Changes In Summer Precipitation Research Articles

Detectable anthropogenic forcing on the long-term changes of summer precipitation over the Tibetan Plateau

Detectable anthropogenic forcing on the long-term changes of summer precipitation over the Tibetan Plateau

Projected Changes to Spring and Summer Precipitation in the Midwestern United States

Spring and summer precipitation are both important factors for agricultural productivity in the Midwest region of the United States. Adequate summer precipitation, particularly in the reproductive and grain fill stages in July and August, is critical to corn and soybean success. Meanwhile, excessive spring precipitation can cause significant planting delays and introduces challenges with weed and pest management, and soil erosion and compaction. However, uncertainty especially in future summer precipitation changes, translates to uncertainties in how the joint distributions of spring and summer precipitation are expected to change by mid- and late-century across the Midwest. This study examines historical and projected changes in the characteristics of spring and summer precipitation in the Midwest using 12 dynamically downscaled simulations under the high-emission representative concentration pathway (RCP 8.5) from the NA-CORDEX project. Historical increases in spring precipitation and precipitation intensity are projected to continue into the mid- and late-century across the region, with strong model agreement. By comparison, projected changes in Midwest summer precipitation are more modest than for spring and have much less model agreement. Despite a projected three- to four-fold increase in the frequency of wet springs by late-century, relative to the model ensemble historical average, the lack of substantial and robust projected change in summer precipitation results in only a small increase in the risk of dry summers following wet springs in the Midwest by mid- and late-century.

Balanced estimate and uncertainty assessment of European climate change using the large EURO-CORDEX regional climate model ensemble

Abstract. Large multiscenario multimodel ensembles (MMEs) of regional climate model (RCM) experiments driven by global climate models (GCMs) are made available worldwide and aim at providing robust estimates of climate changes and associated uncertainties. Due to many missing combinations of emission scenarios and climate models leading to sparse scenario–GCM–RCM matrices, these large ensembles, however, are very unbalanced, which makes uncertainty analyses impossible with standard approaches. In this paper, the uncertainty assessment is carried out by applying an advanced statistical approach, called QUALYPSO, to a very large ensemble of 87 EURO-CORDEX climate projections, the largest MME based on regional climate models ever produced in Europe. This analysis provides a detailed description of this MME, including (i) balanced estimates of mean changes for near-surface temperature and precipitation in Europe, (ii) the total uncertainty of projections and its partition as a function of time, and (iii) the list of the most important contributors to the model uncertainty. For changes in total precipitation and mean temperature in winter (DJF) and summer (JJA), the uncertainty due to RCMs can be as large as the uncertainty due to GCMs at the end of the century (2071–2099). Both uncertainty sources are mainly due to a small number of individual models clearly identified. Due to the highly unbalanced character of the MME, mean estimated changes can drastically differ from standard average estimates based on the raw ensemble of opportunity. For the RCP4.5 emission scenario in central–eastern Europe for instance, the difference between balanced and direct estimates is up to 0.8 ∘C for summer temperature changes and up to 20 % for summer precipitation changes at the end of the century.

Impact of Stratospheric Aerosol Injection Geoengineering on the Summer Climate Over East Asia

AbstractAs a potential approach to counteract global warming, geoengineering has attracted much attention in recent years. We investigate the impacts of stratospheric aerosol injection (SAI) geoengineering on summer (June‐August, JJA) temperature and precipitation over East Asia as well as the East Asian summer monsoon (EASM) by using model outputs archived in the G4 stratospheric aerosol injection experiments of the Geoengineering Model Intercomparison Project (GeoMIP). In the G4 experiment, injected sulfate aerosols cause decreases in top‐of‐atmosphere radiative forcing, surface air temperature, and precipitation, and changes in the EASM and drought/flood pattern in summer over East Asia. The SAI‐induced temperature changes show consistent cooling with strong magnitudes over the East Asian continent, while the precipitation and EASM changes vary among regions and models. SAI leads to anomalous anticyclones in the lower troposphere, mainly due to the strong cooling in the middle‐to‐upper troposphere. The thermodynamic and dynamic mechanisms of SAI‐induced summer precipitation change over East Asia are analyzed through the moisture budget equation. The results show that the spatial pattern of precipitation change is dominated by a dynamic divergent component under SAI forcing, indicating the leading role of atmospheric circulation change. This change is closely associated with anomalous cyclones and anticyclones in the lower troposphere.

