scholarly journals Atmospheric conditions of extreme precipitation events in western Turkey for the period 2006–2015

2019 ◽  
Vol 19 (1) ◽  
pp. 107-119 ◽  
Author(s):  
Bulent Oktay Akkoyunlu ◽  
Hakki Baltaci ◽  
Mete Tayanc
Keyword(s):  
Extreme Precipitation ◽  
Eastern Mediterranean ◽  
Balkan Peninsula ◽  
Marmara Region ◽  
Atmospheric Conditions ◽  
Pressure Center ◽  
Western Turkey ◽  
Extreme Precipitation Events ◽  
Synoptic Conditions ◽  
Precipitation Events

Abstract. This paper investigates the precipitation types and background physical mechanisms of extreme precipitation events (EPEs) over western Turkey during the period 2006–2015. The EPEs are described as the precipitation values above the 90th percentile obtained from the hourly precipitation dataset, which has high spatial resolution. Precipitation types associated with EPEs are identified by using radar outputs and the Lamb weather type (LWT) approach. It is found that EPEs occurred more frequently in the Marmara and Aegean regions during autumn and winter months. In Marmara, mainly 21 %, 17 %, and 15 % of total autumn EPEs show convective, cyclonic, and sea-effect precipitation characteristics, respectively. While convective EPEs are seen more commonly in the southern portions, cyclonic and sea-effect-originated EPEs mainly affect the southwest and northeastern parts of Marmara. Among these three precipitation types, convective mechanisms generally produce more intense daily precipitation (66.1 mm on average) in the Marmara Region under the proper synoptic conditions (high-pressure center over the Balkan Peninsula and low-pressure center over the eastern Mediterranean). Based on the hourly observations, convective types of extreme precipitation (EP) show two peak values during afternoon and evening times of the day and are linked to diurnal heating. In terms of the Aegean Region, cyclone-originated EP, which includes 65 % of the total winter EPEs, is more common in the whole territory and reaches its peak value during the early hours of the day.

scholarly journals The Climatology, precipitation types and atmospheric conditions of extreme precipitation events in western Turkey

2018 ◽  
Author(s):  
Bulent Oktay Akkoyunlu ◽  
Hakki Baltaci ◽  
Mete Tayanc
Keyword(s):  
Eastern Mediterranean ◽  
Balkan Peninsula ◽  
Marmara Region ◽  
Atmospheric Conditions ◽  
Pressure Center ◽  
Western Turkey ◽  
Average Value ◽  
Circulation Types ◽  
Extreme Precipitation Events ◽  
Rugged Topography

Abstract. This paper investigates the climatology, precipitation types and background physical mechanisms of extreme precipitations events (EPEs) over western Turkey during the period 2006–2015. The EPEs are described as the precipitation values above the 90th percentile obtained from the hourly precipitation dataset having high spatial resolution. Precipitation types associated with EPEs are identified by using radar outputs and Lamb Weather Type (LWT) approach. It is found that EPEs occurred more frequently in the Marmara and Aegean regions during autumn and winter months. In Marmara, mainly 21 %, 17 % and 15 % of total autumn EPEs are observed as convective (E circulation types (CTs)), cyclonic (C), and sea-effect (NE) extreme precipitations (EPs), in order. While convective EPEs are generally more active in the southern portions having rugged topography, cyclonic and sea effect EPs are more effective in the southwest and northeastern parts of Marmara. Among these three precipitation types, convective CTs produce more intense daily precipitation in the Marmara region with daily average value of 66.1 mm. Based on the hourly observations, convective types of EP which developed by the interaction between high pressure center over Balkan Peninsula and low pressure center over eastern Mediterranean, show two peak values during afternoon and evening times of the day and are linked to diurnal heating. In terms of Aegean region, cyclonic originated EPs, which include 65 % of the total winter EPEs, are more common in the whole territory and reach to its peak value during the first hours of the day.

scholarly journals Review Article: Atmospheric conditions inducing extreme precipitation over the Eastern and Western Mediterranean

2015 ◽  
Vol 3 (6) ◽  
pp. 3687-3732 ◽  
Author(s):  
U. Dayan ◽  
K. M. Nissen ◽  
U. Ulbrich
Keyword(s):  
Extreme Precipitation ◽  
Mediterranean Basin ◽  
Heavy Rainfall ◽  
Eastern Mediterranean ◽  
Western Mediterranean ◽  
Atmospheric Conditions ◽  
Synoptic Scale ◽  
Extreme Precipitation Events ◽  
The Mediterranean ◽  
The Mediterranean Basin

