scholarly journals Evolution of dry and wet spells under climate change over North‐Eastern North America

2021 ◽  
Author(s):  
Pradeebane Vaittinada Ayar ◽  
Alain Mailhot
Keyword(s):  
Climate Change ◽  
North America ◽  
Eastern North America ◽  
North Eastern ◽  
Wet Spells

A radiocarbon chronology of Holocene climate change and sea-level rise at the Delmarva Peninsula, US Mid-Atlantic Coast

The Holocene ◽  
2021 ◽  
pp. 095968362110482
Author(s):  
Kelvin W Ramsey ◽  
Jaime L. Tomlinson ◽  
C. Robin Mattheus
Keyword(s):  
Climate Change ◽  
North America ◽  
Sea Level Rise ◽  
Sea Level ◽  
Early Holocene ◽  
Eastern North America ◽  
Delmarva Peninsula ◽  
The Holocene ◽  
Cool Climate ◽  
And Sea Level

Radiocarbon dates from 176 sites along the Delmarva Peninsula record the timing of deposition and sea-level rise, and non-marine wetland deposition. The dates provide confirmation of the boundaries of the Holocene subepochs (e.g. “early-middle-late” of Walker et al.) in the mid-Atlantic of eastern North America. These data record initial sea-level rise in the early Holocene, followed by a high rate of rise at the transition to the middle Holocene at 8.2 ka, and a leveling off and decrease in the late-Holocene. The dates, coupled to local and regional climate (pollen) records and fluvial activity, allow regional subdivision of the Holocene into six depositional and climate phases. Phase A (>10 ka) is the end of periglacial activity and transition of cold/cool climate to a warmer early Holocene. Phase B (10.2–8.2 ka) records rise of sea level in the region, a transition to Pinus-dominated forest, and decreased non-marine deposition on the uplands. Phase C (8.2–5.6 ka) shows rapid rates of sea-level rise, expansion of estuaries, and a decrease in non-marine deposition with cool and dry climate. Phase D (5.6–4.2 ka) is a time of high rates of sea-level rise, expanding estuaries, and dry and cool climate; the Atlantic shoreline transgressed rapidly and there was little to no deposition on the uplands. Phase E (4.2–1.1 ka) is a time of lowering sea-level rise rates, Atlantic shorelines nearing their present position, and marine shoal deposition; widespread non-marine deposition resumed with a wetter and warmer climate. Phase F (1.1 ka-present) incorporates the Medieval Climate Anomaly and European settlement on the Delmarva Peninsula. Chronology of depositional phases and coastal changes related to sea-level rise is useful for archeological studies of human occupation in relation to climate change in eastern North America, and provides an important dataset for future regional and global sea-level reconstructions.

scholarly journals Effects of aerosols on precipitation in north-eastern North America

2014 ◽  
Vol 14 (10) ◽  
pp. 5111-5125 ◽  
Author(s):  
R. Mashayekhi ◽  
J. J. Sloan
Keyword(s):  
North America ◽  
Atlantic Coast ◽  
Inverse Correlation ◽  
Cloud Droplet ◽  
Cloud Microphysics ◽  
Convective Precipitation ◽  
Eastern North America ◽  
Anthropogenic Aerosols ◽  
Convective Rain ◽  
North Eastern

Abstract. The changes in precipitation in north-eastern North America caused by chemistry – and particularly anthropogenic aerosols – are investigated using the Weather Research Forecasting with Chemistry (WRF/Chem v3.2) model. The simulations were carried out for a five-month period from April to August 2009. The model results show that non-negligible changes in both convective and cloud-resolved (non-convective) precipitation are caused by chemistry and/or aerosols over most parts of the domain. The changes can be attributed to both radiative and microphysical interactions with the meteorology. A chemistry-induced change of approximately −15% is found in the five-month mean daily convective precipitation over areas with high convective rain; most of this can be traced to radiative effects. Total convective rain is greater than total non-convective rain in the domain, but a chemistry-induced increase of about 30% is evident in the five-month mean daily non-convective precipitation over the heavily urbanized parts of the Atlantic coast. The effects of aerosols on cloud microphysics and precipitation were examined for two particle size ranges, 0.039–0.1 μm and 1–2.5 μm, representing the nucleation and accumulation modes respectively. Strongly positive spatial correlation between cloud droplet number and non-convective rain are found for activated (cloud-borne) aerosols in both size ranges. Non-activated (interstitial) aerosols have a positive correlation with cloud droplet number and non-convective rain when they are small and an inverse correlation for larger sizes.

