scholarly journals Source Regions of the First Immigration of Fall Armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae) Invading Australia

Insects ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1104
Author(s):  
Guo-Jun Qi ◽  
Jian Ma ◽  
Jing Wan ◽  
Yong-Lin Ren ◽  
Simon McKirdy ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Significant Risk ◽  
Fall Armyworm ◽  
Reanalysis Data ◽  
Flight Behavior ◽  
Agricultural Pests ◽  
Source Regions ◽  
Risk Period ◽  
Arafura Sea ◽  
Monsoon Winds

Fall armyworm is recognized as one of most highly destructive global agricultural pests. In January 2020, it had first invaded Australia, posing a significant risk to its biosecurity, food security, and agricultural productivity. In this study, the migration paths and wind systems for the case of fall armyworm invading Australia were analyzed using a three-dimensional trajectory simulation approach, combined with its flight behavior and NCEP meteorological reanalysis data. The analysis showed that fall armyworm in Torres Strait most likely came from surrounding islands of central Indonesia on two occasions via wind migration. Specifically, fall armyworm moths detected on Saibai and Erub Islands might have arrived from southern Sulawesi Island, Indonesia, between January 15 and 16. The fall armyworm in Bamaga most likely arrived from the islands around Arafura Sea and Sulawesi Island of Indonesia, between January 26 and 27. The high risk period for the invasion of fall armyworm is only likely to have occurred in January–February due to monsoon winds, which were conducive to flight across the Timor Sea towards Australia. This case study is the first to confirm the immigration paths and timing of fall armyworm from Indonesia to Australia via its surrounding islands.

scholarly journals Occurrence and Evolution of Mesoscale Thermodynamic Phenomena in the Northern Part of the East Sea (Japan Sea) Derived from Satellite Altimeter Data

2021 ◽  
Vol 13 (6) ◽  
pp. 1071
Author(s):  
Taekyun Kim ◽  
Hyeong-Jun Jo ◽  
Jae-Hong Moon
Keyword(s):  
Japan Sea ◽  
Reanalysis Data ◽  
East Sea ◽  
Spatiotemporal Variability ◽  
Altimeter Data ◽  
Intermediate Water ◽  
Dipole Structure ◽  
Northwestern Region ◽  
New Perspective ◽  
Monsoon Winds

Based on satellite measurements and oceanic reanalysis data, it has been possible to investigate the spatiotemporal variability of the mesoscale phenomena in the northern part of the East Sea (NES) where direct observations of currents and hydrographical conditions are scarce. For the first time, this study identifies the detailed spatiotemporal structure of the mesoscale features in the NES and the mechanism of its occurrence and evolution, which have important consequences on the distribution of the intermediate water masses in the East Sea. Here, we show that mesoscale thermodynamic phenomena in the northwestern region of the East Sea are characterized by a dipole structure associated with positive and negative sea surface height anomalies. These result in a strong thermal gradient between the seasonally non-persistent anomalies, which emerge and strengthen during late fall and early winter. In contrast to the previous finding of the relationship between winter monsoon winds and mesoscale features in the NES, we found that this relationship is crucial only to the emergence of the mesoscale phenomena. Consequently, we present a new perspective on the evolution mechanism of the mesoscale features in the NES. Of direct significance to the present study, thermohaline transport into the northwestern region of the East Sea regulates the strengthening and weakening of mesoscale features in the NES. Wind forcing may contribute to the emergence of the mesoscale features in the NES and then the intensification of the mesoscale activities is attributed to the intrusion of warm and fresh surface water advected from the southern part of the East Sea.

scholarly journals Structure-controlled asperities of the 1920 Haiyuan M8.5 and 1927 Gulang M8 earthquakes, NE Tibet, China, revealed by high-resolution seismic tomography

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Quan Sun ◽  
Shunping Pei ◽  
Zhongxiong Cui ◽  
Yongshun John Chen ◽  
Yanbing Liu ◽  
...  
Keyword(s):  
High Resolution ◽  
Seismic Tomography ◽  
High Velocity ◽  
Three Dimensional ◽  
Large Earthquake ◽  
Velocity Model ◽  
Tectonic Stress ◽  
Double Difference ◽  
Source Regions ◽  
Large Earthquakes