Abstract. This review discusses published studies of heavy rainfall events over the Mediterranean Basin, combining them in a more general picture of the dynamic and thermodynamic factors and processes producing heavy rain storms. It distinguishes the Western and Eastern Mediterranean in order to point at specific regional peculiarities. The crucial moisture for developing intensive convection over these regions can be originated not only from the adjacent Mediterranean Sea but also from distant upwind sources. Transport from remote sources is usually in the mid-tropospheric layers and associated with specific features and patterns of the larger scale circulations. The synoptic systems (tropical and extra-tropical) accounting for most of the major extreme precipitation events and the coupling of circulation and extreme rainfall patterns are presented. Heavy rainfall over the Mediterranean Basin is caused at times in concert by several atmospheric processes working at different atmospheric scales, such as local convection, upper-level synoptic-scale troughs, and meso-scale convective systems. Under tropical air mass intrusions, convection generated by static instability seems to play a more important role than synoptic-scale vertical motions. Locally, the occurrence of torrential rains and their intensity is dependent on factors such as temperature profiles and implied instability, atmospheric moisture, and lower-level convergence.

scholarly journals Review Article: Atmospheric conditions inducing extreme precipitation over the eastern and western Mediterranean

2015 ◽  
Vol 15 (11) ◽  
pp. 2525-2544 ◽  
Author(s):  
U. Dayan ◽  
K. Nissen ◽  
U. Ulbrich
Keyword(s):  
Extreme Precipitation ◽  
Mediterranean Basin ◽  
Heavy Rainfall ◽  
Eastern Mediterranean ◽  
Western Mediterranean ◽  
Atmospheric Conditions ◽  
Synoptic Scale ◽  
Extreme Precipitation Events ◽  
The Mediterranean ◽  
The Mediterranean Basin

Abstract. This review discusses published studies of heavy rainfall events over the Mediterranean Basin, combining them in a more general picture of the dynamic and thermodynamic factors and processes that produce heavy rain storms. It distinguishes the western and eastern Mediterranean in order to point out specific regional peculiarities. The crucial moisture for developing intensive convection over these regions can be originated not only from the adjacent Mediterranean Sea but also from distant upwind sources. Transport from remote sources is usually in the mid-tropospheric layers and associated with specific features and patterns of the larger-scale circulations. The synoptic systems (tropical and extratropical) that account for most of the major extreme precipitation events and the coupling of circulation and extreme rainfall patterns are presented. Heavy rainfall over the Mediterranean Basin is caused at times in concert by several atmospheric processes working at different atmospheric scales, such as local convection, upper synoptic-scale-level troughs, and mesoscale convective systems. Under tropical air-mass intrusions, convection generated by static instability seems to play a more important role than synoptic-scale vertical motions. Locally, the occurrence of torrential rains and their intensity is dependent on factors such as temperature profiles and implied instability, atmospheric moisture, and lower-level convergence.

scholarly journals Record summer rains in 2019 led to massive loss of surface and cave ice in SE Europe

2021 ◽  
Vol 15 (5) ◽  
pp. 2383-2399
Author(s):  
Aurel Perşoiu ◽  
Nenad Buzjak ◽  
Alexandru Onaca ◽  
Christos Pennos ◽  
Yorgos Sotiriadis ◽  
...  
Keyword(s):  
Extreme Precipitation ◽  
Climate Models ◽  
Balkan Peninsula ◽  
Rapid Reduction ◽  
Extreme Precipitation Events ◽  
Alpine Glaciers ◽  
Instrumental Observations ◽  
Polar Ice Sheets ◽  
Near Future ◽  
Precipitation Events

Abstract. Glaciers worldwide are shrinking at an accelerated rate as the climate changes in response to anthropogenic influence. While increasing air temperature is the main factor behind glacier mass and volume loss, variable patterns of precipitation distribution also play a role, though these are not as well understood. Furthermore, while the response of surface glaciers (from large polar ice sheets to small alpine glaciers) to climatic changes is well documented and continuously monitored, little to nothing is known about how cave glaciers (perennial ice accumulations in rock-hosted caves) react to atmospheric warming. In this context, we present here the response of cave and surface glaciers in SE Europe to the extreme precipitation events occurring between May and July 2019 in SE Europe. Surface glaciers in the northern Balkan Peninsula lost between 17 % and 19 % of their total area, while cave glaciers in Croatia, Greece, Romania and Slovenia lost ice at levels higher than any recorded by instrumental observations during the past decades. The melting was likely the result of large amounts of warm water delivered directly to the surface of the glaciers, leading to rapid reduction in the area of surface glaciers and the thickness of cave glaciers. As climate models predict that such extreme precipitation events are set to increase in frequency and intensity, the presence of cave glaciers in SE Europe and the paleoclimatic information they host may be lost in the near future. Moreover, the same projected continuous warming and increase in precipitation extremes could pose an additional threat to the alpine glaciers in southern Europe, resulting in faster-than-predicted melting.

