Annual Precipitation Values Research Articles

ВЛИЯНИЕ ГОРНОЙ ОРОГРАФИИ НА ПРОНИКНОВЕНИЕ ВОЗДУШНЫХ МАСС И ФОРМИРОВАНИЕ АТМОСФЕРНЫХ ОСАДКОВ В БАССЕЙНЕ РЕКИ ПЯНДЖ

The results of correlation dependences of mean annual precipitation of the Western and Eastern Pamirs ac- cording to the data of meteorological stations of the corresponding climatic zones for the period 19402022 are presented, using Pearson and Student correlations. It was found that in the mean annual distribution of precipita- tion in the Western Pamir there is a certain regularity in the distribution of precipitation with altitude, i.e. a de- crease in precipitation for each 100 m of altitude by 6.57.1 mm. Seasonal distribution of precipitation in the western and eastern parts of the Pamirs shows that the periods of maximum average annual precipitation values in the Western Pamirs cover winter (December–February), spring (MarchMay) seasons. In the Eastern Pamir, the maximum value of precipitation is observed in the summer season. By studying the correlation of values of mean annual precipitation of the Western and Eastern Pamirs using Pearson and Student correlations, the mutual con- nection of their mean annual precipitation amounts and temperature was investigated using data from meteorolog- ical stations Khorog and Javshangoz of the Western Pamir, Irkht of the Central Pamir, and Murgab and Shaimak of the Eastern Pamir. Generalization of the results of monitoring of spatial distribution of atmospheric precipita- tion by climatic zones of the Pamirs has established that summer Indian monsoons make a significant contribution to the provision of the Eastern Pamirs.

A global Data Assimilation of Moisture Patterns from 21 000–0 BP (DAMP-21ka) using lake level proxy records

Abstract. Global hydroclimate significantly differed from modern climate during the mid-Holocene (6 ka) and Last Glacial Maximum (21 ka). Consequently, both periods have been described as either a partial or reverse analogue for current climate change. To reconstruct past hydroclimate, an offline paleoclimate data assimilation methodology is applied to a dataset of 216 lake status records which provide relative estimates of water level change. The proxy observations are integrated with the climate dynamics of two transient simulations (TraCE-21ka and HadCM3) using a multivariate proxy system model (PSM) which estimates relative lake status from available climate simulation variables. The resulting DAMP-21ka (Data Assimilation of Moisture Patterns 21 000–0 BP) reanalysis reconstructs annual lake status and precipitation values at 500-year resolution and represents the first application of the methodology to global hydroclimate on timescales spanning the Holocene and longer. Validation using Pearson's correlation coefficients indicates that the reconstruction (0.24) is more skillful, on average, than model simulations (0.09), particularly in portions of North America and east Africa, where data density is high and proxy–model disagreement is prominent during the Holocene. Results of the PSM and assimilation are used to evaluate climatic controls on lake status, spatiotemporal patterns of moisture variability, and proxy–model disagreement. During the mid-Holocene, wetter conditions are reconstructed for northern and eastern Africa, Asia, and southern Australia, but in contrast to the model prior, negative anomalies are observed in North America, resulting in drier-than-modern conditions throughout the Northern Hemisphere midlatitudes. Proxy–model disagreement in western North America may reflect a bias in model simulations to stronger sea level pressure gradients in the North Pacific during the mid-Holocene. The data assimilation framework is able to reconcile these differences by integrating the constraints of proxy observations with the dynamics of the model prior to produce a more robust estimation of hydroclimate variability during the past 21 000 years.