A revision of the genus Orchestia Leach, 1814 with the reinstatement of O. inaequalipes (K.H. Barnard, 1951), the designation of a neotype for Orchestia gammarellus (Pallas, 1776) and the description of three new species (Crustacea: Amphipoda: Talitridae: Talitrinae)

Zootaxa ◽  
2020 ◽  
Vol 4808 (2) ◽  
pp. 201-250
Author(s):  
ALAN A. MYERS ◽  
JAMES K. LOWRY
Keyword(s):  
New Species ◽  
North America ◽  
South America ◽  
Type Species ◽  
Pacific Coast ◽  
Species Group ◽  
Eastern North America ◽  
The Pacific ◽  
North Eastern ◽  
Three New Species

The amphipod genus Orchestia is revised. It now includes 10 species of which three are new: O. forchuensis sp. nov. from north-eastern North America and Iceland., O. perezi sp. nov. from Chile and O. tabladoi sp. nov. from Argentina. Orchestia inaequalipes (K.H. Barnard 1951) is reinstated. The type species of the genus, O. gammarellus is redescribed based on material from Fountainstown, Ireland and a neotype is established to stabilize the species. The species was originally described from a garden in Leiden, far from the sea. Its true identity is unknown and no type material exists. Orchestia gammarellus (Pallas, 1776) is shown to be a sibling species group with members in both hemispheres of the temperate Atlantic as well along the Pacific coast of South America. A hypothesis for the establishment of the current distribution of Orchestia species is presented that extends back to the Cretaceous. 

Pre-colonial (A.D. 1100–1600) sedimentation related to prehistoric maize agriculture and climate change in eastern North America

Geology ◽  
2011 ◽  
Vol 39 (4) ◽  
pp. 363-366 ◽  
Author(s):  
G.E. Stinchcomb ◽  
T.C. Messner ◽  
S.G. Driese ◽  
L.C. Nordt ◽  
R.M. Stewart
Keyword(s):  
Climate Change ◽  
North America ◽  
Eastern North America ◽  
Maize Agriculture

Vegetation and Climate Change in Eastern North America Since the Last Glacial Maximum

Ecology ◽  
1991 ◽  
Vol 72 (6) ◽  
pp. 2038-2056 ◽  
Author(s):  
I. Colin Prentice ◽  
Patrick J. Bartlein ◽  
Thompson Webb
Keyword(s):  
Climate Change ◽  
North America ◽  
Last Glacial Maximum ◽  
Glacial Maximum ◽  
Eastern North America ◽  
Last Glacial ◽  
The Last Glacial Maximum ◽  
Vegetation And Climate ◽  
The Last Glacial

The Galium trifidum group (Galium sect. Aparinoides, Rubiaceae)

1976 ◽  
Vol 54 (16) ◽  
pp. 1911-1925 ◽  
Author(s):  
C. Puff
Keyword(s):  
North America ◽  
Eastern North America ◽  
Great Lakes Region ◽  
Western North America ◽  
Eastern Asia ◽  
Chromosome Counts ◽  
New Classification ◽  
North Eastern ◽  
North Western

By using morphology, karyology, pollen size, leaf flavonoids, ecological observations, and modification experiments, a new classification of the Galium trifidum group is proposed. Nine taxa in five species are recognized: (1) G. tinctorium, with ssp. tinctorium and sap. floridanum (new comb.) in eastern North America; (2) G. brevipes, a rare species centered in the Great Lakes region; (3) G. trifidum, with ssp. trifidum in northern North America. Asia, and Europe, ssp. columbianum (new comb.) in (north)western North America and (north)eastern Asia, and ssp. subbiflorum (new comb.) and ssp. halophilum (new comb.) in northern North America; (4) G. innocuum in southeastern Asia; (5) G. karakulense in central Asia.New chromosome counts of n = 12 and 2n = 24 are reported for G. tinctorium ssp. tinctorium and ssp. floridanum; and G. trifidum ssp. trifidum, ssp. columbianum, and ssp. subbiflorum.

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