Decadal-scale variations in extreme precipitation and implications for seasonal scale drought

2021 ◽  
Author(s):  
Mustapha Adamu ◽  
Ailie J. E. Gallant ◽  
Shayne McGregor
Keyword(s):  
Extreme Precipitation ◽  
Seasonal Scale ◽  
Decadal Scale

Two millennia of seasonal rainfall predictability in the neotropics with repercussions for agricultural societies

2021 ◽  
Author(s):  
Tobias Braun ◽  
Sebastian F. M. Breitenbach ◽  
Erin Ray ◽  
James U. L. Baldini ◽  
Lisa M. Baldini ◽  
...  
Keyword(s):  
Climate Variability ◽  
Seasonal Cycle ◽  
Irregular Sampling ◽  
Ice Age ◽  
Terminal Classic ◽  
Hydrological Variability ◽  
Seasonal Scale ◽  
Decadal Scale ◽  
Agricultural Societies ◽  
Maya Collapse

<p><span>The reconstruction and analysis of palaeoseasonality from speleothem records remains a notoriously challenging task. Although the seasonal cycle is obscured by noise, dating uncertainties and irregular sampling, its extraction can identify regime transitions and enhance the understanding of long-term climate variability. Shifts in seasonal predictability of hydroclimatic conditions have immediate and serious repercussions for agricultural societies.</span></p><p><span>We present a highly resolved speleothem record (ca. 0.22 years temporal resolution with episodes twice as high) of palaeoseasonality from Yok Balum cave in Belize covering the Common Era (400-2006 CE) and demonstrate how seasonal-scale hydrological variability can be extracted from δ<sup>13</sup>C and δ<sup>18</sup>O isotope records. We employ a Monte-Carlo based framework in which dating uncertainties are transferred into magnitude uncertainty and propagated. Regional historical proxy data enable us to relate climate variability to agricultural disasters throughout the Little Ice Age and population size variability during the Terminal Classic Maya collapse.</span></p><p><span>Spectral analysis reveals the seasonal cycle as well as nonstationary ENSO- and multi-decadal-scale variability. Variations in both the subannual distribution of rainfall and mean average hydroclimate pose limitations on how reliably farmers can predict crop yield. A characterization of year-to-year predictability as well as the complexity of seasonal patterns unconver shifts in the seasonal-scale variability. These are discussed in the context of their implications for rainfall dependent agricultural societies.</span></p>

scholarly journals Changing seasonality of moderate and extreme precipitation events in the Alps

2018 ◽  
Vol 18 (7) ◽  
pp. 2047-2056 ◽  
Author(s):  
Stefan Brönnimann ◽  
Jan Rajczak ◽  
Erich M. Fischer ◽  
Christoph C. Raible ◽  
Marco Rohrer ◽  
...  
Keyword(s):  
Extreme Precipitation ◽  
Climate Model ◽  
Global Climate Model ◽  
Model Simulations ◽  
Extreme Precipitation Events ◽  
Rate Of Increase ◽  
Decadal Scale ◽  
The Future ◽  
The Impact ◽  
Precipitation Events

Abstract. The intensity of precipitation events is expected to increase in the future. The rate of increase depends on the strength or rarity of the events; very strong and rare events tend to follow the Clausius–Clapeyron relation, whereas weaker events or precipitation averages increase at a smaller rate than expected from the Clausius–Clapeyron relation. An often overlooked aspect is seasonal occurrence of such events, which might change in the future. To address the impact of seasonality, we use a large ensemble of regional and global climate model simulations, comprising tens of thousands of model years of daily temperature and precipitation for the past, present, and future. In order to make the data comparable, they are quantile mapped to observation-based time series representative of the Aare catchment in Switzerland. Model simulations show no increase in annual maximum 1-day precipitation events (Rx1day) over the last 400 years and an increase of 10 %–20 % until the end of the century for a strong (RCP8.5) forcing scenario. This fits with a Clausius–Clapeyron scaling of temperature at the event day, which increases less than annual mean temperature. An important reason for this is a shift in seasonality. Rx1day events become less frequent in late summer and more frequent in early summer and early autumn, when it is cooler. The seasonality shift is shown to be related to summer drying. Models with decreasing annual mean or summer mean precipitation show this behaviour more strongly. The highest Rx1day per decade, in contrast, shows no change in seasonality in the future. This discrepancy implies that decadal-scale extremes are thermodynamically limited; conditions conducive to strong events still occur during the hottest time of the year on a decadal scale. In contrast, Rx1day events are also limited by other factors. Conducive conditions are not reached every summer in the present, and even less so in the future. Results suggest that changes in the seasonal cycle need to be accounted for when preparing for moderately extreme precipitation events and assessing their socio-economic impacts.

scholarly journals Changing seasonality of moderate and extreme precipitation events in the Alps

2018 ◽  
Author(s):  
Stefan Brönnimann ◽  
Jan Rajczak ◽  
Erich Fischer ◽  
Christoph C. Raible ◽  
Marco Rohrer ◽  
...  
Keyword(s):  
Extreme Precipitation ◽  
Climate Model ◽  
Global Climate Model ◽  
Model Simulations ◽  
Extreme Precipitation Events ◽  
Rate Of Increase ◽  
Decadal Scale ◽  
The Future ◽  
The Impact ◽  
Precipitation Events

