scholarly journals A Contrast in Precipitation Characteristics across the Baiu Front near Japan. Part I: TRMM PR Observation

2014 ◽  
Vol 27 (15) ◽  
pp. 5872-5890 ◽  
Author(s):  
Chie Yokoyama ◽  
Yukari N. Takayabu ◽  
Sachie Kanada
Keyword(s):  
Potential Temperature ◽  
Tropical Rainfall Measuring Mission ◽  
The South ◽  
The North ◽  
Precipitation Characteristics ◽  
Stratiform Precipitation ◽  
Northern Regions ◽  
June July ◽  
The Tropics ◽  
Baiu Front

Abstract Contrasts in precipitation characteristics across the baiu front are examined with Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR) data near Japan during June–July (1998–2011). The vertical structure of atmospheric stratification differs between the tropics and midlatitudes. On an average, the baiu front is found around the latitude that roughly divides the midlatitude atmosphere from the tropical atmosphere. Precipitation characteristics are compared between the southern and northern sides of the reference latitude of the baiu front, which is detected with equivalent potential temperature at 1000 hPa of 345 K in terms of the boundary between the tropics and midlatitudes. The results show that there are obvious differences in precipitation characteristics between the southern and northern sides. In the south, convective rainfall ratios (CRRs) are 40%–60%, which are larger than those in the north (20%–40%). Greater rainfall intensity and taller/deeper precipitation are also observed in the south. Moreover, the characteristics of precipitation features (PFs), which are contiguous areas of nonzero rainfall, differ between the southern and northern sides. In the north, wide stratiform precipitation systems with CRRs of 0%–40% and heights of 8–11 km are dominant. In the south, organized precipitation systems with heights of 12–14 km and CRRs of 30%–50% and those with very large heights (14–17 km) and CRRs of 50%–80% are dominant in addition to wide stratiform precipitation systems. These results suggest that the mechanisms to bring rainfall are different between the southern and northern regions of the baiu front.

Changes in Pacific hake (Merluccius productus) migration patterns and juvenile growth related to the 1989 regime shift

2002 ◽  
Vol 59 (12) ◽  
pp. 1969-1979 ◽  
Author(s):  
Ashleen J Benson ◽  
Gordon A McFarlane ◽  
Susan E Allen ◽  
John F Dower
Keyword(s):  
Food Supply ◽  
Regime Shift ◽  
Coastal Upwelling ◽  
Juvenile Growth ◽  
The South ◽  
Migration Patterns ◽  
Merluccius Productus ◽  
The North ◽  
Northern Regions ◽  
Ocean Conditions

The response of Pacific hake (Merluccius productus) to recent changes in ocean conditions has been dramatic, with a larger proportion of the stock moving into Canadian waters in the 1990s. Additionally, after 1994, hake spawned in Canadian waters and a portion of the stock remained year round. The change in distribution corresponded with a change in growth of juvenile hake. These changes were examined in relation to upwelling and temperature. We also examined these changes in relation to changes in the abundance of euphausiids, which are the primary food supply. We propose that the 1989 regime shift differentially affected the availability of euphausiids in the northern and southern Coastal Upwelling Domain, with feeding conditions in the north improved relative to those in the south. This promoted faster growth of juveniles in the northern regions during the 1990s.

Observational Evaluation of a Convective Quasi-Equilibrium View of Monsoons

2010 ◽  
Vol 23 (16) ◽  
pp. 4416-4428 ◽  
Author(s):  
Ji Nie ◽  
William R. Boos ◽  
Zhiming Kuang
Keyword(s):  
Boundary Layer ◽  
South Asian ◽  
Asian Monsoon ◽  
Potential Temperature ◽  
South Asian Monsoon ◽  
Quasi Equilibrium ◽  
Tropospheric Temperature ◽  
The South ◽  
Layer Potential ◽  
The North

