ATMOSPHERIC DROUGHT IN THE POLISH TATRAS AND THEIRFORELAND IN THE YEARS 1951–2017

Aim of the study. The aim of this study is to assess the variability of the lowest monthly totals of precipitation, and to evaluate the impact of atmospheric circulation on the occurrence of months with a deficit of precipitation. Material and methods. Material: The monthly totals of atmospheric precipitation for the years 1951–2017 from 19 meteorological stations located in the Polish Tatra Mountains and in their foreland. and the calendar of atmospheric circulation types for southern Poland, which was developed by Niedźwiedź (1981; 2018). Methods: Standardized Precipitation Index (SPI), the Mann-Kendall test Results and conclusions. No statistically significant trend at a significance level of 0.05 was noted in the course of the lowest monthly precipitation totals at any of the meteorological stations. In the 67-year period, all the measuring stations saw a total of 499 (3.3%) dry months with varying drought severity. The largest number of extremely dry months occurred in August and April, respectively. In the case of months when the lowest totals of precipitation occurred in the same month at all or almost all of the meteorological stations, three types of anticyclonic circulation dominated, i.e. eastern, south-eastern, southern, and the anticyclonic wedge.

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Spatio-temporal changes of drought in Romania (1961-2015), according to atmospheric circulation types and teleconnection indices

10.5194/egusphere-egu2020-5911 ◽

2020 ◽

Author(s):

Radu-Vlad Dobri ◽

Liviu Apostol ◽

Lucian Sfîcă ◽

Simona Țîmpu ◽

Ion-Andrei Niță

Keyword(s):

Atmospheric Circulation ◽

Standardized Precipitation Index ◽

Atmospheric Precipitation ◽

Climatic Conditions ◽

Extreme Drought ◽

Drought Severity ◽

Severe Drought ◽

Circulation Types ◽

Teleconnection Indices ◽

Moderate Drought

Drought can be determined by climatic conditions (atmospheric precipitation, water supply from soil accessible to the plant, moisture and air temperature and wind speed) but is also induced by environmental aspects some of them related to anthropogenic influences.In order to monitor the drought and its impact for Romania, four indices were analyzed in the present study (SPI (Standardized Precipitation Index), PNI (Percent of Normal Index), DI (Deciles index), and ZSI (Z-score Index)), through Meteorological Drought Monitoring software, using the total daily amount of precipitation for 27 weather stations in Romania, of which 22 stations for the period 1961-2015, 4 stations for the period 1961-2000 and one station for the period 1964-2015.Preliminary analyzes resulting from the use of these indices were correlated with 18 GWT (Gro&#223;wettertypen) atmospheric circulation types of daily mean sea level pressure (SLP). This was done using COST733 class software to evaluate the influence of large-scale mechanisms of atmospheric circulation. Also, four teleconnection indices were used, more exactly AO (Arctic Oscillation), NAO (North Atlantic Oscillation), PNA (Pacific-North American Pattern) and AAO (Antarctic Oscillation) that are recognized for their effect on climatic conditions at European scale, &#160; provided by National Oceanic and Atmospheric Administration (NOAA) &#8211; Climate Prediction Center.Therefore, according to the types of circulation, the amount of precipitation produced in certain areas and implicitly the degree of drought severity is influenced. The types of anticyclonal circulation 13, 16 or 18, for example, which occur on average in 46 (12.7%), 14 (3.9%) , respectively 20 (5.4%) days a year, cause less precipitation as known, compared to the types of cyclonal circulation 1, 2 or 17 for example with an average of 12 (3.2%), 12 (3.2%), respectively 19 (4.3%) days a year.In terms of drought analysis indices, according to SPI, the entire analysis interval for Iasi, located in the northeast region of Romania, was 6 years of "moderately dry", 5 years of "severely dry", and one year of "extremely dry", unlike Cluj, located in the central western region, with two years of "moderately dry", 3 years of "severely dry" and two years of "extremely dry". In Bucharest, located in the southern region of Romania there were 4 "moderately dry" years and 5 "severely dry" years. In Iasi, according to the ZSI index with the same classifications as the SPI index, there were 3 "moderately drought" years, 7 "severely drought" years and 7 "extreme drought" years, while in Cluj there were 9, 3 and respectively 6 years and in Bucharest 7, 5 and respectively 6 years with the above classification.According to the PNI index, there were 5 "moderate drought" years in Iasi and Cluj and 6 "moderate drought" years in Bucharest. Also, there were 9 "weak drought" years in Iasi, 3 in Cluj and 5 in Bucharest.And last but not least, according to the DI index, at all 3 stations there were 5 "extreme drought" years, 6 "severe drought" years and 5 "moderate drought" years.

