scholarly journals Long-Term Trend of Climate Change and Drought Assessment in the Horn of Africa

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Mihretab G. Ghebrezgabher ◽  
Taibao Yang ◽  
Xuemei Yang
Keyword(s):  
Climate Change ◽  
Mean Annual Precipitation ◽  
Simple Linear Regression ◽  
Horn Of Africa ◽  
Drought Assessment ◽  
Moderate Drought ◽  
The Mean ◽  
Long Term Trend ◽  
Precipitation And Temperature

Climate change due to global warming is a world concern, particularly in Africa. In this study, precipitation and temperature variables are taken as a proxy to assess and quantify the long-term climate change and drought in the Horn of Africa (HOA) (1930–2014). We adapted a simple linear regression and interpolation to analyze, respectively, the trend and spatial distribution of the mean annual precipitation and temperature. In addition, standardized precipitation evapotranspiration index (SPEI) was applied to evaluate the drought condition of the HOA. The results revealed that statistically the trend of precipitation decreased insignificantly; the trend of temperature was observed to drop very significantly between 1930 and 1969, but it was dramatically elevated very significantly from 1970 to 2014. The SPEI showed that the HOA experienced from mild to moderate drought throughout the study period with severe to extreme drought in some regions, particularly in 1943, 1984, 1991, and 2009. The drought was a very serious environmental problem in the HOA in the last 85 years. Thus, an immediate action is required to tackle drought and hence poverty and famine in the HOA.

Beyond the mean: long-term variabilities in precipitation and temperature on the Qinghai-Tibetan Plateau

2021 ◽  
Author(s):  
Tong Guo ◽  
Yanhong Tang
Keyword(s):  
Climate Change ◽  
Tibetan Plateau ◽  
Interannual Variability ◽  
Daily Precipitation ◽  
Mean Annual Precipitation ◽  
High Altitudes ◽  
Annual Variability ◽  
Mean Temperature ◽  
Precipitation And Temperature

AbstractLong-term variabilities in daily precipitation and temperature are critical for assessing the impacts of climate change on ecosystems. We characterized intra- and interannual variabilities in daily precipitation and temperature obtained from 1960 to 2015 at 78 meteorological stations on the Qinghai-Tibetan Plateau. The results show that 1) The intra-annual variability of daily precipitation increases for 55 meteorological stations with a rate of 0.08 mm per decade. In contrast, the intra-annual variability markedly decreases for daily mean, daytime mean, and nighttime mean temperatures with a rate of 0.09, 0.07, and 0.12 °C per decade, respectively at 90% or more of stations. 2) Variabilities of daily precipitation and temperatures are quite sensitive to high altitudes (> 3500 m). The intra- and interannual variabilities of daily precipitation significantly decrease at 1.0 and 0.07 mm per 1000 m, respectively. However, variations of high altitudes increase the intra- and interannual variabilities of daily mean temperature at 1.0 °C and 0.2 °C per 1000 m. Moreover, the interannual variability of nighttime mean temperature varies at 0.3 °C per 1000 m, the fastest rate among three temperature indices. 3) A larger mean annual precipitation is accompanied by a higher intra- and interannual variability of daily precipitation on the Qinghai-Tibetan Plateau; however, a higher mean annual temperature leads to lower variabilities of daily temperatures. This study illustrates that long-term climatic variability is understudied in alpine ecosystems characterized by high climatic sensitivity. Precipitation and temperature variabilities should be characterized to improve predictions of vulnerable ecosystems responding to climate change.

scholarly journals Different long-term trends of the oxygen red 630.0 nm line nightglow intensity as the result of lowering the ionosphere F2 layer

2008 ◽  
Vol 26 (8) ◽  
pp. 2069-2080 ◽  
Author(s):  
N. B. Gudadze ◽  
G. G. Didebulidze ◽  
L. N. Lomidze ◽  
G. Sh. Javakhishvili ◽  
M. A. Marsagishvili ◽  
...  
Keyword(s):  
Electron Density ◽  
Line Intensity ◽  
Peak Height ◽  
Height Distribution ◽  
Theoretical Simulation ◽  
Type Layer ◽  
Long Term Trends ◽  
The Mean ◽  
Long Term Trend

