scholarly journals The latitudinal dependence in the trend of snow event to precipitation event ratio

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shangyong Shi ◽  
Guosheng Liu
Keyword(s):  
Water Resource Management ◽  
Precipitation Event ◽  
Global Trends ◽  
Latitudinal Dependence ◽  
Low Latitudes ◽  
Multiple Regions ◽  
Land Station ◽  
Pe Ratio ◽  
Precipitation Phase ◽  
Precipitation Events

AbstractPrecipitation phase is expected to shift from solid to liquid with temperature rising, which would in turn bring challenges to regional water resource management. Although in recent decades, consistent decreasing trends in the ratio of snowfall to precipitation rate in a warming climate have been found across multiple regions, a global view of the trends in the precipitation partitioning has not been established. In this study, we investigated the global trends of annual rain and snow frequency of occurrences and the ratio of number of snow events to number of precipitation events (SE/PE ratio) using land station and shipboard synoptic present weather reports from 1978 to 2019. Results show that when averaged over all qualified land stations and over the shipboard reports, both the annual rain frequency and snow frequency decrease over the 42 years. Over both land and ocean, the averaged SE/PE ratio has a significant decreasing trend. Moreover, the trend of SE/PE ratio shows a strong latitudinal dependence. At the mid- and low latitudes in the Northern Hemisphere, the SE/PE ratio has a decreasing trend. In contrast, at high latitudes, the SE/PE ratio has an increasing trend.

Whaling, 1938–39

Polar Record ◽  
1939 ◽  
Vol 3 (18) ◽  
pp. 177-179
Author(s):  
Brian Roberts
Keyword(s):  
Northern Hemisphere ◽  
International Agreements ◽  
Land Station

In order to safeguard the stock of whales in northern seas, special regulations for Svalbard have been proposed by the Norwegian Government. These regulations forbid both Norwegian and foreign subjects to use a land station for the taking and treatment of whales in Svalbard and Jan Mayen. They follow the international agreements of 1937 and 1938 which provide for the closing of the Northern Hemisphere for pelagic baleen whaling and restriction of the activity of land stations to six months of the year.

scholarly journals Group IV humpback whales: their status from aerial and landbased surveys off Western Australia, 2005

2020 ◽  
pp. 223-234
Author(s):  
Charles G.M. Paxton ◽  
Sharon l. Hedley ◽  
John l. Bannister
Keyword(s):  
Aerial Survey ◽  
Group Iv ◽  
Humpback Whales ◽  
Reliable Estimate ◽  
Line Transect ◽  
Absolute Abundance ◽  
Density Estimates ◽  
Abundance Estimates ◽  
Short Period ◽  
Land Station

Single platform aerial line transect and land-based surveys of Southern Hemisphere Group IV humpback whales were undertaken to provide absoluteabundance estimates of animals migrating northward along the western Australian coast during June–August 2005. The aerial survey was designedto cover the whole period of northward migration but the resulting estimates from that survey alone could only, at best, provide relative abundanceestimates as it was not possible to estimate g(0), the detection probability along the trackline, from the data. Owing to logistical constraints, theland-based survey was only possible for a much shorter period (two weeks during the expected peak of the migration in mid-July). This paperproposes three methods that utilise these complementary data in different ways to attempt to obtain absolute abundance estimates. The aerial linetransect data were used to estimate relative whale density (for each day), allowing absolute abundance from the land-based survey to be estimatedfor the short period of its duration. In turn, the land-based survey allowed estimation of g(0) for the aerial survey. Absolute estimates of abundancefor the aerial survey were obtained by combining the g(0) estimate with the relative density estimates, summing over the appropriate number ofdays. The most reliable estimate of northward migrating whales passing the land station for the period of the land-based survey only was 4,700(95% CI 2,700–14,000). The most reliable estimate for the number of whales passing through the aerial survey region for the duration of that survey(55 days from June through to August) was 10,300 (95% CI 6,700–24,500). This is a conservative estimate because the duration of the aerial surveywas almost certainly shorter than the period of the migration. Extrapolation beyond the end of this survey was considered unreliable, but abundancefrom the estimated start of the migration to the end of the survey (87 days from mid-April to August) was estimated to be 12,800 (95% CI 7,500–44,600). The estimated number of whales depends crucially on the assumed migration and period of migration. Results for different migrationparameters are also presented. The point estimates of abundance, whilst higher than those from a previous survey in 1999 (when adjusted for surveyduration) are not significantly so. The peak of the whales’ distribution was found at c.90m water depth.