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Drought and climate change assessment using Standardized Precipitation Index (SPI) for Sarawak River Basin

Journal of Water and Climate Change ◽

10.2166/wcc.2019.036 ◽

2019 ◽

Vol 11 (4) ◽

pp. 956-965 ◽

Cited By ~ 3

Author(s):

C. H. J. Bong ◽

J. Richard

Keyword(s):

Climate Change ◽

River Basin ◽

Drought Index ◽

Standardized Precipitation Index ◽

Recent Decade ◽

Kendall Test ◽

Precipitation Index ◽

Irrigated Agriculture ◽

Drought Event ◽

Monthly Precipitation

Abstract Severe droughts in the year 1998 and 2014 in Sarawak due to the strong El Niño has impacted the water supply and irrigated agriculture. In this study, the Standardized Precipitation Index (SPI) was used for drought identification and monitoring in Sarawak River Basin. Using monthly precipitation data between the year 1975 and 2016 for 15 rainfall stations in the basin, the drought index values were obtained for the time scale of three, six and nine months. Rainfall trend for the years in study was also assessed using the Mann–Kendall test and Sen's slope estimator and compared with the drought index. Findings showed that generally there was a decreasing trend for the SPI values for the three time scales, indicating a higher tendency of increased drought event throughout the basin. Furthermore, it was observed that there was an increase in the numbers of dry months in the recent decade for most of the rainfall stations as compared to the previous 30 to 40 years, which could be due to climate change. Findings from this study are valuable for the planning and formulating of drought strategies to reduce and mitigate the adverse effects of drought.

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Spatial and temporal variability of precipitation and drought in Portugal

Natural Hazards and Earth System Science ◽

10.5194/nhess-12-1493-2012 ◽

2012 ◽

Vol 12 (5) ◽

pp. 1493-1501 ◽

Cited By ~ 65

Author(s):

D. S. Martins ◽

T. Raziei ◽

A. A. Paulo ◽

L. S. Pereira

Keyword(s):

Principal Component Analysis ◽

Standardized Precipitation Index ◽

Principal Component ◽

Component Analysis ◽

Maximum Temperature ◽

Drought Indices ◽

Drought Severity ◽

Spatial And Temporal Variability ◽

Monthly Precipitation ◽

Precipitation Regimes

Abstract. The spatial variability of precipitation and drought are investigated for Portugal using monthly precipitation from 74 stations and minimum and maximum temperature from 27 stations, covering the common period of 1941–2006. Seasonal precipitation and the corresponding percentages in the year, as well as the precipitation concentration index (PCI), was computed for all 74 stations and then used as an input matrix for an R-mode principal component analysis to identify the precipitation patterns. The standardized precipitation index at 3 and 12 month time scales were computed for all stations, whereas the Palmer Drought Severity Index (PDSI) and the modified PDSI for Mediterranean conditions (MedPDSI) were computed for the stations with temperature data. The spatial patterns of drought over Portugal were identified by applying the S-mode principal component analysis coupled with varimax rotation to the drought indices matrices. The result revealed two distinct sub-regions in the country relative to both precipitation regimes and drought variability. The analysis of time variability of the PC scores of all drought indices allowed verifying that there is no linear trend indicating drought aggravation or decrease. In addition, the analysis shows that results for SPI-3, SPI-12, PDSI and MedPDSI are coherent among them.

