The global climatology of the intensity of ionospheric sporadic <i>E</i> layer

Abstract. On the basis of S4max data retrieved from COSMIC GPS radio occultation measurements, the long-term climatology of the intensity of Es layers is investigated for the period from December 2006 to January 2014. The global maps of Es intensity shows a high spatial resolution geographical distributions and strong seasonal dependence of Es layers. The maximum intensity of Es occurs in the midlatitudes, and its value in summer is 2–3 times larger than that in winter. A relatively strong Es layer is observed at the North and South Poles with a distinct boundary dividing the midddle latitudes and high latitudes along 60°–80° geomagnetic latitude bands. Besides, simulation results shows that the convergence of vertical ion velocity could partially explain the seasonal dependence of Es intensity. Furthermore, some disagreements between the distributions of calculated divergence of vertical ion velocity and observed Es intensity indicate that other processes such as magnetic field effects, meteoric mass influx into the earth's atmosphere and chemical processes of metallic ions should also be considered, which play an important role in the spatial and seasonal variations of Es layers.

Download Full-text

The global climatology of the intensity of the ionospheric sporadic <i>E</i> layer

Atmospheric Chemistry and Physics ◽

10.5194/acp-19-4139-2019 ◽

2019 ◽

Vol 19 (6) ◽

pp. 4139-4151 ◽

Cited By ~ 5

Author(s):

Bingkun Yu ◽

Xianghui Xue ◽

Xin'an Yue ◽

Chengyun Yang ◽

Chao Yu ◽

...

Keyword(s):

Gravity Waves ◽

High Spatial Resolution ◽

Geomagnetic Latitude ◽

Metallic Ions ◽

Magnetic Field Effects ◽

The North ◽

Mass Influx ◽

Ion Velocity ◽

Seasonal Dependence

Abstract. On the basis of S4max data retrieved from COSMIC GPS radio occultation measurements, the long-term climatology of the intensity of Es layers is investigated for the period from December 2006 to January 2014. Global maps of Es intensity show the high-spatial-resolution geographical distribution and strong seasonal dependence of Es layers. The maximum intensity of Es occurs over the mid-latitudes, and its value in summer is 2–3 times larger than that in winter. A relatively strong Es layer is observed at the North Pole and South Pole, with a distinct boundary dividing the mid-latitudes and high latitudes along the 60–80∘ geomagnetic latitude band. The simulation results show that the convergence of vertical ion velocity could partially explain the seasonal dependence of Es intensity. Furthermore, some disagreements between the distributions of the calculated divergence of vertical ion velocity and the observed Es intensity indicate that other processes, such as the vertical motions of gravity waves, magnetic-field effects, meteoric mass influx into Earth's atmosphere, and the chemical processes of metallic ions, should also be considered as they may also play an important role in the spatial and seasonal variations in Es layers.

Download Full-text

PACIFIC COD OF THE KURIL ISLANDS: STOCK AND CONTEMPORARY FISHING

Fisheries ◽

10.37663/0131-6184-2020-4-44-51 ◽

2020 ◽

Vol 2020 (4) ◽

pp. 44-51

Author(s):

Aleksandr Zolotov ◽

Nikolay Antonov ◽

Olga Maznikova

Keyword(s):

Kuril Islands ◽

Pacific Cod ◽

The North ◽

Trawl Fishing ◽

Northern Kuril Islands ◽

The Kuril Islands ◽

High Level ◽

North And South ◽

South Kuril Islands

The paper analyzes the long-term dynamics of stocks and annual catches of Pacific cod of the Kuril Islands, and also considers the structure of its modern fishery, taking into account the changes that have occurred in the organization of its coastal fishing in recent years. It was shown that the dynamics of commercial biomass of Pacific cod in the Northern and Southern Kuril Islands is comparable to that in 1975-2020 for groups in the southeastern part of the Bering Sea, the Karagin and Olyutor bays, on the shelf of Western Kamchatka, and in south-western Sakhalin. Development of the cod fishery in the North and South Kuril Islands in 1980-2019 went in accordance with the dynamics of stocks, the maximum catches were observed during the period of a high level of abundance of both groups in the 1980s. While the structure of the cod fishery on the shelf of the Northern Kuril Islands to date can be considered established, the development of fishing in the South Kuril Islands in the last two decades went by the gradual replacement of trawl fishing in the winter-spring period with snorkeling in the summer season.