COLLECTION AND ANALYSIS OF PACIFIC OCEAN‐BOTTOM SEISMIC DATA

Geophysics ◽  
1964 ◽  
Vol 29 (5) ◽  
pp. 745-771 ◽  
Author(s):  
William A. Schneider ◽  
Patrick J. Farrell ◽  
Ross E. Brannian
Keyword(s):  
Pacific Ocean ◽  
Seismic Data ◽  
Ambient Noise ◽  
Power Spectra ◽  
Simultaneous Recording ◽  
Distinct Advantage ◽  
Noise Power ◽  
Ocean Bottom ◽  
Detection And Identification ◽  
Land Station

A total of 500 hours of usable ocean‐bottom seismic data recorded on pressure and three components of velocity has been collected in three geographically separate areas of the Pacific Ocean at depths to 20,000 ft. These data are presently being analyzed to determine the extent to which monitoring seismic motion on the ocean floor can assist Project VELA UNIFORM goals of detection and identification of underground and underwater nuclear blasts. Analysis of three earthquakes and ambient noise recorded simultaneously on the ocean bottom and land reveals: 1. Ocean‐bottom signal‐to‐noise ratios are equal to or less than those seen at a comparative land station; 2. Ocean‐bottom signal and noise levels are higher than those obtained at the land station; and 3. Ocean‐bottom ambient noise power spectra increase in level towards the microseismic 6‐ to 8‐sec peak as do the land data. No strong directional ocean‐bottom noise components have been observed. Simultaneous recording of pressure and particle velocity affords the ocean‐bottom station a distinct advantage over its land counterpart, through exploitation of the relationships between pressure and vertical velocity which exist for various types of arrivals and modes.

scholarly journals ENDURUNS: An Integrated and Flexible Approach for Seabed Survey Through Autonomous Mobile Vehicles

2020 ◽  
Vol 8 (9) ◽  
pp. 633
Author(s):  
Simone Marini ◽  
Nikolla Gjeci ◽  
Shashank Govindaraj ◽  
Alexandru But ◽  
Benjamin Sportich ◽  
...  
Keyword(s):  
Satellite Communication ◽  
Autonomous Underwater Vehicle ◽  
Deep Ocean ◽  
Hydrogen Fuel Cells ◽  
Unmanned Surface Vehicle ◽  
Semantic Classification ◽  
Central Processing ◽  
Land Station ◽  
Extended Duration ◽  
Li Ion

The oceans cover more than two-thirds of the planet, representing the vastest part of natural resources. Nevertheless, only a fraction of the ocean depths has been explored. Within this context, this article presents the H2020 ENDURUNS project that describes a novel scientific and technological approach for prolonged underwater autonomous operations of seabed survey activities, either in the deep ocean or in coastal areas. The proposed approach combines a hybrid Autonomous Underwater Vehicle capable of moving using either thrusters or as a sea glider, combined with an Unmanned Surface Vehicle equipped with satellite communication facilities for interaction with a land station. Both vehicles are equipped with energy packs that combine hydrogen fuel cells and Li-ion batteries to provide extended duration of the survey operations. The Unmanned Surface Vehicle employs photovoltaic panels to increase the autonomy of the vehicle. Since these missions generate a large amount of data, both vehicles are equipped with onboard Central Processing units capable of executing data analysis and compression algorithms for the semantic classification and transmission of the acquired data.

scholarly journals Makrofauna Tanah Di Lahan Hortikultura Desa Losari Kecamatan Sumowono Kabupaten Semarang

2020 ◽  
Vol 13 (1) ◽  
pp. 68
Author(s):  
Nurul Qomariyah ◽  
Ary Susatyo Nugroho ◽  
Mohammad Syaipul Hayat
Keyword(s):  
Species Diversity ◽  
Biological Properties ◽  
Soil Macrofauna ◽  
Soil Biodiversity ◽  
A Value ◽  
Physical Chemical ◽  
Total Soil ◽  
Land Station ◽  
Hand Sorting ◽  
Properties Of Soil