Abstract. Long-term observations of total nightglow intensity of the atomic oxygen red 630.0 nm line at Abastumani (41.75° N, 42.82° E) in 1957–1993 and measurements of the ionosphere F2 layer parameters from the Tbilisi ionosphere station (41.65° N, 44.75° E) in 1963–1986 have been analyzed. It is shown that a decrease in the long-term trend of the mean annual red 630.0 nm line intensity from the pre-midnight value (+0.770±1.045 R/year) to its minimum negative value (−1.080±0.670 R/year) at the midnight/after midnight is a possible result of the observed lowering of the peak height of the ionosphere F2 layer electron density hmF2 (−0.455±0.343 km/year). A theoretical simulation is carried out using a simple Chapman-type layer (damping in time) for the height distribution of the F2 layer electron density. The estimated values of the lowering in the hmF2, the increase in the red line intensity at pre-midnight and its decrease at midnight/after midnight are close to their observational ones, when a negative trend in the total neutral density of the upper atmosphere and an increase in the mean northward wind (or its possible consequence – a decrease in the southward one) are assumed.

Quantifying the Effects of Long-Term Climate Change on Tropical Cyclone Rainfall Using a Cloud-Resolving Model: Examples of Two Landfall Typhoons in Taiwan

2014 ◽  
Vol 28 (1) ◽  
pp. 66-85 ◽  
Author(s):  
Chung-Chieh Wang ◽  
Bo-Xun Lin ◽  
Cheng-Ta Chen ◽  
Shih-How Lo
Keyword(s):  
Climate Change ◽  
Reanalysis Data ◽  
Budget Analysis ◽  
Sensitivity Tests ◽  
Cloud Resolving Model ◽  
Typhoon Rainfall ◽  
Climate Background ◽  
Rain Rates ◽  
Long Term Trend

Abstract To quantify the effects of long-term climate change on typhoon rainfall near Taiwan, cloud-resolving simulations of Typhoon (TY) Sinlaku and TY Jangmi, both in September 2008, are performed and compared with sensitivity tests where these same typhoons are placed in the climate background of 1950–69, which is slightly cooler and drier compared to the modern climate of 1990–2009 computed using NCEP–NCAR reanalysis data. Using this strategy, largely consistent responses are found in the model although only two cases are studied. In control experiments, both modern-day typhoons yield more rainfall than their counterpart in the sensitivity test using past climate, by about 5%–6% at 200–500 km from the center for Sinlaku and roughly 4%–7% within 300 km of Jangmi, throughout much of the periods simulated. In both cases, the frequency of more-intense rainfall (20 to >50 mm h−1) also increases by about 5%–25% and the increase tends to be larger toward higher rain rates. Results from the water budget analysis, again quite consistent between the two cases, indicate that the increased rainfall from the typhoons in the modern climate is attributable to both a moister environment (by 2.5%–4%) as well as, on average, a more active secondary circulation of the storm. Thus, a changing climate may already have had a discernible impact on TC rainfall near Taiwan. While an overall increase in TC rainfall of roughly 5% may not seem large, it is certainly not insignificant considering that the long-term trend observed in the past 40–50 yr, whatever the causes might be, may continue for many decades in the foreseeable future.

scholarly journals Seasonal activity of Dermacentor reticulatus ticks in the era of progressive climate change in eastern Poland

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zbigniew Zając ◽  
Joanna Kulisz ◽  
Aneta Woźniak ◽  
Katarzyna Bartosik ◽  
Adil Khan
Keyword(s):  
Climate Change ◽  
Local Population ◽  
Weather Conditions ◽  
Dermacentor Reticulatus ◽  
Seasonal Activity ◽  
Saturation Deficit ◽  
Annual Basis ◽  
Questing Ticks ◽  
The Mean

AbstractDermacentor reticulatus ticks are one of the most important vectors and reservoirs of tick-borne pathogens in Europe. Changes in the abundance and range of this species have been observed in the last decade and these ticks are collected in areas previously considered tick-free. This may be influenced by progressive climate change. Eastern Poland is an area where the local population of D. reticulatus is one of the most numerous among those described so far. At the same time, the region is characterized by a significant increase in the mean air temperature in recent years (by 1.81 °C in 2020) and a decrease in the average number of days with snow cover (by 64 days in 2020) and in the number of days with frost (by 20 days in 2020) on an annual basis compared to the long-term average. The aim of our research was to investigate the rhythms of seasonal activity and the population size of D. reticulatus in the era of progressive climate change. To this end, questing ticks were collected in 2017–2020. Next, the weather conditions in the years of observation were analyzed and compared with multi-year data covering 30 years preceding the study. The research results show that, in eastern Poland, there is a stable population of D. reticulatus with the peak of activity in spring or autumn (up to a maximum of 359 individuals within 30 min of collection) depending on the year of observation. Ticks of this species may also be active in winter months. The activity of D. reticulatus is influenced by a saturation deficit.