Abstract Idealized dynamical theories that employ a convective quasi-equilibrium (QE) treatment for the diabatic effects of moist convection have been used to explain the location, intensity, and intraseasonal evolution of monsoons. This paper examines whether observations of the earth’s regional monsoons are consistent with the assumption of QE. It is shown here that in local summer climatologies based on reanalysis data, maxima of free-tropospheric temperature are, indeed, nearly collocated with maxima of subcloud equivalent potential temperature, θeb, in all monsoon regions except the North and South American monsoons. Free-tropospheric temperatures over North Africa also exhibit a strong remote influence from the South Asian monsoon. Consistent with idealized dynamical theories, peak precipitation falls slightly equatorward of the maxima in θeb and free-tropospheric temperature in regions where QE seems to hold. Vertical structures of temperature and wind reveal two types of monsoon circulations. One is the deep, moist baroclinic circulation clearly seen in the South Asian monsoon. The other is of mixed type, with the deep moist circulation superimposed on a shallow dry circulation closely associated with boundary layer temperature gradients. While the existence of a shallow dry circulation has been documented extensively in the North African monsoon, here it is shown to also exist in Australia and southern Africa during the local summer. Analogous to moist QE theories for the deep circulation, the shallow circulation can be viewed in a dry QE framework in which shallow ascent occurs just equatorward of the peak boundary layer potential temperature, θb, providing a unified system where the poleward extents of deep and shallow circulations are bounded by maxima in θeb and θb, respectively.

Precipitation Characteristics over East Asia in Early Summer: Effects of the Subtropical Jet and Lower-Tropospheric Convective Instability

2017 ◽  
Vol 30 (20) ◽  
pp. 8127-8147 ◽  
Author(s):  
Chie Yokoyama ◽  
Yukari N. Takayabu ◽  
Takeshi Horinouchi
Keyword(s):  
East Asia ◽  
Convective Instability ◽  
Large Scale ◽  
Early Summer ◽  
Shallow Convection ◽  
The South ◽  
Subtropical Jet ◽  
High Dependency ◽  
Precipitation Characteristics ◽  
Stratiform Precipitation

Abstract A quasi-stationary front, called the baiu front, often appears during the early-summer rainy season in East Asia (baiu in Japan). The present study examines how precipitation characteristics during the baiu season are determined by the large-scale environment, using satellite observation three-dimensional precipitation data. Emphasis is placed on the effect of subtropical jet (STJ) and lower-tropospheric convective instability (LCI). A rainband appears together with a deep moisture convergence to the south of the STJ. Two types of mesoscale rainfall events (REs; contiguous rainfall areas), which are grouped by the stratiform precipitation ratio (SPR; stratiform precipitation over total precipitation), are identified: moderately stratiform REs (SPR of 0%–80%) representing tropical organized precipitation systems and highly stratiform REs (SPR of 80%–100%) representing midlatitude precipitation systems associated with extratropical cyclones. As the STJ becomes strong, rainfall from both types of mesoscale precipitation systems increases, with a distinct eastward extension of a midtropospheric moist region. In contrast, small systems appear regardless of the STJ, with high dependency on the LCI. The results indicate that the STJ plays a role in moistening the midtroposphere owing to ascent associated with secondary circulation to the south of the STJ, producing environments favorable for organized precipitation systems in the southern part of the rainband. The horizontal moisture flux convergence may also contribute to precipitation just along the STJ. On the other hand, the LCI plays a role in generating shallow convection. In high-LCI conditions, deep convection can occur without the aid of mesoscale organization.

scholarly journals Global Distribution of Hot Towers in Tropical Cyclones Based on 11-Yr TRMM Data

2013 ◽  
Vol 26 (4) ◽  
pp. 1371-1386 ◽  
Author(s):  
Cheng Tao ◽  
Haiyan Jiang
Keyword(s):  
Tropical Cyclones ◽  
Inner Core ◽  
Potential Temperature ◽  
Tropical Rainfall Measuring Mission ◽  
Ocean Basin ◽  
North Indian Ocean ◽  
Global Distribution ◽  
Northwest Pacific ◽  
Convective Systems ◽  
The North

