Recent Changes in Mean and Extreme Temperature and Precipitation in the Western Pacific Islands

Abstract Trends in mean and extreme annual and seasonal temperature and precipitation over the 1951–2015 period were calculated for 57 stations in 20 western Pacific Ocean island countries and territories. The extremes indices are those of the World Meteorological Organization Expert Team on Sector-Specific Climate Indices. The purpose of the expert team and indices is to promote the use of globally consistent climate indices to highlight variability and trends in climate extremes that are of particular interest to socioeconomic sectors and to help to characterize the climate sensitivity of various sectors. Prior to the calculation of the monthly means and indices, the data underwent quality control and homogeneity assessment. A rise in mean temperature occurred at most stations, in all seasons, and in both halves of the study period. The temperature indices also showed strong warming, which for the majority was strongest in December–February and weakest in June–August. The absolute and percentile-based indices show the greatest warming at the upper end of the distribution. While changes in precipitation were less consistent and trends were generally weak at most locations, declines in both total and extreme precipitation were found in southwestern French Polynesia and the southern subtropics. There was a decrease in moderate- to high-intensity precipitation events, especially those experienced over multiple days, in southwestern French Polynesia from December to February. Strong drying trends have also been identified in the low- to moderate-extreme indices in the June–August and September–November periods. These negative trends contributed to an increase in the magnitude of meteorological drought in both subregions.

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Indices for daily temperature and precipitation based on quality controlled and homogenized data in Madagascar

10.5194/egusphere-egu2020-19970 ◽

2020 ◽

Author(s):

Luc Yannick Andréas Randriamarolaza ◽

Enric Aguilar ◽

Oleg Skrynyk

Keyword(s):

Climate Change ◽

Missing Data ◽

Extreme Temperature ◽

Maximum Temperature ◽

Daily Minimum Temperature ◽

Daily Maximum Temperature ◽

Climate Indices ◽

Low Density ◽

Climate Data ◽

Temperature And Precipitation

Madagascar is an Island in Western Indian Ocean Region. It is mainly exposed to the easterly trade winds and has a rugged topography, which promote different local climates and biodiversity. Climate change inflicts a challenge on Madagascar socio-economic activities. However, Madagascar has low density station and sparse networks on observational weather stations to detect changes in climate. On average, one station covers more than 20 000 km2 and closer neighbor stations are less correlated. Previous studies have demonstrated the changes on Madagascar climate, but this paper contributes and enhances the approach to assess the quality control and homogeneity of Madagascar daily climate data before developing climate indices over 1950 &#8211; 2018 on 28 synoptic stations. Daily climate data of minimum and maximum temperature and precipitation are exploited.Firstly, the quality of daily climate data is controlled by INQC developed and maintained by Center for Climate Change (C3) of Rovira i Virgili University, Spain. It ascertains and improves error detections by using six flag categories. Most errors detected are due to digitalization and measurement.Secondly, daily quality controlled data are homogenized by using CLIMATOL. It uses relative homogenization methods, chooses candidate reference series automatically and infills the missing data in the original data. It has ability to manage low density stations and low inter-station correlations and is tolerable for missing data. Monthly break points are detected by CLIMATOL and used to split daily climate data to be homogenized.Finally, climate indices are calculated by using CLIMIND package which is developed by INDECIS* project. Compared to previous works done, data period is updated to 10 years before and after and 15 new climate indices mostly related to extremes are computed. On temperature, significant increasing and decreasing decade trends of day-to-day and extreme temperature ranges are important in western and eastern areas respectively. On average decade trends of temperature extremes, significant increasing of daily minimum temperature is greater than daily maximum temperature. Many stations indicate significant decreasing in very cold nights than significant increasing in very warm days. Their trends are almost 1 day per decade over 1950 &#8211; 2018. Warming is mainly felt during nighttime and daytime in Oriental and Occidental parts respectively. In contrast, central uplands are warming all the time but tropical nights do not appear yet. On rainfall, no major significant findings are found but intense precipitation might be possible at central uplands due to shortening of longest wet period and occurrence of heavy precipitation. However, no influence detected on total precipitation which is still decreasing over 1950 - 2018. Future works focus on merging of relative homogenization methodologies to ameliorate the results.-------------------*INDECIS is a part of ERA4CS, an ERA-NET initiated by JPI Climate, and funded by FORMAS (SE), DLR (DE), BMWFW (AT), IFD (DK), MINECO (ES), ANR (FR) with co-funding by the European Union (Grant 690462).