AbstractDetailed crustal structure of large earthquake source regions is of great significance for understanding the earthquake generation mechanism. Numerous large earthquakes have occurred in the NE Tibetan Plateau, including the 1920 Haiyuan M8.5 and 1927 Gulang M8 earthquakes. In this paper, we obtained a high-resolution three-dimensional crustal velocity model around the source regions of these two large earthquakes using an improved double-difference seismic tomography method. High-velocity anomalies encompassing the seismogenic faults are observed to extend to depths of 15 km, suggesting the asperity (high-velocity area) plays an important role in the preparation process of large earthquakes. Asperities are strong in mechanical strength and could accumulate tectonic stress more easily in long frictional locking periods, large earthquakes are therefore prone to generate in these areas. If the close relationship between the aperity and high-velocity bodies is valid for most of the large earthquakes, it can be used to predict potential large earthquakes and estimate the seismogenic capability of faults in light of structure studies.

scholarly journals Data assimilation of dust aerosol observations for CUACE/Dust forecasting system

2007 ◽  
Vol 7 (3) ◽  
pp. 8309-8332 ◽  
Author(s):  
T. Niu ◽  
S. L. Gong ◽  
G. F. Zhu ◽  
H. L. Liu ◽  
X. Q. Hu ◽  
...  
Keyword(s):  
Data Assimilation ◽  
Atmospheric Chemistry ◽  
Three Dimensional ◽  
System A ◽  
Source Regions ◽  
Operational Forecasts ◽  
Forecasting System ◽  
Dust Loading ◽  
Data Assimilation System ◽  
Assimilation System

Abstract. A data assimilation system (DAS) was developed for the Chinese Unified Atmospheric Chemistry Environment – Dust (CUACE/Dust) forecast system and applied in the operational forecasts of sand and dust storm (SDS) in spring 2006. The system is based on a three dimensional variational method (3D-Var) and uses extensively the measurements of surface visibility and dust loading retrieval from the Chinese geostationary satellite FY-2C. The results show that a major improvement to the capability of CUACE/Dust in forecasting the short-term variability in the spatial distribution and intensity of dust concentrations has been achieved, especially in those areas far from the source regions. The seasonal mean Threat Score (TS) over the East Asia in spring 2006 increased from 0.22 to 0.31 by using the data assimilation system, a 41% enhancement. The assimilation results usually agree with the dust loading retrieved from FY-2C and visibility distribution from surface meteorological stations, which indicates that the 3D-Var method is very powerful for the unification of observation and numerical modeling results.

scholarly journals Ocean acidification causes structural deformities in juvenile coral skeletons

2016 ◽  
Vol 2 (2) ◽  
pp. e1501130 ◽  
Author(s):  
Taryn Foster ◽  
James L. Falter ◽  
Malcolm T. McCulloch ◽  
Peta L. Clode
Keyword(s):  
Ocean Acidification ◽  
Structural Changes ◽  
Three Dimensional ◽  
Significant Risk ◽  
Skeletal Structure ◽  
Juvenile Coral ◽  
Mineral Deposition ◽  
Coral Reef Ecosystems ◽  
New Recruits ◽  
Business As Usual

Rising atmospheric CO2is causing the oceans to both warm and acidify, which could reduce the calcification rates of corals globally. Successful coral recruitment and high rates of juvenile calcification are critical to the replenishment and ultimate viability of coral reef ecosystems. Although elevatedPco2(partial pressure of CO2) has been shown to reduce the skeletal weight of coral recruits, the structural changes caused by acidification during initial skeletal deposition are unknown. We show, using high-resolution three-dimensional x-ray microscopy, that ocean acidification (Pco2~900 μatm, pH ~7.7) not only causes reduced overall mineral deposition but also a deformed and porous skeletal structure in newly settled coral recruits. In contrast, elevated temperature (+3°C) had little effect on skeletal formation except to partially mitigate the effects of elevatedPco2. The striking structural deformities we observed show that new recruits are at significant risk, being unable to effectively build their skeletons in thePco2conditions predicted to occur for open ocean surface waters under a “business-as-usual” emissions scenario [RCP (representative concentration pathway) 8.5] by the year 2100.

