Extreme precipitation events during the South Asian summer monsoon season in the past century

The South ◽

The Past ◽

The South Asian monsoon system impacts the livelihoods of over a billion people. While the overall monsoon rainfall is believed to have decreased during the 20th century, there is a good agreement that the extreme precipitation events have been rising in some parts of India. As an important part of the Indian population is dependent on rainfed agriculture, such a rise in extremes, along with resulting flood events, can be all the more problematic. Although studies tend to link this rise in extreme events with anthropogenic forcing, some uncertainties remain on the exact causes. In order to examine the correlation between anthropogenic forcings and the different trends in extreme events, we have analyzed the high-resolution daily rainfall data in the past century delivered by the Indian Meteorological Department alongside several other economic and ecological estimates. The results from this analysis will be presented in detail.

Differences in The Causes of Light And Extreme Precipitation For The Qaidam Basin In Summer

10.21203/rs.3.rs-951750/v1 ◽

2021 ◽

Author(s):

Yan Li ◽

Chunyan Lv ◽

Jun Chen ◽

Juan Feng ◽

Qingyi Yang

Keyword(s):

Heat Source ◽

South Asian ◽

Summer Monsoon ◽

Extreme Precipitation ◽

Moisture Transport ◽

Asian Summer Monsoon ◽

Asian Summer ◽

Abstract The Qaidam Basin (QB) locates over the northeast of the Tibetan Plateau (TP), where precipitation especially extreme precipitation possesses obvious local characteristics compared with that over the whole TP. This study tries to investigate cause of light (50% threshold) and extreme (95% threshold) precipitation in boreal summer in the QB, which is helpful to deepen understanding of the mechanism of precipitation formation in different regions of the TP. The extreme (light) precipitation thresholds in the eastern QB are greater than that in the western QB, with a value of 6~16mm (2mm) for most regions. There are two main moisture transport channels for light and extreme precipitation events. One is from the Eurasia and carried by the westerlies, which provides 48.2% and 55.8% of moisture for light and extreme precipitation events, respectively. The other moisture transport channel is from the Arabian Sea and the Bay of Bengal, which is transported toward the QB at the joint role of the South Asian summer monsoon and the plateau monsoon, contributing 51.8% and 44.2% of moisture for light and extreme precipitation events, respectively. The stronger moisture transport to precipitation mostly attributes to the enhanced moisture influxes from the western and southern boundaries. Additionally, the weaker moisture outflux across the eastern boundary is also responsible for the extreme precipitation. The circulation characteristics shows that, the precipitation in the QB has a closely relationship with the weak ridge over the Caspian Sea and Aral Sea, the enhanced South Asian summer monsoon and plateau monsoon, which are conducive to the moisture transport from the Eurasia and low-latitudes toward the QB. The meridional circulation enhances, meantime the westerly jet stream splits into east- and west-branch, and the south Asian high (SAH) strengthens, which are beneficial for the stronger convective motion. Especially, the trough in the northwest of the QB and the more significant east- and west-branch structure of westerly jet are the main circulation characteristics for the extreme precipitation events. Further analysis reveals that the apparent heat source over the QB is contributed to more synchronous moisture transport around the TP and its surrounding areas for light precipitation events, while the apparent heat source enhances 1 day prior to moisture transport from the east part region of the South Asian summer monsoon to around the eastern TP for extreme precipitation events. Meantime, the apparent heat source triggers an abnormal cyclone over the TP which can positively strength the local convective motion. Such abnormal configuration of atmospheric circulation and the influence of apparent heat source can explain the difference in cause of precipitation with different magnitude to a great extent in the QB.