Distinct Holocene precipitation trends over arid Central Asia and linkages to westerlies and Asian monsoon

The response of precipitation over arid Central Asia since the mid Holocene is long considered to be controlled by astronomical insolation-induced changes in the westerlies. However, it is still controversial in proxy and modeling studies whether the trend of Central Asian precipitation is in accordance with Asian monsoon or not. Compared to the monsoon, the westerlies-associated precipitation changes are complicated and also rely on regional mountain complex. In this study, we conducted a high-resolution transient experiment by a coupled climate model to evaluate the response of Central Asian precipitation. The simulated precipitation changes are distinctly different over regions although they are mainly associated with the westerlies. Since mid Holocene, the annual precipitation increases over Balkhash-Altai region but decreases over Turan Plain, Mongolia-Baikal and Tarim Basin, in all of which the summer precipitation contributes most. Following the summer insolation, the southward shift of westerly jet is accompanied by wave-like anomalies in the upper-tropospheric meridional winds across mid-latitude Eurasia (the Silk Road pattern), which results in distinct summer precipitation changes. The decreased precipitation over Tarim is mainly explained by weakened low-level easterly wind anomaly and less moisture supply from East Asia. In contrast, the responses of winter precipitation are limited even in the winter-rainfall-dominated regime due to the small insolation change. Such simulated complicated precipitation trends during the Holocene are in qualitative agreement with existing proxies, highlighting the modulation of Silk Road pattern on Central Asian rainfall on the orbital timescale.

Hibernation behavior of a federally threatened ground squirrel: climate change and habitat selection implications

Abstract Hibernation is an adaptation to survive periods of stress, from food limitation or harsh thermal conditions. A key question in contemporary ecology is whether rare, range-restricted species can change their behavior in response to climate change (i.e., through behavioral plasticity). The northern Idaho ground squirrel, Urocitellus brunneus (A. H. Howell, 1928), is a federally threatened species that hibernates for approximately 8 months per year within the bounds of its small range in central Idaho, USA. Changes in temperature, snow accumulation, and summer precipitation, all brought about as a result of climate change, may reduce survival or fecundity of northern Idaho ground squirrels if they cannot adapt to these climate changes. Hibernating species can respond to climate-change-induced thermal challenges in two ways: change their hibernation physiology and behavior (i.e., emergence date or number of torpor bouts) or alter their environment (i.e., change hibernacula depth or location). We explored a suite of intrinsic and extrinsic factors to document the extent to which they influenced hibernation behavior of northern Idaho ground squirrels. Emergence date was positively associated with snowpack and negatively associated with mean winter temperature. Mean minimum skin temperature was negatively associated with canopy closure and slope of a squirrel’s hibernaculum. Duration of the heterothermal period, number of euthermic bouts, and total time spent euthermic were positively associated with body mass. Immergence date and duration of the longest torpor bout were negatively associated with body mass. Warmer temperatures and less snow accumulation in the winter—caused by climate change—likely will cause altered emergence dates. Our results suggest that any future climate-induced changes in snowfall, ambient temperature, food availability, or habitat likely will impact survival of this rare ground squirrel, because such changes will cause changes in hibernation behavior, percent mass loss during hibernation, and duration of the active season when small mammals are more susceptible to predation.

