A5002834582- Atmospheric aerosols and clouds
- Atmospheric chemistry and aerosols
- Meteorological Phenomena and Simulations
- Aeolian processes and effects
- Icing and De-icing Technologies
- Atmospheric Ozone and Climate
- Air Quality and Health Impacts
- Cryospheric studies and observations
- Advanced Aircraft Design and Technologies
- Arctic and Antarctic ice dynamics
- Climate variability and models
- Atmospheric and Environmental Gas Dynamics
- Precipitation Measurement and Analysis
- Landslides and related hazards
- Climate change and permafrost
- Air Traffic Management and Optimization
- Aerospace and Aviation Technology
- Physics and Engineering Research Articles
- Fire effects on ecosystems
- Earthquake Detection and Analysis
- Lightning and Electromagnetic Phenomena
- Ionosphere and magnetosphere dynamics
- Geology and Paleoclimatology Research
- Vehicle emissions and performance
- Electrohydrodynamics and Fluid Dynamics
University of Manchester
2016-2025
National Centre for Atmospheric Science
2014-2024
Environmental Earth Sciences
2021
Met Office
2017
Paul Scherrer Institute
2016
Measured ice crystal concentrations in natural clouds at modest supercooling (temperature ~>−10°C) are often orders of magnitude greater than the number concentration primary nucleating particles. Therefore, it has long been proposed that a secondary production process must exist is able to rapidly enhance population following initial nucleation events. Secondary important for prediction and subsequent evolution some types clouds, but physical basis not understood rates well constrained. In...
Abstract. Mineral dust is an important component of the climate system, affecting radiation balance, cloud properties, biogeochemical cycles, regional circulation and precipitation, as well having negative effects on aviation, solar energy generation human health. Dust size composition has impact all these processes. However, changes in distribution during transport, particularly for coarse particles, are poorly understood represented models. Here we present new situ airborne observations...
Abstract Aircraft observations in a cold-air outbreak to the north of United Kingdom are used examine boundary layer and cloud properties an overcast mixed-phase stratocumulus across transition more broken open-cellular convection. The is primarily composed liquid drops with small concentrations ice particles there switch glaciated conditions shallow cumulus clouds downwind. rapid change morphology accompanied by enhanced precipitation secondary processes becoming active greater...
Abstract. During the winter of 2013 and 2014 measurements cloud microphysical properties over a 5-week period at high-alpine site Jungfraujoch, Switzerland, were carried out as part Cloud Aerosol Characterisation Experiments (CLACE) Ice Nucleation Process Investigation Quantification project (INUPIAQ). Measurements aerosol second, lower site, Schilthorn, used input for primary ice nucleation scheme to predict nuclei concentrations Jungfraujoch. Frequent, rapid transitions in liquid clouds...
Abstract Ice nucleating particle (INP) concentrations were measured at the High Altitude Research Station Jungfraujoch, Switzerland, 3580 m above mean sea level during winter months of 2012, 2013, and 2014 with Portable Nucleation Chamber (PINC). During measurement periods, research station was mostly located in free troposphere, low. At temperature T = 241 K, INP deposition regime [relative humidity respect to water (RHw) 93%] were, on average, below 1.09 per standard liter air (stdL−1;...
Abstract. In situ measurements of Arctic clouds frequently show that ice crystal number concentrations (ICNCs) are much higher than the available ice-nucleating particles (INPs), suggesting secondary production (SIP) may be active. Here we use a Lagrangian parcel model (LPM) and large-eddy simulation (LES) to investigate impact three SIP mechanisms (rime splintering, break-up from ice–ice collisions drop shattering) on summer stratocumulus case observed during Aerosol-Cloud Coupling And...
Abstract. During the summertime, dust from Sahara can be efficiently transported westwards within Saharan air layer (SAL). This lead to high aerosol loadings being observed above a relatively clean marine boundary (MBL) in tropical Atlantic Ocean. These layers impart significant radiative effects through strong visible and IR light absorption scattering, also have indirect impacts by altering cloud properties. The processing of result changes both direct effects, leading uncertainty climate...
Abstract. This study investigates the microphysics of winter alpine snowfall occurring in mixed-phase clouds an inner-Alpine valley during January and February 2014. The available observations include high-resolution polarimetric radar situ measurements ice-phase liquid-phase components precipitation. Radar-based hydrometeor classification suggests that riming is important factor to favor efficient growth precipitating mass correlates with snow accumulation rates at ground level. time steps...
Abstract The Diabatic Influences on Mesoscale Structures in Extratropical Storms (DIAMET) project aims to improve forecasts of high-impact weather extratropical cyclones through field measurements, high-resolution numerical modeling, and improved design ensemble forecasting data assimilation systems. This article introduces DIAMET presents some the first results. Four campaigns were conducted by project, one which, late 2011, coincided with an exceptionally stormy period marked unusually...
IAGOS (In-service Aircraft for a Global Observing System) performs long-term routine<italic>in situ</italic>observations of atmospheric chemical composition (O<sub>3</sub>, CO, NO<sub>x</sub>, NO<sub>y</sub>, CO<sub>2</sub>, CH<sub>4</sub>), water vapour, aerosols, clouds, and temperature on global scale by operating compact instruments board passenger aircraft. The unique characteristics the data set originate from sampling air traffic routes with similar instrumentation such that...
