scholarly journals Upper atmosphere tidal oscillations due to latent heat release in the tropical troposphere

1997 ◽  
Vol 15 (9) ◽  
pp. 1165-1175 ◽  
Author(s):  
J. M. Forbes ◽  
M. E. Hagan ◽  
X. Zhang ◽  
K. Hamilton
Keyword(s):  
Heat Release ◽  
Latent Heat ◽  
Lower Thermosphere ◽  
Pressure Oscillation ◽  
Wave Model ◽  
Rain Gauge ◽  
Latent Heating ◽  
Latent Heat Release ◽  
Tropical Troposphere ◽  
Atmospheric Perturbations

Abstract. Latent heat release associated with tropical deep convective activity is investigated as a source for migrating (sun-synchronous) diurnal and semidiurnal tidal oscillations in the 80–150-km height region. Satellite-based cloud brightness temperature measurements made between 1988 and 1994 and averaged into 3-h bins are used to determine the annual- and longitude-average local-time distribution of rainfall rate, and hence latent heating, between ±40° latitude. Regional average rainfall rates are shown to be in good agreement with climatological values derived from surface rain gauge data. A global linearized wave model is used to estimate the corresponding atmospheric perturbations in the mesosphere/lower thermosphere (80–150 km) resulting from upward-propagating tidal components excited by the latent heating. The annual-average migrating diurnal and semidiurnal components achieve velocity and temperature amplitudes of order 10–20 m s–1 and 5–10 K, respectively, which represent substantial contributions to the dynamics of the region. The latent heat forcing also shifts the phase (local solar time of maximum) of the semidiurnal surface pressure oscillation from 0912 to 0936 h, much closer to the observed value of 0944 h.

Latent Heating Retrieved from TRMM and GPM Satellite Measurements

2020 ◽  
Author(s):  
Wei-Kuo Tao ◽  
Steve Lang ◽  
Takamichi Iguchi
Keyword(s):  
Heat Release ◽  
Latent Heat ◽  
Tropical Rainfall Measuring Mission ◽  
Phase Changes ◽  
Latent Heating ◽  
Latent Heat Release ◽  
Satellite Measurements ◽  
Space Time Structure ◽  
Global Precipitation Mission ◽  
Global Precipitation

<p>Latent heat release itself is a consequence of phase changes between the vapor, liquid, and frozen states of water.  This paper will highlight the retrieval of latent heat release from satellite measurements generated by the Tropical Rainfall Measuring Mission (TRMM) and Global Precipitation Mission (GPM) satellite observatory.  Both TRMM and GPM are providing four-dimensional account of rainfall and its associated precipitation properties over the global Tropics and mid-latitudes: information that can be used to estimate the space-time structure of latent heating.</p><p> </p><p>Goddard Convective-Stratiform or CSH retrieved LH is one of two standard LH products (the other one is from Japan Spectral Latent Heating or SLH). This paper will present (1) the new improvements of the CSH LH algorithm by better CRM simulated LH for its look-up table, and (2) the performance of CSH retrieved LH by comparison with surface rainfall rate.  In addition, the similarities and differences of CSH retrieved LH obtained from TRMM and GPM measurements, respectively, will be presented.  At the end of presentation, the further research on latent heating retrieval from satellites will be discussed.</p>

scholarly journals The Importance of Resolving Mesoscale Latent Heating in the North Atlantic Storm Track

2013 ◽  
Vol 70 (7) ◽  
pp. 2234-2250 ◽  
Author(s):  
Jeff Willison ◽  
Walter A. Robinson ◽  
Gary M. Lackmann
Keyword(s):  
Heat Release ◽  
Latent Heat ◽  
North Atlantic ◽  
General Circulation ◽  
Storm Track ◽  
Latent Heating ◽  
Latent Heat Release ◽  
Grid Spacing ◽  
The North ◽  
The North Atlantic

