55 %, 18.9 %, and 26.1 % of total samples of precipitation events. In spite of the smallest percentage, EMP events are characterized by seaward (as well as landward) propagation, flat phase distribution, and large mean amplitudes. The propagating characteristics of EMP are more prominent, with indications of stronger connectivity between precipitation systems over land and ocean, when data are composited by taking the 99th percentile values in each grid to represent extreme precipitation events. The flat phase distribution of EMP events suggests that the timing of coastal precipitation is not necessarily locked to the phase of land–sea breezes, thus allowing precipitation to occur more randomly. Furthermore, the role of the South China Sea cold tongue (SCS-CT) and cross-equatorial northerly surge (CENS) as influencing factors for the occurrences of the EMP event have also been investigated. In agreement with previous studies, we confirmed that the SCS-CT generally prevails in January and February, and morning precipitation events over the northern coast of West Java mainly occurred when there was more enhanced sea surface temperature (SST) cooling in the South China Sea. Additionally, we found that CENS is the most differential factor with regard to the phase of coastal precipitation. In this case, CENS is positively correlated with SCS-CT and, when associated with EMP events, concurrent enhancement of CENS and SCS-CT is connected to a narrow channelling of strong surface northerly wind anomalies just offshore of Indochina and the Malay Peninsula.

scholarly journals Early Morning Peaksin the Diurnal Cycle of Precipitation over the Northern Coast of West Java and Possible Influencing Factors

2019 ◽  
Author(s):  
Erma Yulihastin ◽  
Tri Wahyu Hadi ◽  
Nining Sari Ningsih ◽  
Muhammad Ridho Syahputra
Keyword(s):  
South China Sea ◽  
Influencing Factors ◽  
South China ◽  
Phase Distribution ◽  
Early Morning ◽  
Northern Coast ◽  
West Java ◽  
China Sea ◽  
Extreme Precipitation Events ◽  
Precipitation Events

Abstract. The diurnal cycles of precipitation over the northern coast of West Java have been studied using the Tropical Rainfall Measuring Mission (TRMM) Real Time Multi-satellite Precipitation Analyses (MPA-RT) products with records spanning from 2000 to 2016, with emphasis on the occurrences of early morning precipitation peaks. Diurnal precipitation over the study area during November to March is basically characterised by precipitation peaks that occur in the afternoon to evening time (15:00–21:00 LT) but secondary peaks in night to morning time (01:00–07:00 LT) are also pronounced in January and February. Harmonic analysis method was then applied on data of January and February to objectively determine the diurnal phase and classify the timing of precipitation for each day into three categories, i.e. afternoon-to-evening precipitation (AEP), early morning precipitation (EMP), and late morning precipitation (LMP) with peaks that occur in the time windows of 13:00–24:00 LT, 01:00–04:00 LT, and 05:00–12:00 LT, respectively. In terms of frequency of occurrence, AEP, EMP, and LMP constitute 55 %, 26.1 %, and 18.9 % of total samples of precipitation events. In spite of the smallest percentage, EMP events are characterised by seaward (as well as landward) propagation, flat phase distribution, and large mean amplitudes. The propagating characteristics of EMP are more prominent, with indications of stronger connectivity between precipitation systems over land and ocean, when data are composited by taking the 99th percentile values in each grid to represent extreme precipitation events. The flat phase distribution of EMP events suggests that the timing of coastal precipitation is not necessarily locked to the phase of land/sea-breezes, thus, allowing precipitation to occur more randomly. Furthermore, the role of South China Sea Cold Tongue (SCS-CT) and Cross Equatorial Northerly Surge (CENS) as influencing factors for the occurrences of EMP event have also been investigated. In agreement with previous studies, we confirmed that the SCS-CT generally prevails in January and February and morning precipitation events over the northern coast of West Java mainly occurred when there was more enhanced SST cooling in the South China Sea. Additionally, we found that CENS is the most differential factor with regard to the phase of coastal precipitation. In this case, CENS is positively correlated with SCS-CT and when associated with EMP events, concurrent enhancement of CENS and SCS-CT is connected to a narrow channelling of strong surface northerly wind anomalies just offshore the Indochina and Malay Peninsula.

