scholarly journals Trends in Ship-Reported Oceanic Precipitation Frequency from 1958 through 2014

2020 ◽  
Author(s):  
Grant Petty
Author(s):  
Geoffrey M. Bonnin ◽  
Sanja Perica ◽  
Deborah Martin ◽  
Bingzhang Lin ◽  
Tye Parzybok ◽  
...  

Author(s):  
Milan Gocic ◽  
Lazar Velimirovic ◽  
Miomir Stankovic ◽  
Slavisa Trajkovic

2021 ◽  
Author(s):  
Alessandro Dosio ◽  
Martin W. Jury ◽  
Mansour Almazroui ◽  
Moetasim Ashfaq ◽  
Ismaila Diallo ◽  
...  

AbstractWe provide an assessment of future daily characteristics of African precipitation by explicitly comparing the results of large ensembles of global (CMIP5, CMIP6) and regional (CORDEX, CORE) climate models, specifically highlighting the similarities and inconsistencies between them. Results for seasonal mean precipitation are not always consistent amongst ensembles: in particular, global models tend to project a wetter future compared to regional models, especially over the Eastern Sahel, Central and East Africa. However, results for other precipitation characteristics are more consistent. In general, all ensembles project an increase in maximum precipitation intensity during the wet season over all regions and emission scenarios (except the West Sahel for CORE) and a decrease in precipitation frequency (under the Representative Concentration Pathways RCP8.5) especially over the West Sahel, the Atlas region, southern central Africa, East Africa and southern Africa. Depending on the season, the length of dry spells is projected to increase consistently by all ensembles and for most (if not all) models over southern Africa, the Ethiopian highlands and the Atlas region. Discrepancies exist between global and regional models on the projected change in precipitation characteristics over specific regions and seasons. For instance, over the Eastern Sahel in July–August most global models show an increase in precipitation frequency but regional models project a robust decrease. Global and regional models also project an opposite sign in the change of the length of dry spells. CORE results show a marked drying over the regions affected by the West Africa monsoon throughout the year, accompanied by a decrease in mean precipitation intensity between May and July that is not present in the other ensembles. This enhanced drying may be related to specific physical mechanisms that are better resolved by the higher resolution models and highlights the importance of a process-based evaluation of the mechanisms controlling precipitation over the region.


2017 ◽  
Author(s):  
Chunlüe Zhou ◽  
Yanyi He ◽  
Kaicun Wang

Abstract. Reanalyses have been widely used because they add value to the routine observations by generating physically/dynamically consistent and spatiotemporally complete atmospheric fields. Existing studies have extensively discussed their temporal suitability in global change study. This study moves forward on their suitability for regional climate change study where land–atmosphere interactions play a more important role. Here, surface air temperature (Ta) from 12 current reanalysis products were investigated, focusing on spatial patterns of Ta trends, using homogenized Ta from 1979 to 2010 at ~ 2200 meteorological stations in China. Results show that ~ 80 % of the Ta mean differences between reanalyses and in-situ observations are attributed to station and model-grid elevation differences, denoting good skill in Ta climatology and rebutting the previously reported Ta biases. However, the Ta trend biases in reanalyses display spatial divergence (standard deviation = 0.15–0.30 °C/decade at 1° × 1° grids). The simulated Ta trend biases correlate well with those of precipitation frequency, surface incident solar radiation (Rs), and atmospheric downward longwave radiation (Ld) among the reanalyses (r = −0.83, 0.80 and 0.77, p 


2008 ◽  
Vol 21 (22) ◽  
pp. 5807-5819 ◽  
Author(s):  
Hengchun Ye

Abstract Potential benefits or disadvantages of increasing precipitation in high-latitude regions under a warming climate are dependent on how and in what form the precipitation occurs. Precipitation frequency and type are equally as important as quantity and intensity to understanding the seasonality of hydrological cycles and the health of the ecosystem in high-latitude regions. This study uses daily historical synoptic observation records during 1936–90 over the former USSR to reveal associations between the frequency of precipitation types (rainfall, snowfall, mixed solid and liquid, and wet days of all types) and surface air temperatures to determine potential changes in precipitation characteristics under a warming climate. Results from this particular study show that the frequency of precipitation of all types generally increases with air temperature during winter. However, both solid and liquid precipitation days predominantly decrease with air temperature during spring with a reduction in snowfall days being most significant. During autumn, snowfall days decrease while rainfall days increase resulting in overall decreases in wet days as air temperature increases. The data also reveal that, as snowfall days increase in relationship to increasing air temperatures, this increase may level out or even decrease as mean surface air temperature exceeds −8°C in winter. In spring and autumn, increasing rainfall days switch to decreasing when the mean surface air temperature goes above 6°C. The conclusion of this study is that changes in the frequency of precipitation types are highly dependent on the location’s air temperature and that threshold temperatures exist beyond which changes in an opposite direction occur.


2021 ◽  
Vol 7 (5) ◽  
pp. 1113-1122
Author(s):  
Bo Chen ◽  
Shi-jun Xu ◽  
Xin-ping Zhang ◽  
Yi Xie

Using the methods of literature review, regression analysis and moving average, this paper selects the daily precipitation of Changsha and Chengde from 1951 to 1986 as samples, and analyzes the average precipitation, precipitation frequency, precipitation intensity, extreme precipitation time and other indicators of Changsha and Chengde from the perspective of interannual and seasonal changes Trends. The researches show that: the average precipitation of Changsha in the 36 years is 1151.2mm, spring is the wet season, autumn and winter are the dry seasons, and the maximum average precipitation is in spring; the average annual precipitation, precipitation frequency in spring, summer and winter, annual precipitation frequency, annual precipitation intensity and extreme precipitation events show a decreasing trend. The average annual precipitation of Chengde city is 454.1 mm, wet season in summer and dry season in spring, autumn and winter; the average annual precipitation, precipitation in four seasons, annual precipitation frequency, precipitation frequency in spring, autumn and winter, annual precipitation intensity and extreme precipitation events show a decreasing trend, while the precipitation frequency in summer shows an increasing trend. The study of regional climate change based on the time series data of this stage is of great significance to comprehensively understand the law of regional climate change and predict the future trend of climate change.


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