Impact of climate change on vegetation growth trends in a citrus farmland in the south-eastern Sicily

Abstract. The environmental repercussions of climate change triggered substantial alterations in existing ecosystem balances leading to a gradual reduction in biodiversity and the increasing degradation of soil and the built environment. This has a direct effect on agricultural production in particular, leading to increased crop water requirements, the spread of new pests and pathogens that are difficult to manage, and, thus, a general reduction in productivity. Through the analysis of multispectral data remotely sensed with latest generation of optical sensors (RGB, thermal, NIR and multi-spectral cameras), it is possible to recognize the health status and growth stages of crops. In fact, in relation to the amount of radiation reflected in the different bands it is possible to calculate spectral indices, or vegetation indices. The main vegetative indices are NDVI, SAVI, MSAVI2, GNDVI and NDRE, which are calculated by differentially combining the ultraviolet spectrum, the visible range, and the near and mid-infrared band.In this paper the outcomes of a multi-year monitoring of a citrus grove field near Rosolini (Syracuse), in south-eastern Sicily-Italy, are presented. This monitoring activity was conducted to highlight areas of productive greenery under stress, on which to act as a priority with specific agronomic interventions. In parallel with the direct monitoring phases of the citrus grove, the trend of average monthly and annual temperature and precipitation values over the past 24 years was also studied to more specifically contextualize the possible presence of significant variations in climatic trends and relate them to the results returned by the calculation of the indices.

Determination of Climatic Changes in Düzce Province Using Three Different Climate Classification Methods

Aim of this study is to determine the climate characteristics of Düzce province referring to different climate classification systems. The study was carried out in Düzce province. Climate characteristics and climatic changes were analyzed by using De Martonne, Köppen, and Thornthwaite classification methods. The study utilized 60 years of precipitation and temperature data recorded by the General Directorate of Meteorology. Data analyses were conducted within five-year intervals. According to the results, the average annual temperature of Düzce province has been on the rise since 1994, and the average precipitation data for the last 10 years exceeded the 60-year average. In the simple linear regression analysis, it was determined that there was an increase in both average temperature and annual average total precipitation values. According to De Martonne climate classification, the province lies within the semi-humid climate class. Examining the data of the last 10 years, it was determined to be within the Cfak (Hot summer, cool winters, subtropical humid climate) climate class according to the Köppen-Trewartha climate classification and within the B1rB2'b4' (Humid, second-degree mesothermal region with almost no water deficit, and under the influence of oceanic climate) climate class according to the Thornthwaite climate classification. For Düzce province, both the change in climate types according to Köppen-Trewartha and Thorntwaite classifications and the changes in temperature and precipitation data in recent years may indicate climate change.

Modern Abies, Picea, and Tsuga pollen distribution along the elevation gradient in East Asia

Sub-alpine dark coniferous forests (SCFs) exhibit distinct latitudinal and longitudinal elevation distributions in East Asia. The SCF genera Abies, Picea, and Tsuga produce distinctive pollen and have specific elevation and climate requirements, allowing for the reconstruction of paleo-climatic and paleo-elevational changes from fossil pollen sequences. However, the relationship between SCF elevational distribution and the percentage of coniferous pollen has not been elucidated at the continental scale. In this study, we determined the relationship between Abies, Picea, and Tsuga pollen percentages and SCF elevation distributions in East Asia using an integrated pollen dataset comprising 4863 modern samples. The total percentage of these pollen types showed bimodal patterns with elevation and unimodal patterns with climate. Maximum pollen percentages occurred at elevations of 0–1000 and 2000–4600 m, mean annual temperatures of −5–10 ℃, and mean annual precipitation values of 100–1500 mm. The elevation with the highest proportion of Abies + Picea + Tsuga pollen increased with decreasing latitude: from 500 m (>43°N) to 2300 m (37–43°N), to 3500 m (30–37°N), and to 4000 m (18–30°N). Elevation also exhibited non-monotonic variations with longitude, first increasing from 2500 m (<93°E) to 3500 m (93–102°E), and then decreased to 2500 m (102–113°E) and 500 m (>113°E). The spatial patterns of Abies, Picea, and Tsuga pollen abundance were closely correlated with modern SCF distributions, which are largely modulated by climate and elevation. This study lays the foundation for reconstructing paleo-climate and paleo-elevation variations across East Asia.

Do Precipitation and Temperature Influence Perceptions of Urban Cleanliness?