Hydroclimatic anomalies in China during the post-Laki years and the role of concurring El Niño

Arctic is warming at an alarming speed causing accelerated melting of Greenland and rising of sea level, and geoengineering by injecting aerosol into stratosphere (SAI) has been proposed as a backup approach to mitigate warming. However, studies suggest that SAI implementation may have adverse impacts on global especially monsoon precipitation, and Northern Hemisphere high-latitude injections may have disproportionally high effects than tropical injections. The 1783–1784 CE Laki eruption in Iceland provides an analogy to study the climatic and the subsequent socioecological responses to Arctic SAI, and China possesses a rich legacy of documents recording climatic disasters and describing their direct impacts on agriculture and society. Using the most recent summer precipitation reconstructions and the documentary data, this study presents a systemic analysis of the hydroclimatic anomalies as well as the societal and ecological consequences in China following the 1783–1784 CE Laki eruption. The results from multi-proxies show severe drought conditions in eastern China during the post-Laki years, accompanied by large scale locust breakout, famine and human pestilence. The drought and associated disasters first emerged in the North China Plain in 1784 CE, intensified and expanded to the middle and lower reaches of the Yangtze River in 1785 CE. The drought and famine stresses in China are part of the very unsettled climate conditions experienced across the Northern Hemispheric world during the 1780s. By isolating the ENSO-induced precipitation from the reconstructed summer precipitation changes, our results indicate that the Laki eruption did cause severe drought in monsoon China during the next three years. The drought responses in the 1783–1784 were largely counter-balanced by the wetting induced by the concurring strong El Niño event. The results help to enhance our understanding of the hydroclimate consequence of NH high latitude volcanic eruption in China, and the potential role climate internal variation such as ENSO may play in modifying volcanic-induced perturbation.

Pre‐instrumental summer precipitation variability in northwestern Greece from a high‐elevation Pinus heldreichii network

AbstractThe spatiotemporal variability of precipitation is of vital importance to Mediterranean ecology and economy, but pre‐instrumental changes are not well understood. Here, we present a millennial‐length June–July precipitation reconstruction derived from a network of 22 Pinus heldreichii high‐elevation sites in the Pindus Mountains of northwestern Greece. Tree‐ring width chronologies from these sites cohere exceptionally well over the past several hundred years (r1467–2015 = 0.64) revealing coherence at inter‐annual to centennial timescales across the network. The network mean calibrates significantly against instrumental June–July precipitation over the past 40 years (r1976–2015 = 0.71), even though no high‐elevation observational record is available representing the moist conditions at the treeline above 1,900 m a.s.l. For the final reconstruction, the instrumental target data are adjusted to provide realistic estimates of high‐elevation summer rainfall back to 729 CE. The reconstruction contains substantially more low‐frequency variability than other high‐resolution hydroclimate records from the eastern Mediterranean including extended dry periods from 1,350 to 1,379 CE (39 ± 4.5 mm) and 913 to 942 (40 ± 8.4 mm), and moist periods from 862 to 891 (86 ± 11 mm) and 1,522 to 1,551 (80 ± 3.5 mm), relative to the long‐term mean of 61 mm. The most recent 30‐year period from 1986 to 2015 is characterized by above average June–July precipitation (73 ± 2 mm). Low‐frequency changes in summer precipitation are likely related to variations in the position and persistence of storm tracks steering local depressions and causing extensive rainfall (or lack thereof) in high‐elevation environments of the Pindus Mountains.

