A5071691468- Atmospheric chemistry and aerosols
- Atmospheric and Environmental Gas Dynamics
- Atmospheric Ozone and Climate
- Climate variability and models
- Atmospheric aerosols and clouds
- Air Quality and Health Impacts
- Air Quality Monitoring and Forecasting
- Arctic and Antarctic ice dynamics
- Vehicle emissions and performance
- Meteorological Phenomena and Simulations
- Oceanographic and Atmospheric Processes
- Scientific Computing and Data Management
- Distributed and Parallel Computing Systems
- Science and Climate Studies
- Ocean Acidification Effects and Responses
- Methane Hydrates and Related Phenomena
- Scientific Research and Discoveries
- Ionosphere and magnetosphere dynamics
- Geology and Paleoclimatology Research
- Machine Learning in Materials Science
- Arctic and Russian Policy Studies
- Spaceflight effects on biology
- Polar Research and Ecology
- Climate change and permafrost
- Marine and coastal ecosystems
Linköping University
2014-2023
Stockholm University
2009-2016
Bolin Centre for Climate Research
2010-2016
National Institute of Water and Atmospheric Research
2002-2010
Simulations of the stratosphere from thirteen coupled chemistry‐climate models (CCMs) are evaluated to provide guidance for interpretation ozone predictions made by same CCMs. The focus evaluation is on how well fields and processes that important determining distribution represented in simulations recent past. core period 1980 1999 but long‐term trends compared an extended (1960–2004). Comparisons polar high‐latitude temperatures show most CCMs have only small biases Northern Hemisphere...
Abstract. The objective of this study is to document and evaluate recent changes updates the module for aerosols aerosol–cloud–radiation interactions in atmospheric CAM4-Oslo core version Norwegian Earth System Model (NorESM), NorESM1-M. Particular attention paid role natural organics, sea salt, mineral dust determining gross aerosol properties as well anthropogenic contribution these associated direct indirect radiative forcing. extended from earlier versions that have been published,...
Recent measurements of the apparent kinetic isotope effect (KIE) methane (CH 4 ) atmospheric sink in extratropical Southern Hemisphere (ETSH) have shown KIE to be larger magnitude than expected if were hydroxyl radical (OH • alone. We present results from simulations using U.K. Met Office's Unified Model (UM) evaluate whether atomic chlorine (Cl marine boundary layer (MBL) could give this effect. modify UM include sources 12 CH and 13 , soil stratospheric sinks, a tropospheric OH sink. Also...
The 11‐year solar cycles in ozone and temperature are examined using new simulations of coupled chemistry climate models. results show a secondary maximum stratospheric tropical ozone, agreement with satellite observations contrast most previously published simulations. mean model response varies by up to about 2.5% 0.8 K during typical cycle, at the lower end observed ranges peak responses. Neither upper atmospheric effects energetic particles nor presence quasi biennial oscillation is...
Abstract. The representation of the Tropical Tropopause Layer (TTL) in 13 different Chemistry Climate Models (CCMs) designed to represent stratosphere is analyzed. Simulations for 1960–2005 and 1980–2100 are compared reanalysis model output. CCMs able reproduce basic structure TTL. There a large (10 K) spread annual mean tropical cold point tropopause temperatures. historical trends pressure obtained from products. Simulated temperatures not consistent across models or reanalyses. both level...
Abstract. Understanding Arctic climate change requires knowledge of both the external and local drivers as well feedbacks within system. An feedback mechanism relating changes in sea ice extent to an alteration emission salt aerosol consequent radiative balance is examined. A set idealized model simulations were performed quantify effects emissions induced by prescribed extent. The was forced using concentrations consistent with present day conditions projections for 2100. Sea increase...
We investigated the millennial variability (1000 A.D.-2000 A.D.) of global biogenic volatile organic compound (BVOC) emissions by using two independent numerical models: The Model Emissions Gases and Aerosols from Nature (MEGAN), for isoprene, monoterpene, sesquiterpene, Lund-Potsdam-Jena-General Ecosystem Simulator (LPJ-GUESS), isoprene monoterpenes. found trends to be mostly affected land cover atmospheric carbon dioxide changes, whereas monoterpene sesquiterpene emission were dominated...
Coupled chemistry‐climate model simulations covering the recent past and continuing throughout 21st century have been completed with a range of different models. Common forcings are used for halogen amounts greenhouse gas concentrations, as expected under Montreal Protocol (with amendments) Intergovernmental Panel on Climate Change A1b Scenario. The Antarctic ozone hole compared using commonly diagnostics: minimum ozone, maximum area below 220 DU, mass deficit DU. Despite fact that processes...
Recently, it was shown that of the ozone‐depleting substances currently emitted, N 2 O emissions (the primary source stratospheric NO x ) dominate, and are likely to do so throughout 21st century. To investigate links between concentrations, effects on ozone in a changing climate, evolution from 1960 2100 simulated using NIWA‐SOCOL chemistry‐climate model. The yield is reduced due cooling strengthening Brewer‐Dobson circulation. After accounting for yield, additional weakening cycle...
In this study Moderate Resolution Imaging Spectroradiometer (MODIS) Aqua retrievals of aerosol optical thickness (AOT) at 555 nm are compared to Sun photometer measurements from Svalbard for a period 9 years. For the 642 daily coincident that were obtained, MODIS AOT generally varies within predicted uncertainty retrieval over ocean (ΔAOT = ±0.03 ± 0.05 · AOT). The results remote sensing have been used examine accuracy in estimates properties Arctic, generated by global climate models and...