Abstract This study explores the correlation between weather and the perception of urban cleanliness across the 47 largest cities in Spain. Utilizing survey data conducted by the national Consumers and Users Organization (OCU) in 2015, 2019, and 2023 to assess cleanliness perceptions, we analyze potential associations with precipitation and temperature recorded by weather stations of the Spanish Meteorological Agency. Additionally, we consider computed values of the De Martonne aridity index. The OCU data reveal regional disparities in perceived cleanliness quality. Higher cleanliness scores are obtained in cities located in the northern and north-central regions of Spain, characterized by humid and superhumid climates according to the De Martonne index. Conversely, lower cleanliness ratings are given to cities in the southern and eastern regions of Spain, where a Mediterranean climate and lower aridity index values prevail. In conducting a statistical analysis on the perception of cleanliness and variables related to precipitation and temperature, the results of the chi-square and linear correlation tests found no strong statistical correlation, although a tendency is observed. Cities with higher annual precipitation and lower values of average annual temperature tend to receive better cleanliness ratings, while drier and warmer cities exhibit the worst values of perceived urban cleanliness. Furthermore, our findings indicate that the Gompertz model effectively captures a strong statistical correlation in the relationship between cleanliness perception and the De Martonne index: As aridity increases, cleanliness perception decreases. These results are relevant for the development of future cleaning methods and systems, particularly in light of the climate change scenarios that are anticipated in the Mediterranean region due to warmer and drier conditions and, consequently, an increase in aridity.

Comprehensive evaluation of extreme hydrometeorological events coincidence and their interrelationships in the Hanjiang River Basin, China

Extreme hydrometeorological events are often highly destructive and can cause huge damage to the natural environment and social economy. As climate change and human activities intensify, the frequency and intensity of such extreme events continue to increase. This phenomenon is also shown in the Hanjiang River Basin (HRB) in recent decades. In this study, we focus on the coincidence occurrence patterns of extreme hydrometeorological events. First, we used the standardized index method to extract the annual maximum and minimum values of runoff, precipitation, maximum and minimum temperatures from 1961 to 2019 in the control area of the Baihe (BH) hydrological station, with time scales from 1 month to 12 months. Then through the Copula and nested structure Copula functions, the joint occurrence probability of bivariate and multivariate were analyzed. The results show that too high a maximum temperature will inhibit runoff, while an increase in minimum temperature will promote an increase in runoff to a certain extent. Both the maximum and minimum temperatures in the basin shown a significant increasing trend, and the intensity of hydrological drought also shows an increasing trend. An increase in maximum temperature will aggravate hydrological drought, as the combined joint occurrence probability of them is the greatest. Analysis through the nested structure Copula functions show that when extreme hydrometeorological events both occurred at the median of their intervals, their coincidence occurrence probability is the maximum, and when the time scale is eight months, their coincidence occurrence probability is the highest. This study can provide a reference for joint probability analysis of extreme hydrometeorological events.

Пространственная реконструкция климата востока Азии в раннем эоцене

Using the Coexistence Approach, climatic zones were identified for the Early Eocene of East Asia. Data for reconstruction include 48 palynofloras from the East Asia's Lower Eocene continental deposits from 75° to 19° N. The climatic inferences obtained are consistent with global trends, showing high values of mean annual temperature (MAT) and mean annual precipitation (MAP). According to our results, there is a weakly expressed latitudinal temperature gradient from the north to the south, showing an increasing trend for MAT values, while a very weakly expressed latitudinal gradient of precipitation demonstrates a decreasing trend for MAP values. Based on MAT and MAP values, three regional climatic zones are distinguished. The warm moderate climate zone (north of ≈ 55° paleolatitude) is characterized by low values for temperature (14.2-16.2 °C) and high ones for precipitation (1158-1334 mm). In the transition zone (≈ 45-55° paleolatitude), MAT values vary from 15.9 to 19.0 °C, and MAP values range from 874 to 1352 mm. The subtropical climate zone (south of ≈ 45° paleolatitude) is characterized by high values for temperature (16.5-19.1 °C) and low, for precipitation (874-1263 mm).