潍坊市夏季降水量的时空变化特征分析

潍坊市夏季降水量的时空变化特征分析

Evaluation and Expected Changes of Summer Precipitation at Convection Permitting Scale with COSMO-CLM over Alpine Space

There is an ongoing debate in the climate community about the benefits of convection-permitting models that explicitly resolve convection and other thermodynamical processes. An increasing number of studies show improvements in Regional Climate Model (RCM) performances when the grid spacing is increased to 1-km scale. Up until now, such studies have revealed that convection-permitting models confer significant advantages in representing orographic regions, producing high-order statistics, predicting events with small temporal and spatial scales, and representing convective organization. The focus of this work is on the analysis of summer precipitation over the Alpine space. More specifically, the driving data are downscaled using the RCM COSMO-CLM first at an intermediate resolution (12 km) over the European Domain of Coordinated Downscaling Experiment (EURO-CORDEX domain). Then, a further downscaling at 3 km, nested into the previous one, is performed over the Alpine domain to exploit the results over a complex orography context. Experiments of evaluation, historical and far future under the Intergovernmental Panel on Climate Change (IPCC) RCP8.5 scenario have been considered. Indices as mean precipitation, frequency, intensity, and heavy precipitation are employed in daily and hourly analyses. The results, observed from the analysis of 10 year-long simulations, provide preliminary indications, highlighting significant differences of the convection permitting simulations with respect to the driving one, especially at an hourly time scale. Moreover, future projections suggest that the convection permitting simulation refines and enhances the projected patterns, compared with the coarser resolution.

Projection of Future Summer Precipitation over the Yellow River Basin: A Moisture Budget Perspective

The projection of future precipitation over the Yellow River Basin (YRB) is of great importance to regional climate change adaptation and mitigation. Using the historical simulations and projections under the four combined scenarios of the shared socioeconomic pathways and the forcing levels of the Representative Concentration Pathways (SSP1-2.6, SSP2-4.5, SSP3-7.0 and SSP5-8.5) provided by the multimodel ensemble mean of 10 models in phase six of the Coupled Model Intercomparison Project (CMIP6), the projected spatial and temporal changes of future summer precipitation over the YRB and the possible physical mechanisms underlying future summer precipitation changes are investigated. Large discrepancies in precipitation exist among the four scenarios during the latter half period of the 21st century, with precipitation under SSP5-8.5 being the largest. Nevertheless, the precipitation under each of the four scenarios shows a similar spatial pattern over the YRB, with an east–west-oriented gradient. A comparison of projected moisture transport into the YRB among the four scenarios reveals two channels (westerlies and monsoon flow) under SSP5-8.5, whereas the monsoon flow from adjacent oceans is important under the other three scenarios. Further analysis of the unique features of the projected moisture flux and substantial increase in summer precipitation under SSP5-8.5 indicates that the future summer precipitation trend over the YRB can be mainly attributed to an increase in evaporation and moisture advection.

Montane forest productivity across a semiarid climatic gradient.

High-elevation montane forests are disproportionately important to carbon sequestration in semiarid climates where low elevations are dry and characterized by low carbon density ecosystems. However, these ecosystems are increasingly threatened by climate change with seasonal implications for photosynthesis and forest growth. As a result, we leveraged eddy covariance data from six evergreen conifer forest sites in the semiarid western United States to extrapolate the status of carbon sequestration within a framework of projected warming and drying. At colder locations, the seasonal evolution of gross primary productivity (GPP) was characterized by a single broad maximum during the summer that corresponded to snow melt-derived moisture and a transition from winter dormancy to spring activity. Conversely, winter dormancy was transient at warmer locations, and GPP was responsive to both winter and summer precipitation such that two distinct GPP maxima were separated by a period of foresummer drought. This resulted in a predictable sequence of primary limiting factors to GPP beginning with air temperature in winter and proceeding to moisture and leaf area during the summer. Due to counteracting winter (positive) and summer (negative) GPP responses to warming, leaf area index and moisture availability were the best predictors of annual GPP differences across sites. Overall, mean annual GPP was greatest at the warmest site due to persistent vegetation photosynthetic activity throughout the winter. These results indicate that the trajectory of this region's carbon sequestration will be sensitive to reduced or delayed summer precipitation, especially if coupled to snow drought and earlier soil moisture recession, but summer precipitation changes remain highly uncertain. Given the demonstrated potential for seasonally offsetting responses to warming, we project that decadal semiarid montane forest carbon sequestration will remain relatively stable in the absence of severe disturbance.

