The Application of Fred Sanders’ Teaching to Current Research on Extreme Cold-Season Precipitation Events in the Saint Lawrence River Valley Region

2008 ◽  
pp. 241-250 ◽  
Author(s):  
John R. Gyakum
Keyword(s):  
Cold Season ◽  
River Valley ◽  
Saint Lawrence River ◽  
Extreme Cold ◽  
Precipitation Events

scholarly journals The Application of Fred Sanders' Teaching to Current Research on Extreme Cold-Season Precipitation Events in the Saint Lawrence River Valley Region

2008 ◽  
Vol 55 ◽  
pp. 241-250 ◽  
Author(s):  
John R. Gyakum
Keyword(s):  
Precipitable Water ◽  
Heavy Precipitation ◽  
Cold Season ◽  
Circulation Anomaly ◽  
Planetary Scale ◽  
Saint Lawrence River ◽  
Physical Insight ◽  
Extreme Cold ◽  
Upper Level ◽  
Precipitation Events

Abstract Fred Sanders' teaching and research contributions in the area of quasigeostrophic theory are highlighted in this paper. The application of these contributions is made to the topic of extreme cold-season precipitation events in the Saint Lawrence valley in the northeastern United States and southern Quebec. This research focuses on analyses of Saint Lawrence valley heavy precipitation events. Synoptic- and planetary-scale circulation anomaly precursors are typically identified several days prior to these events. These precursors include transient upper-level troughs, strong moisture transports into the region, and anomalously large precipitable water amounts. The physical insight of Fred Sanders' work is used in the analysis of these composite results. Further details of this insight are provided in analyses of one case of heavy precipitation.

Changes in extreme, cold-season synoptic precipitation events under global warming

2008 ◽  
Vol 35 (20) ◽  
Author(s):  
William J. Gutowski ◽  
Stephanie S. Willis ◽  
Jason C. Patton ◽  
Benjamin R. J. Schwedler ◽  
Raymond W. Arritt ◽  
...  
Keyword(s):  
Global Warming ◽  
Cold Season ◽  
Extreme Cold ◽  
Precipitation Events

scholarly journals The effect of atmospheric rivers on cold-season heavy precipitation events in Iran

2020 ◽  
Author(s):  
Neda Esfandiari ◽  
Hassan Lashkari
Keyword(s):  
Extreme Events ◽  
Heavy Precipitation ◽  
Cold Season ◽  
Western Slope ◽  
Arid Areas ◽  
Gulf Of Aden ◽  
Zagros Mountains ◽  
Atmospheric Rivers ◽  
Semi Arid ◽  
Precipitation Events

Abstract Atmospheric rivers (ARs) as massive and concentrated water vapour paths can have a critical impact on extreme events in arid and semi-arid areas. This study investigated the effect of ARs on heavy precipitation events during the cold, rainy months (November–April) in Iran for 11 years. The results showed that 107 ARs had an influence on heavy precipitation, which providing partial moisture for Iran's precipitation. On average, 11 heavy precipitation days were linked to the presence of ARs in the six cold months of each year. During the study period, ARs accounted for almost 20–50% of the country's total heavy precipitation monthly. Although most ARs entered the country from the south through coastal areas, the western part of Iran, especially elevated stations along the western slope of the Zagros Mountains, received the highest heavy precipitation. Accordingly, about 66% of ARs directly originated from the Red Sea and the Gulf of Aden. Moreover, December experienced the highest frequency of ARs linked to heavy precipitation during the statistical period.

scholarly journals Large-Scale Flow Patterns Associated with Extreme Precipitation and Atmospheric Rivers over Norway

2019 ◽  
Vol 147 (4) ◽  
pp. 1415-1428 ◽  
Author(s):  
Imme Benedict ◽  
Karianne Ødemark ◽  
Thomas Nipen ◽  
Richard Moore
Keyword(s):  
Extreme Precipitation ◽  
Large Scale ◽  
Moisture Flux ◽  
Cold Season ◽  
Fuzzy Cluster ◽  
The South ◽  
Atmospheric Rivers ◽  
The North ◽  
Extreme Precipitation Events ◽  
Precipitation Events

Abstract A climatology of extreme cold season precipitation events in Norway from 1979 to 2014 is presented, based on the 99th percentile of the 24-h accumulated precipitation. Three regions, termed north, west, and south are identified, each exhibiting a unique seasonal distribution. There is a proclivity for events to occur during the positive phase of the NAO. The result is statistically significant at the 95th percentile for the north and west regions. An overarching hypothesis of this work is that anomalous moisture flux, or so-called atmospheric rivers (ARs), are integral to extreme precipitation events during the Norwegian cold season. An objective analysis of the integrated vapor transport illustrates that more than 85% of the events are associated with ARs. An empirical orthogonal function and fuzzy cluster technique is used to identify the large-scale weather patterns conducive to the moisture flux and extreme precipitation. Five days before the event and for each of the three regions, two patterns are found. The first represents an intense, southward-shifted jet with a southwest–northeast orientation. The second identifies a weak, northward-shifted, zonal jet. As the event approaches, regional differences become more apparent. The distinctive flow pattern conducive to orographically enhanced precipitation emerges in the two clusters for each region. For the north and west regions, this entails primarily zonal flow impinging upon the south–north-orientated topography, the difference being the latitude of the strong flow. In contrast, the south region exhibits a significant southerly component to the flow.

