Periods Of Storminess Research Articles

It's in your glass: a history of sea level and storminess from the Laphroaig bog, Islay (southwestern Scotland)

Severe winter windstorms have become an increasingly common occurrence over recent decades in northwestern Europe. Although there exists considerable uncertainty, storminess is projected to increase in the future. On centennial to millennial time scales in particular, the mechanisms forcing storminess remain unsettled. We contribute to available palaeostorm records by reconstructing changes over the last 6670 years using a coastal peat sequence retrieved from the ombrotrophic Laphroaig bog on Islay, southwestern Scotland. We use a combination of ash content, grain size and elemental chemistry to identify periods of greater storminess, which are dated to 6605, 6290–6225, 5315–5085, 4505, 3900–3635, 3310–3130, 2920–2380, 2275–2190, 2005–1860, 1305–1090, 805–435 and 275 cal. a BP. Storm signals in the first half of the record up to ~3000 cal. a BP are mainly apparent in the grain‐size changes. Samples from this time period also have a different elemental signature than those later in the record. We speculate that this is due to receding sea levels and the consequent establishment of a new sand source in the form of dunes, which are still present today. The most significant events and strongest winds are found during the Iron Ages Cold Epoch (2645 cal. a BP), the transition into, and in the middle of, the Roman Ages Warm Period (2235 and 1965 cal. a BP) and early in the Little Ice Age (545 cal. a BP). The Laphroaig record generally agrees with regionally relevant peat palaeostorm records from Wales and the Outer Hebrides, although the relative importance of the different storm periods is not the same. In general, stormier periods are coeval with cold periods in the region as evidenced by parallels with increased ice‐rafted debris in the North Atlantic, highlighting that sea‐ice conditions could impact future storminess and storm track position.

8000 years of North Atlantic storminess reconstructed from a Scottish peat record: implications for Holocene atmospheric circulation patterns in Western Europe

ABSTRACTNorth Atlantic storminess can affect human settlements, infrastructure and transport links, all of which strongly impact local, national and global economies. An increase in storm frequency and intensity is predicted over the North‐East Atlantic in the 21st century because of a northward shift in storm tracks and a persistently positive North Atlantic Oscillation (NAO), driven by recent atmospheric warming. Although documentary records of North Atlantic storminess exist, these are generally limited to the last c. 1000 years. This paper presents a continuous high‐resolution proxy record of storminess spanning the last 8000 years from a 6 m‐long core taken from a peat bog in northern Scotland. Bromine concentrations in the peat, derived from sea spray, are used to reconstruct storm frequency and storm intensity, and mire surface wetness is used as an indicator of longer‐term climate shifts. The results suggest a relationship between positive phases of the NAO and increased North Atlantic storminess. However, subtle differences between bromine concentrations and mire surface wetness suggest that high‐intensity but perhaps less frequent periods of storminess are not necessarily associated with a wetter climate.

Solar pacing of storm surges, coastal flooding and agricultural losses in the Central Mediterranean.

Storm surges, leading to catastrophic coastal flooding, are amongst the most feared natural hazards due to the high population densities and economic importance of littoral areas. Using the Central Mediterranean Sea as a model system, we provide strong evidence for enhanced periods of storminess leading to coastal flooding during the last 4500 years. We show that long-term correlations can be drawn between storminess and solar activity, acting on cycles of around 2200-yr and 230-yr. We also find that phases of increased storms and coastal flooding have impacted upon mid- to late Holocene agricultural activity on the Adriatic coast. Based on the general trend observed during the second half of the 20th century, climate models are predicting a weakening of Mediterranean storminess. By contrast, our new data suggest that a decrease in solar activity will increase and intensify the risk of frequent flooding in coastal areas.

The UK’s wet and stormy winter of 2013/2014

The <scp>UK</scp>’s wet and stormy winter of 2013/2014

Middle- to late-Holocene storminess in Brittany (NW France): Part I – morphological impact and stratigraphical record

Our study aims to understand the recurring climatic conditions prevailing during the largest storms reaching NW France (Brittany). These storms are responsible for the breaching of coastal barriers and major flooding of lowlands. In a first part of our work, we examine the morphological impact and stratigraphic record of storm events along Western Brittany rocky coasts, with a special focus on the southern coast of the Bay of Audierne, the most exposed coast of the region. In a second paper (‘Middle- to Late-Holocene Storminess in Brittany (NW France): Part II’), we shall focus on the chronology of storm events and their climate forcing conditions. Drilling transects and stratigraphic analyses were first undertaken to constrain chronology, strength and wind direction during the main Holocene storm events. New dates, observations and a relative sea-level (RSL) curve were then used to inform discussion of the necessary climatic and morphologic conditions leading to destructive storm events. Most recorded events appear to be linked with cooling episodes of the Holocene and a RSL close to present. Some storms are clearly responsible for breaching and dune building or remobilisation. We demonstrate that storm frequency and intensity appear to rise in a stepwise manner during the late Holocene. Maximum efficiency is reached during the ‘Little Ice Age’ with clustered events probably lasting several days, but major storms also occurred immediately prior to the ‘Medieval Warm Period’. We suggest that recent coastal dune building from c.ad 1100 until now, despite a sea level close to present and continuously rising, may be a direct consequence of the restoration of beaches after periods of recurrent storminess. This building activity often occurred during dry negative North Atlantic Oscillation (NAO) events, in connection with the available sedimentary supply.