Decadal increase of the summer precipitation in Thailand after the mid-1990s

Summer precipitation in Thailand is a major resource for water and agriculture. Understanding the decadal variations of summer precipitation is useful for water resource management planning for long-term periods. This study investigates decadal changes in summer precipitation in Thailand. An evident increase in summer precipitation was found after the mid-1990s, and the possible causes have been discussed. An analysis of precipitation from observational stations revealed a significant shift in 1994; an increase in summer precipitation can be observed over most of Thailand after 1994. Inspections of the atmospheric circulation revealed cyclonic anomalies over the Indochina Peninsula in the lower troposphere, facilitating enhanced moisture transport towards Thailand. Meanwhile, the anomalous local Hadley circulation over eastern Thailand demonstrated stronger ascending motion after 1994, facilitating enhanced precipitation. The abovementioned changes in the atmospheric circulation and summer precipitation are closely related to the decadal changes in the sea surface temperature over the Atlantic Multidecadal Oscillation.

Changes in seasonal and diurnal precipitation types during summer over the upper reaches of the Yangtze River Basin in the middle twenty-first century (2020–2050) as projected by RegCM4 forced by two CMIP5 global climate models

Changes in summer and diurnal precipitation in the upper reaches of the Yangtze River Basin (UYRB) in the middle of the twenty-first century were estimated by RegCM4 with a resolution of 50 km under two representative concentration pathway scenarios. ERA-Interim, CSIRO-MK3.6.0 and MPI-ESM-MR were used as the initial and lateral boundary conditions, and two observation data sets (CN05.1 and CRU) were used to evaluate the precipitation performance. RegCM4 captured the spatial characteristics of summer precipitation in the UYRB during the reference period. Compared with the two observational data sets, the three groups of downscaling results underestimated the precipitation in the eastern part of the basin by 20% and overestimated that in the west by more than 80%. In the middle of the twenty-first century, the total precipitation (TPR) in the UYRB varied significantly from east to west. The multiyear average TPR in the eastern plains was projected to significantly decrease, while it significantly increased in the western mountains. As a major contributor to the TPR in the UYRB, convective precipitation (CPR) differed between the eastern and western regions, especially at night. The TPR changes in the east (decrease) and west (increase) were projected to be strongest in the afternoon. The probability of high-intensity precipitation in the central and western areas will increase, implying a potential increase in the risk of flooding in these areas. The diametric changes in the TPR between the east and west may further exacerbate the spatial heterogeneity of water resources, resulting in large impacts to surface hydrological processes. The spatial variations in precipitation were mainly due to the variation in precipitation mechanisms between the western mountainous area and the eastern basin, while the changes in water vapour transport and atmospheric stability also played a role.

Global Land Monsoon Precipitation Changes in CMIP6 Projections

AbstractChanges in global land monsoon (GLM) precipitation determine the local water resource, affecting two thirds of global population. The future changes in GLM summer precipitation and the sources of projection uncertainty under four scenarios are investigated using the Coupled Model Intercomparison Project Phase 6 (CMIP6) models. The GLM summer precipitation is projected to increase by 1.76 ± 1.57% (2.54 ± 2.22%), 1.33 ± 1.97% (3.52 ± 3.05%), 0.96 ± 2.04% (3.51 ± 4.97%), and 1.71 ± 2.38% (5.75 ± 5.92%) in the near (long) term under Shared Socioeconomic Pathway (SSP) 1–2.6, SSP2–4.5, SSP3–7.0, and SSP5–8.5, respectively. The enhancement is caused by thermodynamic responses due to increased moisture, which is partly offset by dynamic responses due to weakened circulation. The uncertainty in GLM precipitation projection is the largest in SSP5–8.5 long‐term projection. The uncertainty of submonsoon precipitation projections is larger than that in GLM precipitation. The uncertainty of monsoon precipitation projection arises from the circulation changes, which can be partly explained by model‐dependent response to uniform sea surface temperature warming.