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Decoupling of seasonal temperature and precipitation over the western Pacific during the early mid-Holocene

International Journal of Climatology ◽

10.1002/joc.4009 ◽

2014 ◽

Vol 35 (5) ◽

pp. 794-800 ◽

Cited By ~ 4

Author(s):

Wenfeng Deng ◽

Gangjian Wei

Keyword(s):

Western Pacific ◽

Seasonal Temperature ◽

Temperature And Precipitation ◽

The Western Pacific

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Unpacking future climate extremes and their sectoral implications in western Nepal

Climatic Change ◽

10.1007/s10584-021-03216-8 ◽

2021 ◽

Vol 168 (1-2) ◽

Author(s):

Dipesh Chapagain ◽

Sanita Dhaubanjar ◽

Luna Bharati

Keyword(s):

Climate Models ◽

Regional Climate ◽

Extreme Temperature ◽

Climate Extremes ◽

Climate Indices ◽

Climate Projections ◽

Temperature And Precipitation ◽

Extreme Precipitation Events ◽

The Impact ◽

Precipitation Events

AbstractExisting climate projections and impact assessments in Nepal only consider a limited number of generic climate indices such as means. Few studies have explored climate extremes and their sectoral implications. This study evaluates future scenarios of extreme climate indices from the list of the Expert Team on Sector-specific Climate Indices (ET-SCI) and their sectoral implications in the Karnali Basin in western Nepal. First, future projections of 26 climate indices relevant to six climate-sensitive sectors in Karnali are made for the near (2021–2045), mid (2046–2070), and far (2071–2095) future for low- and high-emission scenarios (RCP4.5 and RCP8.5, respectively) using bias-corrected ensembles of 19 regional climate models from the COordinated Regional Downscaling EXperiment for South Asia (CORDEX-SA). Second, a qualitative analysis based on expert interviews and a literature review on the impact of the projected climate extremes on the climate-sensitive sectors is undertaken. Both the temperature and precipitation patterns are projected to deviate significantly from the historical reference already from the near future with increased occurrences of extreme events. Winter in the highlands is expected to become warmer and dryer. The hot and wet tropical summer in the lowlands will become hotter with longer warm spells and fewer cold days. Low-intensity precipitation events will decline, but the magnitude and frequency of extreme precipitation events will increase. The compounding effects of the increase in extreme temperature and precipitation events will have largely negative implications for the six climate-sensitive sectors considered here.

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Temporal trends in extreme temperature and precipitation events in an arid area: case of Chichaoua Mejjate region (Morocco)

Journal of Water and Climate Change ◽

10.2166/wcc.2020.234 ◽

2020 ◽

Author(s):

Abdessamad Hadri ◽

Mohamed El Mehdi Saidi ◽

Tarik Saouabe ◽

Abdelhafid El Alaoui El Fels

Keyword(s):

Interpolation Method ◽

Temporal Trends ◽

Extreme Temperature ◽

Kendall Test ◽

Future Climate Change ◽

Climate Indices ◽

Mountainous Area ◽

Weighted Interpolation ◽

Extreme Climate ◽

Temperature And Precipitation

Abstract Extreme climate events often have a significant and direct impact on social, economic, and environmental systems. This study is an attempt to characterize the current trends and future projections of extreme climatic indices in an arid region of Morocco on both an annual and a seasonal scale using 12 precipitation and temperature-based indices. The Mann–Kendall test was used to assess the trends, and the inverse distance weighted interpolation method was employed to analyze the spatial distribution of extreme precipitation indices. The results showed that the most extreme climate indices are spatially distributed with a clear gradient from the mountainous area toward the plains. Furthermore, the analysis indicates nonsignificant downward trends in the number of days with a rainfall amount greater than 10 or 20 mm. However, a significant negative trend in the consecutive dry days was observed at the Iloujdane and Sidi Bouathmane stations. The temperature indices have recorded statistically significant upward trends at all the stations. Finally, based on the RCP4.5 and RCP8.5 scenarios, future climate change simulations show, respectively, annual precipitation decreases of 23 and 34% and temperature increases of 1.9 and 2.8 °C, which could imply substantial losses of cereal yield in the rainfed agriculture.

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Evaluating the impact of climate change on extreme temperature and precipitation events over the Kashmir Himalaya

Climate Dynamics ◽

10.1007/s00382-021-05984-6 ◽

2021 ◽

Author(s):

Shafkat Ahsan ◽

M. Sultan Bhat ◽

Akhtar Alam ◽

Hakim Farooq ◽

Hilal Ahmad Shiekh

Keyword(s):