Ice residual (IR) and total aerosol properties were measured in mixed-phase clouds (MPCs) at the high-alpine Jungfraujoch research station. Black carbon (BC) content coating thickness of BC-containing particles determined using single-particle soot photometers. The ice activated fraction (IAF), derived from a comparison IR particle size distributions, showed an enrichment large IR, with increase IAF values on order 10-4 to 10-3 for 100 nm (diameter) 0.2 0.3 1 μm particles. Nonetheless, due...
Abstract. Measurements from four case studies in spring and summer-time Arctic stratocumulus clouds during the Aerosol-Cloud Coupling And Climate Interactions (ACCACIA) campaign are presented. We compare microphysics observations between cases with previous measurements made Antarctic. During ACCACIA, were observed to consist of liquid at cloud tops, often distinct temperature inversions. The top regions precipitated low concentrations ice into below. median number (~ 0.5 L−1) found be lower...
Abstract. The fluorescent nature of aerosol at a high-altitude Alpine site was studied using wide-band integrated bioaerosol (WIBS-4) single particle multi-channel ultraviolet – light-induced fluorescence (UV-LIF) spectrometer. This supported by comprehensive cloud microphysics and meteorological measurements with the aims cataloguing concentrations bio-fluorescent aerosols this also investigating possible influences UV–fluorescent types on cloud–aerosol processes. Analysis background free...
Abstract. This paper assesses the reasons for high ice number concentrations observed in orographic clouds by comparing situ measurements from Ice NUcleation Process Investigation And Quantification field campaign (INUPIAQ) at Jungfraujoch, Switzerland (3570 m a.s.l.) with Weather Research and Forecasting model (WRF) simulations over real terrain surrounding Jungfraujoch. During 2014 winter campaign, between 20 January 28 February, regularly underpredicted concentration 103 L−1. Previous...
Abstract. In situ airborne observations of cloud microphysics, aerosol properties, and thermodynamic structure over the transition from sea ice to ocean are presented Aerosol-Cloud Coupling And Climate Interactions in Arctic (ACCACIA) campaign. A case study 23 March 2013 provides a unique view microphysical changes this under cold-air outbreak conditions. Cloud base lifted depth increased ocean. Mean droplet number concentrations, Ndrop, also 110 ± 36 cm−3 145 54 marginal zone (MIZ)....
Abstract We present detailed airborne in situ measurements of cloud microphysics two midlatitude cirrus clouds, collected as part the Cirrus Coupled Cloud‐Radiation Experiment. A new habit recognition algorithm for sorting particle images using a neural network is introduced. Both flights observed clouds that were related to frontal systems, but one was actively developing while other dissipated it sampled. The showed distinct differences number, habit, and size. However, number common...
Abstract. In this paper we show that the origin of ice phase in tropical cumulus clouds over sea may occur by primary nucleation small crystals at temperatures just between 0 and −5 ∘C. This was made possible through use a holographic instrument able to image cloud particles very high resolution size (6 µm). The environment which observations were conducted notable for presence desert dust advected ocean from Sahara. However, there is no laboratory evidence suggest these can act as nuclei...
Abstract During the Cloud and Aerosol Characterization Experiment (CLACE) 2013 field campaign at High Altitude Research Station Jungfraujoch, Switzerland, optically thin pure ice clouds crystal precipitation were measured using holographic other in situ particle instruments. For cloud particles, images, positions space, concentrations, size distributions obtained, allowing one to extract classified by habit. Small crystals occurring under conditions with a vertically layer above...
Abstract. A key challenge for numerical weather prediction models is representing boundary layer clouds in cold air outbreaks (CAOs). One important aspect the evolution of microphysical properties as stratocumulus transitions to open cellular convection. Abel et al. (2017) have shown, first time from situ field observations, that break-up CAOs over eastern Atlantic may be controlled by development precipitation cloud system while becomes decoupled. This paper describes case and examines...
Abstract. The Saharan Air Layer (SAL) in the summertime eastern Atlantic is typically well mixed and 3–4 km deep, overlying marine boundary layer (MBL). In this paper, we show experimental evidence that at times a very different structure can be observed. During AERosol properties – Dust (AER-D) airborne campaign August 2015, typical described above was observed most of time, associated with moderate dust content yielding an aerosol optical depth (AOD) 0.3–0.4 355 nm. intense event, however,...
Abstract Three case studies in frontal clouds from the Diabatic Influences on Mesoscale Structures Extratropical Storms (DIAMET) project are described to understand microphysical development of mixed phase regions these clouds. The cases a kata-type cold front, wintertime warm and summertime occluded system. were observed by radar, satellite, situ microphysics measurements U.K. Facility for Airborne Atmospheric Measurements (FAAM) research aircraft. kata front cloud was shallow with...
Abstract In situ measurements associated with the passage of a kata cold front over United Kingdom on 29 November 2011 are used to initialize Lagrangian parcel model for purpose calculating rates diabatic heating and cooling phase changes water within cloud system. The calculations performed both bin-resolved bulk treatments microphysical processes. in data from this case study reveal droplet number concentrations up 100 cm −3 , planar ice crystals detected at top, as well columnar produced...
Abstract. During the winter of 2013 and 2014 measurements cloud microphysical properties over a five week period at high Alpine site Jungfraujoch, Switzerland were carried out as part Cloud Aerosol Characterisation Experiments (CLACE) Ice Nucleation Process Investigation Quantification project (INUPIAQ) Measurements aerosol second, lower site, Schilthorn, Switzerland, used input for primary ice nucleation scheme to predict nuclei concentrations Jungfraujoch Frequent, rapid transitions in...