Enhanced western mediterranean rainfall during past interglacials driven by North Atlantic pressure changes

There is increasing concern with anthropogenic greenhouse gas emissions that ocean warming, in concert with summer and winter precipitation changes, will induce anoxia in multiple ocean basins, such as in the Mediterranean Sea. Although the hydrological changes in the eastern Mediterranean are quite well constrained, quantitative evidence of changes in sea surface temperature (SST) and winter rainfall in the western Mediterranean across the past interglacials is relatively scarce. In this study, we use a combination of trace element (Ba/Ca and Mg/Ca) and stable oxygen isotope composition of planktonic foraminifera from a sediment core located off the Golo River, Corsica (northern Tyrrhenian Sea) to reconstruct variations in SSTs and sea surface salinities (SSS) during the Holocene (MIS 1) and warm periods of the past two interglacials (MIS 5, 7). We also analyse PMIP3 model simulations for the mid-Holocene to investigate the mechanism for moisture transport in the western Mediterranean. Our Mg/Ca-SSTs, Ba/Ca-salinity and derived δ18O-seawater records suggest that the warm periods of the past interglacials were characterized by high river discharge and lower SSS in the northern Tyrrhenian Sea. Since this region is ideally located on the trajectory of wintertime storm tracks across the North Atlantic into the Mediterranean Sea and is also outside the influence of the ITCZ-controlled summer monsoon rains, we suggest enhanced winter rainfall during the past interglacials. Our analysis of PMIP3 model simulations for mid-Holocene also support increased south-westerly moisture transport into the western Mediterranean originating from the North Atlantic. We also find evidence that long-term amplitude of the salinity decrease tightly follows eccentricity. We suggest that these hydrologic changes in the western Mediterranean, and the northern Mediterranean borderlands as a whole, were a contributing factor, together with local cyclogenesis and African summer monsoon rainfall, to basin-wide anoxia in the past. Our findings offer new constraints to the amplitude and cause of winter rainfall changes in the Mediterranean during past warm periods.

Contribution of precipitation events with different consecutive days to summer rainfall change over China

The climatological features, regional trends, and interdecadal changes of summer precipitation over China are investigated in this study from the perspective of four types of precipitation events with different consecutive days. The precipitation events are classified based on the consecutive days of precipitation into 1-to-3-, 4-to-7-, 8-to-14-, and over-14-day events. The contribution of 1-to-3-day events to climatological precipitation is larger than the other events over central Asia. Longer duration events contributed more than the shorter duration events to precipitation in tropical regions. The positive precipitation trend in northwestern and southern China is mainly due to 4-to-7-day and 8-to-14-day events, respectively; and the negative precipitation trend in North China is largely related to 4-to-7-day events. In general, the frequency change of precipitation events is a major reason for the precipitation change of these events in the concerned regions. The precipitation decrease in northern China around the mid-1960s is attributed to the reduction in 4-to-7-day events. The precipitation increase in northeastern and central China in the late 1970s is due to a combination of increases in 4-to-7-day and 8-to-14-day events. The precipitation increase in southern China around 1993 is mainly contributed by over-14-day events. The precipitation decrease in the mid-latitude Asia is due to the decrease in 4-to-7-day events. Most of the interdecadal precipitation changes are related to decrease or increase in the activity of anomalous cyclones. Results suggest that the frequency of occurrence of cyclonic perturbations is a major factor for interdecadal changes in summer precipitation over China.

