Satellites reveal the strongest increase in duration of extreme dry periods in global monsoon regions

2020 ◽  
Author(s):  
Irina Y. Petrova ◽  
Diego G. Miralles ◽  
Hendrik Wouters
Keyword(s):  
Tropical Rainfall Measuring Mission ◽  
Annual Number ◽  
Drought Indices ◽  
Monsoon Circulation ◽  
Precipitation Data ◽  
Global Monsoon ◽  
Global Trends ◽  
Dry Spells ◽  
Hourly Data ◽  
The Future

<p align="justify">Drought is <span>arguably the climate phenomenon that most strongly impacts societies worldwide,</span> causing severe socioeconomic and ecologic damage. While models unanimously project an overall increase in aridity and drought occurrence in the future, observational evidence has so far been inconclusive. The discrepancies between the various drought definitions and drought indices has been a major factor contributing to our <span>low confidence in observed dryness trends. In this study we investigate global trends in meteorological dry spells using a simple, unambiguous and intuitive diagnostic: the maximum annual number of consecutive dry days (CDDs). In contrast to popular drought indices, the number of CDDs is a direct measure of the duration of rainfall scarcity, easy to quantify based on rain data, free of parametrizations, and independent from other proxies. </span></p><p align="justify"><span>Because the time-span of available satellite-based precipitation data records is constantly increasing, current products are becoming an alternative to </span><span><em>in situ</em></span><span> rain gauges </span><span>for</span><span> study</span><span>ing</span><span> long-term trends. In particular, the Tropical Rainfall Measuring Mission (TRMM) has now been operational for over twenty years, thus offering a unique opportunity to analyse temporally-coherent, single-platform precipitation data. Here, we use TRMM3B42 3-hourly data for 1998–2018 to calculate and analyse changes in the maximum annual number of CDDs worldwide. The robustness of the identified relationships among observational products is tested using recently-compiled gauge and satellite precipitation data from the </span><span>Frequent Rainfall Observations on GridS (</span><span>FROGS</span><span>)</span><span> database. </span></p><p align="justify">The r<span>esults reveal that almost 70% of the continental land monitored by TRMM has experienced an increase in duration of the longest annual dry period over the past 20 years, and in 20% of these regions trends </span><span>are found to be </span><span>significant (</span><span><em>p</em></span><span> < 0.01). Agreement among various observational products is regionally dependent. However, most of the data sets suggest that the signal largely originates, not from arid regions (which would support the dry–gets–drier paradigm), but from monsoon areas. Further analysis shows that the same areas experience clear increasing (decreasing) trends in rain seasonality (amount), suggesting a link to the monsoon circulation dynamics. A preliminary analysis confirms this connection and additionally points to the potentially important role of land feedbacks, revealing a tendency for later moisture build up and, hence, a monsoon onset after more prolonged dry seasons. Altogether, our findings emphasize the vulnerability of global monsoon regions to </span><span>climate</span><span> change. An increasing length of dry spells as we progress into the future might lead to devastating </span><span>socioeconomic and ecologic consequences in these regions.</span></p><p align="justify"> </p>

scholarly journals Understanding Future Change of Global Monsoons Projected by CMIP6 Models

2020 ◽  
Vol 33 (15) ◽  
pp. 6471-6489 ◽  
Author(s):  
Bin Wang ◽  
Chunhan Jin ◽  
Jian Liu
Keyword(s):  
North American ◽  
Rainy Season ◽  
Monsoon Rainfall ◽  
North American Monsoon ◽  
Convective Heating ◽  
Monsoon Circulation ◽  
Future Change ◽  
Global Monsoon ◽  
African Monsoon ◽  
The Future

