Extreme Rainfall Events and Lake Level Changes in East Africa: Recent Events and Historical Precedents

Conway, Declan

doi:10.1007/0-306-48201-0_2

Cited by 74 publications

(49 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…A similar anomalous event but less in magnitude occurred in 1997, a period when the Indian Ocean dipole (IOD) and El Niño co-occurred. The anomalous rainfall events in 1905 to 1906 and 1916 to 1917 have also been reported by Conway (2002). These results suggest that the amplitude of seasonal cycle tends to be high/low during anomalous rainfall years.…”

Section: Spatial and Temporal Structures Of Modulated Annual Cycle (Mac)supporting

confidence: 69%

“…Lake Victoria rose 2 m in little more than a year (Conway, 2002;Flohn, 1987). This was not an ENSO year, but exceedingly high sea surface temperatures (SSTs) occurred in the nearby Indian Ocean as well as the Atlantic.…”

Section: Resultsmentioning

confidence: 99%

“…The extreme rainfall event of 1961 to 1962 was unprecedented in intensity, duration, and extent during the 20 th century in the East African region (Conway, 2002) and was triggered by the Indian Ocean Dipole (IOD) mode (Black et al, 2003;Owiti et al, 2008). A similar anomalous event but less in magnitude occurred in 1997, a period when the Indian Ocean dipole (IOD) and El Niño co-occurred.…”

Section: Spatial and Temporal Structures Of Modulated Annual Cycle (Mac)mentioning

confidence: 99%

See 2 more Smart Citations

East African rainfall seasonality based on modulated annual cycle (MAC)

Owiti¹

2012

Int. J. Phys. Sci.

View full text Add to dashboard Cite

The spatial and temporal variability of East African rainfall seasonal cycle is investigated based on modulated annual cycle (MAC). Ensemble empirical mode decomposition (EEMD) is used to extract MAC from monthly data for the period 1900 to 2008. The MAC is given by year-to-year changes in annual and semi-annual components. Results show that MAC account for between 45 to 80% proportion of rainfall variability. Spatial structure of MAC shows that it captures the north-south (equatorial) pattern for annual (semi-annual) mode with explained variance of 54% (22%). The spatial structure of MAC further reveals that the seasonality of rainfall over the whole region does not follow the north/south classical scheme where the semi-annual component dominates the equatorial while the annual component dominates areas relatively far from the equator. MAC amplitude tends to be high during anomalous rainfall indicating that the impact of major climate processes that produce seasonal cycle are amplified or suppressed by interannual to longer timescale climate variability modes. This study has shown variability in the seasonal cycle of East African rainfall on interannual-to-longer time scales, which should be considered in studies on variability of rainfall and in seasonal-to-longer time scale prediction of rainfall over the region.

show abstract

Section: Spatial and Temporal Structures Of Modulated Annual Cycle (Mac)supporting

confidence: 69%

Section: Resultsmentioning

confidence: 99%

Section: Spatial and Temporal Structures Of Modulated Annual Cycle (Mac)mentioning

confidence: 99%

See 1 more Smart Citation

East African rainfall seasonality based on modulated annual cycle (MAC)

Owiti¹

2012

Int. J. Phys. Sci.

View full text Add to dashboard Cite

show abstract

“…2a), the catchment experienced two of the wettest climatic periods on record in 1961-1963 and 1977-1979. Heavy rains affected large parts of Africa and India in 1961 (Conway 2002), extending at least into 1962 in the Lake Malawi catchment, while the late 1970s heavy rains were spatially more limited to southeastern Africa. During both periods, the total mean river inflow to the lake was more than 25% above the long-term average (Kidd 1983) and the lake levels increased over the course of 2 consecutive years, reaching its maximum level in the century-long record in 1980 (Fig.…”

Section: ϫ2mentioning

confidence: 99%

Deep-water warming trend in Lake Malawi, East Africa

et al. 2005

View full text Add to dashboard Cite

We use historic water temperature measurements to define a deep‐water warming trend in Lake Malawi, East Africa. Over the past six decades, the temperature of the deep water below 300 m has increased by ~0.7°C. The warming trend is due mainly to the reduction of cold‐water deep convection over this period, which is associated with milder winters in the region. Despite deep‐water warming, density stratification was maintained at depths below 100 m. The observed warming trend was interrupted at least twice by abyssal cooling events that were associated with the wettest years on record. We propose that rainfall and cool river inflow are critical factors that control thermal structure and the rate of deep‐water recharge in this deep, tropical lake.

show abstract

“…They concluded that levels have remained relatively high since the early 1960s due to a sustained increase in lake rainfall. Analysis of rainfall events reinforces this: persistence of high lake levels is related to the combined effects of large catchment size and potential for storage, the wettest October-November on record in 1961, very high rainfall in 1963 and an increase in rainfall between 1931-1960 and 1961-1990 of about 8% over much of the basin (Conway, 2002).…”

Section: Previous Workmentioning

confidence: 73%