Daily rainfall occurrence and amount at 11 stations over North Queensland are examined during summer 1958–1998, using a Hidden Markov Model (HMM). Daily rainfall variability is described in terms of the occurrence of five discrete “weather states,” identified by the HMM. Three states are characterized respectively by very wet, moderately wet, and dry conditions at most stations; two states have...

The dynamics of a mosquito population depends heavily on climatic variables such as temperature and precipitation. Since climate change models predict that global warming will impact on the frequency and intensity of rainfall, it is important to understand how these variables affect the mosquito populations. We present a model of the dynamics of a Culex quinquefasciatus mosquito population that...

This paper investigates the role that air–sea interaction processes may play in interannual variability of south-eastern African summer rainfall. The principal spatial modes of south-eastern African summer rainfall are first identified using principal component analysis. Four modes are retained. The most important mode of variability is found to represent rainfall variability over most of the d...

In Sub-Saharan Africa, mobility through transhumance is a much-valued strategy of pastoralists for dealing with rainfall variability (see Swallow 1994; van den Brink, Bromley, and Chavas 1995; Ellis and Swift 1988). Transhumance is generally practiced in the arid to semi-arid regions of Sub-Saharan Africa, an environment characterized by low mean rainfall and high rainfall variability. Higher r...

continuous and lengthy droughts in previous years not only in the southern provinces of iran but also in the whole country necessitate optimized water management. indian ocean and adjacent seas in south of iran are suppliers of part of the humidity in the region and the variation on indian ocean sea surface temperature has an important role in evaporation from oceans and input humidity into atm...

Farmers in semi-arid Zimbabwe prioritise climate variability as their major agricultural productivity-reducing problem. This paper raises the importance of considering local farmers’ perceptions on climate risk, as this greatly influences on-farm investments and decision-making in agricultural management and production in semiarid Zimbabwe. A study was conducted in two districts of semi-arid Zi...

A k-means cluster analysis is used to summarize unfiltered daily atmospheric variability at regional-scale over the western Sahel and eastern tropical North Atlantic during the boreal summer season (July—September, JAS) 1961—1998. It employs zonal and meridional regional wind fields at 925, 700 and 200 hPa from the European Centre for Medium Range Weather Forecast Reanalyses. An 8-cluster solut...

[1] This study investigates relationships between variability in the Pacific and extreme rainfall in eastern Australia. Using an index of extreme precipitation derived from a daily gridded precipitation data set from 1900 to 2011, we find that a nonlinear relationship between El Niño–Southern Oscillation and extreme rainfall exists. That is, the strength of a La Niña episode has a much greater ...

This paper begins with an overview of the African rainfall regime, noting in particular the contrast among various regions Ž . of the continent, followed by a description of the nature of climatic i.e., rainfall variability over Africa on time scales of decades and centuries. The decadal scale is examined using modern data covering the twentieth century. The century scale is examined using hist...