Laying date of marsh tits Parus palustris in relation to climate change

Biologia ◽  
2006 ◽  
Vol 61 (5) ◽  
Author(s):  
Zdravko Dolenec
Keyword(s):  
Climate Change ◽  
Life History Traits ◽  
Laying Date ◽  
Bird Breeding ◽  
Spring Temperatures ◽  
The Mean ◽  
The Relationship ◽  
Marsh Tit ◽  
Term Data

AbstractIncreasing evidence suggests that climate change affects bird breeding phenology and other life-history traits of wildlife. This study is based on the mean spring temperatures (February, March, April) and laying dates of first eggs of the marsh tit Parus palustris. We collected data from 1984 to 2004 for the Mokrice area in NW Croatia. Correlation between laying date and mean spring temperatures was significant. The relationship between mean laying date (y) and air temperature (x) can be expressed as y = 44.69 − 2.08x. Results indicate that spring temperatures are a good predictor of timing of laying eggs. Such long-term data could than be used in order to assess the effects on biological systems if human activities influence climate.

scholarly journals Climate Change Impacts on Groundwater Recharge in Cold and Humid Climates: Controlling Processes and Thresholds

Climate ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 6
Author(s):  
Emmanuel Dubois ◽  
Marie Larocque ◽  
Sylvain Gagné ◽  
Marco Braun
Keyword(s):  
Climate Change ◽  
Groundwater Recharge ◽  
Water Resource Management ◽  
Global Climate Models ◽  
Future Climate Change ◽  
Temperature Changes ◽  
Wide Range ◽  
Long Term Changes ◽  
Precipitation And Temperature

Long-term changes in precipitation and temperature indirectly impact aquifers through groundwater recharge (GWR). Although estimates of future GWR are needed for water resource management, they are uncertain in cold and humid climates due to the wide range in possible future climatic conditions. This work aims to (1) simulate the impacts of climate change on regional GWR for a cold and humid climate and (2) identify precipitation and temperature changes leading to significant long-term changes in GWR. Spatially distributed GWR is simulated in a case study for the southern Province of Quebec (Canada, 36,000 km2) using a water budget model. Climate scenarios from global climate models indicate warming temperatures and wetter conditions (RCP4.5 and RCP8.5; 1951–2100). The results show that annual precipitation increases of >+150 mm/yr or winter precipitation increases of >+25 mm will lead to significantly higher GWR. GWR is expected to decrease if the precipitation changes are lower than these thresholds. Significant GWR changes are produced only when the temperature change exceeds +2 °C. Temperature changes of >+4.5 °C limit the GWR increase to +30 mm/yr. This work provides useful insights into the regional assessment of future GWR in cold and humid climates, thus helping in planning decisions as climate change unfolds. The results are expected to be comparable to those in other regions with similar climates in post-glacial geological environments and future climate change conditions.

scholarly journals Future Scenarios of Soil Erosion in the Alps under Climate Change and Land Cover Transformations Simulated with Automatic Machine Learning

Climate ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 28 ◽  
Author(s):  
Marco Gianinetto ◽  
Martina Aiello ◽  
Renata Vezzoli ◽  
Francesco Niccolò Polinelli ◽  
Maria Cristina Rulli ◽  
...  
Keyword(s):  
Climate Change ◽  
Machine Learning ◽  
Soil Erosion ◽  
Land Cover ◽  
Erosion Rate ◽  
Automatic Machine ◽  
Mean Annual Precipitation ◽  
Future Scenarios ◽  
The Alps ◽  
The Mean

Erosion is one of the major threats listed in the Soil Thematic Strategy of the European Commission and the Alps are one of the most vulnerable ecosystems, with one of the highest erosion rates of the whole European Union. This is the first study investigating the future scenarios of soil erosion in Val Camonica and Lake Iseo, which is one of the largest valleys of the central Italian Alps, considering both climate change and land cover transformations. Simulations were done with the Dynamic Revised Universal Soil Loss Equation (D-RUSLE) model, which is able to account also for snow cover and land cover dynamics simulated with automatic machine learning. Results confirm that land cover projections, usually ignored in these studies, might have a significant impact on the estimates of future soil erosion. Our scenario analysis for 2100 shows that if the mean annual precipitation does not change significantly and temperature increases no more than 1.5–2.0 °C, then the erosion rate will decrease by 67% for about half of the study area. At the other extreme, if the mean annual precipitation increases by more than 8% and the temperature increases by more than 4.0 °C, then about three-quarters of the study area increases the erosion rate by 92%. What clearly emerges from the study is that regions with higher erosion anomalies (positive and negative) are expected to expand in the future, and their patterns will be modulated by future land transformations.