AbstractProjecting future change of monsoon rainfall is essential for water resource management, food security, disaster mitigation, and infrastructure planning. Here we assess the future change and explore the causes of the changes using 15 models that participated in phase 6 of the Coupled Model Intercomparison Project (CMIP6). The multimodel ensemble projects that, under the shared socioeconomic pathway (SSP) 2–4.5, the total land monsoon rainfall will likely increase in the Northern Hemisphere (NH) by about 2.8% per one degree Celsius of global warming (2.8% °C−1) in contrast to little change in the Southern Hemisphere (SH; −0.3% °C−1). In addition, in the future the Asian–northern African monsoon likely becomes wetter while the North American monsoon becomes drier. Since the humidity increase is nearly uniform in all summer monsoon regions, the dynamic processes must play a fundamental role in shaping the spatial patterns of the global monsoon changes. Greenhouse gas (GHG) radiative forcing induces a “NH-warmer-than-SH” pattern, which favors increasing the NH monsoon rainfall and prolonging the NH monsoon rainy season while reducing the SH monsoon rainfall and shortening the SH monsoon rainy season. The GHG forcing induces a “land-warmer-than-ocean” pattern, which enhances Asian monsoon low pressure and increases Asian and northern African monsoon rainfall, and an El Niño–like warming, which reduces North American monsoon rainfall. The uncertainties in the projected monsoon precipitation changes are significantly related to the models’ projected hemispheric and land–ocean thermal contrasts as well as to the eastern Pacific Ocean warming. The CMIP6 models’ common biases and the processes by which convective heating drives monsoon circulation are also discussed.

A corpus-based investigation of techno-optimism and propositional certainty in the National Intelligence Council’s ‘Future Global Trends Reports’ (2010–2035)

2017 ◽  
Vol 12 (1) ◽  
pp. 39-57
Author(s):  
Jamie McKeown
Keyword(s):  
Global Trends ◽  
Future Role ◽  
Ideological Bias ◽  
The Past ◽  
The Us ◽  
The Future ◽  
The Subject ◽  
Global Peace ◽  
Discursive Representations

This article reports the findings from a study of discursive representations of the future role of technology in the work of the US National Intelligence Council (NIC). Specifically, it investigates the interplay of ‘techno-optimism’ (a form of ideological bias) and propositional certainty in the NIC’s ‘Future Global Trends Reports’. In doing so, it answers the following questions: To what extent was techno-optimism present in the discourse? What level of propositional certainty was expressed in the discourse? How did the discourse deal with the inherent uncertainty of the future? Overall, the discourse was pronouncedly techno-optimist in its stance towards the future role of technology: high-technological solutions were portrayed as solving a host of problems, despite the readily available presence of low-technology or no-technology solutions. In all, 75.1% of the representations were presented as future categorical certainties, meaning the future was predominantly presented as a known and closed inevitability. The discourse dealt with the inherent uncertainty of the subject matter, that is, the future, by projecting the past and present into the future. This was particularly the case in relation to the idea of technological military dominance as a guarantee of global peace, and the role of technology as an inevitable force free from societal censorship.

Book Review: The Future of Evaluation: Global Trends, New Challenges, Shared Perspectives

2017 ◽  
Vol 38 (3) ◽  
pp. 453-458
Author(s):  
Charmagne E. Campbell-Patton ◽  
Michael Quinn Patton
Keyword(s):  
Global Trends ◽  
The Future ◽  
New Challenges

Enhancing Global Competency of Future Construction Professionals

2017 ◽  
pp. 272-287 ◽  
Author(s):  
Begum Sertyesilisik
Keyword(s):  
Construction Industry ◽  
Global Market ◽  
Labour Markets ◽  
Employment Rate ◽  
Multicultural Teams ◽  
Global Competency ◽  
Global Trends ◽  
Global Citizens ◽  
The Future ◽  
Globalized World

A globalized world requires future professionals to be global citizens; to perceive their market as a global market. Globalization challenges future professionals due to its potential impacts on the labour profile. Labour markets' skills and talents as well as their adaptation to the global trends can contribute to the sustainability of the labour market and to the competitiveness of the companies globally. This chapter focuses on the future construction professionals' global competency as the construction industry is labour intensive and site based. Site based nature of the construction industry requires construction professionals to work in different countries within multidisciplinary and multicultural teams. This chapter covers the following topics: construction industry's contribution to the economy and employment rate of the countries; globalization in the construction industry; globalization as a challenge for future construction professionals; impacts of the globalization on the future construction professionals' profile; education of future construction professionals.

scholarly journals Application of TRMM Precipitation Data to Evaluate Drought and Its Effects on Water Resources Instability

