Variability and Trends of Precipitation in Quelimane, Central Mozambique, and Their Relation to El Niño Southern Oscillation

Abstract

Understanding precipitation variability and trends is very important for sustainable water management. In this paper, we used 65 years longterm precipitation data to evaluate the precipitation variability and trends in Quelimane, and their relation to El Niño Southern Oscillation (ENSO). The analysis includes annual, inter-annual inter-decadal variations, Mann-Kendall trend test, and drought frequency. The study also evaluated the relationship between Oceanic Niño Index (ONI) and precipitation patterns during ENSO positive, normal and negative phases. The results show two distinct seasons of precipitation in Quelimane, the wet season extending between December and April and the dry season extending from May to November. ENSO was found to influence the inter-annual variations of precipitation during the wet season, with warm ENSO (El Niño) and cold (La Niña) events tending to reduce and increase the precipitation amounts, respectively. Decreasing trends in inter-annual variations of precipitation and increase of drought frequency and severity are highlighted in this study. Both decreasing trend of inter-annual variations and increasing of drought frequency and severity have intensified after the 1970s climate shift. These intensifications seem to be associated with the strengthening of ENSO after the 1970s climate shift. The results of the present study may be useful for the design of the climate change adaptation plans in central Mozambique.

The influence of tropical and subtropical modes of climate variability on precipitation in Mozambique

“…In contrast, below‐normal precipitation in the southern and central regions tends to accompany El Niño through Rossby wave propagation similar to that of La Niña, but with opposite phase. Our results are also consistent with those of previous studies by Gaughan et al (2016), Harp et al (2021) and Machaieie et al (2020). Our novel finding is that even in atypical La Niña and El Niño events, which did not accompany precipitation anomalies in southern and central Mozambique, there was also Rossby wave propagation over the South Pacific as in typical ENSO events, but it did not reach the South Atlantic and South Africa.…”

“…Harp et al (2021) studied the relationship between interannual variability of malaria outbreaks and climate in Mozambique and demonstrated that La Niña and positive SIOD lead to wetter conditions over southern Mozambique. Other studies have indicated that ENSO plays a crucial role in interannual precipitation variability in Mozambique, associating its warm phase (i.e., El Niño) with drier conditions and cold phases (i.e., La Niña) with wetter conditions (Machaieie et al, 2020; Manhique et al, 2023; O'Brien & Vogel, 2003). However, the influence of modes of climate on interannual precipitation variability in Mozambique is not well understood.…”

Analyzing Precipitation Acidity Changes Post Train Derailment and Vinyl Chloride Release in East Palestine, Ohio: Exploring Biomedical and Environmental Ramifications

“…The Litmus pH scale, as depicted in Figure 2, illustrates the pH levels of various specimens such as natural rain (pH 6), pure water (pH 5), and seawater (pH 8) [3] [4] [5]. A pH rating of 7 is considered typical for water, indicating a high degree of stability.…”