A multi-model analysis of the resolution influence on precipitation climatology in the Gulf Stream region
Using climate simulations from coupled and uncoupled general circulation models, this study investigates the influence of horizontal resolution in both atmospheric and oceanic model components on the mean precipitation over the Gulf Stream (GS) region. For this purpose, three sets of model experiments are analyzed. The first two examine the effects of increasing horizontal resolution of an atmospheric general circulation model (AGCM) gradually from 100 to 10 km under fixed oceanic settings.
The Arctic: A greenhouse gas hotspot?
Vast amounts of organic carbon are stored in Arctic permafrost soils and in the seabed of the Arctic shelves. In a warming world, some of this carbon might be degraded as carbon dioxide or methane and amplify the terrestrial greenhouse effect. How fast and how strong is this climate feedback? Earth System Model simulations predict increasing carbon losses from thawing permafrost during this century. However the global context, Arctic surface-atmosphere fluxes of these gases are currently still very modest.
Rapid Evolutionary Responses to Radical Habitat Change
How can we assess whether populations have the potential to evolve in response to catastrophic environmental change, such as biological invasions, oil spills, or climate change? To what extent are populations constrained from undergoing an evolutionary response? And would independently derived populations show evidence of parallel evolution?
Dynamics-Oriented Diagnostics for the Madden–Julian Oscillation
Realistic simulations of the Madden–Julian oscillation (MJO) by global climate models (GCMs) remain a great challenge. To evaluate GCM simulations of the MJO, the U.S. CLIVAR MJO Working Group developed a standardized set of diagnostics, providing a comprehensive assessment of statistical properties of the MJO. Here, a suite of complementary diagnostics has been developed that provides discrimination and assessment of MJO simulations based on the perception that the MJO propagation has characteristic dynamic and thermodynamic structures.
Speleothems at the interface of climatology, ecology and archaeology
In 2006, Professor Gideon Henderson (Oxford University) stated that "For paleoclimate, the past two decades have been the age of the ice core. The next two may be the age of the speleothem". This rather bold statement suggests that speleothems (stalagmites, stalactites, and flowstones) have the potential to deliver ice-core-like records of past climatic and environmental changes. In his talk, Prof.
Mechanism sustaining carbon/ climate feedbacks under 21st century climate change investigated using GFDL’s Earth System Model ESM2M
Satellite observations of convection–wind coupling
Satellite scatterometers measure surface winds over the global oceans, but these observations have historically been limited by rain-related errors. We have recently developed techniques to circumvent these rain-related errors, allowing for direct observational study of convection–wind coupling over the ocean. We use these corrected wind data to detect cool downdrafts from mesoscale convective systems (MCSs) for the first time. These wind observations are validated against surface buoys and satellite observations of cloud-top temperature.
Heating and Moistening of the MJO during DYNAMO in ECMWF Reforecasts
The Madden-Julian oscillation (MJO), the dominant mode of tropical intraseasonal variability, has profound impacts on a wide range of weather and climate phenomena in the tropics and extratropics. Despite decades of intensive studies, our understanding of its physical mechanisms has remained controversial. While most previous work has focused on processes associated with the MJO itself, comparing the MJO and other types of tropical convection might provide valuable insights into understanding the MJO.