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Full-Text Articles in Physical Sciences and Mathematics

Recurrent Pattern Of Extreme Fire Weather In California, Rackhun Son, S-Y Simon Wang, Seung Hee Kim, Hyungjun Kim, Jee-Hoon Jeong, Jin-Ho Yoon Aug 2021

Recurrent Pattern Of Extreme Fire Weather In California, Rackhun Son, S-Y Simon Wang, Seung Hee Kim, Hyungjun Kim, Jee-Hoon Jeong, Jin-Ho Yoon

Mathematics, Physics, and Computer Science Faculty Articles and Research

Historical wildfire events in California have shown a tendency to occur every five to seven years with a rapidly increasing tendency in recent decades. This oscillation is evident in multiple historical climate records, some more than a century long, and appears to be continuing. Analysis shows that this 5–7 year oscillation is linked to a sequence of anomalous large-scale climate patterns with an eastward propagation in both the ocean and atmosphere. While warmer temperature emerges from the northern central Pacific to the west coast of California, La Niña pattern develops simultaneously, implying that the lifecycle of the El Niño-Southern Oscillation …


Reaction Intensity Partitioning: A New Perspective Of The National Fire Danger Rating System Energy Release Component, Francis M. Fujioka, David R. Weise, Shyh-Chin Chen, Seung Hee Kim, Menas C. Kafatos Apr 2021

Reaction Intensity Partitioning: A New Perspective Of The National Fire Danger Rating System Energy Release Component, Francis M. Fujioka, David R. Weise, Shyh-Chin Chen, Seung Hee Kim, Menas C. Kafatos

Mathematics, Physics, and Computer Science Faculty Articles and Research

The Rothermel fire spread model provides the scientific basis for the US National Fire Danger Rating System (NFDRS) and several other important fire management applications. This study proposes a new perspective of the model that partitions the reaction intensity function and Energy Release Component (ERC) equations as an alternative that simplifies calculations while providing more insight into the temporal variability of the energy release component of fire danger. We compare the theoretical maximum reaction intensities and corresponding ERCs across 1978, 1988 and 2016 NFDRS fuel models as they are currently computed and as they would be computed under the proposed …


Investigating Decadal Changes Of Multiple Hydrological Products And Land-Cover Changes In The Mediterranean Region For 2009–2018, Wenzhao Li, Sachi Perera, Erik Linstead, Rejoice Thomas, Hesham El-Askary, Thomas Piechota, Daniele Struppa Mar 2021

Investigating Decadal Changes Of Multiple Hydrological Products And Land-Cover Changes In The Mediterranean Region For 2009–2018, Wenzhao Li, Sachi Perera, Erik Linstead, Rejoice Thomas, Hesham El-Askary, Thomas Piechota, Daniele Struppa

Mathematics, Physics, and Computer Science Faculty Articles and Research

Land-cover change is a critical concern due to its climatic, ecological, and socioeconomic consequences. In this study, we used multiple variables including precipitation, vegetation index, surface soil moisture, and evapotranspiration obtained from different satellite sources to study their association with land-cover changes in the Mediterranean region. Both observational and modeling data were used for climatology and correlation analysis. Famine Early Warning Systems Network (FEWS NET) Land Data Assimilation System (FLDAS) and Global Land Data Assimilation System (GLDAS) were used to extract surface soil moisture and evapotranspiration data. Intercomparing the results of FLDAS and GLDAS suggested that FLDAS data had better …


Changes In Fire Weather Climatology Under 1.5 ◦C And 2.0 ◦C Warming, Rackhun Son, Hyungjun Kim, Shih-Yu (Simon) Wang, Jee-Hoon Jeong, Sung-Ho Woo, Ji-Yoon Jeong, Byung-Doo Lee, Seung Hee Kim, Matthew Laplante, Chun-Geun Kwon, Jin-Ho Yoon Mar 2021

Changes In Fire Weather Climatology Under 1.5 ◦C And 2.0 ◦C Warming, Rackhun Son, Hyungjun Kim, Shih-Yu (Simon) Wang, Jee-Hoon Jeong, Sung-Ho Woo, Ji-Yoon Jeong, Byung-Doo Lee, Seung Hee Kim, Matthew Laplante, Chun-Geun Kwon, Jin-Ho Yoon