Abstract Theoretical, observational, and modeling studies have established an important role for latent heating in midlatitude cyclone development. Models simulate some contribution from condensational heating to cyclogenesis, even with relatively coarse grid spacing (on the order of 100 km). Our goal is to more accurately assess the diabatic contribution to storm-track dynamics and cyclogenesis while bridging the gap between climate modeling and synoptic dynamics. This study uses Weather Research and Forecasting model (WRF) simulations with 120- and 20-km grid spacing to demonstrate the importance of resolving additional mesoscale features that are associated with intense precipitation and latent heat release within extratropical cyclones. Sensitivity to resolution is demonstrated first with a case study, followed by analyses of 10 simulated winters over the North Atlantic storm track. Potential vorticity diagnostics are employed to isolate the influences of latent heating on storm dynamics, and terms in the Lorenz energy cycle are analyzed to determine the resulting influences on the storm track. The authors find that the intensities of individual storms and their aggregate behavior in the storm track are strongly sensitive to horizontal resolution. An enhanced positive feedback between cyclone intensification and latent heat release is seen at higher resolution, resulting in a systematic increase in eddy intensity and a stronger storm track relative to the coarser simulations. These results have implications for general circulation models and their projections of climate change.

scholarly journals Using Satellite Observations to Evaluate the Relationships between Ice Condensate, Latent Heat Release, and Tropical Cyclone Intensification in a Mesoscale Model

2021 ◽  
Vol 149 (1) ◽  
pp. 113-129
Author(s):  
Shun-Nan Wu ◽  
Brian J. Soden ◽  
Yoshiaki Miyamoto ◽  
David S. Nolan ◽  
Stefan A. Buehler
Keyword(s):  
Tropical Cyclone ◽  
Heat Release ◽  
Water Content ◽  
Latent Heat ◽  
Satellite Observations ◽  
Latent Heating ◽  
Latent Heat Release ◽  
Model Simulations ◽  
Ice Water Content ◽  
Ice Water

AbstractThis study examines the relationship between frozen hydrometeors and latent heating in model simulations and evaluates the capability of the Weather Research and Forecasting (WRF) Model to reproduce the observed frozen hydrometeors and their relationship to tropical cyclone (TC) intensification. Previous modeling studies have emphasized the importance of both the amount and location of latent heating in modulating the evolution of TC intensity. However, the lack of observations limits a full understanding of its importance in the real atmosphere. Idealized simulations using WRF indicate that latent heating is strongly correlated to the amount of ice water content, suggesting that ice water content can serve as an observable proxy for latent heat release in the mid- to upper troposphere. Based on this result, satellite observations are used to create storm-centered composites of ice water path as a function of TC intensity. The model reasonably captures the vertical and horizontal distribution of ice water content and its dependence upon TC intensity, with differences typically less than 20%. The model also captures the signature of increased ice water content for intensifying TCs, suggesting that observations of ice water content provide a useful diagnostic for understanding and evaluating model simulations of TC intensification.

The Sensitivity of Persistent Geopotential Anomalies to the Climate of a Moist Channel Model

2021 ◽  
pp. 1-52
Author(s):  
Gregory Tierney ◽  
Walter A. Robinson ◽  
Gary Lackmann ◽  
Rebecca Miller
Keyword(s):  
Climate Change ◽  
Heat Release ◽  
Latent Heat ◽  
Channel Model ◽  
Heat Waves ◽  
Latent Heat Release ◽  
Mean Flow ◽  
Flow Variability ◽  
Virtual Temperature ◽  
Channel Configuration

