Climate of the Past

What speleothems can tell about the past climates !

Carole Nehme (University of Rouen) and Michael Deininger (University College Dublin) September 5, 2017

Speleothem laminas used to reproduce past precipitation patterns, soil productivity and its carbon dioxide content. Modified from Tan et al. (2006) and Johnson et al. (2006).

Name of the proxy: Stable isotope ratios of carbonates in speleothems Type of proxy: Precipitation, atmospheric circulation, CO2 availability in soil, soil productivity Paleoenvironment: Continental environments Period of time investigated: Present day to 10 million years How does it work? Speleothems are inorganic carbonate deposits growing in caves that form from super-saturated cave waters (wit ...[Read More]

Of butterflies and climate: how mathematics helps us to better understand the atmosphere

Gabriele Messori and Davide Faranda August 1, 2017

Applied mathematics is often seen as an obscure field, which the general public has no hope of ever understanding. In the context of climate science, this is far from the truth. In fact, many mathematical concepts and ideas applied to the study of the climate system stem from intuitive arguments. While their implementation can be very complex, understanding the basic ideas behind them does not req ...[Read More]

Corals, the thermometers of the past!

Emilie Dassié July 3, 2017

Picture of a diver on top of a coral colony in the American Samoa (credit B.K. Linsley).

Name of proxy: Coral Type of record: Oceanic variability Paleoenvironment: Fringing reefs, barrier reefs, or atoll Period of time investigated: Mainly the last 200 years How does it works ? What we usually picture as a coral is actually a colony of tiny living animals called coral polyps, which are closely related to jellyfish or anemones. They live in symbiosis with photosynthetic algae called Zo ...[Read More]

Ostracods, the sentinels of past oceanic circulation

Marie-Béatrice Forel April 28, 2017

Figure 1. Left: Inside view of a dissected male of Cyprideis torosa with soft parts and appendages visible (Photo Dietmar Keyser). Right: Fossil specimen of the species Cytheropteron eximium Alexander, 1933 from the Cenomanian, Late Cretaceous (about 93 Ma) of the Western Interior Basin, USA (Photo MBF). For both photos, scale bar is 100 µm.

Name of the proxy Ostracoda Type of proxy Paleoenvironment proxy Paleoenvironment All types of aquatic environments but here we will focus on marine waters Period of time investigated Phanerozoic How does it work? Ostracoda are crustacean of millimetre size which have inhabited all types of marine environments from the Ordovician to today (e.g. Salas et al. 2007) and colonized continental water bo ...[Read More]