The anatomy of extreme precipitation events over Srinagar, Kashmir, India, over the past 50 years

Arabian Journal of Geosciences ◽

10.1007/s12517-021-07820-x ◽

2021 ◽

Vol 14 (14) ◽

Author(s):

Junaid Dar ◽

Sakiba Nabi ◽

Abdul Qayoom Dar ◽

Manzoor Ahmad Ahanger

Keyword(s):

Extreme Precipitation ◽

The Past ◽

Changes in Intense Precipitation over the Central United States

Journal of Hydrometeorology ◽

10.1175/jhm-d-11-039.1 ◽

2012 ◽

Vol 13 (1) ◽

pp. 47-66 ◽

Cited By ~ 137

Author(s):

Pavel Ya. Groisman ◽

Richard W. Knight ◽

Thomas R. Karl

Keyword(s):

United States ◽

Extreme Precipitation ◽

Heavy Precipitation ◽

The Past ◽

Intense Precipitation ◽

Central United States ◽

Extreme Rain ◽

Rain Events ◽

Abstract In examining intense precipitation over the central United States, the authors consider only days with precipitation when the daily total is above 12.7 mm and focus only on these days and multiday events constructed from such consecutive precipitation days. Analyses show that over the central United States, a statistically significant redistribution in the spectra of intense precipitation days/events during the past decades has occurred. Moderately heavy precipitation events (within a 12.7–25.4 mm day−1 range) became less frequent compared to days and events with precipitation totals above 25.4 mm. During the past 31 yr (compared to the 1948–78 period), significant increases occurred in the frequency of “very heavy” (the daily rain events above 76.2 mm) and extreme precipitation events (defined as daily and multiday rain events with totals above 154.9 mm or 6 in.), with up to 40% increases in the frequency of days and multiday extreme rain events. Tropical cyclones associated with extreme precipitation do not significantly contribute to the changes reported in this study. With time, the internal precipitation structure (e.g., mean and maximum hourly precipitation rates within each preselected range of daily or multiday event totals) did not noticeably change. Several possible causes of observed changes in intense precipitation over the central United States are discussed and/or tested.

Spatiotemporal Variability in Extreme Precipitation in China from Observations and Projections

Water ◽

10.3390/w10081089 ◽

2018 ◽

Vol 10 (8) ◽

pp. 1089 ◽

Cited By ~ 9

Author(s):

Yifeng Peng ◽

Xiang Zhao ◽

Donghai Wu ◽

Bijian Tang ◽

Peipei Xu ◽

...

Keyword(s):

Global Warming ◽

Extreme Precipitation ◽

Spatiotemporal Variability ◽

Tibet Plateau ◽

Cmip5 Models ◽

Ecological Processes ◽

The Past ◽

Spatiotemporal Characteristics ◽

Extreme precipitation events, which have intensified with global warming over the past several decades, will become more intense in the future according to model projections. Although many studies have been performed, the occurrence patterns for extreme precipitation events in past and future periods in China remain unresolved. Additionally, few studies have explained how extreme precipitation events developed over the past 58 years and how they will evolve in the next 90 years as global warming becomes much more serious. In this paper, we evaluated the spatiotemporal characteristics of extreme precipitation events using indices for the frequency, quantity, intensity, and proportion of extreme precipitation, which were proposed by the World Meteorological Organization. We simultaneously analyzed the spatiotemporal characteristics of extreme precipitation in China from 2011 to 2100 using data obtained from the Coupled Model Intercomparison Project Phase 5 (CMIP5) models. Despite the fixed threshold, 95th percentile precipitation values were also used as the extreme precipitation threshold to reduce the influence of various rainfall events caused by different geographic locations; then, eight extreme precipitation indices (EPIs) were calculated to evaluate extreme precipitation in China. We found that the spatial characteristics of the eight EPIs exhibited downward trends from south to north. In the periods 1960–2017 and 2011–2100, trends in the EPIs were positive, but there were differences between different regions. In the past 58 years, the extreme precipitation increased in the northwest, southeast, and the Tibet Plateau of China, while decreased in northern China. Almost all the trends of EPIs are positive in the next two periods (2011–2055 and 2056–2100) except for some EPIs, such as intensity of extreme precipitation, which decrease in southeastern China in the second period (2056–2100). This study suggests that the frequency of extreme precipitation events in China will progressively increase, which implies that a substantial burden will be placed on social economies and terrestrial ecological processes.