AbstractHigh-impact events such as heat waves and droughts are often associated with persistent positive geopotential height anomalies (PAs). Understanding how PA activity will change in a future warmer climate is therefore fundamental to projecting associated changes in weather and climate extremes. This is a complex problem because the dynamics of PAs and their associated blocking activity are still poorly understood. Furthermore, climate-change influences on PA activity may be geographically dependent and encompass competing influences. To expose the salient impacts of climate change, we use an oceanic channel configuration of the Weather Research and Forecasting model (WRF) in a bivariate experiment focused on changes in environmental temperature, moisture, and baroclinicity. The 500-hPa wind speed and flow variability are found to increase with increasing temperature and baroclinicity, driven by increases in latent heat release and a stronger virtual temperature gradient. Changes to 500-hPa sinuosity are negligible. PAs are objectively identified at the 500-hPa level using an anomaly threshold method. When using a fixed threshold, PA trends indicate increased activity and strength with warming, but decreased activity and strength with Arctic amplification. Use of a climate-relative threshold hides these trends and highlights the importance of accurate characterization of the mean flow. Changes in PA activity mirror corresponding changes in 500-hPa flow variability and are found to be attributable to changes in three distinct dynamical mechanisms: baroclinic wave activity, virtual temperature effects, and latent heat release.

Change in inter-atomic communication character in the formation of solid and liquid solutions. Relationship of vibrational and configuration entropy and their physical interpretation

2021 ◽  
pp. 28-40
Author(s):  
A. M. Savchenko ◽  
Yu. V. Konovalov ◽  
A. V. Laushkin
Keyword(s):  
Heat Capacity ◽  
Heat Release ◽  
Latent Heat ◽  
Physical Interpretation ◽  
Latent Heat Release ◽  
Statistical Entropy ◽  
Average Heat ◽  
Configuration Entropy ◽  
Liquid Solutions ◽  
Relationship Of

The purpose of this work is to show that during mixing, two hidden (latent) processes proceed simultaneously and compensate each other: the first initiates an increase in the average heat capacity, equal in magnitude to the entropy of mixing, which requires energy absorption to ensure a constant temperature, the second initiates simultaneous latent heat release by strengthening interatomic bonds. The passage of these two processes during mixing shows the identity of the vibrational and configurational (statistical) entropy.

Measurement and Modeling of Latent Heat Release During Freezing of Aqueous Solutions in a Small Container

2000 ◽  
Author(s):  
Ramachandra V. Devireddy ◽  
John C. Bischof ◽  
Perry H. Leo ◽  
John S. Lowengrub
Keyword(s):  
Mass Transport ◽  
Heat Release ◽  
Latent Heat ◽  
Pure Water ◽  
Heat Of Fusion ◽  
Freezing Process ◽  
Latent Heat Release ◽  
Aqueous Systems ◽  
Heat And Mass Transport ◽  
Latent Heat Of Fusion

Abstract The latent heat of fusion, ΔHf of a cryobiological medium (a solute laden aqueous solution) is a crucial parameter in the cryopreservation process. The latent heat has often been approximated by that of pure water (∼ 335 mJ/mg). However, recent calorimetric (DSC - Pyris 1) measurements suggest that the actual magnitude of latent heat of fusion during freezing of solute laden aqueous systems is far less. Fourteen different pre-nucleated solute laden aqueous systems (NaCl-H2O, Phosphate Buffered Saline or PBS, serum free RPMI, cell culture medium, glycerol and Anti Freeze Protein solutions) were found to have significantly lower ΔHf than that of pure water (Devireddy and Bischof, 1998). In the present study additional calorimetric experiments are performed at 1, 5 and 20 °C/min in five representative cryobiological media (isotonic or 1× NaCl-H2O, 10× NaCl-H2O, 1× PBS, 5× PBS and 10× PBS) to determine the kinetics of ice crystallization. The temperature (T) and time (t) dependence of the latent heat release is measured. The experimental data shows that at a fixed temperature, the fraction of heat released at higher cooling rates (5 and 20 °C/min) is lower than at 1 °C/min for all the solutions studied. We then sought a simple model that could predict the experimentally measured behavior and examined the full set of heat and mass transport equations during the freezing process in a DSC sample pan. The model neglects the interaction between the growing ice crystals and is most appropriate during the early stages of the freezing process. An examination of the coefficients in the heat and mass transport equations shows that heat transport occurs much more rapidly than solute transport. Hence, the full model reduces to one in which the temperature profile is constant in space while the solute concentration profile obeys the full time and space dependent diffusion equation. The model reveals the important physical parameters controlling the mass transport at the freezing interface and further elucidates the experimental results, i.e. the temperature and time dependence of the latent heat release.

