On the Development and Demise of the Fall 2019 Southeast U. S. Flash Drought: Links to an Extreme Positive IOD

2020 ◽  
pp. 1-60
Author(s):  
Siegfried D. Schubert ◽  
Yehui Chang ◽  
Anthony M. DeAngelis ◽  
Hailan Wang ◽  
Randal D. Koster
Keyword(s):  
Indian Ocean ◽  
Rossby Wave ◽  
Wave Train ◽  
Temperature And Precipitation ◽  
Ocean Region ◽  
Dry Conditions ◽  
Underlying Causes ◽  
The Indian Ocean ◽  
Precipitation Anomalies ◽  
Rossby Wave Train

AbstractMuch of the southeast United States experienced record dry conditions during September of 2019, with the area in abnormally dry to exceptional drought conditions growing from 25% at the beginning of the month to 80% by the end of the month. The drought ended just as abruptly due to above normal rain that fell during the second half of October. In this study we employed MERRA-2 and the GEOS-5 AGCM to diagnose the underlying causes of the drought’s onset, maintenance, and demise. The basic approach involves performing a series of AGCM simulations in which the model is constrained to remain close to MERRA-2 over pre-specified areas that are external to the drought region. The start of the drought appears to have been forced by anomalous heating in the central/western tropical Pacific that resulted in low level anti-cyclonic flow and a tendency for descending motion over much of the southeast. An anomalous ridge associated with a Rossby wave train (emanating from the Indian Ocean region) is found to be the main source of the most intense temperature and precipitation anomalies that develop over the southeast during the last week of September. A second Rossby wave train (emanating from the same region) is responsible for the substantial rain that fell during the second half of October to end the drought. The links to the Indian Ocean Dipole (with record positive values) as well as a waning El Nino allow some speculation as to the likelihood of similar events occurring in the future.

A Contest of Status and Legitimacy in the Indian Ocean

2018 ◽  
Author(s):  
David Brewster
Keyword(s):  
Indian Ocean ◽  
International System ◽  
Special Role ◽  
Indian Ocean Region ◽  
Major Powers ◽  
Threat Perceptions ◽  
Ocean Region ◽  
The Status ◽  
The Indian Ocean ◽  
The Asymmetry

This chapter examines Indian and Chinese perspectives of each other as major powers and their respective roles in the Indian Ocean. It focuses on the following elements: (a) China’s strategic imperatives in the Indian Ocean Region, (b) India’s views on its special role in the Indian Ocean and the legitimacy of the presence of other powers, (c) China’s strategic vulnerabilities in the Indian Ocean and India’s wish to leverage those vulnerabilities, (d) the asymmetry in Indian and Chinese threat perceptions, and (d) Chinese perspectives of the status of India in the international system and India’s claims to a special role in the Indian Ocean. The chapter concludes that even if China were to take a more transparent approach to its activities, significant differences in perceptions of threat and over status and legitimacy will produce a highly competitive dynamic between them in the maritime domain.

Heat and freshwater changes in the Indian Ocean region

2021 ◽  
Author(s):  
Caroline C. Ummenhofer ◽  
Sujata A. Murty ◽  
Janet Sprintall ◽  
Tong Lee ◽  
Nerilie J. Abram
Keyword(s):  
Indian Ocean ◽  
Indian Ocean Region ◽  
Ocean Region ◽  
The Indian Ocean

scholarly journals Spatiotemporal Evolution and Determinant Factors of the Intra-Regional Trade Community Structures of the Indian Ocean Region

2021 ◽  
Vol 10 (4) ◽  
pp. 214
Author(s):  
Lihua Yuan ◽  
Xiaoqiang Chen ◽  
Changqing Song ◽  
Danping Cao ◽  
Hong Yi
Keyword(s):  
Indian Ocean ◽  
Explanatory Power ◽  
Community Structures ◽  
Indian Ocean Region ◽  
Spatiotemporal Evolution ◽  
Regional Trade ◽  
Determinant Factors ◽  
Ocean Region ◽  
The Indian Ocean ◽  
The Impact

The Indian Ocean Region (IOR) has become one of the main economic forces globally, and countries within the IOR have attempted to promote their intra-regional trade. This study investigates the spatiotemporal evolution of the community structures of the intra-regional trade and the impact of determinant factors on the formation of trade community structures of the IOR from 1996 to 2017 using the methods of social network analysis. Trade communities are groups of countries with measurably denser intra-trade ties but with extra-trade ties that are measurably sparser among different communities. The results show that the extent of trade integration and the trade community structures of the IOR changed from strengthening between 1996 and 2014 to weakening between 2015 and 2017. The largest explanatory power of the formation of the IOR trade community structures was the IOR countries’ economic size, indicating that market remained the strongest driver. The second-largest explanatory power was geographical proximity, suggesting that countries within the IOR engaged in intra-regional trade still tended to select geographically proximate trading partners. The third- and the fourth-largest were common civilization and regional organizational memberships, respectively. This indicates that sharing a common civilization and constructing intra-regional institutional arrangements (especially open trade policies) helped the countries within the IOR strengthen their trade communities.

The Sino-Indian Geopolitics and Maritime Security of the Indian Ocean Region

2021 ◽  
pp. 1-17
Author(s):  
Sainandan S. Iyer ◽  
Ranadhir Mukhopadhyay ◽  
Sridhar D. Iyer
Keyword(s):  
Indian Ocean ◽  
Maritime Security ◽  
Indian Ocean Region ◽  
Ocean Region ◽  
The Indian Ocean

scholarly journals The Influence of the Madden–Julian Oscillation on Canadian Wintertime Surface Air Temperature

2009 ◽  
Vol 137 (7) ◽  
pp. 2250-2262 ◽  
Author(s):  
Hai Lin ◽  
Gilbert Brunet
Keyword(s):  
Air Temperature ◽  
Wave Train ◽  
Winter Season ◽  
Surface Air Temperature ◽  
Madden Julian Oscillation ◽  
Eastern Canada ◽  
Central Pacific ◽  
Sea Level Pressure ◽  
The Indian Ocean ◽  
Rossby Wave Train

Using the homogenized Canadian historical daily surface air temperature (SAT) for 210 relatively evenly distributed stations across Canada, the lagged composites and probability of the above- and below-normal SAT in Canada for different phases of the Madden–Julian oscillation (MJO) in the winter season are analyzed. Significant positive SAT anomalies and high probability of above-normal events in the central and eastern Canada are found 5–15 days following MJO phase 3, which corresponds to an enhanced precipitation over the Indian Ocean and Maritime Continent and a reduced convective activity near the tropical central Pacific. On the other hand, a positive SAT anomaly appears over a large part of northern and northeastern Canada about 5–15 days after the MJO is detected in phase 7. An analysis of the evolution of the 500-hPa geopotential height and sea level pressure anomalies indicates that the Canadian SAT anomaly is a result of a Rossby wave train associated with the tropical convection anomaly of the MJO. Hence, the MJO phase provides useful information for the extended-range forecast of Canadian winter surface air temperature. This result also provides an important reference for numerical model verifications.

Evaluation of the benefits of assimilation of Meteosat-8 observations in an NWP system over the Indian Ocean region

2021 ◽  
Author(s):  
M. T. Bushair ◽  
S. Indira Rani ◽  
Buddhi Prakash Jangid ◽  
Priti Sharma ◽  
Sumit Kumar ◽  
...  
Keyword(s):  
Indian Ocean ◽  
Indian Ocean Region ◽  
Ocean Region ◽  
The Indian Ocean
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