A Lagrangian Perspective on Tropical Anvil Cloud Lifecycle in Present and Future Climate

Gasparini, Blaž; Rasch, Philip J.; Hartmann, Dennis L.; Wall, Casey J.; Dütsch, Marina

doi:10.1029/2020jd033487

Cited by 18 publications

(13 citation statements)

References 117 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As previously shown (Cesana & Chepfer, 2012;Guzman et al, 2017;Stubenrauch et al, 2019), the model fails to reproduce the observed behavior of C THIN . Due to their different responses to SST variations, and to their different interactions with radiation and implications for weather and climate, our observations confirm that more attention should be paid to the evolution of the balance between opaque and thin high clouds with SST (Gasparini et al, 2019(Gasparini et al, , 2021Hartmann & Berry, 2017;Hartmann et al, 2001) on various time scales from instantaneous to diurnal, decadal and climate.…”

Section: Discussionsupporting

confidence: 63%

Satellite Observed Sensitivity of Tropical Clouds and Moisture to Sea Surface Temperature on Various Time and Space Scales: 1. Focus on High Level Cloud Situations Over Ocean

2022

View full text Add to dashboard Cite

This study examines variations in high cloud properties and relative humidity (RH) with sea surface temperature (SST) over tropical oceans (30°N–30°S) using spaceborne lidar and microwave radiometer observations. The mean values over the tropics indicate that middle‐tropospheric RH increases, high cloud covers decrease and cloud altitudes rise with SST. These signatures are consistent with the hypotheses proposed in the literature. The analysis of this same data set but at the scale of local processes shows different behaviors for SSTs <302 K and SSTs >302 K. Between 299 and 302 K, middle‐tropospheric RH, opaque cloud cover, and cloud top altitude increase together with SST, while optically thin cloud cover decreases. Over SSTs >302 K, middle‐tropospheric RH, opaque cloud cover, and opaque cloud top altitude decrease with SST, while the cover of optically thin clouds increases. Interestingly, the altitude of high clouds (not the cloud top) increases monotonically with SST from 299 to 305 K on a range of space and time scales, and the altitude of optically thin clouds remains higher than that of opaque clouds. The observed relationships on different time and space scales are compared to simulations of a global atmospheric model. Despite systematic biases, the model reproduces the sensitivity of the middle‐tropospheric RH and cloud altitude to SST rather well but fails to reproduce the variations of the balance between high opaque cloud cover and high optically thin cloud cover.

show abstract

Section: Discussionsupporting

confidence: 63%

Satellite Observed Sensitivity of Tropical Clouds and Moisture to Sea Surface Temperature on Various Time and Space Scales: 1. Focus on High Level Cloud Situations Over Ocean

2022

View full text Add to dashboard Cite

show abstract

“…The number of RSP ice cloud observations within 500-m cloud top height bins over land and ocean surfaces is shown in Figure 2a. Similar to previous observations (Kubar et al, 2007; and model studies (Gasparini et al, 2021) of convective clouds, the number of observations peak at cloud top heights of around 12 km or 220 K, corresponding to the estimated level of neutral buoyancy (van . Compared to over land, relatively more cloud tops occur below the homogeneous freezing level over ocean, which is likely related to the weaker convection over ocean.…”

Section: Observational Resultssupporting

confidence: 84%

Variation of Ice Microphysical Properties With Temperature and Humidity at Tops of Convective Clouds

Diedenhoven

2021

Geophysical Research Letters

View full text Add to dashboard Cite

The sizes and shapes of ice crystals in cold clouds influence the clouds' evolution and radiative properties (Russotto et al., 2016;Jensen, Harrington, & Morrison, 2018;. In turn, the variation of ice crystal sizes and shapes within clouds are determined by a complex interaction between ice microphysics and dynamic and thermodynamic properties of the atmosphere (Bailey & Hallett, 2004). A better understanding of the many interacting processes governing the formation of complex mixtures of ice of various shapes and sizes in natural ice clouds is required to improve the representation of ice clouds in global circulation models modeling current and future climates (Gasparini et al., 2021;Waliser et al., 2009;Zelinka et al., 2020). In recent work using satellite retrievals over thick ice clouds globally (van Diedenhoven et al., 2020, VD2020 hereafter), we found that systematic variations of ice size and shape with cloud top temperature show a remarkable agreement with simplified ice crystal vapor growth theory and in situ and laboratory data. This agreement suggests that the temperature dependence of the cloud top ice sizes and shapes could be dominated by the vapor growth process and that ice particle distributions observed at cloud top have generally been subjected to depositional growth for a uniform amount of time at average conditions similar to the observed cloud top, which is somewhat surprising given the many processes involved and the large variation in dynamical variables.

show abstract

“…Most tropical radiative studies are confined to models. Looking at the CRE along Lagrangian trajectories in simulation, Gasparini et al (2021) found that large SW and LW values dominate close to convection as expected. The net CRE oscillates close to zero and is a function of the solar insolation.…”

Section: Introductionsupporting

confidence: 70%

The evolution of deep convective systems and their associated cirrus outflows

Horner

Gryspeerdt

2022

Preprint

View full text Add to dashboard Cite

Abstract. Tropical deep convective clouds, particularly their large cirrus outflows, play an important role in modulating the energy balance of the Earth’s atmosphere. Whilst the cores of these deep convective clouds have a significant shortwave (SW) cooling effect, they dissipate quickly. Conversely, the thin cirrus that flow from these cores can persist for days after the core has dissipated, reaching hundreds of kilometers in extent. These thin cirrus have a potential for large warming in the tropics. Understanding the evolution of these clouds and how they change in response to anthropogenic emissions is therefore important to understand past and future climate change. This work uses a novel approach to investigate the evolution of tropical convective clouds by introducing the concept of ‘Time Since Convection’ (TSC). This is used to build a composite picture of the lifecycle of deep convection, from anvil cirrus to thin detrained cirrus. Cloud properties are a strong function of time since convection, showing decreases in the optical thickness, cloud top height, and cloud fraction over time. After an initial dissipation of the convective core, changes in thin cirrus cloud amount were seen beyond 200 hours from convection. Finally, in the initial stages of convection there was a large net negative cloud radiative effect (CRE). However, once the convective core had dissipated after 6–12 hours, the sign of the CRE flipped, and there was a sustained net warming CRE beyond 120 hours from the convective event. Changes are present in the cloud properties long after the main convective activities have dissipated, signalling the need to continue further analysis at longer time scales than previously studied.

show abstract

A Lagrangian Perspective on Tropical Anvil Cloud Lifecycle in Present and Future Climate

Cited by 18 publications

References 117 publications

Satellite Observed Sensitivity of Tropical Clouds and Moisture to Sea Surface Temperature on Various Time and Space Scales: 1. Focus on High Level Cloud Situations Over Ocean

Satellite Observed Sensitivity of Tropical Clouds and Moisture to Sea Surface Temperature on Various Time and Space Scales: 1. Focus on High Level Cloud Situations Over Ocean

Variation of Ice Microphysical Properties With Temperature and Humidity at Tops of Convective Clouds

The evolution of deep convective systems and their associated cirrus outflows

Contact Info

Product

Resources

About