Detectable Anthropogenic Influence on Changes in Summer Precipitation in China

AbstractIn China, summer precipitation contributes a major part of the total precipitation amount in a year and has major impacts on society and human life. Whether any changes in summer precipitation are affected by external forcing on the climate system is an important issue. In this study, an optimal fingerprinting method was used to compare the observed changes of total, heavy, moderate, and light precipitation in summer derived from newly homogenized observation data with the simulations from multiple climate models participating in phase 5 of the Coupled Model Intercomparison Project (CMIP5). The results demonstrate that the anthropogenic forcing signal can be detected and separated from the natural forcing signal in the observed increase of seasonal accumulated precipitation amount for heavy precipitation in summer in China and eastern China (EC). The simulated changes in heavy precipitation are generally consistent with observed change in China but are underestimated in EC. When the changes in precipitation of different intensities are considered simultaneously, the human influence on simultaneous changes in moderate and light precipitation can be detected in China and EC in summer. Changes attributable to anthropogenic forcing explain most of the observed regional changes for all categories of summer precipitation, and natural forcing contributes little. In the future, with increasing anthropogenic influence, the attribution-constrained projection suggests that heavy precipitation in summer will increase more than that from the model raw outputs. Society may therefore face a higher risk of heavy precipitation in the future.

Summer Water Vapor Sources in Northeast Asia and East Siberia Revealed by a Moisture-Tracing Atmospheric Model

AbstractPrevious studies found a seesaw pattern of summer precipitation between northeast Asia and east Siberia on an interannual time scale, which is associated with an eastward-propagating atmospheric wave train over Eurasia and corresponding water vapor transport circulations. Using a general circulation model with an embedded water-tagging module, the main water vapor sources of the two regions, as well as the relative contributions of each source region to the total precipitation for both the climatological mean and interdecadal variation, are further compared in this study. The model simulation results show that local evaporation, the Pacific Ocean, and East Asia are the dominant moisture sources for northeast Asian precipitation. In contrast, for east Siberia, moisture mainly originates from the Pacific Ocean, northeast Asia, west Siberia, and local evaporation. This suggests that the local evaporation and Pacific Ocean are both crucial to the moisture supply of the two regions, implying the important roles of the land processes and adjacent oceanic sources. In addition, northeast Asia appears to be the major moisture source for east Siberia, whereas east Siberia has weak impacts on the moisture input for northeast Asia. Further analysis finds that the model simulation can capture interdecadal changes in summer precipitation over the two regions around the late 1990s. This interdecadal change is mainly manifested in the moisture supplies from the Pacific Ocean, North Atlantic Ocean, and east Siberia, which suggests a link with the circulation anomalies under the combined impacts of the Pacific decadal oscillation and the Atlantic multidecadal oscillation.

Изменение некоторых метеорологических показателей в бассейне Азовского моря

The results of research of trends in temperature and precipitation variability in the Azov sea basin are presented. The territory is an important agricultural and industrial area, the nature of which has undergone major changes. The paper considers changes in temperature and precipitation at stations located mainly in the steppe zone. The analysis of both long – term data and for the period 2001-2015 is carried out. Over the past 15-20 years there have been sig-nificant changes in climate features. A comparative analysis of annual and season changes is given. A steady warming trend has been established. An increase in annual temperatures by 0.4-2.8 °C, January - by 2.6-3.1 °C and July - by 0.7-2.1 °C. The study of air temperature by season showed that winter become warmer by 1.1 (Krasnodar) - 5.8 °C (Gigant). The temperature changed the least in summer in Uryupinsk and Frolovo (0.8-0.9 °C), the most in Krasnodar (2.2 °C). The precipitation trend is less noticeable. There is an increase in the amount of precipitation in the winter and autumn periods. In the spring the amount of precipitation increases for all the stations under unvestigation, with the exception for Voronezh and Chertkovo. In summer precipitation changes complicatedly. A decrease in precipita-tion prevails (Voronezh, Krasnodar, Matveev Kurgan, Taganrog, Gigant, Frolovo, Tsimlyansk) and a slight increase (Chertkovo, Armavir, Rostov, Uryupinsk, and Remontnoye).