scholarly journals More frequent flash flood events and extreme precipitation favouring atmospheric conditions in temperate regions of Europe

2021 ◽  
Author(s):  
Judith Meyer ◽  
Malte Neuper ◽  
Luca Mathias ◽  
Erwin Zehe ◽  
Laurent Pfister
Keyword(s):  
Extreme Precipitation ◽  
Western Europe ◽  
Flash Flood ◽  
Flash Floods ◽  
Water Levels ◽  
Specific Humidity ◽  
Atmospheric Conditions ◽  
Flood Events ◽  
Extreme Precipitation Events ◽  
Precipitation Events

Abstract. In recent years, flash floods repeatedly occurred in temperate regions of central western Europe. Unlike in Mediterranean catchments, this flooding behaviour is unusual. In the past, and especially in the 1990s, floods were characterized by predictable, slowly rising water levels during winter and driven by westerly atmospheric fluxes (Pfister et al., 2004). The intention of this study is to link the recent occurrence of flash floods in central western Europe to extreme precipitation and specific atmospheric conditions to identify the cause for this apparent shift. Therefore, we hypothesise that an increase in extreme precipitation events has subsequently led to an increase in the occurrence of flash flood events in central western Europe and all that being caused by a change in the occurrence of flash flood favouring atmospheric conditions. To test this hypothesis, we compiled data on flash floods in central western Europe and selected precipitation events above 40 mm h−1 from radar data (RADOLAN, DWD). Moreover, we identified proxy parameters representative for flash flood favouring atmospheric conditions from the ERA5 reanalysis dataset. High specific humidity in the lower troposphere (q ≥ 0.004 kg kg−1), sufficient latent instability (CAPE ≥ 100 J kg−1) and weak deep-layer wind shear (DLS ≤ 10 m s−1) proved to be characteristic for long-lasting intense rainfall that can potentially trigger flash floods. These atmospheric parameters, as well as the flash flood and precipitation events were then analysed using linear models. Thereby we found significant increases in atmospheric moisture contents and increases in atmospheric instability. Parameters representing the motion and organisation of convective systems occurred slightly more often or remained unchanged in the time period from 1981–2020. Moreover, a trend in the occurrence of flash floods was confirmed. The number of precipitation events, their maximum 5-minute intensities as well as their hourly sums were however characterized by large inter-annual variations and no trends could be identified between 2002–2020. This study therefore shows that the link from atmospheric conditions via precipitation to flash floods cannot be traced down in an isolated way. The complexity of interactions is likely higher and future analyses should include other potentially relevant factors such as intra-annual precipitation patterns or catchment specific parameters.

Are extreme precipitation events becoming stronger and warmer in the Andes?

2021 ◽  
Author(s):  
Miguel Lagos-Zúñiga ◽  
Pablo A. Mendoza ◽  
Roberto Rondanelli
Keyword(s):  
Air Temperature ◽  
Extreme Precipitation ◽  
High Elevation ◽  
Atmospheric Conditions ◽  
Freezing Level ◽  
The Andes ◽  
Extreme Precipitation Events ◽  
Hydrological Impacts ◽  
Orographic Enhancement ◽  
Precipitation Events

<p>The Andes Cordillera serves as a physical barrier that modulates the atmospheric fluid dynamics, affecting the occurrence and intensity of precipitation events through orographic enhancement and the blocking and deviation of humidity transported by jets. The quantification of extreme precipitation events (EPEs) and their associated temperature is critical to address hydrological impacts and water availability for the Andes that also feeds the majority of the river and population in the region. </p><p>As the atmosphere is getting warmer, the increasing amount of water vapor available in the troposphere is expected to enhance warm precipitation events during the 21st century. In this study, we examine observational trends in extreme precipitation events by season and analyze possible connections with air temperature. To this end, we perform Sen's Tests and compute Mann-Kendall values Maximum Precipitation daily precipitation and its associated temperature at ~80 meteorological stations. Then, we cluster the results geographically finding positive trends in high elevation areas for extreme precipitation events (EPEs) and their temperature, especially in mid-latitudes. In low stations (<800 m a.s.l.), we obtain a decrease in the magnitude of EPEs but and a decrease in air temperature (up to -0.4 [°C/decade]). In general, the temperature increase in EPEs for high elevation stations < 0.12 °C/year and could rise the freezing level up to 1000 [m], during the fall season.  The presented here suggest positive feedback between warmer atmospheric conditions and the open further pathways regarding hydrological impacts such as debris flow, floods, and less snow availability in the Andes regions.</p>

