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Articles 1 - 6 of 6

Full-Text Articles in Physical Sciences and Mathematics

A Novel Shortwave Infrared Proximal Sensing Approach To Quantify The Water Stability Of Soil Aggregates, Azadeh Gholoubi, Hojat Emami, Scott B. Jones, Markus Tuller Oct 2018

A Novel Shortwave Infrared Proximal Sensing Approach To Quantify The Water Stability Of Soil Aggregates, Azadeh Gholoubi, Hojat Emami, Scott B. Jones, Markus Tuller

Plants, Soils, and Climate Faculty Publications

Soil structure and aggregate stability (AS) are critical soil properties affecting water infiltration, root growth, and resistance to soil and wind erosion. Changes in AS may be early indicators of soil degradation, pointing to low organic matter (OM) content, reduced biological activity, or poor nutrient cycling. Hence, efficient and reliable AS measurement techniques are essential for detection, management, and remediation of degraded soil resources. Here we quantify soil AS by developing a novel proximal sensing technique based on shortwave infrared (SWIR) reflectance measurements. The novel approach is similar to the well-documented high energy moisture characteristic (HEMC) method, which yields a …


The Influence Of Arctic Amplification On Mid-Latitude Summer Circulation, Dim Coumou, Giorgia Di Capua, Steve Vavrus, Lei Wang, Shih-Yu (Simon) Wang Aug 2018

The Influence Of Arctic Amplification On Mid-Latitude Summer Circulation, Dim Coumou, Giorgia Di Capua, Steve Vavrus, Lei Wang, Shih-Yu (Simon) Wang

Plants, Soils, and Climate Faculty Publications

Accelerated warming in the Arctic, as compared to the rest of the globe, might have profound impacts on mid-latitude weather. Most studies analyzing Arctic links to mid-latitude weather focused on winter, yet recent summers have seen strong reductions in sea-ice extent and snow cover, a weakened equator-to-pole thermal gradient and associated weakening of the mid-latitude circulation. We review the scientific evidence behind three leading hypotheses on the influence of Arctic changes on mid-latitude summer weather: Weakened storm tracks, shifted jet streams, and amplified quasi-stationary waves. We show that interactions between Arctic teleconnections and other remote and regional feedback processes could …


El Niño-Southern Oscillation Complexity, Axel Timmermann, Soon-Il An, Jong-Seong Kug, Fei-Fei Jin, Wenju Cai, Antonietta Capotondi, Kim Cobb, Matthieu Lengaigne, Michal J. Mcphaden, Malte F. Stuecker, Karl Stein, Andrew T. Wittenberg, Kyung-Sook Yun, Tobias Bayr, Han-Ching Chen, Yoshimitsu Chikamoto, Et Al. Jul 2018

El Niño-Southern Oscillation Complexity, Axel Timmermann, Soon-Il An, Jong-Seong Kug, Fei-Fei Jin, Wenju Cai, Antonietta Capotondi, Kim Cobb, Matthieu Lengaigne, Michal J. Mcphaden, Malte F. Stuecker, Karl Stein, Andrew T. Wittenberg, Kyung-Sook Yun, Tobias Bayr, Han-Ching Chen, Yoshimitsu Chikamoto, Et Al.

Plants, Soils, and Climate Faculty Publications

El Niño events are characterized by surface warming of the tropical Pacific Ocean and weakening of equatorial trade winds that occur every few years. Such conditions are accompanied by changes in atmospheric and oceanic circulation, affecting global climate, marine and terrestrial ecosystems, fisheries and human activities. The alternation of warm El Niño and cold La Niña conditions, referred to as the El Niño–Southern Oscillation (ENSO), represents the strongest year-to-year fluctuation of the global climate system. Here we provide a synopsis of our current understanding of the spatio-temporal complexity of this important climate mode and its influence on the Earth system.


Ocean Impacts On Australian Interannual To Decadal Precipitation Variability, Zachary F. Johnson, Yoshimitsu Chikamoto, Jing-Jia Luo, Takashi Mochizuki Jul 2018

Ocean Impacts On Australian Interannual To Decadal Precipitation Variability, Zachary F. Johnson, Yoshimitsu Chikamoto, Jing-Jia Luo, Takashi Mochizuki

Plants, Soils, and Climate Faculty Publications

In Australia, successful seasonal predictions of wet and dry conditions are achieved by utilizing the remote impact of sea surface temperature (SST) variability in tropical oceans, particularly the Pacific Ocean, on the seasonal timescale. Beyond seasonal timescales, however, it is still unclear which processes and oceans contribute to interannual-to-decadal wet/dry conditions in Australia. This research examines the interannual-to-decadal relationship between global SST anomalies (SSTAs) and Australian wet/dry variability by analyzing observational data and global climate model experiments conducted with the NCAR Community Earth System Model (CESM) and the Model for Interdisciplinary Research on Climate (MIROC). A 10-member ensemble simulation suite …


Regional Trends In Early-Monsoon Rainfall Over Vietnam And Ccsm4 Attribution, Rong Li, S.-Y. Simon Wang, Robert R. Gillies, Brendan Buckley, Jin-Ho Yoon, Changrae Cho Apr 2018

Regional Trends In Early-Monsoon Rainfall Over Vietnam And Ccsm4 Attribution, Rong Li, S.-Y. Simon Wang, Robert R. Gillies, Brendan Buckley, Jin-Ho Yoon, Changrae Cho

Plants, Soils, and Climate Faculty Publications

The analysis of precipitation trends for Vietnam revealed that early-monsoon precipitation has increased over the past three decades but to varying degrees over the northern, central and southern portions of the country. Upon investigation, it was found that the change in early-monsoon precipitation is associated with changes in the low-level cyclonic airflow over the South China Sea and Indochina that is embedded in the large-scale atmospheric circulation associated with a “La Niña-like” anomalous sea surface temperature pattern with warming in the western Pacific and Indian Oceans and cooling in the eastern Pacific. The Community Climate System Model version 4 (CCSM4) …


Multidecadal Variability In The Subseasonal Peak Of Low-Level Convergence Over The Pacific Warm Pool, Yen-Heng Lin, Shih-Yu (Simon) Wang Apr 2018

Multidecadal Variability In The Subseasonal Peak Of Low-Level Convergence Over The Pacific Warm Pool, Yen-Heng Lin, Shih-Yu (Simon) Wang

Plants, Soils, and Climate Faculty Publications

In the Western North Pacific (WNP), the atmospheric low-level convergence is one of the main factors that influences the genesis of tropical cyclones (TC). It has been observed that the timing of the seasonal maxima in the low-level convergence and TC genesis has shifted since the mid-1990s from mid-August to late-July, with this shift having also affected the number of TC. A multidecadal frequency of 20 years was revealed in the timing variation of the tropical intraseasonal oscillation (ISO) in the Western Pacific, in which a weak WNP low-level convergence in spring may trigger an advanced ISO phase in summer …