Convective boundary layer structure over the equatorial Indian oceanic region

Results of an investigation of the Convective Boundary Layer (CBL) structure over the oceanic region in the vicinity of the equator during the summer monsoon season are presented. The data were obtained from stationary research vessels viz., Shirshov, Okean, Shokalsky and Priboy during the MONSOON-77 Experiment. Variations in structure between convective boundary layers over the four ships with respect to their position about the equator have been studied. The technique of saturation point, mixing line and conserved variable diagrams has been used to bring out these differences. The CBL structure over the four ships showed that in the vicinity of the equator there are no marked differences. However, the analysis carried out for the period of study revealed that the ships situated south of the equator represented more convective activity, higher moisture content and deep layer clouds as compared to the ships which were located at the equator and north of equator. The two ships, located at the equator, showed approximately similar convective boundary layer structure.

Progress of Indian summer monsoon onset and convective episodes over Indo-Pacific region observed during 2009-2014

Summer monsoon onset progress from the oceanic region of Southeast Bay of Bengal / Andaman Sea (Oceanr) up to extreme southwestern part of India (Kerala) for the years 2009 to 2014 is investigated. Synoptic weather information, INSAT/KALPANA-1 as well as cloud imageries archived from Dundee Satellite Receiving Station for May and early June for these years are used in the analysis. Upper-air reanalyzed winds from NCEP/NCAR and OLR data archived through NOAA satellites are also used. During the study period, the dates of monsoon onset as well as the time required for the advancement of onset from Oceanr to Kerala have shown a large variation. An attempt is made to investigate the causes for such variations. The results indicate that intense disturbances which formed over north Indian Ocean in 2009, 2010, 2013 and 2014 and over west-north Pacific Oceanic region in 2011 and 2012 have contributed for the same. Analysis is carried out, limiting its focus to bring out the role of these convective events in the observed variation of onset timing and its progress by taking case to case review of these events and bringing out their influence through synoptic analysis. Utility of this information in prediction of the progress of Indian summer monsoon onset is also brought out.

High-resolution and high-accuracy global ionosphere maps estimated by GNSS and LEO constellations: simulative and real data experimental results

<p>Global ionospheric total electron content (TEC) map has been employed in many high-precision areas. However, its spatial and temporal resolution is not ideal since the ground-based Global Navigation Satellite Systems (GNSS) stations distributed unevenly. Fortunately, many low earth orbit (LEO) satellite constellations will provide a large number of observations that can be used for ionospheric monitoring in the future. In this contribution, we presented two methods, which are the single-layer normalization (SLN) method and the dual-layer superposition (DLS) method, for ionospheric modeling based on the simulative and real data of GNSS+LEO satellites.</p><p>For simulative data, a constellation with 192 LEO satellites is simulated. And then,  the global ionospheric maps (GIMs) are estimated by all Multi-GNSS and simulative LEO satellite observations. The results showed that the root mean square (RMS) is reduced by approximately 25% and 21% for SLN method and DLS method, respectively. For real data,  20 available scientific LEO satellites, such as Jason-2/3, COSMIC-1/-2, Swarm missions, etc.,  are employed in the ground-based GNSS ionospheric modeling. The results showed that the differences between the ionospheric model estimated by GNSS+LEO and that by GNSS data are mainly over the oceanic region, which may exceed ±20 TECU. The improvement of RMS over the oceanic region is about 15% for the ionospheric model estimated by GNSS+LEO. The RMS of the ionospheric model improved approximately 4.0% compared with that by GNSS data using the dSTEC assessment method.</p>

The Economies of Oceania

This chapter provides an overview of the economic performance and current situation of the economies in the Oceanic region. Oceania comprises the economically developed countries of Australia and New Zealand plus the more than 20 island countries and protectorates of Melanesia, Micronesia, and Polynesia. In 2018, Australia dominated the region in terms of population (71% of the total for Oceania) and gross domestic product (86%). Melanesia, which includes Papua New Guinea, Fiji, and New Caledonia, contained 26% of the region's population and generated 4% of its gross regional product. According to the authors' forecasting model, Oceania's share of both world population and gross world product will rise strongly during the coming three decades, admittedly from a low base. Reflecting the high degree of complementarity of the Oceanic economies with those of Asia, this strong growth in the Oceanic region should support increasingly attractive opportunities for trade and investment with the economies of Asia.

PEOPLING OF OCEANIA: CLARIFYING AN INITIAL SETTLEMENT HORIZON IN THE MARIANA ISLANDS AT 1500 BC

ABSTRACT Radiocarbon (14C) has been instrumental in clarifying how people came to inhabit the expanse of Pacific Oceania, now supporting an “incremental growth model” that shows a number of long-distance sea-crossing migrations over the last few millennia. A crucial step in this narrative involved the initial settlement of the remote-distance Oceanic region, in the case of the Mariana Islands around 1500 BC. The Marianas case can be demonstrated through delineation of stratigraphic layers, dating of individual points or features within those layers, redundant dating of samples in secure contexts, localized and taxon-specific corrections for marine samples, and cross-constraining dating of superimposed layer sequences. Based on the technical and methodological lessons from the Marianas example, the further steps of the incremental growth model will continue to be refined across Pacific Oceania. Many of these issues may be relevant for broader research of ancient settlement horizons in other regions.