Thermodynamic and cloud evolution in a cold-air outbreak during HALO-(AC)3: quasi-Lagrangian observations compared to the ERA5 and CARRA reanalyses DOI Creative Commons
Benjamin Kirbus, Imke Schirmacher, Marcus Klingebiel

et al.

Atmospheric chemistry and physics, Journal Year: 2024, Volume and Issue: 24(6), P. 3883 - 3904

Published: April 2, 2024

Abstract. Arctic air masses undergo intense transformations when moving southward from closed sea ice to warmer open waters in marine cold-air outbreaks (CAOs). Due the lack of measurements diabatic heating and moisture uptake rates along CAO flows, studies often depend on atmospheric reanalysis output. However, uncertainties connected those datasets remain unclear. Here, we present height-resolved airborne observations heating, uptake, cloud evolution measured a quasi-Lagrangian manner. The investigated was observed 1 April 2022 during HALO-(AC)3 campaign. Shortly after passing sea-ice edge, maximum over 6 K h−1 0.3 gkg-1h-1 were near surface. Clouds started forming vertical mixing within deepening boundary layer intensified. are compared with fifth-generation global (ERA5) Copernicus Regional Reanalysis (CARRA). Compared these observations, mean absolute errors ERA5 versus CARRA data 14 % higher for temperature (1.14 1.00 K) 62 specific humidity ice-free ocean (0.112 g kg−1 0.069 kg−1). We relate differences issues representation marginal zone corresponding surface fluxes ERA5, as well scheme producing excess liquid-bearing, precipitating clouds, which causes too-dry layer. CARRA's high spatial resolution demonstrated fidelity towards make it promising candidate further mass transformations.

Language: Английский

Simulating the Transport and Rupture of Pollen in the Atmosphere DOI Creative Commons
Tamanna Subba, Yingxiao Zhang, Allison L. Steiner

et al.

Journal of Advances in Modeling Earth Systems, Journal Year: 2023, Volume and Issue: 15(3)

Published: March 1, 2023

Abstract Pollen, one type of primary biological aerosol particle (PBAP), is emitted from the terrestrial biosphere and can undergo physical changes in atmosphere via rupture. To examine fate pollen its atmospheric processing, a emission transport scheme coupled to Weather Research Forecasting Model with Chemistry (WRF‐Chem). We simulate impacts on cloud properties precipitation Southern Great Plains 12 19 April 2013, period both high emissions convective activity. conduct suite ensemble runs that three different rupture mechanisms generate subpollen particles, including (a) humidity‐induced surface rupture, (b) in‐atmosphere plus (c) lightning‐induced where in‐cloud cloud‐to‐ground lightning strikes trigger events. When relative humidity (>80%), coarse (∼1 μg m −3 ) converted into fine particles (∼1.2e −4 ), which produces 80% more than The humidity‐driven predominantly further enhanced during frontal thunderstorm. During strong convection, vertical updrafts lift (∼0.5e upper troposphere (∼12 km) laterally transports ruptured anvil top outflow. In regions influence warm formation by decreasing low (<4 water mixing ratios increasing ice phase hydrometeors aloft (>10 km).

Language: Английский

Citations

16
Spatial Aggregation of Satellite Observations Leads to an Overestimation of the Radiative Forcing due to Aerosol‐Cloud Interactions DOI Creative Commons
Tom Goren, Odran Sourdeval, Jan Kretzschmar

et al.

Geophysical Research Letters, Journal Year: 2023, Volume and Issue: 50(18)

Published: Sept. 14, 2023

Abstract The estimation of cloud radiative forcing due to aerosol‐cloud interactions, RF aci (also known as the first indirect effect), relies on approximating albedo susceptibility changes in droplet concentration, β . depends and both which can be observed by satellites. Satellite observations are often spatially aggregated coarser resolutions, typically 1 × 1° scenes. However, such spatial scales, tends heterogeneous, whereas approximation assumes homogeneity. Here, we demonstrate that common practice aggregating satellite data neglecting heterogeneity results an average overestimation 10% previous estimates Additionally, establish a relationship between magnitude bias Stratocumulus morphologies, providing physical context for associated bias. Lastly, propose correction method applied gridded data.

Language: Английский

Citations

15
Investigating the development of clouds within marine cold-air outbreaks DOI Creative Commons
Rebecca J. Murray-Watson, Edward Gryspeerdt, Tom Goren

et al.