Reconstruction of palaeoenvironmental conditions that led to the formation of Eocene sub-bituminous coal seams in the Hungarian Paleogene Basin

Although in the second half of the Eocene, thick sub-bituminous coal seams were deposited in the Hungarian Paleogene Basin, it is not known under what climatic conditions these strata were formed. To investigate this, the paleoenvironmental conditions were reconstructed for the upper Lutetian-middle Priabonian period. The reconstruction of paleoclimatic conditions was based on the Coexistence Approach, for which the climatic data of the extant relatives of 15 fossil plant genera provided the basis of the analysis. Most (87%) of the extant relatives of the studied fossil plant genera can be found most frequently in tropical climate regions. Plotting the reconstructed average mean annual temperature (23.4 ± 3.9 °C) and precipitation (2375 mm ± 964 mm) values to the Whittaker Plot and Peltier's plots it was found that the region had a tropical monsoon climate during the upper Lutetian- middle Priabonian period. At the same time, there was a great difference between the precipitation sums of the wettest and driest months (409 ± 178 mm and 59 ± 56 mm), indicating a tropical monsoon-like climate with strong chemical weathering conditions. Currently, in climatically similar regions, tropical rainforest and tropical moist deciduous forest vegetation grow under tropical rainforest and tropical monsoon climates, and lateritic soils are formed. Furthermore, relatively rich mangrove plant associations flourish along the coasts of these regions, indicating that a part of the peat may have been deposited in mangroves. The contemporary lateritic soils, which later became the protoliths of bauxites, provided a poor nutrient supply for coastal vegetation, likely due to peat accumulation.

Исследование многолетней изменчивости элементов водного баланса речного бассейна в современном климате

The assessment of changes in the elements of the water balance of the Volga River basin in the formation zone near Volgograd for the entire period of the twentieth century and at the beginning of the first half of the XXI century is considered. The conducted retrospective conjugate analysis of the EWB of the Volga River basin is based on the use of sufficiently long hydro meteorological arrays of initial observation data covering the period 1891/1892‑2020/2021. Two time series of annual and seasonal values of atmospheric precipitation, river runoff, total evaporation of land, changes in basin moisture reserves and changes in surface air temperature of the cold and warm periods and the year as a whole are organized. It was established that until 1935, in the long-term course of the runoff of the Volga River basin, natural factors were of decisive importance, i.e. the nature of the humidification of the territory, the regime of total evaporation from its surface and the change in moisture reserves in the soil-soils. Since 1935, the water content of the river has changed. Human economic activity began to have a significant impact on the Volga, especially the operating modes of the Volga-Kama cascade of waterworks. However, anthropogenic influences do not affect the formation of lateral tributaries, which are controlled by 11 reservoirs of the Volga-Kama cascade. Therefore, for a retrospective conjugate analysis of the EWB of the Volga River basin, two conditionally natural time series of different durations were used

Transformation of Level of Humidification in the Eastern Part of Cuba

The work is devoted to analysing the transformation of humidification in a changing climate in the eastern part of Cuba, the case of Holguin (east of the island). The importance of the study is related to the need to study precipitation trends in certain regions. Based on the analysis of the long-term dynamics of annual precipitation values, relative humidity, and the number of days with precipitation, trends in the degree of moisture in the east of the island was established. The practical significance of the work lies in identifying and developing long-term weather forecasts and planning the economic and recreational development of the territory. The 1970–2020 period was considered. Changes in the amount of precipitation and days with precipitation were analysed. The moisture coefficient for the territory was calculated. The wettest and driest periods were identified, with the wettest being from 1981 to 1985 and the driest being from 1991 to 1995. The average rainfall for the wettest period was 1365 mm, while the average rainfall for the driest period was 335 mm. There was an increase in the number of days with precipitation from 39 days (1970) to 150 (2007). The maximum values of days with precipitation occurred in the period from 2006 to 2010. The calculated balance of humidification of the territory revealed heterogeneity of conditions of humidification of the territory. The maximum moisture deficit falls in the period from February to April, and the minimum – in June. The annual moisture balance was -653 mm. The territory is experiencing a lack of moisture.