Abstract. The intensity of precipitation events is expected to increase in the future. The rate of increase depends on the strength or rarity of the events; very strong and rare events tend to follow the Clausius-Clapeyron relation, whereas weaker events or precipitation averages do not. An often overlooked aspect is seasonal occurrence of such events, which might change in the future. To address the impact of seasonality, we use a large ensemble of regional and global climate model simulations, comprising tens of thousands of model years of daily temperature and precipitation for the past, present and future. In order to make the data comparable, they are quantile-mapped to observation-based time series representative of the Aare catchment in Switzerland. Model simulations show no increase in annual maximum 1-day precipitation events (Rx1day) over the last 400 yrs and an increase of 10–20 % until the end of the century for a strong (RCP8.5) forcing scenario. This fits with a Clausius-Clapeyron scaling of temperature at the event day, which increases less than annual mean temperature. An important reason for this is a shift in seasonality. Rx1day events become less frequent in late summer and more frequent in early summer and early fall, when it is cooler. The seasonality shift is shown to be related to summer drying. Models with decreasing annual mean or summer mean precipitation show this behavior more strongly. The highest Rx1day per decade, in contrast, shows no change in seasonality in the future. This discrepancy implies that decadal-scale extremes are thermodynamically limited; conditions conducive to strong events still occur during hottest time of the year on a decadal scale. In contrast, Rx1day events are also limited by other factors. Conducive conditions are not reached every summer in the present, and even less so in the future. Results suggest that changes in the seasonal cycle need to be accounted for when preparing for moderately extreme precipitation events and assessing their socio-economic impacts.

The Impacts of cloud condensation nuclei on the extreme precipitation of a monsoon coastal mesoscale convection system

2020 ◽  
Vol 31 (2) ◽  
pp. 131-139
Author(s):  
Chun-Yian Su ◽  
Wei-Ting Chen ◽  
Jen-Ping Chen ◽  
Wei-Yu Chang ◽  
Ben Jong-Dao Jou
Keyword(s):  
Extreme Precipitation ◽  
Cloud Condensation Nuclei ◽  
Condensation Nuclei ◽  
Mesoscale Convection

Reconstruction of maximum temperature on Zhegu Mountain, western Sichuan Plateau (China)

2020 ◽  
Vol 81 ◽  
pp. 1-14
Author(s):  
M Keyimu ◽  
Z Li ◽  
Y Zhao ◽  
Y Dong ◽  
B Fu ◽  
...  
Keyword(s):  
Tree Growth ◽  
Ring Width ◽  
Volcanic Eruptions ◽  
Southwestern China ◽  
Maximum Temperature ◽  
Driving Mechanism ◽  
Western Sichuan ◽  
Relationship Analysis ◽  
Decadal Scale ◽  
Thermal Variability

Historical temperature reconstructions at high altitudes are still insufficient in southwestern China, which is considered one of the most sensitive areas to climate change in the world. Here we developed a tree ring-width chronology of Faxon fir Abies fargesii var. faxoniana at the upper timber line on Zhegu Mountain, Miyaluo Scenic Area, western Sichuan, China. The climate-tree growth relationship analysis indicated temperature as the dominant regulator on radial tree growth in this region. The reconstruction of aggregated maximum temperature (TMX) of autumn and winter for the period 1856-2016 was achieved with a linear regression model that accounted for 43.6% of the actual variability in the common time series (1954-2016). The reconstruction identified 4 warm periods and 3 cold periods. Similarities of warm and cold periods with previously published reconstructions from nearby sites indicated the reliability of our reconstruction. The significant positive correlation between TMX reconstruction and the Asian-Pacific Oscillation index and the Atlantic Multi-decadal Oscillation index suggested a linkage between large-scale climate circulations and the thermal variability at a multi-decadal scale on the western Sichuan Plateau. We also found that solar activity exerted a strong influence on decadal temperature variability in this region. The cold periods were matched well with historical large volcanic eruptions. Our results strengthen the historical climatic information in southwestern China and contribute to further understanding the regional thermal variability as well as its driving mechanism.

Assessment of changes in extreme precipitation affecting the degree of soil erosion in crop rotation

2020 ◽  
Author(s):  
V.V. Ilinich ◽  
◽  
A.A. Naumova
Keyword(s):  
Soil Erosion ◽  
Crop Rotation ◽  
Extreme Precipitation ◽  
Crop Rotations

the presented research is dedicate to confirming the hypothesis about increase in extreme precipitation of recent decades, affecting the degree of soil erosion in crop rotations.

An extreme precipitation event in Central Norway

2011 ◽  
Author(s):  
Birthe Marie Steensen ◽  
Haraldur Ólafsson ◽  
Marius O. Jonassen
Keyword(s):  
Extreme Precipitation ◽  
Extreme Precipitation Event ◽  
Precipitation Event
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