GLORIA observations of pollution tracers C2H6, C2H2, HCOOH, and PAN in the North Atlantic UTLS region

2020 ◽  
Author(s):  
Gerald Wetzel ◽  
Felix Friedl-Vallon ◽  
Norbert Glatthor ◽  
Jens-Uwe Grooß ◽  
Thomas Gulde ◽  
...  
Keyword(s):  
High Altitude ◽  
North Atlantic ◽  
Atmospheric Chemistry ◽  
Emission Spectra ◽  
Infrared Region ◽  
Reanalysis Data ◽  
Lagrangian Model ◽  
Back Trajectories ◽  
Source Regions ◽  
Research Aircraft

<p>The Gimballed Limb Observer for Radiance Imaging of the Atmosphere (GLORIA) is an imaging Fourier transform spectrometer (iFTS) using a 2-dimensional detector array to record emission spectra in the mid-infrared region with high spatial resolution. GLORIA is operated on high altitude research aircraft, mainly in the limb observational geometry to measure vertical profiles of temperature and atmospheric trace species with high vertical resolution.</p><p>In autumn 2017, the Wave-driven ISentropic Exchange (WISE) aircraft campaign took place from Shannon (Ireland). Sixteen flights with the High Altitude and Long Range Research Aircraft (HALO) were performed between 31 August and 21 October 2017 over the eastern North Atlantic region.</p><p>GLORIA observations were analysed with regard to pollutant species like C<sub>2</sub>H<sub>6</sub>, C<sub>2</sub>H<sub>2</sub>, HCOOH, and PAN, which are produced at distinct source regions near the ground and transported to remote regions due to their atmospheric lifetime of several weeks. Enhanced volume mixing ratios of these molecules were detected along some parts of the flight track in the upper troposphere and lowermost stratosphere (UTLS).</p><p>Measured profiles of these species are compared to simulations from the ECHAM/MESSy Atmospheric Chemistry (EMAC) model and reanalysis data from the Copernicus Atmosphere Monitoring Service (CAMS). Furthermore, emission tracers and back-trajectories from the Chemical Lagrangian Model of the Stratosphere (CLaMS) are used to analyse the source regions of these pollution events.</p>

scholarly journals Contribution of Asian emissions to upper tropospheric CO over the remote Pacific

2021 ◽  
Author(s):  
Linda Smoydzin ◽  
Peter Hoor
Keyword(s):  
Seasonal Cycle ◽  
Transport Model ◽  
Source Region ◽  
Reanalysis Data ◽  
Transport Pathways ◽  
Trajectory Calculations ◽  
Source Regions ◽  
Spatial Coverage ◽  
High Regularity ◽  
Pollution Events

Abstract. We use CO data from the MOPITT satellite instrument from 2000–2019 to compose a climatology of severe pollution events in the mid- and upper troposphere over the northern-hemispheric (NH-) Pacific. To link each individual pollution event detected by MOPITT with a CO source region, we performed trajectory calculations using MPTRAC, a lagrangian transport model. To analyse transport pathways and uplift mechanisms we combine MOPITT data, the trajectory calculations and ERA-Interim reanalysis data. Events of elevated CO which we detect at level between 500 hPa and 300 hPa over the NH-Pacific throughout the year, occur with a surprisingly high regularity and frequency (70 % of all days during winter, 80 % respectively during spring). Our study further indicates, that the spatial coverage of individual upper tropospheric pollution cluster increased in spring time during the 20 years we analysed. The position of upper tropospheric pollution plumes show a strong seasonal cycle. During winter, most pollution events are detected over the north-eastern and central NH-Pacific, during spring over the central NH-Pacific and during summer over the western NH-Pacific. We detect most pollution episodes during spring. Trajectory simulations reveal China as the major CO-source region throughout the year. The contribution of other source regions shows a strong seasonal cycle: NE-Asia is a significant CO-source region during winter and summer while India and SE-Asia are important source regions mainly during spring.

scholarly journals CHANGES IN THE HYDROLOGICAL CHARACTERISTICS OF THE ARCTIC OCEAN UNDER THE INFLUENCE OF INCREASING RIVER RUNOFF

2021 ◽  
Vol 4 (1) ◽  
pp. 210-216
Author(s):  
Marina A. Tarkhanova ◽  
Elena N. Golubeva
Keyword(s):  
Arctic Ocean ◽  
River Runoff ◽  
Three Dimensional ◽  
Heat Content ◽  
Water Layer ◽  
Atlantic Water ◽  
Reanalysis Data ◽  
The Arctic ◽  
The Stability ◽  
Stability Of Water

