The Role of Diabatic Heating in Ferrel Cell Dynamics

2020 ◽  
Vol 47 (23) ◽  
Author(s):  
Orli Lachmy ◽  
Yohai Kaspi
Keyword(s):  
Diabatic Heating ◽  
Cell Dynamics ◽  
Ferrel Cell

The role of diabatic heating in Ferrel cell dynamics

2021 ◽  
Author(s):  
Orli Lachmy ◽  
Yohai Kaspi
Keyword(s):  
Heat Flux ◽  
Heating Rate ◽  
Diabatic Heating ◽  
Heat Budget ◽  
Reanalysis Data ◽  
Cell Dynamics ◽  
Data Set ◽  
Eddy Heat Flux ◽  
Ferrel Cell ◽  
Meridional Winds

<p>The Ferrel cell consists of the zonal mean vertical and meridional winds in the midlatitudes. The continuity of the Ferrel circulation and the zonal mean momentum and heat budgets imply a collocation of the eddy-driven jet and poleward eddy heat flux maxima, under certain assumptions, including the negligibility of diabatic heating. The latter assumption is questioned, since midlatitude storms are associated with latent heating in the midtroposphere. In this study, the heat budget of the Ferrel cell in both hemispheres is examined, using the JRA55 reanalysis data set. The diabatic heating rate is significant close to the center of the Ferrel cell during winter and at the ascending branch during summer in both hemispheres. The interannual variability shows a positive correlation between the diabatic heating rate in the midlatitude midtroposphere and the latitudinal separation between the eddy heat flux and the eddy-driven jet maxima during winter in both hemispheres.</p>

scholarly journals Influential Role of Moisture Supply from the Kuroshio/Kuroshio Extension in the Rapid Development of an Extratropical Cyclone

2015 ◽  
Vol 143 (10) ◽  
pp. 4126-4144 ◽  
Author(s):  
Hidetaka Hirata ◽  
Ryuichi Kawamura ◽  
Masaya Kato ◽  
Taro Shinoda
Keyword(s):  
Diabatic Heating ◽  
Rapid Development ◽  
Kuroshio Extension ◽  
Lower Troposphere ◽  
Active Role ◽  
Conveyor Belt ◽  
Synoptic Scale ◽  
Warm Front ◽  
The Kuroshio

Abstract This study focused on an explosive cyclone migrating along the southern periphery of the Kuroshio/Kuroshio Extension in the middle of January 2013 and examined how those warm currents played an active role in the rapid development of the cyclone using a high-resolution coupled atmosphere–ocean regional model. The evolutions of surface fronts of the simulated cyclone resemble the Shapiro–Keyser model. At the time of the maximum deepening rate, strong mesoscale diabatic heating areas appear over the bent-back front and the warm front east of the cyclone center. Diabatic heating over the bent-back front and the eastern warm front is mainly induced by the condensation of moisture imported by the cold conveyor belt (CCB) and the warm conveyor belt (WCB), respectively. The dry air parcels transported by the CCB can receive large amounts of moisture from the warm currents, whereas the very humid air parcels transported by the WCB can hardly be modified by those currents. The well-organized nature of the CCB plays a key role not only in enhancing surface evaporation from the warm currents but also in importing the evaporated vapor into the bent-back front. The imported vapor converges at the bent-back front, leading to latent heat release. The latent heating facilitates the cyclone’s development through the production of positive potential vorticity in the lower troposphere. Its deepening can, in turn, reinforce the CCB. In the presence of a favorable synoptic-scale environment, such a positive feedback process can lead to the rapid intensification of a cyclone over warm currents.

scholarly journals A numerical modelling investigation of the role of diabatic heating and cooling in the development of a mid-level vortex prior to tropical cyclogenesis – Part 1: The response to stratiform components of diabatic forcing

2018 ◽  
Vol 18 (19) ◽  
pp. 14393-14416 ◽  
Author(s):  
Melville E. Nicholls ◽  
Roger A. Pielke Sr. ◽  
Donavan Wheeler ◽  
Gustavo Carrio ◽  
Warren P. Smith
Keyword(s):  
Numerical Modelling ◽  
Diabatic Heating ◽  
Tropical Cyclogenesis ◽  
Minor Role ◽  
Microphysics Scheme ◽  
Heating And Cooling ◽  
Physics Simulation ◽  
Diabatic Forcing ◽  
Convective Cells