scholarly journals Morning Precipitation Peak over the Strait of Malacca under a Calm Condition

2010 ◽  
Vol 138 (4) ◽  
pp. 1474-1486 ◽  
Author(s):  
Mikiko Fujita ◽  
Fujio Kimura ◽  
Masanori Yoshizaki
Keyword(s):  
Numerical Model ◽  
Observational Data ◽  
Diurnal Cycle ◽  
Early Morning ◽  
Malay Peninsula ◽  
Maritime Continent ◽  
Precipitation System ◽  
Calm Condition ◽  
Diurnal Cycle Of Precipitation ◽  
Strait Of Malacca

Abstract This paper describes the formation mechanism of morning maximum in the diurnal cycle of precipitation, at the Strait of Malacca under a calm condition, with a nonhydrostatic mesoscale numerical model and ship-based observational data. The morning precipitation peak at the strait is induced by the convergence of two cold outflows that have been produced by the precipitation systems in the previous evening over Sumatra and the Malay Peninsula. The outflows converge at the Strait of Malacca around midnight; a new precipitation system is thus generated and reaches its peak in the early morning. Sensitivity experiments using the numerical model suggest that the timing and position of the morning precipitation peak are affected by the width of the strait. In the case of the Strait of Malacca, its width favors the formation of the morning precipitation system around the center of the strait, which explains why its diurnal cycle of precipitation can be observed much clearer than those in other coastal areas over the Maritime Continent.

scholarly journals Spatial Variations in the Diurnal Pattern of Precipitation over Nepal Himalayas

2015 ◽  
Vol 15 (2) ◽  
pp. 57-64 ◽  
Author(s):  
Dibas Shrestha ◽  
Rashila Deshar
Keyword(s):  
Summer Monsoon ◽  
Diurnal Cycle ◽  
Monsoon Season ◽  
Tropical Rainfall Measuring Mission ◽  
Early Morning ◽  
Temporal Variations ◽  
Diurnal Cycles ◽  
Diurnal Cycle Of Precipitation ◽  
Spatio Temporal ◽  
The Impact

The Central Himalayan Region (Nepal Himalayas), comprised of two clear sub-parallel mountain ranges, is atypical location for studying the impact of rugged topography on spatio temporal variations of precipitation. The relationship between topography and diurnal cycles of rainfall have been investigated utilizing 13-year (1998–2010) high resolution (0.05° × 0.05°) Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR) data. An investigation of diurnal cycle of precipitation revealed an afternoon maximum during the pre-monsoon season (March–May) and midnight–early morning maximum during the summer monsoon season (June–August)over the southern slopes of the Himalayas. The summer monsoon exhibited a robust spatial variation of diurnal cycle of precipitation, during afternoon-evening time, primary rainfall peak appeared along the Lesser Himalayas (~2,000–2,200 m above mean sea level), while early-morning rain in contrast showed maximum concentration along the southern margin of the Himalayas (~500–700 m above MSL). An afternoon-evening rainfall peak was attributed to higher rain frequency, whereas early-morning rainfall peak was attributed to fewer but rather intense rainfall. It is suggested that, confluence between down slope and moist south easterly monsoon flow triggers convection near the foothills of the Himalayas during early morning period. The results further suggested the morning precipitation moves southward in the mature monsoon season.DOI: http://dx.doi.org/njst.v15i2.12116Nepal Journal of Science and Technology Vol. 15, No.2 (2014), 57-64

Evaluating Diurnal and Semi-Diurnal Cycle of Precipitation in CMIP6 Models Using Satellite- and Ground-Based Observations