Effect of climatic conditions on some physicochemical and physiological characteristics of the plum fruits Horvin variety growth

Contextualization: Climatic conditions are determining factors of fruits quality at the time of harvesting and are defined by the physicochemical and physiological characteristics of the fruit. Knowledge gap: knowing the relationship between different variables that can affect the production of the Horvin plum variety. Purpose: To observe the effect of climatic conditions on some physicochemical and physiological characteristics of plum fruits Horvin variety from its set to harvest. Methodology: Thermo-hygrometers were installed in each location placed at four different altitudes in order to obtain the temperature and relative humidity during the observation period. Moreover, the precipitation was measured with pluviometers installed at each location. The fruits were removed from different branches of the middle part of the trees on each of the study days. Results and conclusions: Climatic conditions greatly influenced the growth and development of plum fruit. Changes in weight and size were observed from harvest to harvest in the four locations studied. It was observed that the climatic conditions of the first harvest, especially the temperature, and precipitation, were affected by the El Niño phenomenon. Thus, a difference was reached between the average temperature of 6 °C each month. In addition, there was a difference of 19 °C between the coldest and warmest months, respectively, with average annual precipitation values of 907.2mm concentrated from July to November. For the second harvest, the temperature decreased, and there was more precipitation in the zone with an average temperature of 7 °C, and an average maximum temperature of 22 °C each month with average annual precipitation values of 1100mm concentrated from April to July.

Variability of East Asian Summer Monsoon precipitation during the Early Pleistocene based on pollen analysis from the western Loess Plateau, China

Understanding Early Pleistocene variability in precipitation associated with the East Asian Summer Monsoon (EASM) may help improve understanding of the effects of future global warming on this system. In this study, a quantitative EASM precipitation record with ∼2.7 kyr resolution was reconstructed for the Early Pleistocene (∼2.2–1.7 Ma) based on a pollen record from a loess-paleosol sequence in Lanzhou Basin, on the western Chinese Loess Plateau (CLP). The results show that the average annual precipitation (Pann) value was ∼505 mm, almost ∼1.6 times as much as today (∼310 mm), implying much stronger EASM intensity from ∼2.2–1.7 Ma. The EASM experienced a period of stronger intensity from ∼2.2 to 2.07 Ma, with Pann up to ∼525 mm and vegetation dominated by forest-steppe, as well as a period of weaker intensity between ∼2.07 and 1.99 Ma with lower average Pann (∼481 mm) and steppe dominated vegetation. A gradual intensification followed from ∼1.99 to 1.7 Ma, with increasing Pann (∼503 mm) accompanied by a significant increase in arboreal abundance. Our analysis suggests that the west to east temperature gradients across the Equatorial Pacific region influenced the Early Pleistocene EASM evolution over geological timescales. This finding differs from the traditional view that high-latitude ice sheet fluctuations were the primary driving force of Quaternary EASM. On orbital timescales, the Pann exhibits a dominant ∼41 kyr obliquity periodicity between ∼2.2–1.99 Ma and a ∼18 kyr precession periodicity between ∼1.99–1.7 Ma, indicating that Northern Hemisphere ice sheet and low-latitude solar insolation were the dominant drivers of EASM precipitation cycles in these two periods.

