scholarly journals Unusual Surface Latent Heat Flux Variations and Their Critical Dynamics Revealed before Strong Earthquakes

Entropy ◽  
2021 ◽  
Vol 24 (1) ◽  
pp. 23
Author(s):  
Soujan Ghosh ◽  
Swati Chowdhury ◽  
Subrata Kundu ◽  
Sudipta Sasmal ◽  
Dimitrios Z. Politis ◽  
...  
Keyword(s):  
Heat Flux ◽  
Latent Heat ◽  
Latent Heat Flux ◽  
Seismic Events ◽  
Critical Dynamics ◽  
Thermal Anomalies ◽  
Surface Latent Heat Flux ◽  
Natural Time ◽  
Natural Time Analysis ◽  
Criticality Analysis

We focus on the possible thermal channel of the well-known Lithosphere–Atmosphere–Ionosphere Coupling (LAIC) mechanism to identify the behavior of thermal anomalies during and prior to strong seismic events. For this, we investigate the variation of Surface Latent Heat Flux (SLHF) as resulting from satellite observables. We demonstrate a spatio-temporal variation in the SLHF before and after a set of strong seismic events occurred in Kathmandu, Nepal, and Kumamoto, Japan, having magnitudes of 7.8, 7.3, and 7.0, respectively. Before the studied earthquake cases, significant enhancements in the SLHF were identified near the epicenters. Additionally, in order to check whether critical dynamics, as the signature of a complex phenomenon such as earthquake preparation, are reflected in the SLHF data, we performed a criticality analysis using the natural time analysis method. The approach to criticality was detected within one week before each mainshock.

How surface latent heat flux is related to lower-tropospheric stability in southern subtropica marine stratus and stratocumulus regions

2009 ◽  
Vol 1 (3) ◽  
Author(s):  
Yanping He
Keyword(s):  
Heat Flux ◽  
Latent Heat ◽  
Latent Heat Flux ◽  
Radiation Flux ◽  
Surface Wind ◽  
Surface Radiation ◽  
Near Surface ◽  
Marine Stratus ◽  
Surface Latent Heat Flux ◽  
Lower Tropospheric Stability

AbstractThe relationship between surface latent heat flux and the lower-tropospheric stability (LTS) is examined using ERA-40 reanalysis, NCEP reanalysis and COADS (Comprehensive Ocean-Atmosphere Data Set) ship data in two southern subtropical marine stratus and stratocumulus regions. The change of surface latent heat flux with LTS is determined by a comparison of the correlation of LTS with surface wind speed and with near surface humidity difference. At intermediate LTS (10 K-15 K), both surface evaporation and downward surface radiation flux amplify small LTS perturbations due to the surface wind-LTS relationship and cloud-radiation feedback. At high LTS, surface latent heat flux exceeds its peak value and becomes a regulating mechanism to keep LTS at its commonly observed equilibrium value. Surface radiation flux is seen to decrease at a smaller rate with LTS than surface latent heat flux. By applying the regulating effect of LTS on near surface humidity differences, monthly surface latent heat flux can be better represented.

scholarly journals Brief Communication: An exclusive example of surface latent heat flux variation before Russia M6.1 earthquake

2014 ◽  
Vol 2 (1) ◽  
pp. 347-359
Author(s):  
Y. Jie ◽  
G. Guangmeng
Keyword(s):  
Heat Flux ◽  
Latent Heat ◽  
Latent Heat Flux ◽  
Satellite Image ◽  
High Temporal Resolution ◽  
Flux Variation ◽  
Daily Data ◽  
Surface Latent Heat Flux ◽  
First Time ◽  
Very High

Abstract. Recently surface latent heat flux (SLHF) data is widely used to study the anomalies before earthquakes. Most researches use the daily SLHF data, here we use both daily data and high temporal resolution (four times one day) SLHF data, and compare the SLHF change with satellite image at the first time. We check the data from 1 September to 30 October 2011 and the result shows that there is really a very high SLHF anomaly (bigger than 2 σ) just 5 days before the M6.1 Russia earthquake which occurred on 14 October 2011. It should be considered as a preseismic precursor if judged with previously published methods. But our comparison between SLHF change and satellite image shows that the SLHF anomaly is just caused by a thick cloud. This result tells us that scientists must know the data's meaning before they use it, if not, they may get a wrong conclusion. Based on this example, we suggest that previously published SLHF anomaly before earthquake should be reanalyzed by our method to exclude the false anomaly.

scholarly journals Brief Communication: The interaction of clouds with surface latent heat flux variation before the 2011 <i>M</i> = 6.1 Russia earthquake

2014 ◽  
Vol 14 (9) ◽  
pp. 2649-2653 ◽  
Author(s):  
Y. Jie ◽  
G. Guangmeng
Keyword(s):  
Heat Flux ◽  
Latent Heat ◽  
Latent Heat Flux ◽  
Temporal Resolution ◽  
Satellite Images ◽  
High Temporal Resolution ◽  
Flux Variation ◽  
Surface Latent Heat Flux ◽  
First Time ◽  
Very High

Abstract. Recently, surface latent heat flux (SLHF) data have been widely used to study the anomalies before earthquakes. Most studies use the daily SLHF data. Here we use both the daily SLHF data and the high temporal resolution (four times one day) SLHF data, and compare the SLHF changes with satellite cloud images at the first time. We check the data from 1 September to 30 October 2011, and the result shows that there is really a very high SLHF anomaly (more than 2σ) in the epicenter area just 5 days before the M = 6.1 Russia earthquake that occurred on 14 October 2011. It should be considered as a preseismic precursor if judged with previously published methods, but our comparison between SLHF change and satellite images shows that the SLHF anomaly is contaminated by a thick cloud. It is difficult to verify that this SLHF anomaly is caused by an earthquake and our analysis shows that it is more related to meteorological reason. This example tells us that scientists must know the data's meaning before they use it; if not, they may draw a wrong conclusion. Based on this example, we suggest that previously published SLHF anomalies before earthquakes should be reanalyzed with our method to exclude the false anomalies.

Surface latent heat flux anomalies prior to the indonesia Mw9.0 earthquake of 2004

2006 ◽  
Vol 51 (8) ◽  
pp. 1010-1013 ◽  
Author(s):  
Meihua Chen ◽  
Zhihui Deng ◽  
Zhuzhuan Yang ◽  
Xiaojing Ma
Keyword(s):  
Heat Flux ◽  
Latent Heat ◽  
Latent Heat Flux ◽  
Surface Latent Heat Flux
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