Abstract Global distribution of hot towers in tropical cyclones (TCs) is statistically quantified using an 11-yr Tropical Rainfall Measuring Mission (TRMM) Tropical Cyclone Precipitation Feature (TCPF) database. From 6003 individual TRMM overpasses of 869 TCs, about 1.6% of TC convective systems are found to penetrate 14 km and about 0.1% of them even reach the 380-K potential temperature level. Among six TC-prone basins, the highest population of TC convective systems and those with hot towers are found over the northwest Pacific (NWP) basin. However, the greatest percentage of TCPFs that are hot towers [overshooting TCPFs (OTCPFs)] is found over the North Indian Ocean basin. Larger overshooting distance and ice mass are also found in this basin. The monthly variation of OTCPFs resembles that of TC activities in each basin. The percentage of OTCPFs is much higher in the inner core (IC) region (10%) than that in the inner rainband (IB; 2%) and outer rainband (OB; 1%) regions. OTCPFs in the IC region have much larger overshooting distance, area, volume, and ice mass than those in the IB and OB regions. The percentage of OTCPFs in the IC region increases as both TC intensity and intensification rate increase. About 17% of IC features in rapidly intensifying storms penetrate over 14 km, while the percentage is down to 11% for slowly intensifying, 9% for neutral, and 8% for weakening storms. A very good linear relationship is found between TC intensification rate and the percentage of TCPFs that are hot towers in the IC region.

scholarly journals Movers and stayers in STEM enrollment in Italy: who performs better?

Genus ◽  
2021 ◽  
Vol 77 (1) ◽  
Author(s):  
Antonella D’Agostino ◽  
Giulio Ghellini ◽  
Gabriele Lombardi
Keyword(s):  
Multilevel Modelling ◽  
The South ◽  
Social Scientists ◽  
Policy Makers ◽  
The North ◽  
Northern Regions ◽  
Stem Students ◽  
Modelling Techniques ◽  
Mobility Behavior ◽  
Geographical Characteristics

AbstractRecently, the mobility behavior of Italian university students has garnered increasing interest from both social scientists and politicians. The very particular geographical characteristics of the country, together with the recognized persistence of a significant economic gap between the southern and northern regions, drive a large number of students to move from the first macro-region to the latter. As this phenomenon has several economic and social implications for policy-makers—at both central and local levels—it has led to various theories and prejudices. The present article will study the differences between the performance of STEM students who have decided to move from the south to the north and those who have decided to stay close to their hometowns. We devised multilevel modelling techniques to analyze this issue using administrative microdata from the Italian Ministry for Universities and Research (MUR), including eight cohorts of students from AY 2008–2009 to AY 2015–16, who enrolled in STEM fields after earning their high school diploma. One of the main findings is that individuals who moved from the south show lower levels of performance than their stayer counterparts who are enrolled in northern or central universities.

scholarly journals On the Leeuwin Current System and Its Linkage to Zonal Flows in the South Indian Ocean as Inferred from a Gridded Hydrography

2017 ◽  
Vol 47 (3) ◽  
pp. 583-602 ◽  
Author(s):  
Ryo Furue ◽  
Kévin Guerreiro ◽  
Helen E. Phillips ◽  
Julian P. McCreary ◽  
Nathaniel L. Bindoff
Keyword(s):  
Indian Ocean ◽  
Current System ◽  
The South ◽  
South Indian Ocean ◽  
Zonal Flows ◽  
Leeuwin Current ◽  
The North ◽  
South Indian ◽  
The Tropics ◽  
First Time

AbstractThe Leeuwin Current System (LCS) along the coast of Western Australia consists of the poleward-flowing Leeuwin Current (LC), the equatorward-flowing Leeuwin Undercurrent (LUC), and neighboring flows in the south Indian Ocean (SIO). Using geostrophic currents obtained from a highly resolved (⅛°) hydrographic climatology [CSIRO Atlas of Regional Seas (CARS)], this study describes the spatial structure and annual variability of the LC, LUC, and SIO zonal currents, estimates their transports, and identifies linkages among them. In CARS, the LC is supplied partly by water from the tropics (an annual mean of 0.3 Sv; 1 Sv ≡ 106 m3 s−1) but mostly by shallow (200 m) eastward flows in the SIO (4.7 Sv), and it loses water by downwelling across the bottom of this layer (3.4 Sv). The downwelling is so strong that, despite the large SIO inflow, the horizontal transport of the LC does not much increase to the south (from 0.3 Sv at 22°S to 1.5 Sv at 34°S). This LC transport is significantly smaller than previously reported. The LUC is supplied by water from south of Australia (0.2 Sv), by eastward inflow from the SIO south of 28°S (1.6 Sv), and by the downwelling from the LC (1.6 Sv) and in response strengthens northward, reaching a maximum near 28°S (3.4 Sv). North of 28°S it loses water by outflow into subsurface westward flow (−3.6 Sv between 28° and 22°S) and despite an additional downwelling from the LC (1.9 Sv), it decreases to the north (1.7 Sv at 22°S). The seasonality of the LUC is described for the first time.