scholarly journals Major Cold-Season Precipitation Events at Iqaluit, Nunavut

ARCTIC ◽  
2010 ◽  
Vol 63 (3) ◽  
Author(s):  
Gabrielle Gascon ◽  
Ronald E. Stewart ◽  
William Henson
Keyword(s):  
Cold Season ◽  
Precipitation Events

scholarly journals A Climatological Study of Extreme Cold Surges along the African Highlands

2017 ◽  
Vol 56 (6) ◽  
pp. 1731-1738 ◽  
Author(s):  
Caitlin C. Crossett ◽  
Nicholas D. Metz
Keyword(s):  
East Coast ◽  
Cold Season ◽  
Meridional Flow ◽  
Extreme Cold ◽  
Cold Surges ◽  
African Highlands ◽  
Hemisphere Winter ◽  
Type 3

AbstractEquatorward-moving cold surges occur along the lee of high terrain during the cold season. Even though the east coast of Africa features high terrain, little research exists on cold surges along the African highlands despite the fact that these surges could have potentially large agricultural and societal effects. This paper examines a 5-yr climatology of the most extreme African-highlands cold surges spanning the 2008–12 period. During these years, 186 cold surges occurred to the lee of the African highlands, with 84 events extending between 30° and 35°S (type 1), 27 extending between 25° and 30°S (type 2), and 75 extending equatorward of 25°S (type 3) based on the 1000–850-hPa thickness pattern. This climatology reveals that extreme African-highlands cold surges have a climatological maximum in September. Cold surges of type 1 and type 2 tend to occur throughout the Southern Hemisphere winter and spring, whereas surges of type 3 are generally confined to the winter months. These cold surges can last from 2 to 8 days, with the highest frequency of events spanning a 3-day period. A typical cold-surge event features maximum 925-hPa meridional flow of 30.0–39.9 kt (1 kt = 0.51 m s−1) that most frequently advects cold Antarctic air to between 15.0° and 24.9°S and at times as far as the equator.

scholarly journals Surface Water Quality Differs between Functionally Similar Restored and Natural Wetlands of the Saint Lawrence River Valley in New York

Land ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 676
Author(s):  
Brendan Carberry ◽  
Tom A. Langen ◽  
Michael R. Twiss
Keyword(s):  
Water Quality ◽  
New York ◽  
Wetland Restoration ◽  
Fecal Coliform ◽  
Specific Conductivity ◽  
New York State ◽  
River Valley ◽  
Restored Wetlands ◽  
Saint Lawrence River ◽  
Natural Wetlands

We tested the hypothesis that upland wetland restorations provide the same quality of wetland, in terms of ecosystem services and biodiversity, as natural wetlands in the St. Lawrence River Valley. Water quality (pH, alkalinity, colored dissolved organic matter, phytoplankton community composition, chlorophyll-a, fecal coliform, total phosphorus, dissolved nitrate, turbidity, specific conductivity) in 17 natural and 45 restored wetlands was compared to determine whether wetland restoration provided similar physicochemical conditions as natural wetlands in the Saint Lawrence River Valley of northeastern New York State. Natural wetlands were more acidic, which was hypothesized to result from the avoidance of naturally acidic regions by farmers seeking to drain wetlands for crop and pasture use. Natural wetlands had significantly greater fecal coliform concentrations. Restored wetlands had significantly greater specific conductivity and related ions, and this is attributed to the creation of wetlands upon marine clay deposits. Other water quality indicators did not differ between restored and natural wetlands. These findings confirm other research at these same wetlands showing no substantial differences between restored and natural wetlands in major biotic indicators. Thus, we conclude that wetland restoration does result in wetlands that are functionally the same as the natural wetlands they were designed to replicate.

scholarly journals The Seasonal Nature of Extreme Hydrological Events in the Northeastern United States

2015 ◽  
Vol 16 (5) ◽  
pp. 2065-2085 ◽  
Author(s):  
Allan Frei ◽  
Kenneth E. Kunkel ◽  
Adao Matonse
Keyword(s):  
United States ◽  
Extreme Precipitation ◽  
Extreme Event ◽  
Warm Season ◽  
The United States ◽  
Cold Season ◽  
Northeastern United States ◽  
Extreme Precipitation Events ◽  
Extreme Hydrological Events ◽  
Precipitation Events

Abstract Recent analyses of extreme hydrological events across the United States, including those summarized in the recent U.S. Third National Climate Assessment (May 2014), show that extremely large (extreme) precipitation and streamflow events are increasing over much of the country, with particularly steep trends over the northeastern United States. The authors demonstrate that the increase in extreme hydrological events over the northeastern United States is primarily a warm season phenomenon and is caused more by an increase in frequency than magnitude. The frequency of extreme warm season events peaked during the 2000s; a secondary peak occurred during the 1970s; and the calmest decade was the 1960s. Cold season trends during the last 30–50 yr are weaker. Since extreme precipitation events in this region tend to be larger during the warm season than during the cold season, trend analyses based on annual precipitation values are influenced more by warm season than by cold season trends. In contrast, the magnitude of extreme streamflow events at stations used for climatological analyses tends to be larger during the cold season: therefore, extreme event analyses based on annual streamflow values are overwhelmingly influenced by cold season, and therefore weaker, trends. These results help to explain an apparent discrepancy in the literature, whereby increasing trends in extreme precipitation events appear to be significant and ubiquitous across the region, while trends in streamflow appear less dramatic and less spatially coherent.

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