Trends of High and Low Values of Annual and Seasonal Precipitation in Turkey

The exploration of precipitation data trends using innovative analysis methods is anticipated to offer significant contributions to sustainability across various domains, including water resources management, agricultural planning, climate change understanding, environmental protection, risk assessment, and preparedness. This study employs an improved visualization of the innovative trend analysis (IV-ITA) method for detecting annual and seasonal trends in precipitation variables across 194 stations in Turkey over the period 1969–2020. The outcomes derived from the IV-ITA method were further juxtaposed with the results obtained from the classical Mann–Kendall (MK) test. Using the MK test, statistically significant increasing trends were detected in the annual pattern along the northern coasts of Turkey. Based on the results obtained from the IV-ITA, substantial decreasing trends were identified in the basins within the Southeastern Anatolia Region of Turkey. Conversely, an increasing trend was observed in the basins situated in the northwest. It was also established that an increasing trend was observed throughout Turkey, except for some stations in the low-data group. The most significant increasing trend was noted in the basins along the southern coastline, characterized by the prevalence of the Mediterranean climate. In the high-data group, an increase of up to 50% was noted along the southwest coast. Upon comparing the outcomes derived from the IV-ITA method with those obtained using the MK test, it becomes apparent that the IV-ITA yields significantly more detailed results than the MK test. Additionally, applying the IV-ITA method in climate-sensitive regions and basins is envisioned to enhance the accuracy of assessments, foster a sustainable environment, and improve the effective management of water resources.

Impacts of heat and drought on the dynamics of water fluxes in a temperate deciduous forest from 2012 to 2020

Temperate deciduous forests play a significant role in the regional and global water cycles. However, climate change and associated extreme weather events are affecting the growth, water use, and survival of these forests. This study examined nine years of water flux measurements made using the eddy covariance (EC) technique in a temperate deciduous forest in eastern North America from 2012 to 2020 and assessed the impacts of heat and drought events on forest evapotranspiration (ET) and water use efficiency (WUE). Study results showed that the highest annual evapotranspiration (ET) of 521 mm yr−1 was observed in 2020, while the lowest annual ET of 359 mm yr−1 was recorded in 2014. Photosynthetically active radiation (PAR, lmg = 0.33) and air temperature (Tair, lmg = 0.33) were the primary drivers of ET, while vapor pressure deficit (VPD, lmg = 0.41) was the primary regulator of WUE. Over the nine-year study period, observed mean annual ET and precipitation (P) values were 367 ± 40 mm yr−1 and 1148 ± 262 mm yr−1, respectively, while mean annual P-ET value was 729 ± 272 mm yr−1. Annual ET accounted for 38% of P over the study period. Mean growing season WUE, which is an indicator of water utilization by the forest for growth and carbon assimilation, was 3.8 ± 0.4 g C Kg H2O−1, with the highest WUE of 4.4 g C Kg H2O−1 observed in 2014 (cool year), and the lowest values of 3.0 and 3.1 g C Kg H2O−1observed in 2012 (hot-dry year) and 2020 (dry year), respectively. We found an increasing trend in WUE values from 2012 to 2014 and then a decreasing trend from 2015 to 2020, when every year experienced extreme weather conditions (e.g. hot, dry or hot-dry), except 2019. This long-term flux observation study will help to enhance our understanding of water exchanges and water use in temperate deciduous forests in Eastern North America and develop strategies for managing forest water resources and ensuring water security in the region in changing climate.

Evaluating impacts of climate variability on smallholder livelihoods and adaptation practices in the western Shewa Zone, Oromia, Ethiopia