scholarly journals Geographic variation in the prevalence of overweight and economic status in Chinese adults

2009 ◽  
Vol 102 (3) ◽  
pp. 413-418 ◽  
Author(s):  
Qin Zhuo ◽  
Zhiqiang Wang ◽  
Jianhua Piao ◽  
Guansheng Ma ◽  
Fengying Zhai ◽  
...  
Keyword(s):  
Geographic Variation ◽  
Economic Status ◽  
Gdp Per Capita ◽  
The South ◽  
Chinese Adults ◽  
Geographic Variations ◽  
The North ◽  
Northern Regions ◽  
Per Capita ◽  
Low Prevalence

China is experiencing a rapid increase in overweight and related conditions. This study describes the geographic variation in BMI levels and the prevalence of overweight and underweight in Chinese adults, and assesses their relations with regional Gross Domestic Product (GDP) per capita levels. BMI values and the prevalence of overweight and underweight in 143 522 adults from the Chinese National Nutrition and Health Survey (2002) were calculated according to geographic regions in China. Their correlations with GDP were assessed. Linear and logistic regressions were used to adjust for age, sex and city–country composition. BMI and the prevalence of overweight were highest in the Bohai coastal regions while lowest in southern provinces such as Guangdong, Guangxi, Yunnan, Hunan and Fujian. Mean BMI values ranged from 20·72 to 25·48 kg/m2, and the prevalence of overweight ranged from 6·6 to 53·9 %. BMI and the prevalence of overweight were positively correlated with economic development, particularly in the northern regions. However, for regions with similar GDP per capita levels, those in the south had substantially lower BMI and lower prevalence of overweight than those in the north. Interestingly, some southern regions with high GDP per capita had low BMI and low prevalence of overweight. The prevalence of underweight was highest in the south. Substantial geographic variations in the prevalence of overweight and underweight exist in China. Such variations cannot be fully explained by the differences in economic status. China is currently facing challenges of both overweight and underweight but priorities vary in different regions.

Long-term Cyclic Variations of Prominences, Green and Red Coronae over Solar Cycles

2000 ◽  
Vol 179 ◽  
pp. 201-204
Author(s):  
Vojtech Rušin ◽  
Milan Minarovjech ◽  
Milan Rybanský
Keyword(s):  
Emission Lines ◽  
High Latitudes ◽  
Green Line ◽  
Solar Cycles ◽  
The South ◽  
Coronal Emission ◽  
Local Maxima ◽  
The North ◽  
Cyclic Variations

AbstractLong-term cyclic variations in the distribution of prominences and intensities of green (530.3 nm) and red (637.4 nm) coronal emission lines over solar cycles 18–23 are presented. Polar prominence branches will reach the poles at different epochs in cycle 23: the north branch at the beginning in 2002 and the south branch a year later (2003), respectively. The local maxima of intensities in the green line show both poleward- and equatorward-migrating branches. The poleward branches will reach the poles around cycle maxima like prominences, while the equatorward branches show a duration of 18 years and will end in cycle minima (2007). The red corona shows mostly equatorward branches. The possibility that these branches begin to develop at high latitudes in the preceding cycles cannot be excluded.

US and Russian policies and strategies in the Middle East: Iraq and Syria as a model

2019 ◽  
pp. 220
Author(s):  
Esraa Aladdin Noori ◽  
Nasser Zain AlAbidine Ahmed
Keyword(s):  
Middle East ◽  
East Asia ◽  
Balance Of Power ◽  
Western World ◽  
International Conflicts ◽  
The South ◽  
The West ◽  
The North ◽  
East Region ◽  
Middle East Region

The Russian-American relations have undergone many stages of conflict and competition over cooperation that have left their mark on the international balance of power in the Middle East. The Iraqi and Syrian crises are a detailed development in the Middle East region. The Middle East region has allowed some regional and international conflicts to intensify, with the expansion of the geopolitical circle, which, if applied strategically to the Middle East region, covers the area between Afghanistan and East Asia, From the north to the Maghreb to the west and to the Sudan and the Greater Sahara to the south, its strategic importance will seem clear. It is the main lifeline of the Western world.

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