2019 ◽  
Vol 9 (24) ◽  
pp. 5377
Author(s):  
Ata Amini ◽  
Abdolnabi Abdeh Kolahchi ◽  
Nadhir Al-Ansari ◽  
Mehdi Karami Moghadam ◽  
Thamer Mohammad
Keyword(s):  
Water Resources ◽  
Standardized Precipitation Index ◽  
Remote Sensing Data ◽  
Tropical Rainfall Measuring Mission ◽  
Monthly Precipitation ◽  
Precipitation Data ◽  
Discharge Data ◽  
Satellite Precipitation ◽  
Discharge Rates ◽  
Trmm Precipitation

The present research was carried out to study drought and its effects upon water resources using remote sensing data. To this end, the tropical rainfall measuring mission (TRMM) satellite precipitation, the synoptic stations, and fountain discharge data were employed. For monitoring of drought in the study area, in Kermanshah province, Iran, the monthly precipitation data of the synoptic stations along with TRMM satellite precipitation datasets were collected and processed in the geographic information system (GIS) environment. Statistical indicators were applied to evaluate the accuracy of TRMM precipitation against the meteorological stations’ data. Standardized precipitation index, SPI, and normalized fountain discharge were used in the monitoring of drought conditions, and fountains discharge, respectively. The fountains were selected so that in addition to enjoying the most discharge rates, they spread along the study area. The evaluation of precipitation data showed that the TRMM precipitation data were of high accuracy. Studies in temporal scale are indicative of the strike of drought in this region to the effect that for most months of the year, frequency and duration in dry periods are much more than in wet periods. As for seasonal scales, apart from winter, the frequency and duration of drought in spring and autumn have been longer than in wet years. Moreover, the duration of these periods was different. A comparison between the results of changes in fountain discharges and drought index in the region has verified that the drought has caused a remarkable decline in the fountain discharges.

Minimum Inter-Event Times for Rainfall in the Eastern Monsoon Region of China

2019 ◽  
Vol 62 (1) ◽  
pp. 9-18
Author(s):  
Wenting Wang ◽  
Wenting Wang ◽  
Shuiqing Yin ◽  
Yun Xie ◽  
Mark A. Nearing ◽  
...  
Keyword(s):  
Daily Rainfall ◽  
Precipitation Data ◽  
Monsoon Region ◽  
Average Value ◽  
Event Time ◽  
Hourly Data ◽  
Average Precipitation ◽  
Average Rainfall ◽  
Exponential Method ◽  
Event Times

Abstract.Minimum inter-event time (MIT) is an index used to delineate independent storms from sub-daily rainfall records. An individual storm is defined as a period of rainfall with preceding and succeeding dry periods less than MIT. The exponential method was used to determine an appropriate MITexp for the eastern monsoon region of China based on observed 1-min resolution rainfall data from 18 stations. Results showed that dry periods between storms greater than MITexp followed an exponential distribution. MITexp values varied from 7.6 h to 16.6 h using 1-min precipitation data, which were statistically not different from values using hourly data at p = 0.05. At least ten years of records were necessary to obtain a stable MIT. Values of storm properties are sensitive to the change in MIT values, especially when MIT values are small. Average precipitation depths across all stations were 45% greater, durations were 84% longer, maximum 30-min intensities were 27% greater, and average rainfall intensities were 20% less when using an MIT of 10 h, the average value of MITexp over 18 stations, compared to 2 h. This indicates that more attention should be paid to the use of the MIT index as it relates to storm properties. Keywords: China, Exponential method, Minimum inter-event time, Storm, Storm property.

scholarly journals Precipitation Trends over the Indus Basin

Climate ◽  
2019 ◽  
Vol 7 (10) ◽  
pp. 116 ◽  
Author(s):  
Nir Y. Krakauer ◽  
Tarendra Lakhankar ◽  
Ghulam H. Dars
Keyword(s):  
Remote Sensing ◽  
Large Population ◽  
Tropical Rainfall Measuring Mission ◽  
Indus Basin ◽  
Data Sets ◽  
Precipitation Trend ◽  
Precipitation Data ◽  
Data Set ◽  
Station Data ◽  
Precipitation Trends