Download Full-text

Seasonal stratospheric ozone trends over 2000–2018 derived from several merged data sets

Atmospheric Chemistry and Physics ◽

10.5194/acp-20-7035-2020 ◽

2020 ◽

Vol 20 (11) ◽

pp. 7035-7047 ◽

Cited By ~ 1

Author(s):

Monika E. Szeląg ◽

Viktoria F. Sofieva ◽

Doug Degenstein ◽

Chris Roth ◽

Sean Davis ◽

...

Keyword(s):

Stratospheric Ozone ◽

Equatorial Region ◽

Data Sets ◽

Opposite Pattern ◽

The North ◽

Stratospheric Temperature ◽

Temperature Trends ◽

Ozone Trends ◽

Seasonal Dependence

Abstract. In this work, we analyze the seasonal dependence of ozone trends in the stratosphere using four long-term merged data sets, SAGE-CCI-OMPS, SAGE-OSIRIS-OMPS, GOZCARDS, and SWOOSH, which provide more than 30 years of monthly zonal mean ozone profiles in the stratosphere. We focus here on trends between 2000 and 2018. All data sets show similar results, although some discrepancies are observed. In the upper stratosphere, the trends are positive throughout all seasons and the majority of latitudes. The largest upper-stratospheric ozone trends are observed during local winter (up to 6 % per decade) and equinox (up to 3 % per decade) at mid-latitudes. In the equatorial region, we find a very strong seasonal dependence of ozone trends at all altitudes: the trends vary from positive to negative, with the sign of transition depending on altitude and season. The trends are negative in the upper-stratospheric winter (−1 % per decade to −2 % per decade) and in the lower-stratospheric spring (−2 % per decade to −4 % per decade), but positive (2 % per decade to 3 % per decade) at 30–35 km in spring, while the opposite pattern is observed in summer. The tropical trends below 25 km are negative and maximize during summer (up to −2 % per decade) and spring (up to −3 % per decade). In the lower mid-latitude stratosphere, our analysis points to a hemispheric asymmetry: during local summers and equinoxes, positive trends are observed in the south (+1 % per decade to +2 % per decade), while negative trends are observed in the north (−1 % per decade to −2 % per decade). We compare the seasonal dependence of ozone trends with available analyses of the seasonal dependence of stratospheric temperature trends. We find that ozone and temperature trends show positive correlation in the dynamically controlled lower stratosphere and negative correlation above 30 km, where photochemistry dominates. Seasonal trend analysis gives information beyond that contained in annual mean trends, which can be helpful in order to better understand the role of dynamical variability in short-term trends and future ozone recovery predictions.

Download Full-text

The Development of a Split-tail Heliosphere and the Role of Non-ideal Processes: A Comparison of the BU and Moscow Models

The Astrophysical Journal ◽

10.3847/1538-4357/ac2fa6 ◽

2021 ◽

Vol 923 (2) ◽

pp. 179

Author(s):

M. Kornbleuth ◽

M. Opher ◽

I. Baliukin ◽

M. Gkioulidou ◽

J. D. Richardson ◽

...

Keyword(s):

Magnetic Field ◽

Solar Magnetic Field ◽

Three Dimensional ◽

Magnetic Field Effects ◽

The North ◽

Mhd Instabilities ◽

North And South ◽

Numerical Treatments ◽

Numerical Approaches

Abstract Global models of the heliosphere are critical tools used in the interpretation of heliospheric observations. There are several three-dimensional magnetohydrodynamic (MHD) heliospheric models that rely on different strategies and assumptions. Until now only one paper has compared global heliosphere models, but without magnetic field effects. We compare the results of two different MHD models, the BU and Moscow models. Both models use identical boundary conditions to compare how different numerical approaches and physical assumptions contribute to the heliospheric solution. Based on the different numerical treatments of discontinuities, the BU model allows for the presence of magnetic reconnection, while the Moscow model does not. Both models predict collimation of the solar outflow in the heliosheath by the solar magnetic field and produce a split tail where the solar magnetic field confines the charged solar particles into distinct north and south columns that become lobes. In the BU model, the interstellar medium (ISM) flows between the two lobes at large distances due to MHD instabilities and reconnection. Reconnection in the BU model at the port flank affects the draping of the interstellar magnetic field in the immediate vicinity of the heliopause. Different draping in the models cause different ISM pressures, yielding different heliosheath thicknesses and boundary locations, with the largest effects at high latitudes. The BU model heliosheath is 15% thinner and the heliopause is 7% more inwards at the north pole relative to the Moscow model. These differences in the two plasma solutions may manifest themselves in energetic neutral atom measurements of the heliosphere.

