On the Rapid Intensification of Hurricane Wilma (2005). Part III: Effects of Latent Heat of Fusion

2015 ◽  
Vol 72 (10) ◽  
pp. 3829-3849 ◽  
Author(s):  
William Miller ◽  
Hua Chen ◽  
Da-Lin Zhang
Keyword(s):  
Latent Heat ◽  
Inner Core ◽  
Vertical Motion ◽  
Heat Of Fusion ◽  
Rapid Intensification ◽  
Latent Heat Of Fusion ◽  
Hurricane Wilma ◽  
Convective Bursts ◽  
Upper Level ◽  
Reduced Rate

Abstract The impacts of the latent heat of fusion on the rapid intensification (RI) of Hurricane Wilma (2005) are examined by comparing a 72-h control simulation (CTL) of the storm to a sensitivity simulation in which the latent heat of deposition is reduced by removing fusion heating (NFUS). Results show that, while both storms undergo RI, the intensification rate is substantially reduced in NFUS. At peak intensity, NFUS is weaker than CTL by 30 hPa in minimum central pressure and by 12 m s−1 in maximum surface winds. The reduced rate of surface pressure falls in NFUS appears to result hydrostatically from less upper-level warming in the eye. It is shown that CTL generates more inner-core convective bursts (CBs) during RI, with higher altitudes of peak vertical motion in the eyewall, compared to NFUS. The latent heat of fusion contributes positively to sufficient eyewall conditional instability to support CB updrafts. Slantwise soundings taken in CB updraft cores reveal moist adiabatic lapse rates until 200 hPa, where the updraft intensity peaks. These results suggest that CBs may impact hurricane intensification by inducing compensating subsidence of the lower-stratospheric air, and the authors conclude that the development of more CBs inside the upper-level radius of maximum wind and at the higher altitude of latent heating all appear to be favorable for the RI of Wilma.

scholarly journals On the Rapid Intensification of Hurricane Wilma (2005). Part II: Convective Bursts and the Upper-Level Warm Core

2013 ◽  
Vol 70 (1) ◽  
pp. 146-162 ◽  
Author(s):  
Hua Chen ◽  
Da-Lin Zhang
Keyword(s):  
Inner Core ◽  
Static Stability ◽  
Rapid Intensification ◽  
Important Ingredient ◽  
High Resolution Data ◽  
Hurricane Wilma ◽  
Warm Core ◽  
Convective Bursts ◽  
Upper Level ◽  
The Relationship

Abstract Previous studies have focused mostly on the roles of environmental factors in the rapid intensification (RI) of tropical cyclones (TCs) because of the lack of high-resolution data in inner-core regions. In this study, the RI of TCs is examined by analyzing the relationship between an upper-level warm core, convective bursts (CBs), sea surface temperature (SST), and surface pressure falls from 72-h cloud-permitting predictions of Hurricane Wilma (2005) with the finest grid size of 1 km. Results show that both the upper-level inertial stability increases and static stability decreases sharply 2–3 h prior to RI, and that the formation of an upper-level warm core, from the subsidence of stratospheric air associated with the detrainment of CBs, coincides with the onset of RI. It is found that the development of CBs precedes RI, but most subsidence warming radiates away by gravity waves and storm-relative flows. In contrast, many fewer CBs occur during RI, but more subsidence warming contributes to the balanced upper-level cyclonic circulation in the warm-core (as intense as 20°C) region. Furthermore, considerable CB activity can still take place in the outer eyewall as the storm weakens during its eyewall replacement. A sensitivity simulation, in which SSTs are reduced by 1°C, shows pronounced reductions in the upper-level warm-core intensity and CB activity. It is concluded that significant CB activity in the inner-core regions is an important ingredient in generating the upper-level warm core that is hydrostatically more efficient for the RI of TCs, given all of the other favorable environmental conditions.

