Simulating the response of a closed-basin lake to recent climate changes in tropical West Africa (Lake Bosumtwi, Ghana)

2007 ◽  
Vol 21 (13) ◽  
pp. 1678-1691 ◽  
Author(s):  
Timothy M. Shanahan ◽  
Jonathan T. Overpeck ◽  
W. E. Sharp ◽  
Christopher A. Scholz ◽  
Justice A. Arko
Keyword(s):  
West Africa ◽  
Climate Changes ◽  
Closed Basin ◽  
Recent Climate

scholarly journals Hybrid insolation forcing of Pliocene monsoon dynamics in West Africa

2018 ◽  
Vol 14 (1) ◽  
pp. 73-84 ◽  
Author(s):  
Rony R. Kuechler ◽  
Lydie M. Dupont ◽  
Enno Schefuß
Keyword(s):  
West Africa ◽  
Climate Changes ◽  
West African Monsoon ◽  
West African ◽  
Latitudinal Gradients ◽  
Glacial Cycle ◽  
Time Intervals ◽  
Continental Hydrology ◽  
Insolation Forcing ◽  
The Last Glacial

Abstract. The Pliocene is regarded as a potential analogue for future climate with conditions generally warmer-than-today and higher-than-preindustrial atmospheric CO2 levels. Here we present the first orbitally resolved records of continental hydrology and vegetation changes from West Africa for two Pliocene time intervals (5.0–4.6 Ma, 3.6–3.0 Ma), which we compare with records from the last glacial cycle (Kuechler et al., 2013). Our results indicate that changes in local insolation alone are insufficient to explain the full degree of hydrologic variations. Generally two modes of interacting insolation forcings are observed: during eccentricity maxima, when precession was strong, the West African monsoon was driven by summer insolation; during eccentricity minima, when precession-driven variations in local insolation were minimal, obliquity-driven changes in the summer latitudinal insolation gradient became dominant. This hybrid monsoonal forcing concept explains orbitally controlled tropical climate changes, incorporating the forcing mechanism of latitudinal gradients for the Pliocene, which probably increased in importance during subsequent Northern Hemisphere glaciations.

scholarly journals Past climate changes and permafrost depth at the Lake El'gygytgyn site: implications from data and thermal modeling

2013 ◽  
Vol 9 (1) ◽  
pp. 119-133 ◽  
Author(s):  
D. Mottaghy ◽  
G. Schwamborn ◽  
V. Rath
Keyword(s):  
Surface Temperature ◽  
Thermal Regime ◽  
Climate Changes ◽  
Ground Surface ◽  
Temperature Data ◽  
Ice Age ◽  
Drilling Process ◽  
Past Climate ◽  
Ground Surface Temperature ◽  
Recent Climate

Abstract. This study focuses on the temperature field observed in boreholes drilled as part of interdisciplinary scientific campaign targeting the El'gygytgyn Crater Lake in NE Russia. Temperature data are available from two sites: the lake borehole 5011-1 located near the center of the lake reaching 400 m depth, and the land borehole 5011-3 at the rim of the lake, with a depth of 140 m. Constraints on permafrost depth and past climate changes are derived from numerical simulation of the thermal regime associated with the lake-related talik structure. The thermal properties of the subsurface needed for these simulations are based on laboratory measurements of representative cores from the quaternary sediments and the underlying impact-affected rock, complemented by further information from geophysical logs and data from published literature. The temperature observations in the lake borehole 5011-1 are dominated by thermal perturbations related to the drilling process, and thus only give reliable values for the lowermost value in the borehole. Undisturbed temperature data recorded over more than two years are available in the 140 m deep land-based borehole 5011-3. The analysis of these observations allows determination of not only the recent mean annual ground surface temperature, but also the ground surface temperature history, though with large uncertainties. Although the depth of this borehole is by far too insufficient for a complete reconstruction of past temperatures back to the Last Glacial Maximum, it still affects the thermal regime, and thus permafrost depth. This effect is constrained by numerical modeling: assuming that the lake borehole observations are hardly influenced by the past changes in surface air temperature, an estimate of steady-state conditions is possible, leading to a meaningful value of 14 ± 5 K for the post-glacial warming. The strong curvature of the temperature data in shallower depths around 60 m can be explained by a comparatively large amplitude of the Little Ice Age (up to 4 K), with low temperatures prevailing far into the 20th century. Other mechanisms, like varying porosity, may also have an influence on the temperature profile, however, our modeling studies imply a major contribution from recent climate changes.

Phenological behaviour of early spring flowering trees in Spain in response to recent climate changes

2017 ◽  
Vol 132 (1-2) ◽  
pp. 263-273 ◽  
Author(s):  
M. D. Hidalgo-Galvez ◽  
H. García-Mozo ◽  
J. Oteros ◽  
A. Mestre ◽  
R. Botey ◽  
...  
Keyword(s):  
Climate Changes ◽  
Early Spring ◽  
Recent Climate

Recent climate changes over the Tibetan Plateau and their impacts on energy and water cycle: A review

2014 ◽  
Vol 112 ◽  
pp. 79-91 ◽  
Author(s):  
Kun Yang ◽  
Hui Wu ◽  
Jun Qin ◽  
Changgui Lin ◽  
Wenjun Tang ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Climate Changes ◽  
Water Cycle ◽  
The Tibetan Plateau ◽  
Recent Climate

scholarly journals Stock fluctuations of the Japanese common squid, Todarodes pacificus, related to recent climate changes

2002 ◽  
Vol 68 (sup1) ◽  
pp. 226-229 ◽  
Author(s):  
Yasunori SAKURAI ◽  
Hidetada KIYOFUJI ◽  
Sei-ichi SAITOH ◽  
Jun YAMAMOTO ◽  
Tsuneo GOTO ◽  
...  
Keyword(s):  
Climate Changes ◽  
Todarodes Pacificus ◽  
Common Squid ◽  
Recent Climate ◽  
Japanese Common Squid

How far can climate changes help to conserve and restore Garcinia kola Heckel, an extinct species in the wild in Benin (West Africa)

2018 ◽  
Vol 10 (5) ◽  
pp. 203-213 ◽  
Author(s):  
Kévin G. DJOTAN Akotchiffor ◽  
Kossi N. AOUDJI Augustin ◽  
Akouavi F. CODJIA Sylvie ◽  
J. GBÈTOHO Alain ◽  
KOURA Kourouma ◽  
...  
Keyword(s):  
West Africa ◽  
Climate Changes ◽  
Garcinia Kola ◽  
Extinct Species ◽  
In The Wild ◽  
Garcinia Kola Heckel

Recent climate trends for the Volta Basin in West Africa

Weather ◽  
2018 ◽  
Vol 74 (S1) ◽  
Author(s):  
Deborah Darko ◽  
Kwaku A. Adjei ◽  
Samuel N. Odai ◽  
Emmanuel Obuobie ◽  
Ruby Asmah ◽  
...  
Keyword(s):  
West Africa ◽  
Climate Trends ◽  
Volta Basin ◽  
Recent Climate
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