Abstract. Mid-tropospheric mesoscale convective vortices have been often observed to precede tropical cyclogenesis. Moreover, recent cloud-resolving numerical modelling studies that are initialized with a weak cyclonic mid-tropospheric vortex sometimes show a considerable intensification of the mid-level circulation prior to the development of the strong cyclonic surface winds that characterize tropical cyclogenesis. The objective of this two-part study is to determine the processes that lead to the development of a prominent mid-level vortex during a simulation of the transformation of a tropical disturbance into a tropical depression, in particular the role of diabatic heating and cooling. For simplicity simulations are initialized from a quiescent environment. In this first part, results of the numerical simulation are described and the response to stratiform components of the diabatic forcing is investigated. In the second part, the contribution of diabatic heating in convective cells to the development of the mid-level vortex is examined. Results show that after a period of intense convective activity, merging of anvils from numerous cells creates an expansive stratiform ice region in the upper troposphere, and at its base a mid-level inflow starts to develop. Subsequently conservation of angular momentum leads to strengthening of the mid-level circulation. A 12 h period of mid-level vortex intensification is examined during which the mid-level tangential winds become stronger than those at the surface. The main method employed to determine the role of diabatic forcing in causing the mid-level inflow is to diagnose it from the full physics simulation and then impose it in a simulation with hydrometeors removed and the microphysics scheme turned off. Removal of hydrometeors is achieved primarily through artificially increasing their fall speeds 3 h prior to the 12 h period. This results in a state that is in approximate gradient wind balance, with only a weak secondary circulation. Then, estimates of various components of the diabatic forcing are imposed as source terms in the thermodynamic equation in order to examine the circulations that they independently induce. Sublimation cooling at the base of the stratiform ice region is shown to be the main factor responsible for causing the strong mid-level vortex to develop, with smaller contributions from stratiform heating aloft and low-level melting and evaporation. This contrasts with the findings of previous studies of mid-latitude vortices that indicate sublimation plays a relatively minor role. An unanticipated result is that the central cool region that develops near the melting level is to a large degree due to compensating adiabatic ascent in response to descent driven by diabatic cooling adjacent to the central region, rather than in situ diabatic cooling. The mid-level inflow estimated from stratiform processes is notably weaker than for the full physics simulation, suggesting a moderate contribution from diabatic forcing in convective cells.

scholarly journals Nitric Oxide Could Allay Arsenic Phytotoxicity in Tomato (Solanum lycopersicum L.) by Modulating Photosynthetic Pigments, Phytochelatin Metabolism, Molecular Redox Status and Arsenic Sequestration

2020 ◽  
Author(s):  
Abazar Ghorbani ◽  
Leila Pishkar ◽  
Nasim Roudbari ◽  
Necla Pehlivan ◽  
Chu Wu
Keyword(s):  
Photosynthetic Apparatus ◽  
Redox Status ◽  
Protective Effects ◽  
Transcriptional Expression ◽  
Cell Dynamics ◽  
No Donor ◽  
Potential Health ◽  
Tomato Plants ◽  
Solanum Lycopersicum L

Abstract Background: Plants do not always have the genetic capacity to tolerate high quantities of (As) which does not only arrest the plant growth, but commit potential health risks by dietary bioaccumulation. However, the interplay between the tomato plants and As-NO driven molecular cell dynamics are obscure. Hence, seedlings were treated with As (10 mg/L) alone or in combination with 100 µM sodium nitroprusside (SNP, NO donor) and 200 µM 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (cPTIO, NO scavenger).Results: SNP immobilized the As in the roots and reduced the shoot translocation by up-regulating the transcriptional expression of the PCS, GSH1, MT2 and ABC1. SNP further restored the growth retardation by modulating the chlorophyll and proline metabolism, increasing NO accumulation and stomatal conductance along with a clear crosstalk between the activity of antioxidants as well as glyoxalase I and II leading endogenous H2O2 and MG decrease.Conclusion: Higher PCs and glutathione accumulation helped to protect photosynthetic apparatus, however, cPTIO reversed the protective effects of SNP, authenticating the role of NO in the As toxicity alleviation.

scholarly journals ERK Activity Imaging During Migration of Living Cells In Vitro and In Vivo

2019 ◽  
Vol 20 (3) ◽  
pp. 679 ◽  
Author(s):  
Eishu Hirata ◽  
Etsuko Kiyokawa
Keyword(s):  
Cancer Metastasis ◽  
Fluorescent Proteins ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Living Cells ◽  
Cell Dynamics ◽  
Extracellular Signal

Extracellular signal-regulated kinase (ERK) is a major downstream factor of the EGFR-RAS-RAF signalling pathway, and thus the role of ERK in cell growth has been widely examined. The development of biosensors based on fluorescent proteins has enabled us to measure ERK activities in living cells, both after growth factor stimulation and in its absence. Long-term imaging unexpectedly revealed the oscillative activation of ERK in an epithelial sheet or a cyst in vitro. Studies using transgenic mice expressing the ERK biosensor have revealed inhomogeneous ERK activities among various cell species. In vivo Förster (or fluorescence) resonance energy transfer (FRET) imaging shed light on a novel role of ERK in cell migration. Neutrophils and epithelial cells in various organs such as intestine, skin, lung and bladder showed spatio-temporally different cell dynamics and ERK activities. Experiments using inhibitors confirmed that ERK activities are required for various pathological responses, including epithelial repair after injuries, inflammation, and niche formation of cancer metastasis. In conclusion, biosensors for ERK will be powerful and valuable tools to investigate the roles of ERK in situ.

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