Atmospheric chemistry and physics, Journal Year: 2023, Volume and Issue: 23(16), P. 9365 - 9383

Published: Aug. 24, 2023

Abstract. Marine cold-air outbreaks are important parts of the high-latitude climate system and characterised by strong surface fluxes generated air–sea temperature gradient. These promote cloud formation, which can be identified in satellite imagery distinct transformation stratiform “streets” into a broken field cumuliform clouds downwind outbreak. This evolution morphology changes radiative properties therefore is importance to energy budget. While drivers stratocumulus-to-cumulus transitions, such as aerosols or sea gradient, have been extensively studied for subtropical clouds, factors influencing transitions at higher latitudes relatively poorly understood. work uses reanalysis data create set composite trajectories moving off Arctic ice edge co-locates these with generate unique view liquid-dominated development within outbreaks. The results this analysis show that embedded distinctive relative following other region. initial strength outbreak shows lasting effect on properties, differences between weak events visible over 30 h after air has left edge. However, while (measured magnitude marine index) affects it does not affect timing transition top-of-atmosphere albedo. In contrast, aerosol conditions do strongly but correlated break-up, leading an enhanced cooling through high-aerosol due delayed break-up. Both environment frequency expected change future Arctic, provide insight how will clouds. also highlight need information about present-day sources correctly model development.

Language: Английский

Citations

14
Daytime variation in the aerosol indirect effect for warm marine boundary layer clouds in the eastern North Atlantic DOI Creative Commons
Shaoyue Qiu, Xue Zheng, David Painemal

et al.

Atmospheric chemistry and physics, Journal Year: 2024, Volume and Issue: 24(5), P. 2913 - 2935

Published: March 6, 2024

Abstract. Warm boundary layer clouds in the eastern North Atlantic region exhibit significant diurnal variations cloud properties. However, cycle of aerosol indirect effect (AIE) for these remains poorly understood. This study takes advantage recent advancements spatial resolution geostationary satellites to explore daytime variation AIE by estimating susceptibilities changes droplet number concentration (Nd). Cloud retrievals month July over 4 years (2018–2021) from Spinning Enhanced Visible and Infrared Imager (SEVIRI) on Meteosat-11 this are analyzed. Our results reveal a “U-shaped” liquid water path (LWP), albedo, fraction. Clouds found be more susceptible Nd perturbations at noon less morning evening. The magnitude sign depend heavily state defined LWP precipitation conditions. Non-precipitating thin account 44 % all warm July, they contribute most observed variation. thick least frequent (10 %), negative albedo compared clouds. Precipitating dominant (46 but their show minimal throughout day. We find evidence that non-precipitating is influenced combination transition between “lagged” responses perturbations. fraction susceptibility can attributed morphology (e.g., overcast or broken). dissipation development do not adequately explain susceptibilities. Additionally, primarily driven intensity response rather than frequency occurrence states. imply polar-orbiting with an overpass time 13:30 LT underestimate mean values susceptibility, as observe daily minima region.

Language: Английский

Citations

5
Thermodynamic and cloud evolution in a cold-air outbreak during HALO-(AC)3: quasi-Lagrangian observations compared to the ERA5 and CARRA reanalyses DOI Creative Commons
Benjamin Kirbus, Imke Schirmacher, Marcus Klingebiel

et al.

Atmospheric chemistry and physics, Journal Year: 2024, Volume and Issue: 24(6), P. 3883 - 3904

Published: April 2, 2024

Abstract. Arctic air masses undergo intense transformations when moving southward from closed sea ice to warmer open waters in marine cold-air outbreaks (CAOs). Due the lack of measurements diabatic heating and moisture uptake rates along CAO flows, studies often depend on atmospheric reanalysis output. However, uncertainties connected those datasets remain unclear. Here, we present height-resolved airborne observations heating, uptake, cloud evolution measured a quasi-Lagrangian manner. The investigated was observed 1 April 2022 during HALO-(AC)3 campaign. Shortly after passing sea-ice edge, maximum over 6 K h−1 0.3 gkg-1h-1 were near surface. Clouds started forming vertical mixing within deepening boundary layer intensified. are compared with fifth-generation global (ERA5) Copernicus Regional Reanalysis (CARRA). Compared these observations, mean absolute errors ERA5 versus CARRA data 14 % higher for temperature (1.14 1.00 K) 62 specific humidity ice-free ocean (0.112 g kg−1 0.069 kg−1). We relate differences issues representation marginal zone corresponding surface fluxes ERA5, as well scheme producing excess liquid-bearing, precipitating clouds, which causes too-dry layer. CARRA's high spatial resolution demonstrated fidelity towards make it promising candidate further mass transformations.

Language: Английский

Citations

5