Applying luminescence methods to geoarchaeology: a case study from Stronsay, Orkney

ABSTRACTLuminescence methods were used to date a palaeoenvironmental coastal exposure on Stronsay, Orkney. The section consists of glacial sediments that are overlain by intercalated peats and windblown sands, implying varying past environmental conditions. Rapid luminescence characterisation was undertaken using screening methods in combination with quantitative dating of selected samples, providing information on depositional processes and chronology. A temporal discontinuity between the glacial sediments and later peats encompasses the period associated with an important Mesolithic site located inland, and implies erosional episodes. The onset of blanket bog formation on Stronsay dates to 3760±330 yrs BP, consistent with observations elsewhere in Orkney and northern Scotland. Periods of enhanced aeolian activity on Stronsay occurred in the late Bronze Age (2700±265 yrs BP) and at the beginning of the Little Ice Age (650±75 yrs BP). Recent periods of sand deposition in the 19th and 20th centuries (AD 1865±20 and 1960±5) correspond to periods of known historic storminess. These results add to an expanding catalogue of data on sand movements throughout the Holocene in Orkney, and set a framework to interpret the evolution of nearby archaeological and natural landscapes from prehistoric to modern times.

Decadal Behavior of Tidal Inlet-Associated Beach Systems, Northwest Ireland, in Relation to Climate Forcing

Abstract Shoreline and ebb channel evolution between 1834 and 2008 was recorded at three embayed beaches in northwest Ireland with historically stable relative sea level. The beaches are geologically constrained within bedrock valleys and have minimal contemporary sediment input. Their behavior is strongly influenced by tidal-inlet dynamics of adjacent estuaries; major observed changes in shoreline position are linked to fluctuations in inlet ebb-channel orientation. Comparison of the available historical record of geomorphological change with instrumental and proxy climate records suggests that inlet changes may be driven by fluctuations in average storminess: periods of high storminess perturb the inlet system, causing major changes in ebb-channel configuration, after which sediment redistribution returns the system to its former state over a prolonged period (years to decades).

Paleoclimates and the emergence of fortifications in the tropical Pacific islands

Paleoclimatic data from the tropical Pacific islands are compared to archaeological evidence for fortification construction in the Holocene. The results suggest that in some regions, people constructed more fortifications during periods that match the chronology for the Little Ice Age (AD 1450–1850) in the Northern Hemisphere. Periods of storminess and drought associated with the El Niño Southern Oscillation have less temporal correlation with the emergence of fortifications in the Pacific, but significant spatial correlation with the most severe conditions associated with this cycle. These temporal and spatial correlations require additional study to investigate possible causal relationships.

Holocene paleostorms identified by particle size signatures in lake sediments from the northeastern United States

The frequency and timing of Holocene paleofloods in the hilly terrain of New Hampshire and Maine are identified using 14C and high-resolution (cm-by-cm) particle size analysis of sediment cores taken from six post-glacial lakes (~0.1–1.4 km2). A total of nine sediment cores (4.5–6 m long) were taken near the base of stream delta foreslopes. End-member modeling of the particle-size frequency distributions from each core produces 3–5 representative end member distributions, or end members (EMs). Concurrent increases in mean and median particle size, and in the relative abundance of the coarsest EM(s), indicate increased transport capacity of inflowing tributaries, resulting from rainstorms. In all 9 cores, particle size data show clear signs of episodic, high-energy sediment transport events where proxy measurements such as loss-on-ignition and magnetic susceptibility do not, demonstrating the sensitivity of particle size analysis in paleostorm investigations made using lake sediment cores. Floods caused by storms in this region peaked around 1.4, 2.1, 3.0, 3.9, 6.8, 8.2, and 11.5 ka cal BP, and presently appear to be increasing in frequency. Periods of storminess in New Hampshire and Maine correlate well with other records of precipitation and climate in the northeastern United States during the Holocene, further supporting modern records which show tropical air masses as a primary driver of extreme precipitation events in New England (Ludlum 1996; Konrad 2001; Sisson and Gyakum 2004).