A large population relies on water input to the Indus basin, yet basinwide precipitation amounts and trends are not well quantified. Gridded precipitation data sets covering different time periods and based on either station observations, satellite remote sensing, or reanalysis were compared with available station observations and analyzed for basinwide precipitation trends. Compared to observations, some data sets tended to greatly underestimate precipitation, while others overestimate it. Additionally, the discrepancies between data set and station precipitation showed significant time trends in such cases, suggesting that the precipitation trends of those data sets were not consistent with station data. Among the data sets considered, the station-based Global Precipitation Climatology Centre (GPCC) gridded data set showed good agreement with observations in terms of mean amount, trend, and spatial and temporal pattern. GPCC had average precipitation of about 500 mm per year over the basin and an increase in mean precipitation of about 15% between 1891 and 2016. For the more recent past, since 1958 or 1979, no significant precipitation trend was seen. Among the remote sensing based data sets, the Tropical Rainfall Measuring Mission Multi-Satellite Precipitation Analysis (TMPA) compared best to station observations and, though available for a shorter time period than station-based data sets such as GPCC, may be especially valuable for parts of the basin without station data. The reanalyses tended to have substantial biases in precipitation mean amount or trend relative to the station data. This assessment of precipitation data set quality and precipitation trends over the Indus basin may be helpful for water planning and management.

scholarly journals The potential value of seasonal forecasts in a changing climate in southern Africa

2014 ◽  
Vol 18 (4) ◽  
pp. 1525-1538 ◽  
Author(s):  
H. C. Winsemius ◽  
E. Dutra ◽  
F. A. Engelbrecht ◽  
E. Archer Van Garderen ◽  
F. Wetterhall ◽  
...  
Keyword(s):  
Climate Change ◽  
Heat Stress ◽  
Southern Africa ◽  
Weather Conditions ◽  
Stress Conditions ◽  
Mitigation Measures ◽  
Seasonal Forecasts ◽  
Weather Forecasts ◽  
Dry Spells ◽  
The Future

Abstract. Subsistence farming in southern Africa is vulnerable to extreme weather conditions. The yield of rain-fed agriculture depends largely on rainfall-related factors such as total seasonal rainfall, anomalous onsets and lengths of the rainy season and the frequency of occurrence of dry spells. Livestock, in turn, may be seriously impacted by climatic stress with, for example, exceptionally hot days, affecting condition, reproduction, vulnerability to pests and pathogens and, ultimately, morbidity and mortality. Climate change may affect the frequency and severity of extreme weather conditions, impacting on the success of subsistence farming. A potentially interesting adaptation measure comprises the timely forecasting and warning of such extreme events, combined with mitigation measures that allow farmers to prepare for the event occurring. This paper investigates how the frequency of extreme events may change in the future due to climate change over southern Africa and, in more detail, the Limpopo Basin using a set of climate change projections from several regional climate model downscalings based on an extreme climate scenario. Furthermore, the paper assesses the predictability of these indicators by seasonal meteorological forecasts of the European Centre for Medium-Range Weather Forecasts (ECMWF) seasonal forecasting system. The focus is on the frequency of dry spells as well as the frequency of heat stress conditions expressed in the temperature heat index. In areas where their frequency of occurrence increases in the future and predictability is found, seasonal forecasts will gain importance in the future, as they can more often lead to informed decision-making to implement mitigation measures. The multi-model climate projections suggest that the frequency of dry spells is not likely to increase substantially, whereas there is a clear and coherent signal among the models of an increase in the frequency of heat stress conditions by the end of the century. The skill analysis of the seasonal forecast system demonstrates that there is a potential to adapt to this change by utilizing the weather forecasts, given that both indicators can be skilfully predicted for the December–February season, at least 2 months ahead of the wet season. This is particularly the case for predicting above-normal and below-normal conditions. The frequency of heat stress conditions shows better predictability than the frequency of dry spells. Although results are promising for end users on the ground, forecasts alone are insufficient to ensure appropriate response. Sufficient support for appropriate measures must be in place, and forecasts must be communicated in a context-specific, accessible and understandable format.

Sign in / Sign up

Export Citation Format

Share Document