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Influence of Altitude on the Spatiotemporal Variations of Meteorological Droughts in Mountain Regions of the Free State Province, South Africa (1960–2013)

Advances in Meteorology ◽

10.1155/2018/5206151 ◽

2018 ◽

Vol 2018 ◽

pp. 1-11 ◽

Cited By ~ 3

Author(s):

M. Mbiriri ◽

G. Mukwada ◽

D. Manatsa

Keyword(s):

South Africa ◽

Standardized Precipitation Index ◽

Late Summer ◽

Early Summer ◽

Free State ◽

Windward Side ◽

Drought Severity ◽

Significant Shift ◽

Free State Province ◽

The Impact

The Standardized Precipitation Index (SPI) was computed for October to December (OND) and January to March (JFM) summer subseasons for Free State Province, South Africa, to assess the influence of altitude on drought severity and frequency. The observed spatiotemporal heterogeneity in the SPI variability revealed that factors governing drought interannual variability varied markedly within the region for the two subseasons. Strong correlations between r=0.76 and 0.93 across the clusters in both subseasons were observed. Significant shift in average SPI, towards the high during the OND subseason, was detected for the far western low-lying and central regions of the province around the 1990s. An ANOVA test revealed a significant relationship between drought severity and altitude during the OND subseason only. The impact of altitude is partly manifested in the strong relationship between meridional winds and SPI extremes. When the winds are largely northerly, Free State lies predominantly in the windward side of the Drakensberg Mountains but lies in the rain shadow when the winds are mostly southerly. The relationship between ENSO and SPI indicates stronger correlations for the early summer subseason than for the late summer subseason while overall presenting a diminishing intensity with height over the province.

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Analysis of Changes in Precipitation and Drought in Aksu River Basin, Northwest China

Advances in Meteorology ◽

10.1155/2015/215840 ◽

2015 ◽

Vol 2015 ◽

pp. 1-15 ◽

Cited By ~ 15

Author(s):

Yuhu Zhang ◽

Wanyuan Cai ◽

Qiuhua Chen ◽

Yunjun Yao ◽

Kaili Liu

Keyword(s):

Meteorological Data ◽

Standardized Precipitation Index ◽

Northwest China ◽

Precipitation Series ◽

Significance Level ◽

Spatiotemporal Trends ◽

Increasing Trend ◽

Almost All ◽

Increasing Trends ◽

Aksu River Basin

The analysis of the spatiotemporal trends of precipitation and drought is relevant for the future development and sustainable management of water resources in a given region. In this study, precipitation and Standardized Precipitation Index (SPI) trends were analyzed through applying linear regression, Mann–Kendall, and Spearman’s Rho tests at the 5% significance level. For this goal, meteorological data from 9 meteorological stations in and around Aksu Basin during the period 1960–2010 was used, and two main annual drought periods were detected (1978-1979 and 1983–1986), while the extremely dry years were recorded in 1975 and 1985 at almost all of the stations. The monthly analysis of precipitation series indicates that all stations had increasing trend in July, October, and December, while both increasing and decreasing trends were found in other months. For the seasonal scale, precipitation series had increasing trends in summer and winter. 33% of the stations had the decreasing trend on precipitation in the spring series, and it was 11% in the autumn. At the same time, the SPI-12 values of all stations had the increasing trend. The significant trends were detected at Aheqi, Baicheng, Keping, and Kuche stations.

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Influence of springtime atmospheric circulation types on the distribution of air pollutants in the Arctic

10.5194/acp-2021-458 ◽

2021 ◽

Author(s):

Manu Anna Thomas ◽

Abhay Devasthale ◽

Tiina Nygård

Keyword(s):

Atmospheric Circulation ◽

The Arctic ◽

Transport Models ◽

Self Organizing Maps ◽

Atmospheric Circulation Patterns ◽

Circulation Types ◽

Circulation Patterns ◽

European Arctic ◽

Pollutant Distribution ◽

Almost All

Abstract. The transport and distribution of short-lived climate forcers in the Arctic is influenced by the prevailing atmospheric circulation patterns. Understanding the coupling between pollutant distribution and dominant atmospheric circulation types is therefore important, not least to understand the processes governing the local processing of pollutants in the Arctic, but also to test the fidelity of chemistry transport models to simulate the transport from the southerly latitudes. Here, we use a combination of satellite based and reanalysis datasets spanning over 12 years (2007–2018) and investigate the concentrations of NO2, O3, CO and aerosols and their co-variability during 20 different atmospheric circulation types in the spring season (March, April and May) over the Arctic. We carried out a Self-Organizing Maps analysis of MSLP to derive these circulation types. Although almost all pollutants investigated here show statistically significant sensitivity to the circulation types, NO2 exhibits the strongest sensitivity among them. The circulation types with low-pressure systems located over the northeast Atlantic show a clear enhancement of NO2 and AOD in the European Arctic. The O3 concentrations are, however, decreased. The free tropospheric CO is increased over the Arctic during such events. The circulation types with atmospheric blocking over Greenland and northern Scandinavia show the opposite signal in which the NO2 concentrations are decreased and AODs are smaller than the climatological values. The O3 concentrations are, however, increased and the free tropospheric CO decreased during such events. The study provides the most comprehensive assessment so far of the sensitivity of springtime pollutant distribution to the atmospheric circulation types in the Arctic and also provides an observational basis for the evaluation of chemistry transport models.