Abstrak: Makrofauna tanah merupakan bagian dari biodiversitas tanah yang memiliki peran penting dalam perbaikan sifat fisik, kimiawi, dan biologi tanah melalui proses imobilisasi dan humifikasi. Desa Losari merupakan salah satu desa di Kecamatan sumowono Kabupaten semarang yang terletak di kaki Gunung Ungaran sehingga keadaannya masih asri dan alami. Penelitian ini dilakukan pada Bulan Juli 2020. Tujuan penelitian ini adalah untuk mengetahui bagaimana tingkat keanekaragaman jenis makrofauna tanah yang ada di kawasan lahan pertanian Desa Losari dengan tanaman yang berbeda. Pengambilan data dilakukan dengan dua metode yaitu Pit fall trap dan Hand sorting. Hasil penelitian menunjukkan bahwa tingkat keanekaragaman jenis di lokasi penelitian tergolong rendah. Total makrofauna tanah yang tercatat di lokasi penelitian sebanyak 37 jenis yang terdiri dari 3 filum. Lahan pertanian tanaman kubis (stasiun I) memiliki tingkat keanekaragaman yang tertinggi dibandingkan dengan stasiun lainnya dengan nilai H' = 1,064. Filum dengan jumlah terbanyak di lokasi penelitian adalah filum Arthropoda sebanyak 33 jenis dari 98 total jenis makrofauna tanah yang telah ditemukan.Kata Kunci: keanekaragaman makrofauna tanah; hortikultura; pit fall trap; hand sorting.Abstract: Soil macrofauna is part of soil biodiversity which has an important role in improving the physical, chemical, and biological properties of soil through immobilization and humification processes. Losari Village is one of the villages in Sumowono District, Semarang Regency, which is located at the foot of Mount Ungaran so that the condition is still beautiful and natural. This research was conducted in July 2020. The purpose of this study was to determine the level of diversity of soil macrofauna species in the agricultural area of Losari Village with different plants. Data were collected by two methods, namely Pit fall trap and Hand sorting. The results showed that the level of species diversity in the study location was low. The total soil macrofauna recorded at the research location were 37 species consisting of 3 phyla. Cabbage farming land (station I) has the highest level of diversity compared to other stations with a value of H' = 1.064. The phylum with the highest number in the research location was Arthropoda phylum with 33 of the 98 total soil macrofauna species that had been found.Keywords: soil macrofauna diversity; horticulture; pit fall trap; hand sorting.

The modification of climate near the ground by irrigation for pastures on the Riverine plain

1961 ◽  
Vol 12 (2) ◽  
pp. 260 ◽  
Author(s):  
Vries DA de ◽  
JW Birch
Keyword(s):  
Graphical Form ◽  
Atmospheric Humidity ◽  
Dry Land ◽  
Irrigation Area ◽  
Irrigation Rate ◽  
Irrigated Area ◽  
Soil Temperatures ◽  
Screen Height ◽  
Land Station ◽  
Meteorological Observations

Methods are described and results reported of meteorological observations made during the irrigation seasons 1936–57 and 1957–58 at three stations in the Nanneella irrigation area (dimensions approximately 6 by 7 km²) and on a dry-land station nearby. The former stations are situated on irrigated pastures, whilst the latter is on a dry-land pasture. Irrigation gives rise to a decrease of air and soil temperatures and an increase of atmospheric humidity- near the surface of the earth. The magnitudes of these effects depend inter alia on the irrigation rate and the distance down wind in the irrigated area. In summer at an irrigation rate of approximately 0.3 cm/day the observed differences between the dry-land station and a station in the centre of the irrigation area amounted to: 1–2°C for air temperature at screen height (125 cm); approximately 10°C for soil temperatures (at depths of 5 and 30 cm); 5–10% for relative humidity at screen height; 0.5–1.5 mm Hg for vapour pressure at screen height. The differences quoted are for average values of the observed quantities taken over a period of 4 weeks. The observations are presented in more detail in graphical form.

A Nuclear-Fueled Steam Generator-Superheater for Merchant Ship Propulsion

1965 ◽  
Vol 2 (04) ◽  
pp. 390-421
Author(s):  
E. B. Delson ◽  
E. C. Hunt
Keyword(s):  
Steam Generator ◽  
Ship Propulsion ◽  
Merchant Ship ◽  
Nuclear Propulsion ◽  
Land Station ◽  
High Superheat ◽  
Primary Cycle ◽  
Full Utilization ◽  
Economic Comparison

The 630A is a nuclear steam generator-superheater of about the same size and somewhat heavier than the conventional boiler which it can replace in merchant ships. It has a gas primary cycle, transferring heat from the reactor to a once-through boiler-superheater. Feedwater delivered to the boiler is discharged as high superheat steam (1500 psi--1000 F). The 630A technology stems from the nuclear aircraft and land-station technologies. It has gone through a series of design iterations. This paper describes the Mk IV. The latest version, the Mk V, with improved economics is now proposed for ship installation. The paper discusses the general considerations of maritime nuclear propulsion, problems in achieving full utilization, and presents an economic comparison of 13,000-dwt nuclear and conventional ships over a range of speeds.

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