Sökresultat

Sea spray aerosol (SSA) contributes significantly to natural aerosol particle concentrations globally, in marine areas even dominantly. The potential changes of the omnipresent inorganic fraction of SSA due to atmospheric ageing is largely unexplored. In the atmosphere, SSA may exist as aqueous phase solution droplets or as dried solid or amorphous particles. We demonstrate that ageing of liquid N

The multiple-year drought that started in 2011 and reached climax in 2015 was the most severe and prolonged one in the semiarid northeastern (NE) Brazil in recent decades. This study aimed to investigate the reservoir surface water volume (SWV) variation in NE Brazil from 2009 to 2017 in four representative regions covering a total area of approximately 10,000 km2 there and encompassing 2,140 rese

Explosive volcanic eruptions can reach the stratosphere and cause elevated concentrations of sulphate particles for months to years. When these particles descend into the troposphere, they can impact cirrus clouds though to what degree is unknown. In this study, we combine three satellite data sets to investigate the impact of downwelling sulphate aerosol on midlatitude cirrus clouds during spring

A system we denote Seg2Pose is presented which converts pixel coordinate tracks, represented by instance segmentation masks across multiple video frames, into world coordinate pose tracks, for road users seen by static surveillance cameras. The road users are bound to a ground surface represented by a number of 3D points and does not necessarily have to be perfectly flat. The system works with one

Atmospheric new-particle formation (NPF) affects climate by contributing to a large fraction of the cloud condensation nuclei (CCN). Highly oxygenated organic molecules (HOMs) drive the early particle growth and therefore substantially influence the survival of newly formed particles to CCN. Nitrogen oxide (NOx) is known to suppress the NPF driven by HOMs, but the underlying mechanism remains larg

Smoke from western North American wildfires reached the stratosphere in large amounts in August 2017. Limb-oriented satellite-based sensors are commonly used for studies of wildfire aerosol injected into the stratosphere (OMPS-LP (Ozone Mapping and Profiler Suite Limb Profiler) and SAGE III/ISS (Stratospheric Aerosol and Gas Experiment III on the International Space Station)). We find that these m

The Sun sporadically produces eruptive events leading to intense fluxes of solar energetic particles (SEPs) that dramatically disrupt the near-Earth radiation environment. Such events have been directly studied for the last decades but little is known about the occurrence and magnitude of rare, extreme SEP events. Presently, a few events that produced measurable signals in cosmogenic radionuclides

Atmospheric mineral dust not only interacts with the climate system by scattering incoming solar radiation and affecting atmospheric photochemistry, but also contributes critical nutrients to marine and terrestrial ecosystems. In a high-resolution analysis of paleodust deposition, peat development and soil dust sources, we assess the interplay between dust deposition and bog development of the Dav

https://www.sol.lu.se/media/utbildning/dokument/kurser/ARAH03/20121/ARAH03.pdf - 2026-05-28

Investigations of past climate dynamics rely on accurate and precise chronologies of the employed climate reconstructions. The radiocarbon dating calibration curve (IntCal13) and the Greenland ice core chronology (GICC05) represent two of the most widely used chronological frameworks in paleoclimatology of the past 1/4 g50g000 years. However, comparisons of climate records anchored on these chrono

Twenty-five tree-ring width (TRW) chronologies, developed from moisture sensitive peatland trees in Sweden and Lithuania, and representing eight periods during the mid-Holocene to present, were analysed regarding common periodicities (cycles). Periods of 13-15, 20-22, and 30-35 years were found in most chronologies, while 8-10, 18-19, and 60-65 year periodicities were observed as well, but less co

This article focuses on a process of recognition of prior learning (RPL) in higher education. It is based on experiences from a project carried out in collaboration between the University of Lund, Linköping University and two trade unions in Sweden. The aim of the project was to find ways of recognising prior learning for accreditation of course credits at university level. In the project and its

Robustly testing hypotheses of geographic synchroneity of abrupt and extreme change during the late Pleistocene (60,000 to 11,650 years ago) requires a level of chronological precision often lacking in ice, marine and terrestrial sequences. Here we report a bidecadally-resolved New Zealand kauri (Agathis australis) tree-ring sequence spanning two millennia that preserves a record of atmospheric ra

A feedback-based scheme for cooperative content distribu- tion for mobile systems aimed at reducing energy and li- censed spectrum usage is presented. The paper is motivated by the problems in implementing peer-to-peer based content distribution in mobile networks due to the risks of unfair en- ergy expenditure. A technique for incentivizing cooperation and for enforcing agreements between peers i

This note proposes a unified approach to analyse linear time-invariant consensus problems via the use of integral quadratic constraints (IQCs) without recourse to loop transformations, which may cloud the inherent structural properties of the multi-agent networked systems. The main technical hindrance to using IQCs lies in the presence of the marginally stable integral action in consensus setups.