scholarly journals Local Enhancement of Extreme Precipitation during Atmospheric Rivers as Simulated in a Regional Climate Model

2018 ◽  
Vol 19 (9) ◽  
pp. 1429-1446 ◽  
Author(s):  
Raquel Lorente-Plazas ◽  
Todd P. Mitchell ◽  
Guillaume Mauger ◽  
Eric P. Salathé
Keyword(s):  
Extreme Precipitation ◽  
Large Scale ◽  
Regional Climate ◽  
Puget Sound ◽  
Static Stability ◽  
The Other ◽  
Extreme Precipitation Events ◽  
Olympic Mountains ◽  
Synoptic Conditions ◽  
Precipitation Events

Abstract This paper examines the synoptic conditions that yield extreme precipitation in two regions with different orographic features, the Olympic Mountains and Puget Sound. To capture orographic extreme precipitation, a dynamical downscaling is performed, driven by the NCEP–NCAR reanalysis and evaluated for cool-season months from 1970 to 2010. Clustering techniques are applied to the regional climate simulation, which reveals the Olympic Mountains and Puget Sound as regions with distinct temporal variability in precipitation. Results show that approximately one-third of the extreme precipitation events in each region occur without a similarly extreme event in the other, in spite of the fact that the two areas are very closely located and one is downstream of the other. Composites of synoptic conditions for extreme precipitation events show differences in integrated vapor transport (IVT) due to its dynamical component (winds at 850 hPa) and its thermodynamical component [integrated water vapor (IWV)]. For Puget Sound events, IVT is lower compared to Olympic Mountain events because of lower wind speeds. Olympic Mountain events have lower IVT compared to events with extreme precipitation in both regions, but in this case, the difference is due to lower IWV and more southerly winds. These differences in the large-scale conditions promote differences in the mesoscale mechanisms that enhance precipitation in each location. For Puget Sound events, static stability is higher, and there is a weak rain shadow. For Olympic Mountain events, static stability is lower, and a strong rain shadow is present. During extreme events in both regions, orographic modulation is minimized and large-scale effects dominate.

scholarly journals Unprecedented loss of surface and cave ice in SE Europe related to record summer rains in 2019

2020 ◽  
Author(s):  
Aurel Persoiu ◽  
Nenad Buzjak ◽  
Alexandru Onaca ◽  
Christos Pennos ◽  
Yorgos Sotiriadis ◽  
...  
Keyword(s):  
Extreme Precipitation ◽  
Climate Models ◽  
Atmospheric Circulation Patterns ◽  
Extreme Precipitation Events ◽  
Alpine Glaciers ◽  
Circulation Patterns ◽  
Synoptic Conditions ◽  
Catastrophic Loss ◽  
Polar Ice Sheets ◽  
Precipitation Events

Abstract. Glaciers worldwide are shrinking at an accelerated rate as the climate changes in response to anthropogenic influence. While increasing air temperature is the main factor behind glacier mass loss, changing atmospheric circulation patterns and the distribution of precipitation also plays a role, though these are not as well understood. Furthermore, while the mass balance of surface glaciers (from large polar ice sheets to small alpine glaciers) is relatively well documented and continuously monitored, little to nothing is known about the response of cave glaciers (perennial ice accumulations in rock-hosted caves) to atmospheric warming. In this context, we present the response of cave and surface glaciers in SE Europe to synoptic conditions in summer 2019. Our investigation shows that extreme precipitation events occurring between May and July 2019 led to catastrophic loss of ice at levels unprecedented during the last century. As climate models predict that such extreme precipitation events are set to increase in frequency and intensity, the presence of cave glaciers in SE Europe and the paleoclimatic information they host may be lost in the near future. Moreover, the same projected continuous warming and increase in precipitation extremes could pose an additional threat to the Alpine glaciers in southern Europe, resulting in faster than predicted melting.

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