TY  - JOUR
A1  - Kwiecien, Olga
A1  - Arz, Helge Wolfgang
A1  - Lamy, Frank
A1  - Plessen, Birgit
A1  - Bahr, André
A1  - Haug, Gerald H.
T1  - North Atlantic control on precipitation pattern in the eastern Mediterranean/Black Sea region during the last glacial
N2  - Based on Proxy records from western Black Sea cores, we provide a comprehensive Study of climate change during the last glacial maximum and late-glacial period in the Black Sea region. For the first time we present a record of relative changes in precipitation for NW Anatolia based on variations in the terrigenous supply expressed as detrital carbonate concentration. The good correspondence between reconstructed rainfall intensity in NW Anatolia and past western Mediterranean sea Surface temperatures (SSTs) implies that during the glacial period the precipitation variability was controlled, like today, by Mediterranean cyclonic disturbances. Periods of reduced precipitation correlate well with low SSTs in the Mediterranean related to Heinrich events H1 and H2. Stable oxygen isotopes and lithological and mineralogical data point to a significant modification in the dominant freshwater/sediment source concomitant to the meltwater inflow after 16.4 cal ka BP. This change implies intensification of the northern sediment source and, with other records from the Mediterranean region, consistently suggests a reorganization of the atmospheric circulation pattern affecting the hydrology of the European continent. The early deglacial northward retreat of both atmospheric and oceanic polar fronts was responsible for the warming in the Mediterranean region, leading simultaneously to more humid conditions in central and northern Europe.
Y1  - 2009
UR  - http://www.sciencedirect.com/science/journal/00335894
U6  - https://doi.org/10.1016/j.yqres.2008.12.004
SN  - 0033-5894
ER  - 
TY  - JOUR
A1  - Ren, Haojia
A1  - Sigman, Daniel M.
A1  - Meckler, Anna Nele
A1  - Plessen, Birgit
A1  - Robinson, Rebecca S.
A1  - Rosenthal, Yair
A1  - Haug, Gerald H.
T1  - Foraminiferal isotope evidence of reduced nitrogen fixation in the Ice Age Atlantic ocean
N2  - Fixed nitrogen ( N) is a limiting nutrient for algae in the low- latitude ocean, and its oceanic inventory may have been higher during ice ages, thus helping to lower atmospheric CO2 during those intervals. In organic matter within planktonic foraminifera shells in Caribbean Sea sediments, we found that the N-15/N-14 ratio from the last ice age is higher than that from the current interglacial, indicating a higher nitrate N-15/N-14 ratio in the Caribbean thermocline. This change and other species- specific differences are best explained by less N fixation in the Atlantic during the last ice age. The fixation decrease was most likely a response to a known ice age reduction in ocean N loss, and it would have worked to balance the ocean N budget and to curb ice age- interglacial change in the N inventory.
Y1  - 2009
UR  - http://www.sciencemag.org/
U6  - https://doi.org/10.1126/science.1165787
SN  - 0036-8075
ER  -