Module 1 understanding climate variability and climate change. Although global patterns of rainfall and rainfall variability are well documented, our ability to predict shortages or excesses of rainfall is severely limited. Climate variability and climate change, what is the. Knowledge and understanding of such variability can lead to improved risk management practices in. Enso see below is a major influence of interannual variability for many places, especially in the tropics.
What are the factors influencing spatial variation of. Rain is a major component of the water cycle and is responsible for depositing most of the. Understanding climate variability and change climate futures. Spatial and temporal rainfall variability has links to various factors, from a largescale climate forcing to regional scale. Rainfall variability and changes in southern africa during.
Rainfall variability and trend analysis of annual rainfall. The ipcc climate models predict, for the maghreb countries, lower rainfall and increased aridity. Rainfall variability occurs over a wide range of temporal scales. Exhibit 1 shows that gdp in ethiopia rises or falls about a year behind changes in average rainfall. Precipitation variability western north carolina vitality index.
Climate variability synonyms, climate variability pronunciation, climate variability translation, english dictionary definition of climate variability. Chapter 2 presents a discussion of previous research examining the effect of weather variability on agricultural. Rainfall variability, drought characterization, and efficacy. Rainfall variability and droughts in the drylands of. Many aspects of the global climate are changing rapidly, and the primary drivers of that change are human in origin. This module will outline some key concepts such as weather, climate variability and of course, climate change. Climate variability and climate change, what is the difference.
Research article rainfall variability and trend analysis of. Climate change and variability national centers for. Current observations in the three countries of central maghreb morocco, algeria, and tunisia are not consistent with these predictions. Annual rainfall in the sahel from 1900 to 2006, adapted from mason et al, 2015. The study used quantitative and qualitative research methods to assess anomalies in seasonal rainfall amounts, probabilities of dry spells, and perceptions of farmers on impacts of drought and their. Data and methods the basic data set used in this study is the cru05 0. Climate change and variability climate is defined as longterm averages and variations in weather measured over a period of several decades. Climatic variability and change have always presented a threat to food security in kenya through their effect on rainfall, soil moisture and production. The earths climate system includes the land surface, atmosphere, oceans, and ice. Rainfall variability and drought characteristics in two. Rainfall variability and drought characteristics in two agro. This data set has been constructed at the climatic research unit, university of east an.
Summer, when most biological productivity occurs, is the most important season for humanity and thus the season when climate change may have its. The group is characterised by low rainfall and a high variability 24%. Southern africa is subject to high inter annual rainfall variability and the factors influencing southern african rainfall are not fully understood. Most rural people live in the highlands and middlehighlands, which comprise only onethird of the country, and this population tends to be. Rainfall extremes over south australia are connected with broadscale atmospheric rearrangements associated with strong meridional sea surface temperature sst gradients in the eastern indian ocean. Most reporting stations in the central and western coastal plain received at least half the average annual rainfall during septemberoctober table 1. This data set has been constructed at the climatic research unit, university of east anglia. Precipitation variability precipitation is essential to both ecosystem processes and to water supplies for municipalities. Rainfall variability the quality of being uneven and unpredictable in a growing season. States relative to climatic variability and change. Rainfall variability and changes in southern africa over the 20th century areexamined and their potential links to the global warming discussed.
Abstractthis study investigates rainfall and temperature variabilities in nigeria using observations of air temperature c and rainfall mm from 25 synoptic stations from 1971o 2000 30years. Rainfall extremes have increased over africa but without any trend new et al. The region as a whole experienced good rainfall in 1989, but the last run of good years goes back to 19811983. The variability has been linked with various sea surface temperature anomalies sstas in each of the three major ocean basins as well as variability in the strength and position of regional. Increased rainfall variability and reduced rainfall amount decreases soil co 2. Rainfall variability and trend analysis of annual rainfall in. Thirtyseven years of winter radiosonde data is used to calculate a time series of precipitable water pw and convective available potential energy cape in the atmosphere. The rest of this thesis will be organized as follows. One of the atmospheric factors that may play a substantial role in southern african rainfall variability is the botswana high, a high pressure cell which exists at the 500hpa level and is centred over central namibia and western botswana during austral summer. Effects of climate variability and change on agricultural. Rainfall variability, drought characterization, and. This investigation is based on the calculation of the reduced.