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Time Series Trend Analysis of Rainfall and Temperature over Kolkata and Surrounding Region

10.20937/atm.53059 ◽

2021 ◽

Author(s):

Arijit De ◽

Srishty Shreya ◽

Neel Sarkar ◽

Animesh Maitra

Keyword(s):

Time Series ◽

Concentration Index ◽

Kendall Test ◽

Drought Severity ◽

Tropical Region ◽

Monthly Precipitation ◽

Monsoon Period ◽

Precipitation Concentration Index ◽

Precipitation Concentration

Study of long term variability of temperature and rainfall in the context of climate change is of much importance particularly in the region where rainfed agriculture is predominant. Long term trends of temperature and rainfall have been investigated over Kolkata, India, a tropical region using gridded monthly precipitation and temperature data obtained from Global Precipitation and Climate Centre (GPCC V7) with 0.5° X 0.5° resolution for the period 1901 to 2014. Precipitation concentration index, coefficient of variation, rainfall anomaly have been calculated and Palmer drought severity index data have been analyzed. Furthermore, Mann-Kendall test and sen’s slope estimator have been used to detect time series trend. Annual temperature and rainfall have been increased with a rate of 0.0082°C/ year and 0.03 mm/ year respectively. Statistically significant increasing trend has been observed for most of the months for temperature and rainfall. Winter and monsoon period shows highest and lowest inter-annual variability respectively. Rainfall with high precipitation concentration index (16-20) has been observed for the period 1951-1975 and 1976-2000. It has been observed that the number of years with dry conditions have been increased. However, the intensity of dryness is very near to zero. The information from this study will be helpful for the farmers to plan for resilient farming.

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Temporal Characteristics of Heat Waves and Cold Spells and Their Links to Atmospheric Circulation in EURO-CORDEX RCMs

Advances in Meteorology ◽

10.1155/2019/2178321 ◽

2019 ◽

Vol 2019 ◽

pp. 1-13 ◽

Cited By ~ 3

Author(s):

Eva Plavcová ◽

Jan Kyselý

Keyword(s):

Atmospheric Circulation ◽

Heat Waves ◽

Dominant Role ◽

Winter Season ◽

Zonal Flow ◽

Substantial Improvement ◽

Temperature Extremes ◽

Circulation Types ◽

The Mean ◽

Almost All

We study summer heat waves and winter cold spells and their links to atmospheric circulation in an ensemble of EURO-CORDEX RCMs in Central Europe. Results of 19 simulations were compared against observations over 1980–2005. Atmospheric circulation was represented by circulation types and supertypes derived from daily gridded mean sea level pressure. We examined observed and simulated characteristics of hot and cold days (defined using percentiles of temperature anomalies from the mean annual cycle) and heat waves and cold spells (periods of at least three hot/cold days in summer/winter). Although the ensemble of RCMs reproduces on average the frequency and the mean length of heat waves and cold spells relatively well, individual simulations suffer from biases. Most model runs have an enhanced tendency to group hot/cold days into sequences, with several simulations leading to extremely long heat waves or cold spells (the maximum length overestimated by up to 2-3 times). All simulations also produce an extreme winter season with (often considerably) higher number of cold days than in any observed winter. The RCMs reproduce in general the observed circulation significantly conducive to heat waves and cold spells. Zonal flow reduces the probability of temperature extremes in both seasons, while advection of warm/cold air from the south-easterly/north-easterly quadrant plays a dominant role in developing heat waves/cold spells. Because of these links, the simulation of temperature extremes in RCMs is strongly affected by biases in atmospheric circulation. For almost all simulations and all circulation supertypes, the persistence of supertypes is significantly overestimated (even if the frequency of a given supertype is underestimated), which may contribute to development of too-long heat waves/cold spells. We did not identify any substantial improvement in the EURO-CORDEX RCMs in comparison to previous ENSEMBLES RCMs, but the patterns of the biases are generally less conclusive as to general RCMs’ drawbacks.