Climate Change ◽

Extreme Temperature ◽

Climate Indices ◽

General Tendency ◽

Kashmir Himalaya ◽

Impact Of Climate Change ◽

Extreme Climate ◽

Temperature And Precipitation ◽

The Future ◽

The Impact

AbstractThe frequency and severity of climatic extremes is expected to escalate in the future primarily because of the increasing greenhouse gas concentrations in the atmosphere. This study aims to assess the impact of climate change on the extreme temperature and precipitation scenarios using climate indices in the Kashmir Himalaya. The analysis has been carried out for the twenty-first century under different representative concentration pathways (RCPs) through the Statistical Downscaling Model (SDSM) and ClimPACT2. The simulation reveals that the climate in the region will get progressively warmer in the future by increments of 0.36–1.48 °C and 0.65–1.07 °C in mean maximum and minimum temperatures respectively, during 2080s (2071–2100) relative to 1980–2010 under RCP8.5. The annual precipitation is likely to decrease by a maximum of 2.09–6.61% (2080s) under RCP8.5. The seasonal distribution of precipitation is expected to alter significantly with winter, spring, and summer seasons marking reductions of 9%, 5.7%, and 1.7%, respectively during 2080s under RCP8.5. The results of extreme climate evaluation show significant increasing trends for warm temperature-based indices and decreasing trends for cold temperature-based indices. Precipitation indices on the other hand show weaker and spatially incoherent trends with a general tendency towards dry regimes. The projected scenarios of extreme climate indices may result in large-scale adverse impacts on the environment and ecological resource base of the Kashmir Himalaya.

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Unpacking Future Climate Extremes and their Sectoral Implications in Western Nepal

10.21203/rs.3.rs-454177/v1 ◽

2021 ◽

Author(s):

Dipesh Chapagain ◽

Sanita Dhaubanjar ◽

Luna Bharati

Keyword(s):

Climate Models ◽

Regional Climate ◽

Extreme Temperature ◽

Climate Extremes ◽

Climate Indices ◽

Climate Projections ◽

Temperature And Precipitation ◽

Extreme Precipitation Events ◽

The Impact ◽

Precipitation Events

Abstract Existing climate projections and impact assessments in Nepal only consider a limited number of generic climate indices such as means. Few studies have explored climate extremes and their sectoral implications. This study evaluates future scenarios of extreme climate indices from the list of Expert Team on Sector-specific Climate Indices (ET-SCI) and their sectoral implications in the Karnali Basin in western Nepal. First, future projections of 26 climate indices relevant to six climate-sensitive sectors in Karnali were made for the near (2021–2045), mid (2046–2070), and far (2071–2095) future for low- and high-emission scenarios (RCP4.5 and RCP8.5, respectively) using bias-corrected ensembles of 19 regional climate models from the COordinated Regional Downscaling EXperiment for South Asia (CORDEX-SA). Second, a qualitative analysis based on expert interviews and a literature review on the impact of the projected climate extremes on the climate-sensitive sectors was undertaken. Both the temperature and precipitation patterns are projected to deviate significantly from the historical reference already from the near future with increased occurrences of extreme events. Winter in the highlands is expected to become warmer and dryer. The hot and wet tropical summer in the lowlands will become hotter with longer warm spells and fewer cold days. Low-intensity precipitation events will decline, but the magnitude and frequency of extreme precipitation events will increase. The compounding effects of the increase in extreme temperature and precipitation events will have largely negative implications for the six climate-sensitive sectors considered here.

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Comparative Analysis between Daily Extreme Temperature and Precipitation Values Derived from Observations and Gridded Datasets in North-Western Romania

Atmosphere ◽

10.3390/atmos12030361 ◽

2021 ◽

Vol 12 (3) ◽

pp. 361

Author(s):

Mugurel Raul Sidău ◽

Adina-Eliza Croitoru ◽

Diana-Elena Alexandru

Keyword(s):

Extreme Temperature ◽

Observation Data ◽

Seasonal Temperature ◽

Climate Trend ◽

Climate Assessment ◽

Temperature And Precipitation ◽

European Climate ◽

Spatial Level ◽

North Western ◽

Western Romania

Climate gridded datasets are highly needed and useful in conducting data analysis for research and practical purposes. They provide long-term information on various climatic variables for large areas worldwide, making them suitable for use at any spatial level. It is essential to assess the accuracy of gridded data by comparing the data to measured values, especially when they are used as input parameters for hydro-climatic models. From the multitude of databases available for North-western Romania, we selected three, particularly the European Climate Assessment and Dataset (E-OBS), the Romanian Climatic Dataset (ROCADA), and the Climate of the Carpathian Region (CARPATCLIM). In this paper, we analyse the extreme precipitation and temperature data derived from the above-mentioned datasets over a common 50-year period (1961–2010) and compare the data with raw values to estimate the degree of uncertainty for each set of data. The observation data, recorded at two meteorological stations located in a complex topography region, were compared to the output of the gridded datasets, by using descriptive statistics for the mean and extreme annual and seasonal temperature and precipitation data, and trend analyses. The main findings are: the high suitability of the ROCADA gridded database for climate trend analysis and of the E-OBS gridded database for extreme temperature and precipitation analysis.

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