Some of the variability does not appear to be caused systematically and occurs at random times. Rainfall amounts, in inches, associated with hurricanes dennis, floyd, and. Carlisle division of biology, kansas state university, manhattan, ks 66506, usa, wnatural resources research institute, 50 miller trunk highway, duluth, mn 55811, usa. The time series displays a typical pseudoperiodic behaviour with a cycle of 4 to 5 years. Key terms n climate variability the way climate fluctuates yearly above or below a longterm average value. Forest service forest sector technical report for the national climate assessment and includes descriptions of key regional issues and examples of a riskbased framework for as. Stakeholdersall those people who are involved in the daytoday agricultural activities. However, there has been not much research on local understanding of the effect of climate variability on maize yields in arid and semi arid lands asals of lower eastern kenya counties. To link to this object, paste this link in email, im or document to embed this object, paste this html in website. Climpag climate indicators rainfall variability and. Knowledge and understanding of such variability can lead to improved risk management practices in agricultural and other industries. Weather impacts refers to the effect of rainfall variability on potato production. Spline, kriging, and inverse distance weighting interpolation techniques were assessed using daily rainfall data and digital. Wikimatrix the rainfall variability map on the same page shows that the coefficient of variation of annual rainfall for the catlins is between 10% and 15% with variation being highest.
Abstractthis study investigates rainfall and temperature variabilities in nigeria using observations of air temperature c and rainfall mm from 25 synoptic stations from 1971o. Climate is defined as longterm averages and variations in weather measured over a period of several decades. Rainfall variability is the degree to which rainfall amounts vary across an area or through time, it is an important characteristic of the climate of an area and has two components i. What are the factors influencing spatial variation of rainfall. Perkerra and nginyang rainfall stations had data for the period 19702008 and 197420. Study of rainfall trends and variability over tanzania. This variability ranges over many time and space scales such as localized thunderstorms and tornadoes, to largerscale storms, to droughts, to multiyear, multidecade and even multicentury time scales. Interannual variability of surface temperature is larger in the winter hemisphere than in the summer and larger over land than over ocean figure 2.
Analysis of rainfall and temperature variability over nigeria. Anthropogenic forcing is widely addressed for this contribution. Perkerra and nginyang rainfall station was obtained from kenya meteorological services. Rainfall in australia is highly variable, both temporally and spatially, to a greater degree than in other countries and continents nicholls et al. Complex patterns of climate, climate change, and livelihoods. However, the increased rainfall due to cyclonic activities is an interannual processes and enso cycle believed to be causing this variance in the interannual climate regime. With agriculture accounting for half of gdp and 80% of jobs, the ethiopian economy is sensitive to climate variability, particularly variations in rainfall. Research article rainfall variability and trend analysis of annual rainfall in north africa zeineddinenouaceur 1 andovidiumur srescu 2 umr cnrs idees, university of rouen, rouen, france department of geography, valahia university, t argovis. The same problem is evident as with the high and low extremes used as a way of characterizing the temporal variability of rainfall. Weather describes current atmospheric conditions, such as rainfall, temperature, and wind speed, at a particular place and time. Research article rainfall variability and trend analysis.
The degree to which rainfall amounts vary across an area or through time is an important characteristic of the climate of an area. The red dots indicate the yearly observations, so the red line indicates variation in climate from year to year also know as interannual variability. Results and discussion this section examines the rainfall variability for a 19year 19902008 period observed rain gauge data and its comparison with the regcm3 model data. Since the early 1990s, kenya has been affected by the droughts of 19912, 19923, 19956, 19982000 and 2004, the elnino rains that resulted in the floods of 19971998 5 and the.
This paper reported rainfall variability and drought characteristics under climate change in two agroclimatic zones of southwestern nigeria. In the time since the industrial revolution the climate has increasingly been affected by human activities that are causing global warming and climate. It was also found that intraseasonal dry day sequences were an important parameter in the definition of a rainy seasons onset and end in southern africa apart from rainfall amounts. Increased rainfall variability and reduced rainfall amount. Climate variability and change has been the most important determinant of crop yields in kenya and other parts of the world. Nov 11, 2019 of these, the enso and qbo are the interannual processes.
Rainfall variability at decadal and longer time scales. Climate variability a greater aspect of our weather and climate is its variability. Climate variability definition of climate variability by. South australian rainfall variability and climate extremes. However, the increased rainfall due to cyclonic activities is an interannual processes and enso cycle believed to be causing this. The basic reason for the large winter variability is the huge difference in temperature between low latitudes and high latitudes in winter.
Rainfall trends and variability geography project topics. Effects of climate variability on maize yield in the arid. Rainfall and rainfall variability ifpri publications. Effects of climatic variability and change on forest ecosystems. Department of agriculture, forest service, southern research station. Climate variability is the term to describe variations in the mean state and other characteristics of climate such as chances or possibility of extreme weather, etc.
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