Mathematics, Physics, and Computer Science Faculty Articles and Research

The 2015 Paris Agreement led to a number of studies that assessed the impact of the 1.5 ◦C and 2.0 ◦C increases in global temperature over preindustrial levels. However, those assessments have not actively investigated the impact of these levels of warming on fire weather. In view of a recent series of high-profile wildfire events worldwide, we access fire weather sensitivity based on a set of multi-model large ensemble climate simulations for these low-emission scenarios. The results indicate that the half degree difference between these two thresholds may lead to a significantly increased hazard of wildfire in certain parts of …


Investigating The Lagged Relationship Between Smap Soil Moisture And Live Fuel Moisture In California, Usa, Shenyue Jia, Seung Hee Kim, Son V. Nghiem, Keun Hang S. Yang, Menas Kafatos Feb 2021

Investigating The Lagged Relationship Between Smap Soil Moisture And Live Fuel Moisture In California, Usa, Shenyue Jia, Seung Hee Kim, Son V. Nghiem, Keun Hang S. Yang, Menas Kafatos

Mathematics, Physics, and Computer Science Faculty Articles and Research

Live fuel moisture (LFM), defined as the ratio between water in the fresh biomass out of the dry biomass, is a vital measurement of vegetation water content and flammability. In this study, we investigated the dynamics of in-situ measurement of LFM at all the active sites in California, USA and revealed the difference between evergreen forest and shrub/scrub, the two dominant land cover types in California's fire-prone regions. We found that LFM of evergreen forest responses to soil moisture increase later than shrub/scrub, due to a later occurrence of major precipitation, a lower air temperature, and the different plant physiology. …


From Hector Mine M7.1 To Ridgecrest M7.1 Earthquake. A Look From A 20-Year Perspective, Sergey Pulinets, Marina Tsidilina, Dimitar Ouzounov, Dmitry Davidenko Feb 2021

From Hector Mine M7.1 To Ridgecrest M7.1 Earthquake. A Look From A 20-Year Perspective, Sergey Pulinets, Marina Tsidilina, Dimitar Ouzounov, Dmitry Davidenko

Mathematics, Physics, and Computer Science Faculty Articles and Research

The paper provides a comparative analysis of precursory phenomena in the ionosphere and atmosphere for two strong earthquakes of the same magnitude M7.1 that happened in the same region (North-East from Los Angeles) within a time span of 20 years, the Hector Mine and Ridgecrest earthquakes. Regardless of the similarity of their location (South-Eastern California, near 160 km one from another), there was one essential difference: the Hector Mine earthquake happened during geomagnetically disturbed conditions (essential in the sense of ionospheric precursors identification). In contrast, the quiet geomagnetic conditions characterized the period around the time of the Ridgecrest earthquake. The …


An Assessment Of The Filling Process Of The Grand Ethiopian Renaissance Dam And Its Impact On The Downstream Countries, Prakrut Kansara, Wenzhao Li, Hesham El-Askary, Venkat Lakshmi, Thomas Piechota, Daniele Struppa, Mohamed Abdelaty Sayed Feb 2021

An Assessment Of The Filling Process Of The Grand Ethiopian Renaissance Dam And Its Impact On The Downstream Countries, Prakrut Kansara, Wenzhao Li, Hesham El-Askary, Venkat Lakshmi, Thomas Piechota, Daniele Struppa, Mohamed Abdelaty Sayed

Mathematics, Physics, and Computer Science Faculty Articles and Research

The Grand Ethiopian Renaissance Dam (GERD), formerly known as the Millennium Dam, has been filling at a fast rate. This project has created issues for the Nile Basin countries of Egypt, Sudan, and Ethiopia. The filling of GERD has an impact on the Nile Basin hydrology and specifically the water storages (lakes/reservoirs) and flow downstream. In this study, through the analysis of multi-source satellite imagery, we study the filling of the GERD reservoir. The time-series generated using Sentinel-1 SAR imagery displays the number of classified water pixels in the dam from early June 2017 to September 2020, indicating a contrasting …