2021 ◽  
pp. 1-56
Author(s):  
Shuaiqi Tang ◽  
Peter Gleckler ◽  
Shaocheng Xie ◽  
Jiwoo Lee ◽  
Min-Seop Ahn ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Diurnal Cycle ◽  
Climate Models ◽  
Early Morning ◽  
Mesoscale Convective Systems ◽  
Convective Systems ◽  
Ensemble Mean ◽  
Mesoscale Convective ◽  
Diurnal Cycle Of Precipitation

AbstractThe diurnal and semi-diurnal cycle of precipitation simulated from CMIP6 models during 1996-2005 are evaluated globally between 60°S and 60°N, as well as at ten selected locations representing three categories of diurnal cycle of precipitation: (1) afternoon precipitation over land, (2) early morning precipitation over ocean, and (3) nocturnal precipitation over land. Three satellite-based and two ground-based rainfall products are used to evaluate the climate models. Globally, the ensemble mean of CMIP6 models shows a diurnal phase of 3 to 4 hours earlier over land and 1 to 2 hours earlier over ocean, when compared with the latest satellite products. These biases are in line with what were found in previous versions of climate models but reduced compared to the CMIP5 ensemble mean. Analysis at the selected locations complimented with in-situ measurements further reinforces these results. Several CMIP6 models have shown a significant improvement in the diurnal cycle of precipitation compared to their CMIP5 counterparts, notably on delaying afternoon precipitation over land. This can be attributed to the use of more sophisticated convective parameterizations. Most models are still unable to capture the nocturnal peak associated with elevated convection and propagating mesoscale convective systems, with a few exceptions that allow convection to be initiated above the boundary layer to capture nocturnal elevated convection. We also quantify an encouraging consistency between the satellite- and ground-based precipitation measurements despite differing spatiotemporal resolutions and sampling periods, which provides confidence in using them to evaluate the diurnal and semi-diurnal cycle of precipitation in climate models.

scholarly journals Seasonal Variation of the Diurnal Cycle of Rainfall in Southern Contiguous China

2008 ◽  
Vol 21 (22) ◽  
pp. 6036-6043 ◽  
Author(s):  
Jian Li ◽  
Rucong Yu ◽  
Tianjun Zhou
Keyword(s):  
Seasonal Variation ◽  
Diurnal Cycle ◽  
Radiative Forcing ◽  
Early Morning ◽  
Rain Gauge ◽  
Rainfall Events ◽  
Late Afternoon ◽  
Long Duration ◽  
China Region ◽  
Afternoon Peak

Abstract Hourly station rain gauge data are employed to study the seasonal variation of the diurnal cycle of rainfall in southern contiguous China. The results show a robust seasonal variation of the rainfall diurnal cycle, which is dependent both on region and duration. Difference in the diurnal cycle of rainfall is found in the following two neighboring regions: southwestern China (region A) and southeastern contiguous China (region B). The diurnal cycle of annual mean precipitation in region A tends to reach the maximum in either midnight or early morning, while precipitation in region B has a late-afternoon peak. In contrast with the weak seasonal variation of the diurnal phases of precipitation in region A, the rainfall peak in region B shifts sharply from late afternoon in warm seasons to early morning in cold seasons. Rainfall events in south China are classified into short- (1–3 h) and long-duration (more than 6 h) events. Short-duration precipitation in both regions reaches the maximum in late afternoon in warm seasons and peaks in either midnight or early morning in cold seasons, but the late-afternoon peak in region B exists during February–October, while that in region A only exists during May–September. More distinct differences between regions A and B are found in the long-duration rainfall events. The long-duration events in region A show dominant midnight or early morning peaks in all seasons. But in region B, the late-afternoon peak exists during July–September. Possible reasons for the difference in the diurnal cycle of rainfall between the two regions are discussed. The different cloud radiative forcing over regions A and B might contribute to this difference.

Sign in / Sign up

Export Citation Format

Share Document