scholarly journals Moist versus Dry Baroclinic Instability in a Simplified Two-Layer Atmospheric Model with Condensation and Latent Heat Release

2012 ◽  
Vol 69 (4) ◽  
pp. 1405-1426 ◽  
Author(s):  
Julien Lambaerts ◽  
Guillaume Lapeyre ◽  
Vladimir Zeitlin
Keyword(s):  
Life Cycle ◽  
Heat Release ◽  
Latent Heat ◽  
Baroclinic Instability ◽  
Underlying Mechanism ◽  
Linear Instability ◽  
Vapor Condensation ◽  
Water Model ◽  
Finite Volume Scheme ◽  
Latent Heat Release

Abstract The authors undertake a detailed analysis of the influence of water vapor condensation and latent heat release upon the evolution of the baroclinic instability. The framework consists in a two-layer rotating shallow-water model with moisture coupled to dynamics through mass exchange between the layers due to condensation/precipitation. The model gives all known in literature models of this kind as specific limits. It is fully nonlinear and ageostrophic. The reference state is a baroclinic Bickley jet. The authors first study its “dry” linear instability and then use the most unstable mode to initialize high-resolution numerical simulations of the life cycle of the instability in nonprecipitating (moisture being a passive tracer) and precipitating cases. A new-generation well-balanced finite-volume scheme is used in these simulations. The evolution in the nonprecipitating case follows the standard cyclonic wave-breaking life cycle of the baroclinic instability, which is reproduced with a high fidelity. In the precipitating case, the onset of condensation significantly increases the growth rate of the baroclinic instability at the initial stages due to production of available potential energy by the latent heat release. Condensation occurs in frontal regions and wraps up around the cyclone, which is consistent with the moist cyclogenesis theory and observations. Condensation induces a clear-cut cyclone–anticyclone asymmetry. The authors explain the underlying mechanism and show how it modifies the equilibration of the flow at the late stages of the saturation of the instability. In spite of significant differences in the evolution, only weak differences in various norms of the perturbations remain between precipitating and nonprecipitating cases at the end of the saturation process.

scholarly journals Atmospheric Dynamics Triggered by an Oceanic SST Front in a Moist Quasigeostrophic Model

2012 ◽  
Vol 69 (5) ◽  
pp. 1617-1632 ◽  
Author(s):  
Bruno Deremble ◽  
Guillaume Lapeyre ◽  
Michael Ghil
Keyword(s):  
Heat Flux ◽  
Heat Release ◽  
Latent Heat ◽  
Sensible Heat Flux ◽  
Sensible Heat ◽  
Latent Heat Release ◽  
Sst Front ◽  
Moist Processes ◽  
Surface Sensible Heat Flux ◽  
Sst Fronts

Abstract To understand the atmospheric response to a midlatitude oceanic front, this paper uses a quasigeostrophic (QG) model with moist processes. A well-known, three-level QG model on the sphere has been modified to include such processes in an aquaplanet setting. Its response is analyzed in terms of the upper-level atmospheric jet for sea surface temperature (SST) fronts of different profiles and located at different latitudes. When the SST front is sufficiently strong, it tends to anchor the mean atmospheric jet, suggesting that the jet’s spatial location and pattern are mainly affected by the latitude of the SST front. Changes in the jet’s pattern are studied, focusing on surface sensible heat flux and on moisture effects through latent heat release. It is found that latent heat release due to moist processes is modified when the SST front is changed, and this is responsible for the meridional displacement of the jet. Moreover, both latent heat release and surface sensible heat flux contribute to the jet’s strengthening. These results highlight the role of SST fronts and moist processes in affecting the characteristics of the midlatitude jet stream and of its associated storm track, particularly their positions.

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