Long-term trend in spatial and temporal distribution of southern African aerosols over the southern Indian Ocean during the austral winter: Patterns and implications

2008 ◽  
Author(s):  
Deborah Claire Stein Zweers
Keyword(s):  
Indian Ocean ◽  
Temporal Distribution ◽  
Southern Indian Ocean ◽  
Spatial And Temporal Distribution ◽  
Austral Winter ◽  
Term Trend ◽  
African Aerosols ◽  
Long Term Trend

scholarly journals Spatial and temporal distribution of foot and mouth disease outbreaks in Amhara region of Ethiopia in the period 1999 to 2016

2020 ◽  
Vol 16 (1) ◽  
Author(s):  
Endris Aman ◽  
Wassie Molla ◽  
Zeleke Gebreegizabher ◽  
Wudu Temesgen Jemberu
Keyword(s):  
Temporal Distribution ◽  
Foot And Mouth Disease ◽  
Dry Season ◽  
Mouth Disease ◽  
Spatial And Temporal Distribution ◽  
Amhara Region ◽  
Term Trend ◽  
Foot And Mouth ◽  
Long Term Trend

Abstract Background Foot and mouth disease (FMD) is an economically important trans-boundary viral disease of cloven-hoofed animals. It is caused by FMD virus, which belongs to the genus Aphthovirus and family Picornaviridae. FMD is a well-established endemic disease in Ethiopia since it was first detected in 1957. This retrospective study was carried out to identify the spatial and temporal distribution of FMD outbreaks in Amhara region of Ethiopia using 18 years (January 1999–December 2016) reported outbreak data. Results A total of 636 FMD outbreaks were reported in Amhara region of Ethiopia between 1999 and 2016 with an average and median of 35 and 13 outbreaks per year respectively. In this period, FMD was reported at least once in 58.5% of the districts (n = 79) and in all administrative zones of the region (n = 10). The average district level incidence of FMD outbreaks was 4.68 per 18 years (0.26 per district year). It recurs in a district as epidemic, on average in 5.86 years period. The incidence differed between administrative zones, being the lowest in East Gojjam and highest in North Shewa. The occurrence of FMD outbreaks was found to be seasonal with peak outbreaks in March and a low in August. The long-term trend of FMD outbreaks indicates a slight, but statistically significant (p < 0.001) decrease over the study period. Conclusion FMD occurred in all zones of the region and showed statistically significant decrease in the long-term trend. Numbers of outbreaks were relatively higher during dry season. The spatial and temporal distribution identified in this study should be considered in controlling the disease. As unregulated and frequent animal movements are the likely causes of high outbreak occurrence during the dry season, animal movement regulations should be considered for the long-term control of FMD.

Rates of Recovery of Bands, Harvest Patterns and Estimates for Black Duck, Chestnut Teal, Grey Teal and Mountain Duck Shot during Victorian Open Seasons, 1953-1977

1981 ◽  
Vol 8 (3) ◽  
pp. 659 ◽  
Author(s):  
FI Norman ◽  
DGM Powell
Keyword(s):  
Temporal Distribution ◽  
Specific Population ◽  
Term Trend ◽  
Black Duck ◽  
Population Sizes ◽  
Long Term Trend

The temporal distribution of recoveries of bands from black duck Anas superciliosa, chestnut teal A. castanea, grey teal A. gibberifrons and mountain duck Tadorna tadornoides shot in Victoria during open seasons on waterfowl between 1953 and 1977 is examined. Recoveries were higher on the opening day and during the opening week of each season; recoveries on Saturdays exceeded those on other 'days', and Sunday recovery totals were minimal. No increase or long-term trend in weekday recoveries, and hence shooting, was evident during the study period. Speculative harvest estimates are provided for 1972-77, but such figures must be refined and related to data concerning specific population sizes and distribution before implications for management can be formulated.

scholarly journals Analysis of Segmented Sea level Time Series

2020 ◽  
Vol 10 (2) ◽  
pp. 625
Author(s):  
Alberto Boretti
Keyword(s):  
Data Mining ◽  
Time Series ◽  
Indian Ocean ◽  
Break Point ◽  
Tide Gauges ◽  
Sea Levels ◽  
Term Trend ◽  
The Indian Ocean ◽  
Long Term Trend

Records of measurements of sea levels from tide gauges are often “segmented”, i.e., obtained by composing segments originating from the same or different instruments, in the same or different locations, or suffering from other biases that prevent the coupling. A technique is proposed, based on data mining, the application of break-point alignment techniques, and similarity with other segmented and non-segmented records for the same water basin, to quality flag the segmented records. This prevents the inference of incorrect trends for the rate of rise and the acceleration of the sea levels for these segmented records. The technique is applied to the four long-term trend tide gauges of the Indian Ocean, Aden, Karachi, Mumbai, and Fremantle, with three of them segmented.

scholarly journals Sea Surface Salinity Change since 1950: Internal Variability Versus Anthropogenic Forcing

2020 ◽  
pp. 1-46 ◽  
Author(s):  
Qiwei SUN ◽  
Yan DU ◽  
Shang-Ping XIE ◽  
Yuhong ZHANG ◽  
Minyang WANG ◽  
...  
Keyword(s):  
Indian Ocean ◽  
Internal Variability ◽  
Tropical Pacific ◽  
Sea Surface ◽  
Sea Surface Salinity ◽  
Surface Salinity ◽  
Term Trend ◽  
Western Tropical Pacific ◽  
Long Term Trend

AbstractUsing an eastern tropical Pacific pacemaker experiment called the Pacific Ocean–Global Atmosphere (POGA) run, this study investigated the internal variability in sea surface salinity (SSS) and its impacts on the assessment of long-term trends. By constraining the eastern tropical Pacific sea surface temperature variability with observations, the POGA experiment successfully simulated the observed variability of SSS. The long-term trend in POGA SSS shows a general pattern of salty regions becoming saltier (e.g., the northern Atlantic) and fresh regions becoming fresher, which agrees with previous studies. The 1950-2012 long-term trend in SSS is modulated by the internal variability associated with the Interdecadal Pacific Oscillation (IPO). Due to this variability, there are some regional discrepancies in the SSS 1950–2012 long-term change between POGA and the free-running simulation forced with historical radiative forcing, especially for the western tropical Pacific and southeastern Indian Ocean. Our analysis shows that the tropical Pacific cooling and intensified Walker Circulation caused the SSS to increase in the western tropical Pacific and decrease in the southeastern Indian Ocean during the 20-year period of 1993–2012. This decadal variability has led to large uncertainties in the estimation of radiative-forced trends on a regional scale. For the 63-year period of 1950–2012, the IPO caused an offset of ∼40% in the radiative-forced SSS trend in the western tropical Pacific and ∼170% enhancement in the trend in the southeastern Indian Ocean. Understanding and quantifying the contribution of internal variability to SSS trends help improve the skill for estimates and prediction of salinity/water cycle changes.

NAEP Trends: Main NAEP vs. Long-Term Trend

2010 ◽  
Author(s):  
Albert E. Beaton ◽  
James R. Chromy
Keyword(s):  
Term Trend ◽  
Long Term Trend
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