Abstract. The connection between the El Niño Southern Oscillation (ENSO) and Northern polar stratosphere has been established from observations atmospheric modeling. Here a systematic inter-comparison of sensitivity modeled to ENSO in Chemistry Climate Models (CCMs) is reported. This work uses results number CCMs included 2006 ozone assessment. In lower stratosphere, mean all model simulations reports warming vortex during strong events February–March, consistent with but smaller than...
The dependence of Antarctic ozone depletion on midlatitude planetary wave activity and South Pole temperatures was examined from 1979–2003 using NCEP/NCAR reanalyses column data. annual severity quantified the seasonal mean daily mass deficit (OMD). OMD effective equivalent stratospheric chlorine (EESC) removed to produce an anomaly time series (OMD′). Similar for 100 hPa (T′) 20 hPa, 60°S (PWA′) were calculated. Regression OMD′ against T′ PWA′ shows that most interannual variability in can...
Abstract Global climate model output is combined with an emission parameterization to estimate the change in global and regional sea salt aerosol number from 1870 2100. average results suggest a general increase due increasing surface wind speed. However, changes are not uniform over size spectrum temperature. From 2100 of coarse mode particles (dry diameter D P >655 nm) by approximately 10 % (global average), whereas no significant ultrafine aerosols p <76 was found same period....
Over the past two decades both severity of Antarctic ozone depletion and size hole have increased. A satellite‐based, assimilated total column data set NCEP/NCAR meteorological fields from 1979 to 2000 been used examine long‐term evolution its dependence on dynamical vortex region low temperatures. Equivalent latitude zonal means these calculated show more directly expansion encroachment edge. While with temperatures below 195 K (where polar stratospheric clouds are expected form) has...
We present methane mixing ratio and δ 13 C time series measured at Baring Head, New Zealand, Scott Base, Antarctica, over the years 1991–2003. These data demonstrate that apparent kinetic isotope effect (KIE) of atmospheric sink (derived from amplitudes seasonal cycles) is generally much larger than would be expected if were hydroxyl radical alone has changed significantly during observation period on a timescale ∼3 years. show using global transport model this technique for deriving KIE...
Abstract. While chemistry-climate models are able to reproduce many characteristics of the global total column ozone field and its long-term evolution, they have fared less well in simulating commonly used diagnostic area Antarctic hole i.e. within 220 Dobson Unit (DU) contour. Two possible reasons for this are: (1) underlying Global Climate Model (GCM) does not correctly simulate size polar vortex, (2) stratospheric chemistry scheme incorporated into GCM, and/or model dynamics, results...
Abstract. This paper presents a novel approach to investigate cloud-aerosol interactions by coupling Markov chain Monte Carlo (MCMC) algorithm an adiabatic cloud parcel model. Despite the number of numerical sensitivity studies previously conducted few have used statistical analysis tools global model input aerosol physiochemical parameters. Using numerically generated droplet concentration (CDNC) distributions (i.e. synthetic data) as observations, this inverse modelling framework is shown...
Abstract. Observational results of diurnal variations humidity from Odin-SMR and AURA-MLS, cloud ice mass CloudSat are presented for the first time. Comparisons show that retrievals these two satellite combinations in good agreement. The retrieved data combined four almost evenly distributed times day allowing mean values, amplitudes phases around 200 hpa to be estimated. This analysis is applied six climatologically distinct regions, five located tropics one over subtropical northern...
Ozone profiles from the Microwave Limb Sounder (MLS) instrument flown on board Upper Atmosphere Research Satellite (UARS) and total ozone columns measured by Global Monitoring Experiment (GOME) Second European Remote Sensing (ERS‐2) have been assimilated using a troposphere‐stratosphere data assimilation system. The analysis system is based global used for operational of stratosphere at Meteorological Office 1991 to 2000. Three runs completed three‐week period in April 1997 test advantage...
Temperature results from multi‐decadal simulations of coupled chemistry climate models for the recent past are analyzed using multi‐linear regression including a trend, solar cycle, lower stratospheric tropical wind, and volcanic aerosol terms. The climatology years is in good agreement with observations troposphere but model diverge each other stratosphere. Overall, agree better than previous assessments, primarily because corrections observed temperatures. annually averaged global polar...
Abstract. Single-column models (SCMs) have been used as tools to help develop numerical weather prediction and global climate for several decades. SCMs decouple small-scale processes from large-scale forcing, which allows the testing of physical parameterisations in a controlled environment with reduced computational cost. Typically, either ocean, sea ice or atmosphere is fully modelled assumptions be made regarding boundary conditions other subsystems, adding potential source error. Here,...
Abstract. Trends in derived from a 45 year integration of chemistry-climate model (CCM) run have been compared with ground-based measurements at Lauder (45° S) and Arrival Heights (78° S). Observed trends both sites exceed the modelled N2O, primary source gas for stratospheric NO2. This suggests that processes driving trend are not solely dictated by changes but coupled to global atmospheric change, either chemically or dynamically both. If CCMs accurately estimate future ozone, it is...
Abstract. The representation of the Tropical Tropopause Layer in 13 different Chemistry Climate Models designed to represent stratosphere is analyzed. Simulations for 1960–present and 1980–2100 are analyzed compared reanalysis model output. Results indicate that models able reproduce basic structure TTL. There a large spread cold point tropopause temperatures may be linked variation TTL ozone values. generally historical trends pressure obtained from products. Simulated meridional extent not...
Abstract. The objective of this study is to document and evaluate recent changes updates the module for aerosols aerosol-cloud-radiation interactions in atmospheric CAM4-Oslo Norwegian Earth System Model (NorESM). Particular attention paid role natural organics, sea salt, mineral dust determining gross aerosol properties as well anthropogenic contribution these associated direct indirect radiative forcing. extended from earlier versions that have been published, includes life-cycling...