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Analysis of Temporal-Spatial Variation Characteristics of Drought: A Case Study from Xinjiang, China

Water ◽

10.3390/w12030741 ◽

2020 ◽

Vol 12 (3) ◽

pp. 741 ◽

Cited By ~ 2

Author(s):

Qiang An ◽

Huaxiang He ◽

Juanjuan Gao ◽

Qianwen Nie ◽

Yingjie Cui ◽

...

Keyword(s):

Comprehensive Evaluation ◽

Standardized Precipitation Index ◽

Winter Season ◽

Animal Husbandry ◽

Scientific Basis ◽

Drought Severity ◽

Monthly Precipitation ◽

North West ◽

The North ◽

The Standardized Precipitation Index

It is of great significance to study the characteristics and change trends of drought in Xinjiang to provide a basis for implementing local strategies. Based on monthly precipitation and temperature data from 95 meteorological stations in Xinjiang, from 1960 to 2018, the Standardized Precipitation Evapotranspiration Index (SPEI) was calculated, and the characteristics and trends of drought in Xinjiang were analysed, in details. Furthermore, a comprehensive evaluation index, i.e., Regional Drought Severity (RDS), was proposed to analyse the effects of duration of the drought and the extent of the drought affected area. The results from our study suggested: (1) In consideration of global warming, droughts in Xinjiang have intensified during the past 59 years, and the frequency and range of droughts have increased significantly; (2) During the plant growing season, spring, summer, and autumn, a drying trend was observed, while, a wetting trend was identified for winter season; (3) The drought-prone months shifted from January and December to March-November in the 1970s, and April was identified as a month with the highest frequency of droughts; (4) The meteorological change occurred a period near 1997. It can be speculated that the intensified droughts can be triggered by the excessive temperature rise, through comparing the changes in SPEI and the Standardized Precipitation Index (SPI), before and after the meteorological change; (5) After the meteorological change, the frequency of droughts with different levels had significantly increased, in addition, the drought-prone areas shifted from the north-west to the south-east. The results from this research provide important support for drought management in Xinjiang, also offer scientific basis for the formulation of relevant policies on agricultural and animal husbandry production.

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Analysis of Drought Investigation Using Standard Precipitation Index (SPI) of Historical Rainfall Data (1979-2013) Under Temperate Conditions Over Anand, Gujarat (India)

International Journal of Advanced Research in Science, Communication and Technology ◽

10.48175/ijarsct-948 ◽

2021 ◽

pp. 117-124

Author(s):

G. J. Kamani ◽

N. K. Pampania ◽

S. S. Chinchorkar

Keyword(s):

Standardized Precipitation Index ◽

Extended Period ◽

Precipitation Index ◽

Extreme Drought ◽

Reference Level ◽

Drought Severity ◽

Monthly Precipitation ◽

The World ◽

Intermediate Time ◽

Drought Occurrence

Drought is a naturally occurring event caused due to deficiency in precipitation over an extended period of time. It is a slow-onset, creeping natural hazard that affects continuously all parts of the world. It occurs in all climatic zones such as high as well as low precipitation areas and causes high economic and social losses around the world. Droughts are generally measured in terms of deficiency in the rainfalls or streams flows below a predefined reference level. The magnitude of departure from the reference level during a drought spell is known as the severity of drought. Droughts are occurring in different regions of the world with increased frequency and severity. In this study, temporal pattern of droughts was analyzed in the Anand Station using SPI approach. Monthly precipitation data from 1979 to 2013 were used to compute Standardized Precipitation Index (SPI) values. The computation of SPI series was done for short as well as intermediate time scales. Analysis of SPI values were done to study the temporal patterns of drought occurrence. The drought severity and duration were also estimated. From the analysis, it was observed that in the years 1980, 1984,1985,1986,1987, 1989, 1991,1992,1993,1995, 1999,2000,2001,2002 and 2009 drought occurred in the area in Anand station. Extreme drought occurred in the year 1987 when the SPI value was -2.27. Also, SPI in the severe and extreme drought years indicate only moderate dryness instead of extreme dryness.

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