Download Full-text

INVESTIGATION OF THE NORTH AND SOUTH KUZBASS AGGLOMERATIONS FEATURES TO JUSTIFY CONDITIONS FOR REGION LONG-TERM DEVELOPMENT

Vestnik Tomskogo gosudarstvennogo universiteta Ekonomika ◽

10.17223/19988648/38/7 ◽

2017 ◽

pp. 73-81

Author(s):

Vladimir A. Shabashev ◽

◽

Victor V. Barylnikov ◽

Boris N. Medvedev ◽

Valery A. Salikhov ◽

...

Keyword(s):

The North ◽

North And South

Download Full-text

The Louisiana Amphibian Monitoring Program from 1997 to 2017: Results, analyses, and lessons learned

PLoS ONE ◽

10.1371/journal.pone.0257869 ◽

2021 ◽

Vol 16 (9) ◽

pp. e0257869

Author(s):

Jacoby Carter ◽

Darren Johnson ◽

Jeff Boundy ◽

William Vermillion

Keyword(s):

Urban Areas ◽

Monitoring Program ◽

Lessons Learned ◽

The North ◽

Osteopilus Septentrionalis ◽

Species Lists ◽

Demographic Patterns ◽

North And South ◽

Term Monitoring

To determine trends in either frog distribution or abundance in the State of Louisiana, we reviewed and analyzed frog call data from the Louisiana Amphibian Monitoring Program (LAMP). The data were collected between 1997 and 2017 using North American Amphibian Monitoring Program protocols. Louisiana was divided into three survey regions for administration and analysis: the Florida Parishes, and 2 areas west of the Florida parishes called North and South. Fifty-four routes were surveyed with over 12,792 stops and 1,066 hours of observation. Observers heard 26 species of the 31 species reported to be in Louisiana. Three of the species not heard were natives with ranges that did not overlap with survey routes. The other two species were introduced species, the Rio Grande Chirping Frog (Eleutherodactylus cystignathoides) and the Cuban Treefrog (Osteopilus septentrionalis). Both seem to be limited to urban areas with little to no route coverage. The 15 most commonly occurring species were examined in detail using the percentage of stops at which they observed along a given survey and their call indices. Most species exhibited a multimodal, concave, or convex pattern of abundance over a 15-year period. Among LAMP survey regions, none of the species had synchronous population trends. Only one group of species, winter callers, regularly co-occur. Based on the species lists, the North region could be seen as a subset of the South. However, based on relative abundance, the North was more similar to Florida parishes for both the winter and summer survey runs. Our analyses demonstrate that long-term monitoring (10 years or more) may be necessary to determine population and occupancy trends, and that frog species may have different local demographic patterns across large geographic areas.

Download Full-text

To the Richest Go the Spoils? Immigration, Development, and the North-South Divide, 1970–2005

Sociology of Development ◽

10.1525/sod.2016.2.3.273 ◽

2016 ◽

Vol 2 (3) ◽

pp. 273-292

Author(s):

Matthew R. Sanderson

Keyword(s):

Economic Development ◽

Global South ◽

Positive Effects ◽

The North ◽

National Economic ◽

Global North ◽

First Time ◽

The Relationship ◽

North And South

This paper empirically assesses, for the first time, the relationship between immigration and national economic development in both the global North and the global South. A series of panel models demonstrate that immigration exacerbates North-South inequalities through differential effects on average per capita incomes in the global North and global South. Immigration has positive effects on average incomes in both the North and the South, but the effect is larger in the global North. Thus the relationship between immigration and development evinces a Matthew Effect at the world level: by contributing to differential levels of economic development in the North and South, immigration widens international inequalities in the long term, resulting in the accumulation of advantage in the North. The implications of the results are discussed in the context theory and policy on the migration-development nexus.