Inner-core dynamics during the rapid intensification of Hurricane Wilma (2005) with a steady radius of the maximum wind

2020 ◽  
Author(s):  
Nannan Qin ◽  
Da-Lin Zhang ◽  
William Miller ◽  
Chanh Kieu
Keyword(s):  
Inner Core ◽  
Vertical Motion ◽  
Rapid Intensification ◽  
Flux Divergence ◽  
Hurricane Wilma ◽  
Maximum Wind ◽  
Budget Analysis ◽  
Core Dynamics ◽  
Major Process ◽  
Frictional Dissipation

<p>Recent studies show that some hurricanes may undergo rapid intensification (RI) without contracting the radius of maximum wind (RMW). A cloud-resolving WRF-prediction of Hurricane Wilma (2005) is used herein to examine what controls the RMW contraction and how a hurricane could undergo RI without contraction. Results show that the processes controlling the RMW contraction are different within and above the planetary boundary layer (PBL). In the PBL, radial inflows contribute to contraction, with frictional dissipation acting as an inhibiting factor. Above the PBL, radial outflows and vertical motion govern the RMW contraction, with the former inhibiting it. A budget analysis of absolute angular momentum (AAM) shows that the radial AAM flux convergence is the major process accounting for the spinup of the maximum rotation, while the vertical flux divergence of AAM and the frictional sink in the PBL oppose the spinup. During the RI stage with no RMW contraction, the local AAM tendencies in the eyewall are smaller in magnitude and narrower in width than those during the contracting RI stage. In addition, the AAM following the time-dependent RMW decreases with time in the PBL and remains nearly constant aloft during the contracting stage, whereas it increases during the non-contracting stage. These results reveal different constraints for the RMW contraction and RI, and help explain why a hurricane vortex can still intensify after the RMW ceases contraction</p>

Determination of the latent heat of fusion and solid fraction evolution of metals and alloys by an improved cooling curve analysis method

2019 ◽  
Vol 140 (4) ◽  
pp. 1825-1836 ◽  
Author(s):  
Carlos González-Rivera ◽  
Anthony Harrup ◽  
Carla Aguilar ◽  
Adrián M. Amaro-Villeda ◽  
Marco A. Ramírez-Argáez
Keyword(s):  
Latent Heat ◽  
Solid Fraction ◽  
Metals And Alloys ◽  
Curve Analysis ◽  
Cooling Curve ◽  
Heat Of Fusion ◽  
Analysis Method ◽  
Latent Heat Of Fusion ◽  
Cooling Curve Analysis

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 Effects of Egg Yolk, Glycerol and the Freezing Rate on the Viability and Acrosomal Structures of Frozen Ram Spermatozoa

1975 ◽  
Vol 28 (2) ◽  
pp. 153 ◽  
Author(s):  
PF Watson ◽  
ICA Martin
Keyword(s):  
Latent Heat ◽  
Significant Interaction ◽  
Freezing Point ◽  
Egg Yolk ◽  
Freezing Rate ◽  
Heat Of Fusion ◽  
Significant Deterioration ◽  
Cooling Rates ◽  
Latent Heat Of Fusion ◽  
Cooling Phase

The influence of egg yolk, glycerol and the freezing rate on the survival of ram spermatozoa and on the structure of their acrosomes after freezing was investigated. Egg yolk was shown to be beneficial not only during chilling but also during freezing; of the levels examined, 1� 5 % gave the greatest protection. Although the presence of glycerol in the diluent improved the survival of spermatozoa, increasing concentrations produced significant deterioration of the acrosomes. With closely controlled linear cooling rates, no overall difference was detected in the survival of spermatozoa frozen at rates between 6 and 24�C per min. However, a significant interaction between freezing rate and the inclusion of glycerol in the diluent showed that glycerol was less important at the highest freezing rate. A sudden cooling phase near to the freezing point following the release of the latent heat of fusion was not detrimental to spermatozoa.

scholarly journals Consideration of Latent Heat of Fusion of Ice in Aqueous Solution

Netsu Bussei ◽  
2008 ◽  
Vol 22 (1) ◽  
pp. 18-24
Author(s):  
Tatsunori ASAOKA ◽  
Hiroyuki KUMANO ◽  
Akio SAITO ◽  
Seiji OKAWA
Keyword(s):  
Aqueous Solution ◽  
Latent Heat ◽  
Heat Of Fusion ◽  
Latent Heat Of Fusion
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