EXTREME EVENTS OF PRECIPITATION AND OCCURRENCES OF FLOODING, RUNOFF AND INUNDATION IN THE METROPOLITAN REGION OF CURITIBA, BRAZIL

Geografia em Questão ◽

10.48075/geoq.v14i02.25902 ◽

2021 ◽

Vol 14 (2) ◽

Author(s):

Nathan Felipe da Silva Caldana ◽

Leonardo Rodrigues ◽

Luis Gustavo Batista Ferreira ◽

Marcelo Augusto De Aguiar e Silva

Keyword(s):

Extreme Events ◽

Rural Areas ◽

Extreme Precipitation ◽

Rainfall Variability ◽

Metropolitan Region ◽

Severe Damage ◽

Urban And Rural Areas ◽

Extreme precipitation events cause severe damage in both urban and rural areas. The objective of this work was to analyze rainfall variability, understand the dynamics of extreme precipitation events and to find out the occurrence of floods, runoff and inundation in the Metropolitan Region of Curitiba (MRC). Data from 39 rainfall stations distributed in the MRC area were used, as well as data by municipality of occurrence of flooding, runoff or inundation, from 1976 to 2018. Extreme precipitation events were identified in all months, most frequently in the summer. Totaling 48 decrees of emergency or public calamity and 397,516 people affected by one of the three socioenvironmental disasters.

Large-Scale Flow Patterns Associated with Extreme Precipitation and Atmospheric Rivers over Norway

Monthly Weather Review ◽

10.1175/mwr-d-18-0362.1 ◽

2019 ◽

Vol 147 (4) ◽

pp. 1415-1428 ◽

Cited By ~ 7

Author(s):

Imme Benedict ◽

Karianne Ødemark ◽

Thomas Nipen ◽

Richard Moore

Keyword(s):

Extreme Precipitation ◽

Large Scale ◽

Moisture Flux ◽

Cold Season ◽

Fuzzy Cluster ◽

The South ◽

Atmospheric Rivers ◽

The North ◽

Abstract A climatology of extreme cold season precipitation events in Norway from 1979 to 2014 is presented, based on the 99th percentile of the 24-h accumulated precipitation. Three regions, termed north, west, and south are identified, each exhibiting a unique seasonal distribution. There is a proclivity for events to occur during the positive phase of the NAO. The result is statistically significant at the 95th percentile for the north and west regions. An overarching hypothesis of this work is that anomalous moisture flux, or so-called atmospheric rivers (ARs), are integral to extreme precipitation events during the Norwegian cold season. An objective analysis of the integrated vapor transport illustrates that more than 85% of the events are associated with ARs. An empirical orthogonal function and fuzzy cluster technique is used to identify the large-scale weather patterns conducive to the moisture flux and extreme precipitation. Five days before the event and for each of the three regions, two patterns are found. The first represents an intense, southward-shifted jet with a southwest–northeast orientation. The second identifies a weak, northward-shifted, zonal jet. As the event approaches, regional differences become more apparent. The distinctive flow pattern conducive to orographically enhanced precipitation emerges in the two clusters for each region. For the north and west regions, this entails primarily zonal flow impinging upon the south–north-orientated topography, the difference being the latitude of the strong flow. In contrast, the south region exhibits a significant southerly component to the flow.

Spatial and Temporal Analysis of Precipitation Extremities of Eastern Nepal in the Last Two Decades (1997–2016)

10.5194/egusphere-egu2020-2784 ◽

2020 ◽

Author(s):

Sunil Subba ◽

Yaoming Ma ◽

Weiqiang Ma

Keyword(s):