Download Full-text

Reciprocal Garden Study Reveals Acute Spatial-Edaphic Adaptation for Cycas micronesica

Diversity ◽

10.3390/d13060237 ◽

2021 ◽

Vol 13 (6) ◽

pp. 237

Author(s):

Thomas E. Marler

Keyword(s):

Local Adaptation ◽

Plant Size ◽

Plant Performance ◽

Stem Height ◽

The South ◽

The North ◽

Survival And Growth ◽

Local Genotypes ◽

North And South

A long-term reciprocal garden study was used to determine adaptive variation between Cycas micronesica K.D. Hill plants from north versus south Guam. Half-siblings from each location were planted as one-leaf seedlings in north and south gardens and monitored for 15 years. Stem height and diameter, and leaf number and maximum length were measured yearly. Survival and plant size traits were evaluated using a two-way factorial. In both locations, the local genotypes out-performed the foreign genotypes in terms of survival and growth. Survival of the foreign genotypes began to decline by year 4 and was less than 10% by year 15. Survival of the local genotypes was 70% for the north garden and 100% for the south garden. The north site was more hostile to plant performance because overall survival and plant growth were less than for the south site. The most likely environmental factor provoking local adaptation was highly contrasting soil characteristics between north and south Guam. The results indicates that long-term conservation success for C. micronesica and other cycad species must include the concept of local adaptation into decisions for transplantation and restoration projects.

Download Full-text

NEW JETTIES FOR TUNG-KANG FISHING HARBOR, TAIWAN

Coastal Engineering Proceedings ◽

10.9753/icce.v17.133 ◽

1980 ◽

Vol 1 (17) ◽

pp. 133

Author(s):

Chi-Fu Su

Keyword(s):

Water Depth ◽

The South ◽

Littoral Drift ◽

The North ◽

Study Planning ◽

South West ◽

South West Coast ◽

Three Rivers ◽

North And South

Tung-Kang Fishing Harbor, which is about 16 km to the south of Kaohsiung Harbor, is a river harbor on the south-west coast of Taiwan. This harbor is located at the estuary of the Niu-Pu River, which meets the Tung- Kang River and the Kao-Ping River on the north side, (see Fig. 1) The original north and south jetties were constructed in 1959. Because the entrance is located at the meeting of the three rivers and the water depth at the entrance is shallower than that in the breaking zone, the entrance is easily chocked with sand during the summer season when the south-west wind and waves are strong. Therefore, dredging is always necessary to maintain the required depth. On. the other hand, because of the increasing number of fishing boats and deeper draft, the port cannot function effectively. There-fore, how to keep the required water depth at the entrance and to obtain a wider and stable water basin is an urgent problem with this harbor. Based on the sounding of 1973, the littoral drift is mainly from the south. In the next year the construction of a 176 m long new south jetty was begun to protect the entrance and to facilitate the sedimentation study. In 1975, the Taiwan Fisheries Consultants was appointed to undertake the investigation and long-term planning work. This project includes littoral process study, planning, model test and design. Finally it is recommended that an adequate layout of south and north jetties can solve the problem of accretation of the harbor entrance. The purpose of this paper is to describe some aspects with emphasis on how to prevent the shoaling of the entrance channel located at the meeting of the rivers.

Download Full-text

Factors Affecting the Long-Term Development of Specialized Agricultural Villages North and South of Huai River

Land ◽

10.3390/land10111215 ◽

2021 ◽

Vol 10 (11) ◽

pp. 1215

Author(s):

Li Li ◽

Ning Niu ◽

Xiaojian Li

Keyword(s):

Economic Factors ◽

Spatial And Temporal Patterns ◽

Location Factors ◽

Factors Affecting ◽

Time Points ◽

The North ◽

Huai River ◽

Market Factors ◽

North And South

Village-level agricultural specialization in China is becoming increasingly important for rural development. However, existing knowledge of specialized agricultural villages (SAVs) based on singular assessment criteria and data describing static time points becomes insufficient in addressing multifaceted developmental questions today. We examined the long-term development patterns of SAVs in Anhui, China, with attributes from multiple angles, and explored how local factors affected SAV development across space and time using random forest regression. We found that as time elapsed, economic rationality drove specialized farmers closer to sale dependency and made SAVs more susceptible to market and economic factors, which builds upon previous findings analyzing SAVs at specific time points and consolidates the importance of market factors in the long-term development of SAVs. However, this susceptibility manifests differently in these two geographically contrasting regions north and south of Huai River. The northern SAVs received increased influences from market and economic factors, while the southern SAVs were continuously controlled by market and location factors. The dynamic spatial and temporal patterns of the two regions point to different dependencies, which emphasized local sales in the north and distant sales in the south. We propose that policies and strategies regarding SAV development accommodate these dynamics and address appropriate influencing factors accordingly.

Download Full-text