Winter freezes of fruit trees in the Okanagan Valley, British Columbia: Relationship with the Pacific North America teleconnection and the El Nino/Southern Oscillation

1994 ◽  
Vol 74 (4) ◽  
pp. 841-846 ◽  
Author(s):  
J. W. Hall ◽  
H. A. Quamme
Keyword(s):  
North America ◽  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
El Niño Southern Oscillation ◽  
El Nino Southern Oscillation ◽  
Cold Event ◽  
Warm Event ◽  
The Pacific ◽  
Okanagan Valley

Every 5–7 years there are severe winter freezes in the Okanagan Valley which lower yields or kill apple trees. Our goal was to determine whether winter freezes (December, January and February) could be related to the Pacific North America teleconnection (PNA) and the El Nino/Southern Oscillation (ENSO). Fall and spring freezes were also discussed. A list of ENSO warm event, cold event and neutral years was available from 1947 to 1986 as well as monthly temperature and precipitation records. Months were classified as having a PNA, reverse PNA (r-PNA) or neutral pattern. There was a tendency for the r-PNA pattern to occur more and the PNA pattern less frequently in cold event winters than in warm event winters. The average temperature was lower when the r-PNA predominated but ENSO events had no additional effect. No relationship was detected with precipitation. Fall and winter freezes occurred when there was an r-PNA pattern combined with either a neutral or a cold event ENSO. These results suggest that the risk of winter freezes will be low during ENSO warm events and high when the r-PNA pattern predominates. Key words:Malus domestica, Prunus persica, freezing injury, teleconnexions, El Nino/Southern Oscillation

scholarly journals Coastal vulnerability across the Pacific dominated by El Niño/Southern Oscillation

2015 ◽  
Vol 8 (10) ◽  
pp. 801-807 ◽  
Author(s):  
Patrick L. Barnard ◽  
Andrew D. Short ◽  
Mitchell D. Harley ◽  
Kristen D. Splinter ◽  
Sean Vitousek ◽  
...  
Keyword(s):  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
El Niño Southern Oscillation ◽  
El Nino Southern Oscillation ◽  
Coastal Vulnerability ◽  
The Pacific

scholarly journals Influence of Modes of Climate Variability on Global Precipitation Extremes

2010 ◽  
Vol 23 (23) ◽  
pp. 6248-6262 ◽  
Author(s):  
Jesse Kenyon ◽  
Gabriele C. Hegerl
Keyword(s):  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
Precipitation Extremes ◽  
El Niño Southern Oscillation ◽  
El Nino Southern Oscillation ◽  
Northern Annular Mode ◽  
The North ◽  
The Pacific ◽  
The North Atlantic Oscillation

Abstract The probability of climate extremes is strongly affected by atmospheric circulation. This study quantifies the worldwide influence of three major modes of circulation on station-based indices of intense precipitation: the El Niño–Southern Oscillation, the Pacific interdecadal variability as characterized by the North Pacific index (NPI), and the North Atlantic Oscillation–Northern Annular Mode. The study examines which stations show a statistically significant (5%) difference between the positive and negative phases of a circulation regime. Results show distinct regional patterns of response to all these modes of climate variability; however, precipitation extremes are most substantially affected by the El Niño–Southern Oscillation. The effects of the El Niño–Southern Oscillation are seen throughout the world, including in India, Africa, South America, the Pacific Rim, North America, and, weakly, Europe. The North Atlantic Oscillation has a strong, continent-wide effect on Eurasia and affects a small, but not negligible, percentage of stations across the Northern Hemispheric midlatitudes. This percentage increases slightly if the Northern Annular Mode index is used rather than the NAO index. In that case, a region of increase in intense precipitation can also be found in Southeast Asia. The NPI influence on precipitation extremes is similar to the response to El Niño, and strongest in landmasses adjacent to the Pacific. Consistently, indices of more rare precipitation events show a weaker response to circulation than indices of moderate extremes; the results are quite similar, but of opposite sign, for negative anomalies of the circulation indices.

scholarly journals South Carolina's Climate Report Card: The Influence of the El Niño Southern Oscillation Cold Warm Event Cycles on South Carolina's Seasonal Precipitation

2015 ◽  
pp. 3-10 ◽  
Author(s):  
Hope Mizzell ◽  
Jennifer Simmons
Keyword(s):  
El Niño ◽  
Water Resource Management ◽  
El Nino ◽  
Southern Oscillation ◽  
The United States ◽  
El Niño Southern Oscillation ◽  
El Nino Southern Oscillation ◽  
Seasonal Precipitation ◽  
Seasonal Temperature ◽  
Warm Event

This study was driven by the need to better understand variations in South Carolina’s seasonal precipitation. Numerous weather-sensitive sectors such as agriculture and water resource management are impacted by the seasonal variability and distribution of precipitation. Studies have shown that El Niño-Southern Oscillation (ENSO) has varying effects on seasonal temperature and precipitation across the United States. The purpose of this study was to determine the relative influence of ENSO cold and warm event cycles on interannual variations of South Carolina’s seasonal precipitation (1950- 2015). The relationship between seasonal precipitation departures from normal and the average Multivariate ENSO Index was analyzed. Seasonal precipitation totals for each of South Carolina’s seven climate divisions and for three key city locations (Greenville-Spartanburg Airport, Columbia Airport, and Charleston Downtown) were examined. Results from the study indicate that the magnitude, seasonal variation, and consistency of the precipitation response to ENSO vary spatially and from episode to episode. Winter precipitation tends to be enhanced during the warm phase (El Niño) and reduced during the cold phase (La Niña). There is a less consistent signal during fall and no evident connection between ENSO and spring and summer precipitation.

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