Evidence for millennial-scale climatic events in the sedimentary infilling of a macrotidal estuarine system, the Seine estuary (NW France)

High-resolution sedimentological and rock magnetic analyses from sediment cores collected in the Seine estuary record changes in coastal sedimentary dynamics linked to climatic variations during the late Holocene. Using AMS 14C and paleomagnetic data we present a first attempt in developing a reliable age model on macrotidal estuarine archives, with a decadal resolution. Correlations between sedimentary successions from the outer Seine estuary document the main sedimentary infilling phases of the system during the last 3000 years. Between 3000 and 1150 cal. BP sedimentary patterns reveal that sequence deposition and preservation are predominantly controlled by marine and tidal hydrodynamics while severe storm events are recorded at ca. 2700 and 1250 cal. BP in the outermost estuary. Conversely, the Medieval Warm Period (MWP; 900–1200 AD) is characterized by a drastic waning of the influence of marine hydrodynamics on sediment preservation. Pronounced episodes of Seine river floods indicate a much stronger impact of continental inputs on sedimentary patterns during this period. The onset of the Little Ice Age marks a diminishing influence of continental inputs while tidal and open marine hydrodynamics again exerted a primary control on the sedimentary evolution of the system during 1200–2003 AD. Coastal sedimentary dynamics as preserved within sedimentary successions appear to have been largely influenced by changes in storminess during the last 3000 years. We have matched the preservation of MWP Seine river floods, as revealed by sedimentological and rock magnetic proxy data, to a prolonged interval of weakened storminess in Normandy permitting the preservation of estuarine flood deposits within a context of reduced coastal erosion in northern Europe. The preservation of sedimentary successions in the Seine estuary is therefore maximal when climate conditions resembled those of the preferred low phase of the NAO on multidecadal timescales such as during 800–1200 AD (MWP). In contrast, increased removal and transport of estuarine sediments occur when winter storm activity greatly intensified over northwestern France. We report four prominent centennial-scale periods of stronger storminess, occurring with a pacing of ∼1500 years, which are likely to be related to the last four Bond's Holocene cold events. Our results documenting a close link between coastal sedimentary dynamics, millennial-scale variations in Holocene climate and North Atlantic atmospheric circulation are fairly consistent with other records from Scandinavia, central Greenland and southern Europe.

Historical evidence of a cold, dry summer during 1849 in the northeastern Great Basin and adjacent Rocky Mountains

This study reconstructs weather conditions of the northeastern Great Basin and adjacent Rocky Mountains in the western United States during the summer of 1849. Weather information were extracted from 84 diaries written by westward travelers and Mormon settlers. Periods of storminess were analyzed temporally and spatially for June 1 to September 31 on a daily basis from temperature and precipitation descriptions. Monthly frequencies of daily ice and frost, and precipitation descriptions were summed for July and August, and compared with modern meteorological data. Results of this study were compared with military metorological data and proxy evidence. Results indicate that the weather was colder and drier than today, suggesting that the Great American Desert Myth faded due to abnormally cold conditions experienced by westward travelers.

Major periods of erosion and alluvial sedimentation in New Zealand during the Late Holocene

Abstract During the last 1,800 years there have been eight major periods of erosion and alluvial sedimentation in New Zealand. These and their probable times of occurrence are: Taupo (1,764 years BP), Post-Taupo (1,600–1,500 years BP), Pre-Kaharoa (1,300–900 years BP), Waihirere (680–600 years BP), Matawhero (450–330 years BP), Wakarara (180–150 years BP), Tamaki (1870–1900 AD) and Waipawa (1950 to present). The Taupo period, which is identified only in North Island, possibly resulted from heavy rainfalls induced by the Taupo Pumice eruption. The other seven periods, which probably occurred universally in both main islands of New Zealand, were almost certainly caused by increased northerly airflow and atmospheric warming over New Zealand, and the associated increased magnitude of major rainstorms and floods, producing increased rates of erosion and channel sediment transport. Such changes were due primarily to a temporary strengthening of the meridional upper atmospheric circulation in the Southwest Pacific region. The total amount of sediment deposited in successive erosion periods has generally decreased, even though, since c. 1,000 years BP, human populations and their impacts on the environment have generally increased. In some other regions of the earth, periods of greater alluvial sedimentation or storminess have coincided with one or more of the last seven periods recognised in New Zealand since 1,600 years BP. Within New Zealand, periods of alluvial sedimentation have coincided closely with episodes of coastal sand deposition. If sedimentation periods are dominated by meridional atmospheric circulation, soil-forming intervals are dominated by zonal circulation (westerly) with cooler air temperatures and less storminess. Accordingly, this chronological pattern represents long-term irregular fluctuations of warm, stormy periods separated by cooler, less stormy intervals. This periodic climatic regime fluctuation may constitute a widely applicable unifying hypothesis to explain many patterns of environmental change with time which are not understood. In particular, it can illuminate important aspects of indigenous vegetation and cultural history.