Analysis of temperature data over semi-arid Botswana: trends and break points

Mphale, Kgakgamatso; Adedoyin, Akintayo; Nkoni, Godiraone; Ramaphane, Galebonwe; Wiston, Modise; Chimidza, Oyapo

doi:10.1007/s00703-017-0540-y

Cited by 6 publications

(4 citation statements)

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“…Focusing finally on the principal home of the Bushmen, the Kalahari desert, a plateau region where the altitude is typically 800–1200 m above sea level, almost no data from prior to 1960 have been published. However, Mphale and colleagues (2018) et al ( 2018 ) thoroughly analyzed the interannual rate of change of wintertime daily minimum T a between 1961 and 2010, and the average rate of change was about 0.10°C per decade (see also van Regenmortel 1995 ). Therefore, for our present purposes, it seems straightforward to use the T a data reported by Andringa ( 1984 ) for eight locations over the years 1958–1980.…”

Section: A New Perspective On the Feasibility Of Living Naked In The ...mentioning

confidence: 99%

“…The average daily minimum T a in June–August ranged from 2.4°C (at Tshabong in the south) to 7.9°C (at Maun in the north), with a grand average of 5.4°C; the monthly minimum T a s were typically from –3.9°C to –7.5°C. Yellon and Lee ( 1976 ) commented that, in the northern Kalahari (which is warmer than the southern; Mphale et al 2018 ) during the months of June–August, the people could expect T a s below 5°C during about 60 nights per year. Van Regenmortel ( 1995 ), using data from the 1960 s to 1980 s, reported a relatively consistent relationship in the Kalahari between average winter T a and number of days with early morning ground frost.…”

Section: A New Perspective On the Feasibility Of Living Naked In The ...mentioning

confidence: 99%

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Living Naked in the Cold: New Insights into Metabolic Feasibility in Primeval Cultures

Hill

2023

BioScience

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The people of three primeval cultures lived naked or nearly naked in regions where they experienced air temperatures of ± 5 degrees Celsius during cold seasons. These were the Australian Aboriginal peoples, the Bushmen of southern Africa, and the Yamana and the Alakaluf of Tierra del Fuego. Recent meta-analyses of data on human metabolic rate and metabolic endurance enable a quantitative demonstration of feasibility: Thermoregulation at winter air temperatures while naked was feasible in the three cultures for significantly longer than 50–180 days per year (sufficient for the duration of winter). Considering the life histories of the people, their estimated, time-averaged daily (24 hours) metabolic rates in winter were 2.6 times basal—similar to the highest daily rates empirically measured in extant peoples. Although the primeval peoples’ way of life was metabolically expensive, it was as feasible as the lifestyles of peoples in today's world who live at the upper bound of the metabolically possible.

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Section: A New Perspective On the Feasibility Of Living Naked In The ...mentioning

confidence: 99%

Section: A New Perspective On the Feasibility Of Living Naked In The ...mentioning

confidence: 99%

Living Naked in the Cold: New Insights into Metabolic Feasibility in Primeval Cultures

Hill

2023

BioScience

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“…Surface pressure fields in the post-trough stages can produce a strong onshore flow along the southeastern/western coast of the subcontinent. A strong high-pressure circulation developing over southern Angola could promote the influx of cold dry air flow through the Namib-Kalahari desert into most parts of the subcontinent [62]. These features could help sustain convection over southern Africa and favorable for uplift of moisture through the There is a tendency for convective initiation to be favored within the highland regions [44,[58][59][60][61].…”

Section: Rainfall Distributionmentioning

confidence: 99%

Mesoscale Convective Systems: A Case Scenario of the ‘Heavy Rainfall’ Event of 15–20 January 2013 over Southern Africa

Wiston

Mphale

2019

Climate

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Southern east Africa is prone to some extreme weather events and interannual variability of the hydrological cycle, including tropical cyclones and heavy rainfall events. Most of these events occur during austral summer and are linked to shifts in the intertropical convergence zone, changes in El Niño Southern Oscillation signatures, sea surface temperature and sea level pressure. A typical example include mesoscale convective systems (MCSs) that occur between October and March along the eastern part, adjacent to the warm waters of Mozambique Channel and Agulhas Current. In this study we discuss a heavy rainfall event over southern Africa, focusing particularly on the period 15-20 January 2013, the period during which MCSs were significant over the subcontinent. This event recorded one of the historic rainfalls due to extreme flooding and overflows, loss of lives and destruction of economic and social infrastructure. An active South Indian Convergence Zone was associated with the rainfall event sustained by a low-level trough linked to a Southern Hemisphere planetary wave pattern and an upper-level ridge over land. In addition, also noteworthy is a seemingly strong connection to the strength of the African Easterly Jet stream. Using rainfall data, satellite imagery and re-analysis (model processed data combined with observations) data, our analysis indicates that there was a substantial relation between rainfall totals recorded/observed and the presence of MCSs. The low-level trough and upper-level ridge contributed to moisture convergence, particularly from tropical South East Atlantic Ocean, which in turn contributed to the prolonged life span of the rainfall event. Positive temperature anomalies favored the substantial contribution of moisture fluxes from the Atlantic Ocean. This study provides a contextual assessment of rainfall processes and insight into the physical control mechanisms and feedback of large-scale convective interactions over tropical southern Africa.

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“…Climate models predict that Southern Africa will be hotter and drier by the end of the century [2]. The hot, dry climate promotes increase in plant litter fall and creates atmospheric conditions conducive to occurrence of frequent wildfires.…”

Section: Introductionmentioning

confidence: 99%

Measurement of Breakdown Electric Field Strength for Vegetation and Hydrocarbon Flames

Maabong¹,

Mphale²,

Letsholathebe³

et al. 2018

JEMAA

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A significant number of fire-induced power disruptions are observed in several countries every year. The faults are normally phase-to-phase short circuiting or conductor-to-ground discharges at mid-span region of the high-voltage transmission system. In any case, the wildfire plumes provide a conductive path. The electrical conductivity is due to intense heat in combustion zone of the fire which creates ion and electrons from flame inherent particulates. Increase in the ion concentration increases the electrical conductivity of the fire plume. The main purpose of this study was to measure dielectric breakdown electric field for vegetation and hydrocarbon flames. The experimental data is needed for validation of simulation schemes which are necessary for evaluation of power grid systems reliability under extreme wildfire weather conditions. In this study, hydrocarbon and vegetation fuels were ignited in a cylindrically shaped steel burner which was fitted with type-K thermocouples to measure flame temperature. The fuels consisted of dried weeping wattle (Peltophorum africanum) litter, butane gas and candle wax. Two pinned copper electrodes supported by retort stands were mounted to the burner and energized to a high voltage. This generated a strong electric field sufficient to initiate dielectric breakdown in the flames. Breakdown electric field strength (E crit) obtained from the experiment decreased from 10.5 to 6.9 kV/cm for the flames with temperature range of 1003 to 1410 K, respectively.

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Analysis of temperature data over semi-arid Botswana: trends and break points

Cited by 6 publications

References 77 publications

Living Naked in the Cold: New Insights into Metabolic Feasibility in Primeval Cultures

Living Naked in the Cold: New Insights into Metabolic Feasibility in Primeval Cultures

Mesoscale Convective Systems: A Case Scenario of the ‘Heavy Rainfall’ Event of 15–20 January 2013 over Southern Africa

Measurement of Breakdown Electric Field Strength for Vegetation and Hydrocarbon Flames

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