@article {2960,
	title = {The dynamics of warming during the last deglaciation in high-elevation regions of Eastern Equatorial Africa},
	journal = {Quaternary Science Reviews},
	volume = {281},
	year = {2022},
	month = {Jan-04-2022},
	pages = {107416},
	abstract = {Tropical mountain environments, such as the Rwenzori Mountains in equatorial Africa, are thought to be particularly sensitive to climate change. Ongoing warming in the Rwenzori is impacting local environments and communities through glacial retreat, fires, and flooding. Paleoclimate reconstructions from elsewhere in Africa suggest considerable warming accompanied glacier retreat during the last glacial termination, from \~{}21 thousand years before present (ka) through the early to mid-Holocene. Quantifying these changes has been difficult but could help to assess future impacts in the Rwenzori. Here, we present a \~{}21 thousand-year (kyr) temperature reconstruction based on the relative abundance of branched glycerol dialkyl glycerol tetraethers (brGDGTs) from Lake Mahoma (2,990 m above sea level; m asl) in the Rwenzori Mountains, Uganda. Our record, paired with existing Rwenzori glacial moraine 10Be exposure ages, suggests that deglacial warming and glacial retreat began by \~{}20 ka and accelerated at \~{}18{\textendash}18.5 ka. The timing of the onset of rapid warming matches the timing of the post-glacial rise in radiative forcing from atmospheric greenhouse gases (GHGs) from Antarctic ice cores (Brook et al., 1996; Marcott et al., 2014; Monnin et al., 2004; Schilt et al., 2010). Our temperature reconstruction registers \~{}4.9 {\textdegree}C warming from the Last Glacial Maximum (LGM) to the late Holocene. This increase is larger than the average \~{}2-4 {\textdegree}C warming observed in records from lower elevation sites in tropical East Africa, but similar to that observed at other high-elevation sites in this region. The increased warming at higher elevations thus confirms that the temperature lapse rate steepened during the LGM over this region. Our results also indicate \~{}3 {\textdegree}C of warming during the mid-Holocene relative to the late Holocene. This suggests that the freezing-level height rose above Rwenzori summit elevations at that time, likely causing complete deglaciation of the Rwenzori Mountains from \~{}5 to 7 ka. The mid-Holocene is thus a potential analog for the glacial and environmental changes that these mountains are likely to experience in the coming decades. Overall, the timing and magnitude of temperature change observed in our record has important implications for climate model projections of future warming in tropical Africa.},
	issn = {02773791},
	doi = {10.1016/j.quascirev.2022.107416},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0277379122000476},
	author = {Garelick, Sloane and Russell, James and Richards, Adin and Smith, Jamila and Kelly, Meredith and Anderson, Nathan and Jackson, Margaret S. and Doughty, Alice and Nakileza, Bob and Ivory, Sarah and Dee, Sylvia and Marshall, Charlie}
}
@article {2800,
	title = {Changes in glacial meltwater alter algal communities in lakes of Scoresby Sund, Renland, East Greenland throughout the Holocene: Abrupt reorganizations began 1000 years before present},
	journal = {The Holocene},
	volume = {27},
	year = {2017},
	month = {Feb-07-2018},
	pages = {929 - 940},
	abstract = {We investigated the response of lake algal communities to changes in glacial meltwater from the Renland Ice Cap (Greenland) through the Holocene to assess whether influxes always elicit consistent responses or novel responses. We measured sedimentary algal pigments in two proximal lakes, snow-fed Raven and glacier- and snow-fed Bunny Lake, and diatom community structure and turnover in Bunny Lake. Diatom data were not available in Raven Lake. We also modeled lake-level change in Bunny Lake to identify how glacial meltwater may have altered diatom habitat availability through time. Through a series of glacier advances and retreats over the Holocene, the algal response in Bunny Lake was relatively constant until approximately 1015 yr BP, after which there were major changes in sedimentary algal remains. Algal pigment concentrations sharply declined, and diatom species richness increased. Diatom community structure underwent three reorganizations. Until 1015 yr BP, assemblages were dominated by Pinnularia braunii and Aulacoseira pffaffiana. However, approximately 1015{\textendash}480 yr BP, these species declined and Tabellaria flocculosa and Hannaea arcus became a significant component of the assemblage. Approximately 440 yr BP, A. pfaffiana increased along with species indicating elevated nitrogen. In contrast, the algal pigment records from nearby snow-fed Raven Lake showed different and minimal change through time. Our results suggest that changes in the magnitude and composition of meltwater in our two study lakes were unique over the last 1000 yr BP and elicited a non-linear threshold response absent during other periods of glacier advance and retreat. Deciphering the degree to which glaciers structure algal communities over time has strong implications for lakes as glaciers continue to recede.
},
	keywords = {climate, Diatom, East Greenland, glacier, Holocene, Lake level},
	issn = {0959-6836},
	doi = {10.1177/0959683616678468},
	url = {http://journals.sagepub.com/doi/10.1177/0959683616678468},
	author = {Slemmons, Krista EH and Medford, Aaron and Hall, Brenda L and Stone, Jeffery R and McGowan, Suzanne and Lowell, Thomas and Kelly, Meredith and Saros, Jasmine E}
}