Knowledge level and constraints in adopting the recommended mitigation strategies on climate change in Haryana

2020 ◽  
Vol 36 (2) ◽  
pp. 7-11
Author(s):  
Dilip S ◽  
, Joginder Singh Malik ◽  
R.N. Sheokand
Keyword(s):  
Climate Change ◽  
New Technologies ◽  
Mitigation Strategies ◽  
Knowledge Level ◽  
Advisory Services ◽  
Growing Seasons ◽  
Lack Of Information ◽  
High Knowledge ◽  
The Mean

The greatest influencer of agricultural productivity is the weather. Climate is typically defined as the normal weather, or more precisely, as the statistical explanation of important parameters in relations of the mean and variability over time scales extending from months to thousands or millions of years. Agriculture in India, as well as the respite of the world, is mostly reliant on the weather. Global warming has had an important impact on agriculture and its output. The shift in growing seasons and changes in agricultural zones have been exacerbated by rising temperatures. Changes in rainfall patterns, on the other hand, pose a severe threat to agriculture, affecting the country’s economy and food security. The sale of agricultural products such as fertilizers, agro-chemicals and tractors are also affected by the delayed or insufficient monsoons. As a result, the farmer’s income is impacted. The present study conducted during 2020-21 focuses on Knowledge level farmers on climate change and constraint experienced by the farmers in adopting recommended mitigation strategies in Hisar district. The majority of beneficiary farmers (48.89 per cent) had high knowledge level on Agro-met Advisory Services whereas majority of non-beneficiary farmers (67.76 per cent) had low knowledge level on Agro-met Advisory Services. Lack of technical skills and capacities for technology adoption, lack of awareness and sensitization about the creation and use of new technologies, non-availability of timely inputs, and lack of information about long-term mitigation strategies were the major constraints

scholarly journals Impact of climate change and man-made irrigation systems on the transmission risk, long-term trend and seasonality of human and animal fascioliasis in Pakistan

2014 ◽  
Vol 8 (2) ◽  
pp. 317 ◽  
Author(s):  
Kiran Afshan ◽  
Cesar A. Fortes-Lima ◽  
Patricio Artigas ◽  
M. Adela Valero ◽  
Mazhar Qayyum ◽  
...  
Keyword(s):  
Climate Change ◽  
Transmission Risk ◽  
Irrigation Systems ◽  
Term Trend ◽  
Impact Of Climate Change ◽  
Long Term Trend

scholarly journals Toward Estimating Climatic Trends in SST. Part I: Methods of Measurement

2006 ◽  
Vol 23 (3) ◽  
pp. 464-475 ◽  
Author(s):  
Elizabeth C. Kent ◽  
Peter K. Taylor
Keyword(s):  
Measurement Method ◽  
Early Period ◽  
Sea Surface ◽  
Data Set ◽  
Climatic Trends ◽  
The Pacific ◽  
The Mean ◽  
Seasonal Signal ◽  
Long Term Trend

Abstract To assess climatic changes in sea surface temperature (SST), changes in the measurement method with time and the effect of these changes on the mean SST must be quantified. Observations from the International Comprehensive Ocean–Atmosphere Data Set (ICOADS) have been analyzed for the period from 1970 to 1997 using both SST measurement metadata contained within the dataset and a World Meteorological Organization (WMO) catalog of observing ships. The WMO metadata were particularly important in identifying engine-intake SSTs during the 1970s, but increased method identification over the entire period. There are strong regional variations in the preferred SST measurement method, with engine-intake SST most common in the Pacific and bucket SST preferred by countries bordering the Atlantic. The number of engine-intake SSTs increases over time and becomes more numerous than buckets by the early 1980s. There are significant differences between SST observations made by different methods. The rounding of reports is more common for engine-intake SST than for either bucket or hull sensor SST, which degrades its quality. Significant time-varying biases exist between SST derived from buckets and from engine intakes. The SST difference has a strong seasonal signal with bucket SST being relatively cold in winter, probably resulting from heat loss from the buckets, and warm in summer, probably resulting from solar warming or the sampling of a shallow warm layer. There is also a long-term trend with engine-intake SST being relatively warm in the early period but with a small annual mean difference between the two methods by 1990.

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