Sökresultat

Cloud microphysics is substantially affected by aerosol loading and the resulting changes in the reflective properties of the clouds can significantly affect the global radiation budget. A study of how marine low-level clouds over Barents Sea and the northern parts of the Norwegian Sea are affected by air mass origin has been performed by combining ground-based aerosol measurements with satellite

The Murray Basin is a low-lying but extensive intracratonic depocentre in southeastern Australia, preserving an extraordinary record of Late Neogene sedimentation. New stratigraphic and sedimento-logic data allow the long-term evolution of the basin to be re-evaluated and suggest a significant role for: (1) tectonism in controlling basin evolution, and (2) progressive and step-wise climatic change

Sparse tensor computations suffer from irregular memory access patterns that degrade cache performance. While software prefetching can mitigate this, existing compiler approaches lack the semantic insight needed for effective optimization. We present ASaP, an automatic software prefetching framework integrated within MLIR’s sparse tensor dialect. By leveraging semantic information-tensor formats a

The Asian Summer Monsoons (ASM) represent the main source of precipitation in China and East Asia with about one third of the world population and a region of widespread civilizations. Identifying the temporal and spatial patterns (pathways) of these monsoonal events during the Late Holocene to today has been a matter of debate amongst the scientific community. Here we show that the distribution

We present a method for augmenting a nominal controller with a peak filter to achieve improved rejection of narrowband disturbances. The method is based on consideration of the open-loop Nyquist curve, which arguably makes it more intuitive and flexible than previous approaches. We also comment on some implementation aspects, and give an application example based on a control problem at a particle

The Northern Hemisphere experienced dramatic changes during the last glacial, featuring vast ice sheets and abrupt climate events, while high northern latitudes during the last interglacial (Eemian) were warmer than today. Here we use high-resolution aerosol records from the Greenland NEEM ice core to reconstruct the environmental alterations in aerosol source regions accompanying these changes. S

This package facilitates working with probability distributions by means of Monte-Carlo methods, in a way that allows for propagation of probability distributions through functions. This is useful for, e.g., nonlinear uncertainty propagation. A variable or parameter might be associated with uncertainty if it is measured or otherwise estimated from data. We provide two core types to represent proba

Simulations of a regional (approx. 50 km resolution) circulation model REMOiso with embedded stable water isotope module covering the period 1958-2001 are compared with the two instrumental climate and four isotope series (δ18O) from western Svalbard. We examine the data from ice cores drilled on Svalbard ice caps in 1997 (Lomonosovfonna, 1250 m asl) and 2005 (Holtedahlfonna, 1150 m asl) and the G

Ice core studies have proved thed18O in Greenland precipitation to be correlated to thephase of the North Atlantic Oscillation (NAO). This subject has also been investigated inmodeling studies. However, these studies have either had severe biases in thed18O levels,or have not been designed to be compared directly with observations. In this study wenudge a meso‐scale climate model fitted with stabl

We consider the problem of feasible coordination control for multiple homogeneous or heterogeneous mobile vehicles subject to various constraints (nonholonomic motion constraints, holonomic coordination constraints, equality/inequality constraints etc). We develop a general framework involving differential-algebraic equations and viability theory to describe and determine coordination feasibility

The sensitivity of interglacial Greenland temperature to orbital and CO 2 forcing is investigated using the NorthGRIP ice core data and coupled ocean-atmosphere IPSL-CM4 model simulations. These simulations were conducted in response to different interglacial orbital configurations, and to increased CO 2 concentrations. These different forcings cause very distinct simulated seasonal and latitudina

Future internet-of-things systems need to be able to combine heterogeneous services and support weak connectivity. In this paper, we introduce ComPOS, a new domain-specific language for composing services in IoT systems. We show how Maria, a bird watcher, can use ComPOS to build a system that allows her to spy on birds in the garden while she is not at home. We demonstrate how ComPOS handles the u

Cosmogenic radionuclides, such as 10Be and 14C, share a common production signal, with their formation in the Earth's upper atmosphere modulated by changes to the geomagnetic field, as well as variations in the intensity of the solar wind. Here, we use this common production signal to compare between the radiocarbon (IntCal)and Greenland ice-core (GICC05)timescales, utilising the most pronounced c

Current global models of the carbon (C) cycle consider only vertical gas exchanges between terrestrial or oceanic reservoirs and the atmosphere, thus not considering the lateral transport of carbon from the continents to the oceans. Therefore, those models implicitly consider all of the C which is not respired to the atmosphere to be stored on land and hence overestimate the land C sink capability

The Arctic is warming at twice the global average speed, and the warming-induced increases in biogenic volatile organic compounds (BVOCs) emissions from Arctic plants are expected to be drastic. The current global models' estimations of minimal BVOC emissions from the Arctic are based on very few observations and have been challenged increasingly by field data. This study applied a dynamic ecosyst

Monoterpenes emitted from plants have an important role in atmospheric chemistry through changing atmospheric oxidative capacity, forming new particles and secondary organic aerosols. The emission rates and patterns can be affected by changing climate. In this study, emission responses to six years of climatic manipulations (elevated CO2, extended summer drought and night-time warming) were invest