IntroductionThe objective of this research was to assess the trends and variability in the BakoTibe district as well as raise awareness among rural farmers.MethodsThe sample of homes included 141 out of 29 participants, all from families headed by a female. The Mann-Kendall trend test and the Sen-slope estimator were used to assess the trend of annual minimum and maximum temperatures and seasonal precipitation for the study areas.Results and discussionThe year, summer, and spring climate variability results were examined, and the CV of spring precipitation was found to be 34.8%, indicating high variability of rainfall. Spring precipitation was more unstable than summer precipitation. Statistically, total annual precipitation, the summer season, and the autumn season all showed positive or no significant trends, while spring and winter precipitation both showed a negative or decreasing trend. The probability of 7, 10, 15, and 20-day dry spells in June, July, August, and September during the main rainy season (summer) was zero. The chance of a 20-day dry spell occurrence was highest from March 1 (61 days) to April 23 (115 days), lowest from April 23 (130 days) to June, July, August, and September 20 (265 days), and highest after the end of September. The dry period lasted 15 days, beginning on March 1 (61 days), ending on May 8 (130 days), and returning to zero from May 8 (130 days) to June, July, August, and September 5 (250 days). The probability of a 10-day dry spell began in March (61) and ended on May 23 (145), with the 7-day dry spell ending on June 23 (160). In this study, annual precipitation and temperature values from 2010 to 2019 were examined. Precipitation and temperature have a positive and significant relationship with corn and teff. Approximately 65.2% of the population reported late precipitation, while 34.8% reported no late precipitation. A premature end to the rains affected the livelihoods of ~73% of those polled. Crop diversification, terracing, tree planting, irrigation cultivation for precocious crops, and non-agricultural activities have all been used to adapt to the effects of climate variability and change.

Analysis of Radial Growth Dynamics of Pinus Nigra Subsp. Pallasiana (Lamb.) Holmboe in Different Parts of the Slope Profile

The results of the research of radial growth of Pinus nigra trees growing in the foothill-forest-steppe zone (in Belogorosk district) with continental climate type of the Crimean Peninsula are presented. The research was con[1]ducted to evaluate the influence of the location of the growth site on the local slope on the total width of the annual ring. Geomorphologically, the sampling points were located along the profile of a gentle convex slope of eastern exposure. Wood samples were collected at sites within the lower, middle and watershed parts of the slope, as well as at the top of the Biyuk-Karasu River watershed. Generalised tree-ring chronologies were obtained for each part of the slope, the average age of the chronologies being 50 years. As a result of the research, a synchronism in growth dynamics of trees growing in the lower part of the slope and in the watershed was established; the radial growth of Pinus nigra trees in the middle parts of the slope reacts the earliest to the influence of environmental factors. The reaction lag of radial growth in the watershed part of the slope is about 11 years. Analysis of the constructed chronologies shows that over the past 50 years, the radial growth is comparable to the dynamics of meteorological parameters. The analysis of correlations of the obtained chronologies with the values of average monthly air temperatures and annual precipitation according to the data of the Simferopol meteorological station was carried out. For the lower and middle parts of the slope, as well as for the watershed, the amount of precipitation is more significant than air temperature. Correlations have been established between the radial growth index of the lower and middle parts of the slope, as well as watershed and the sum of precipitation in May, and the summer months of both the current and previous years. For Pinusnigra trees growing on the watershed parts of the slope, air temperatures of summer months of the current and previous year are more significant. The established close relationship can be used to reconstruct climatic conditions of Pinus nigra trees.

Future climate projections using the LARS-WG6 downscaling model over Upper Indus Basin, Pakistan.

This study investigates the projections of precipitation and temperature at the local scale in the Upper Indus Basin (UIB) in Pakistan using six Regional Climate Models (RCMs) from CORDEX under two Representative Concentration Pathways (RCP 4.5 and RCP 8.5). For twenty-four stations spread across the study area, the Long Ashton Research Station Weather Generator, version six (LARS-WG6), was used to downscale the daily data from the six different RCMs for maximum temperature (Tmax), minimum temperature (Tmin), and precipitation (pr) at a spatial resolution of 0.44°. Investigations were made to predict changes in mean annual values of Tmax, Tmin, and precipitation during two future periods, i.e., the mid-century (2041-2070) and end-century (2071-2100). The model results from statistical and graphical comparison validated that the LARS-WG6 can simulate the temperature and the precipitation in the UIB. Each of the six RCMs and their ensemble revealed a continuously increased temperature projection in the basin; nevertheless, there is variation in projected magnitude across RCMs and between RCPs. The rise in average Tmax and Tmin was more significant under RCP 8.5 than RCP 4.5, possibly due to unmitigated greenhouse gas emissions (GHGs). The precipitation projections follow the non-uniform trend, i.e., not all RCMs agree on whether the precipitation will increase or decrease in the basin, and no orderly variations were detected during any future periods under any RCP. However, an overall increase in precipitation is projected by the ensemble of RCMs.