Climate Change ◽

Extreme Events ◽

Extreme Precipitation ◽

Tropical Rainfall Measuring Mission ◽

Heavy Precipitation ◽

Temporal Analysis ◽

Slope Estimator ◽

The Impact ◽

In recent days there have been discussions regarding the impact of climate change and its vagaries of the weather, particularly concerning extreme events. Nepal, being a mountainous country, is more susceptible to precipitation extreme events and related hazards, which hinder the socioeconomic development of the nation. In this regard, this study aimed to address this phenomenon for one of the most naturally and socioeconomically important regions of Nepal, namely, Eastern Nepal. The data were collected for the period of 1997 to 2016. The interdecadal comparison for two periods (1997&#8211;2006 and 2007&#8211;2016) was maintained for the calculation of extreme precipitation indices as per recommended by Expert Team on Climate Change Detection and Indices. Linear trends were calculated by using Mann&#8208;Kendall and Sen's Slope estimator. The average annual precipitation was found to be decreasing at an alarming rate of &#8722;20 mm/year in the last two decades' tenure. In case of extreme precipitation events, consecutive dry days, one of the frequency indices, showed a solo increase in its trend (mostly significant). Meanwhile, all the intensity indices of extreme precipitation showed decreasing trends (mostly insignificant). Thus, it can be concluded that Eastern Nepal has witnessed some significant drier days in the last two decades, as the events of heavy, very heavy, extremely heavy precipitation events, and annual wet day precipitation (PRCPTOT) were found to be decreasing. The same phenomena were also seen in the Tropical Rainfall Measuring Mission 3B42 V7 satellite precipitation product for whole Nepal.

Observed changes in extreme wet and dry spells during the South Asian summer monsoon season

Nature Climate Change ◽

10.1038/nclimate2208 ◽

2014 ◽

Vol 4 (6) ◽

pp. 456-461 ◽

Cited By ~ 195

Author(s):

Deepti Singh ◽

Michael Tsiang ◽

Bala Rajaratnam ◽

Noah S. Diffenbaugh

Keyword(s):

South Asian ◽

Summer Monsoon ◽

Asian Summer Monsoon ◽

Monsoon Season ◽

Summer Monsoon Season ◽

The South ◽

Dry Spells ◽

Asian Summer

Interannual to centennial variability of the South Asian summer monsoon over the past millennium

Climate Dynamics ◽

10.1007/s00382-016-3493-9 ◽

2016 ◽

Vol 49 (7-8) ◽

pp. 2803-2814 ◽

Cited By ~ 9

Author(s):

Feng Shi ◽

Keyan Fang ◽

Chenxi Xu ◽

Zhengtang Guo ◽

H. P. Borgaonkar

Keyword(s):

South Asian ◽

Summer Monsoon ◽

Asian Summer Monsoon ◽

The South ◽

The Past ◽

Asian Summer ◽

Past Millennium

A Comparison of CMIP3 Simulations of Precipitation over North America with Observations: Daily Statistics and Circulation Features Accompanying Extreme Events

Journal of Climate ◽

10.1175/jcli-d-12-00374.1 ◽

2013 ◽

Vol 26 (10) ◽

pp. 3209-3230 ◽

Cited By ~ 26

Author(s):

Anthony M. DeAngelis ◽

Anthony J. Broccoli ◽

Steven G. Decker

Keyword(s):

North America ◽

Extreme Events ◽

Extreme Precipitation ◽

Large Scale ◽

Climate Model ◽

Heavy Precipitation ◽

Convective Precipitation ◽

Southern Mexico ◽

Abstract Climate model simulations of daily precipitation statistics from the third phase of the Coupled Model Intercomparison Project (CMIP3) were evaluated against precipitation observations from North America over the period 1979–99. The evaluation revealed that the models underestimate the intensity of heavy and extreme precipitation along the Pacific coast, southeastern United States, and southern Mexico, and these biases are robust among the models. The models also overestimate the intensity of light precipitation events over much of North America, resulting in fairly realistic mean precipitation in many places. In contrast, heavy precipitation is simulated realistically over northern and eastern Canada, as is the seasonal cycle of heavy precipitation over a majority of North America. An evaluation of the simulated atmospheric dynamics and thermodynamics associated with extreme precipitation events was also conducted using the North American Regional Reanalysis (NARR). The models were found to capture the large-scale physical mechanisms that generate extreme precipitation realistically, although they tend to overestimate the strength of the associated atmospheric circulation features. This suggests that climate model deficiencies such as insufficient spatial resolution, inadequate representation of convective precipitation, and overly smoothed topography may be more important for biases in simulated heavy precipitation than errors in the large-scale circulation during extreme events.