On the Estimation of Deep Atlantic Ventilation from Fossil Radiocarbon Records. I. Modern Reference Estimates

نویسندگان

چکیده

Abstract Radiocarbon dates of fossil carbonates sampled from sediment cores and the seafloor have been used to infer that deep ocean ventilation during last ice age was different today. In this first paired papers, time-averaged abyssal circulation in modern Atlantic is estimated by combining a hydrographic climatology, observational estimates volume transports, Argo float velocities at 1000 m, radiocarbon data, geostrophic dynamics. Different circulation, obtained prior assumptions about flow errors balance, are produced for use robust interpretation records terms deviations present-day flow, which undertaken second paper. For all estimates, meridional transport integrated zonally averaged over hemisphere, 〈 V k 〉, southward between 1000-4000 m both hemispheres, northward 4000-5000 South Atlantic, insignificant North Atlantic. Estimates 〉 two distinct circulations - one based on level no motion 4000 oat become statistically indistinguishable when Δ 14 C data considered. The time scale, defined as τ = /〈 where th layer, century 1000-3000 124±9 yr (203±23 yr) 3000-4000 (North) 269±115

برای دانلود باید عضویت طلایی داشته باشید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

the effect of traffic density on the accident externality from driving the case study of tehran

در این پژوهش به بررسی اثر افزایش ترافیک بر روی تعداد تصادفات پرداخته شده است. به این منظور 30 تقاطع در شهر تهران بطور تصادفی انتخاب گردید و تعداد تصادفات ماهیانه در این تقاطعات در طول سالهای 89-90 از سازمان کنترل ترافیک شهر تهران استخراج گردید و با استفاده از مدل داده های تابلویی و نرم افزار eviews مدل خطی و درجه دوم تخمین زده شد و در نهایت این نتیجه حاصل شد که تقاطعات پر ترافیک تر تعداد تصادفا...

15 صفحه اول

Spider crabs of the Western Atlantic with special reference to fossil and some modern Mithracidae

Spider crabs (Majoidea) are well-known from modern oceans and are also common in the western part of the Atlantic Ocean. When spider crabs appeared in the Western Atlantic in deep time, and when they became diverse, hinges on their fossil record. By reviewing their fossil record, we show that (1) spider crabs first appeared in the Western Atlantic in the Late Cretaceous, (2) they became common ...

متن کامل

Radiocarbon evidence for alternating northern and southern sources of ventilation of the deep Atlantic carbon pool during the last deglaciation.

Recent theories for glacial-interglacial climate transitions call on millennial climate perturbations that purged the deep sea of sequestered carbon dioxide via a "bipolar ventilation seesaw." However, the viability of this hypothesis has been contested, and robust evidence in its support is lacking. Here we present a record of North Atlantic deep-water radiocarbon ventilation, which we compare...

متن کامل

Ventilation of the deep ocean constrained with tracer observations and implications for radiocarbon estimates of ideal mean age

Article history: Received 31 May 2011 Received in revised form 12 January 2012 Accepted 31 January 2012 Available online xxxx Editor: G. Henderson

متن کامل

Impact of fossil fuel emissions on atmospheric radiocarbon and various applications of radiocarbon over this century.

Radiocarbon analyses are commonly used in a broad range of fields, including earth science, archaeology, forgery detection, isotope forensics, and physiology. Many applications are sensitive to the radiocarbon ((14)C) content of atmospheric CO2, which has varied since 1890 as a result of nuclear weapons testing, fossil fuel emissions, and CO2 cycling between atmospheric, oceanic, and terrestria...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

ژورنال

عنوان ژورنال: Journal of Physical Oceanography

سال: 2021

ISSN: ['1520-0485', '0022-3670']

DOI: https://doi.org/10.1175/jpo-d-20-0153.1