City-Wise Assessment of Suitable CMIP6 GCM in Simulating Different Urban Meteorological Variables over Major Cities in Indonesia

This study evaluates the performance of 6 global climate models (GCMs) from the Coupled Model Intercomparison Project Phase 6 (CMIP6) for simulating temperature, precipitation, wind speed, and relative humidity over 29 cities in Indonesia. Modern-Era Retrospective Analysis for Research Applications (MERRA-2) was considered as reference data to assess the city-wise performance of surface air temperature, precipitation, wind speed, and relative humidity simulated by the CMIP6 GCMs during 1980–2014. Six statistical measures were computed in this process (mean annual, seasonal amplitude, mean annual bias, root mean square error, correlation coefficient, and standard deviation). For 29 cities, the mean annual values of surface air temperature, precipitation, wind speed, and relative humidity obtained from the GCMs range between 290 to 302 K, 100 cm to 450 cm, 1 to 6 m/s, and 70 to 94%, respectively. The correlation coefficient between the GCMs and the surface air temperature (precipitation) reanalysis dataset ranges from 0.3 to 0.85 (−0.14 to 0.77). The correlation coefficient for wind speed (relative humidity) varies from 0.2 to 0.6 and is positive in some cases (0.2 to 0.8). Subsequently, the relative error that combines the statistical measurement results was calculated for each city and meteorological variable. Results show that for surface air temperature and precipitation, the performance of TaiESM was outstanding over the 10 or more cities. In contrast, for wind speed and relative humidity, NOR-MM and MPI-HR were the best over 7 and 19 cities, respectively. For all the meteorological variables, the performance of AWI was found to be worst over all the cities. The outcomes of this study are essential for climate-resilience planning and GCM selection while performing downscaling experiments. It will also be useful for producing updated national climate change projections for each city in Indonesia and providing new insights into the climate system.

Weak precipitation δ2H response to large Holocene hydroclimate changes in eastern North America

In eastern North America, annual precipitation increased by >40% over the Holocene, largely in response to melting of the Laurentide Ice Sheet. The change substantially raised lake levels and transformed conifer-dominated ecosystems into mesic deciduous forests. δ2H values of terrestrially derived leaf-wax n-alkanes can facilitate diagnoses of the climate dynamics involved by reconstructing δ2H values of mean annual precipitation (δ2HMAP). However, competing influences on δ2HMAP values in the mid-latitudes, such as changes in moisture sources and in the seasonal distribution of precipitation, can generate confounding effects. To test δ2HMAP sensitivity to potential changes associated with the final Holocene phases of deglaciation in eastern North America, we used 14 fossil-pollen records to reconstruct monthly precipitation changes and to model δ2HMAP values during the Holocene. The pollen-inferred precipitation increased by 100–200 mm during both cold and warm seasons, but modeled δ2HMAP values changed by only ∼10‰, because isotopically-heavy summer precipitation increased by nearly as much as the cold-season isotopically-light winter precipitation. Three new leaf wax n-C29-alkane (δ2HC29) records spanning the Holocene from Vermont, Pennsylvania, and Massachusetts closely follow modeled δ2HMAP trends and confirm only a small decline in δ2HMAP values over the Holocene. Because the shifts in precipitation seasonality accurately predict the n-alkane records, changes in moisture sources or pathways appear to play only a minor role in the regional δ2HMAP history despite the effects of deglaciation on atmospheric circulation. Soil evaporation also did not significantly alter δ2HC29 values from the values predicted using the pollen-derived reconstructions. The results affirm that δ2HC29 values faithfully detected anticipated isotopic changes in δ2HMAP values, but that important paleoclimate events may not always yield strong changes in δ2HMAP values.