The paper considers issues related to the influence of increased Arctic river runoff on the formation of the thermohaline structure of waters outside the Arctic shelf and, in particular, on the variability of heat content of the deep Arctic Ocean. The study is carried out using the three-dimensional numerical model of the ocean and sea ice SibCIOM and atmospheric reanalysis data NCEP/NCAR. Numerical simulation results showed that increased flow of Arctic rivers contributes to the stability of water stratification outside the shelf areas, which reduces the depth of autumn-winter mixing and allows Atlantic waters spreading along the continental slope to retain their heat. This is evidenced by an increase in the heat content of the upper 200 m layer waters of the eastern Eurasian basin and the rise of the Atlantic water layer upper boundary in this region.

scholarly journals Tracking the global flows of atmospheric moisture

2019 ◽  
Author(s):  
Obbe A. Tuinenburg ◽  
Arie Staal
Keyword(s):  
Vertical Mixing ◽  
Three Dimensional ◽  
Reanalysis Data ◽  
Point Sources ◽  
Atmospheric Moisture ◽  
Reanalysis Dataset ◽  
Considerable Uncertainty ◽  
Moisture Recycling ◽  
Trade Offs ◽  
Spatial Dimensions

Abstract. Many processes in hydrology and Earth system science relate to moisture recycling, the contribution of terrestrial evaporation to precipitation. For example, the effects of land-cover changes on regional rainfall regimes depend on this process. To study moisture recycling, a range of moisture tracking models are in use that are forced with output from atmospheric models, but differ in various ways. They can be Eulerian (grid-based) or Lagrangian (trajectory-based), have two or three spatial dimensions, and rely on a range of other assumptions. Which model is most suitable depends on the purpose of the study, but also on the quality and resolution of the data with which it is forced. Recently, the high-resolution ERA5 reanalysis dataset has become the state-of-the-art, paving the way for a new generation of moisture tracking models. However, it is unclear how the new data can best be used to obtain accurate estimates of atmospheric moisture flows. Here we develop a set of moisture tracking models forced with ERA5 data and systematically test their performance regarding continental evaporation recycling ratio, distances of moisture flows, and footprints of evaporation from seven point sources across the globe. We report simulation times to assess possible trade-offs between accuracy and speed. Three-dimensional Lagrangian models were most accurate and ran faster than Eulerian versions for tracking water from single grid cells. The rate of vertical mixing of moisture in the atmosphere was the greatest source of uncertainty in moisture tracking. We conclude that the recently improved resolution of atmospheric reanalysis data allows for more accurate moisture tracking results in a Lagrangian setting, but that considerable uncertainty regarding turbulent mixing remains. We present an efficient Lagrangian method to track atmospheric moisture flows from any location globally using ERA5 reanalysis data and make the code for this model publicly available.

A comparison study on gust factor considering non-stationary effects under typhoon and monsoon conditions

2018 ◽  
Vol 21 (12) ◽  
pp. 1853-1864 ◽  
Author(s):  
Shouqiang Wang ◽  
Lin Zhao ◽  
Shuyang Cao ◽  
Yufeng Zhang ◽  
Feng Yin ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Field Measurements ◽  
Stationary Model ◽  
Gust Factor ◽  
Wind Speeds ◽  
Turbulence Flow ◽  
Mean Wind Speed ◽  
Averaging Time ◽  
Monsoon Winds ◽  
The Relationship

This article studies the feasibility and effectiveness of a non-stationary model using field measurements. Gust factors are compared for both typhoon and monsoon winds whose maximum 10-min mean wind speeds were all greater than 20 m/s using non-stationary models. Wind speeds were recorded by three-dimensional anemometers by the Structural Health Monitoring System of Xihoumen Bridge. The study focuses on the dependences of gust factor on gust averaging time, sample duration, and mean wind speed for both typhoon and monsoon climates. The gust factor curve and the relationship between gust factor and turbulence intensity are also studied. The results suggest that a non-stationary model is more suitable for actual turbulence flow, particularly under typhoon conditions. The article also compares resulting gust factor curves with those obtained in former studies and shows that accurate gust factor curves can be obtained by field measurements for monsoon wind. It is thus recommended that gust factor research should differentiate between typhoon and monsoon winds.

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