Asymmetric Mean Annual Temperature Wavelets Surface Air Layer of Berlin for 1701-2021

The regularities of the dynamics of the average annual temperature of Ber­lin from 1701 to 2021 are revealed.A total of 65 wavelets were received.The temperature has a high quantum certainty,and the change in the aver­age annual temperature of Berlin was identified by a model that contains only two components for prediction.The basis of the forecast at 320 years makes it possible to look into the future until the year 2340.The forecast confirms the conclusions made in the CMIP5 report on global warming.With an increase in the number of components in the model up to five,the forecast is possible only until 2060.Therefore,the model with only two components is workable.The trend is characterized by a modified Man­delbrot equation showing exponential growth with a high growth rate of 1.47421.The wave equation also has an amplitude in the form of the Man­delbrot law(in mathematics,the Laplace law,in biology,the Zipf-Pearl law,in econometrics,the Pareto law),when the exponential growth activity is equal to 1.For 1701,the period of oscillation was 2×60.33333≈120.7 years.By 2021,the period decreased and became equal to 87.6 years.The trend is such that by 2340 the period of oscillation will decrease to 30.2 years.Such an increase in fluctuations indicates an imbalance in climate disturbances in temperature in Berlin.For Berlin,the last three years are characterized by sharp decreases in the average annual temperature from 11.8℃ to 10.5℃,i.e.by 12.4% in 2021.Therefore,the forecast is still unstable,as a further decrease in the average annual temperature of Berlin in the near future may change the picture of the forecast.

Temporal and spatial variation of annual mean air temperature in arid and semiarid region in northwest China over a recent 46 year period

We analyzed the 1961-2006 mean surface air temperature data of 138 stations in China’s northwest arid and semi-arid areas(CNASA),to measure climate change in terms of annual mean air temperature changes.We used methods of linear regression analysis,multinomial fitting,Empirical Or-thogonal Function(EOF),Rotated Empirical Orthogonal Function(REOF),Mann-Kendall,Glide T-examination,wavelet analysis and power spectrum analysis.The results show that(1) the warming rate of the annual mean air temperature in CNASA was 0.35oC/10a during the 1961-2006 study period.Some places in the west part of Xinjiang and east part of the Qinghai plateau,which is impacted by the terrain of leeward slope,exhibit smaller increasing trends.However,the majority of region has shown distinct warming in line with general global warming;(2) The standard deviation of the annual mean temperature distribution is non-uniform.The south Xinjiang and east Qinghai-south Gansu areas show relatively small standard deviations,but the inter-annual variation in annual mean air temperature in the greater part of the region is high;(3) Inner Mongolia,Shaanxi,Gansu,Ningxia and Tarim Basin are the areas where the temperature changes are most sensitive to the environment.The degree of uniformity in annual mean air temperature increase is higher in the arid and semi-arid area.From the early 1970s,the trend in tempera-ture changed from a decrease to an increase,and there was a marked increase in mean temperature in 1986.After that mean temperature went through a period of rapid increase.The entire area’s 10 hottest years all occurred in or since the 1990s,and 90% of various sub-districts’ hottest years also occurred after 1990.The process of temperature change appears to have a roughly 5-year and a 10-year cycle;(4) An-nual mean air temperature variation has regional differences.In Inner Mongolia-Xinjiang and Shaanxi-Gansu-Ningxia-Qinghai areas,the temperature variation in their northern areas was very different from that in their southern areas;(5) Using the REOF method we divided the region into 4 sub-regions:the Northern region,the Plateau region,the Southern Xinjiang region and the Eastern region.The region’s annual mean air temperature transition has regional differences.The Plateau and Southern Xinjiang re-gions got warmer steadily without any obvious acceleration in the rate of warming.The Northern region’s warming started about 5-years earlier than that of the low latitude Eastern region.The ’Startup region’ of the Qinghai-Tibet Plateau,appears to undergo temperature changes 3 to 10 years earlier than the other regions,and exhibits inter-decadal variations 1 to 2 years ahead of the other regions.

Global Annual Mean Surface Air Temperature Anomalies and Their Link with Indian Summer Monsoon Failures

Analysis of the global mean annual temperature anomalies based on land and marine data for the last 88 years (1901-1988) of this century has been carried out with a view to find any relationship with failures in Indian summer monsoon rainfall. On the climatological scale (i.e. 30 years) it has been noticed that there is an abnormal increase in the frequency of drought years during epochs of global warming and cooling, while it is considerably less when global temperatures are near normal. Results are unchanged even when the data are filtered out for ENSO (El-Nino Southern Oscillation) effect.It has also been noticed that during warm and cold epochs in global temperatures the amount of summer monsoon rainfall decreases as compared to the rainfall during a normal temperature epoch.

ESTIMATES OF CLIMATE NOISES OF ANNUAL MEAN TEMPERATURES OVER CHINA

In this paper,a design to estimate climate noise of annual mean temperature has been made by means of the mini- mum interannual variance and effectively independent observations in time series.By using it the climate noises of annu- al mean surface air temperatures have been estimated based on the data from 1960 to 1991 in this country.The low val- ues of climate noises of annual mean temperatures are found in the southeastern Tibet Plateau,Yunnan,the Sichuan Ba- sin and south of the middle and lower reaches of the Changjiang River Valley.The high values are seen in the northwestern and northeastern China and the rest of the Tibet Plateau.A relatively low value region is in the southern Xinjiang.

Biomass Components and Environmental Controls in Ningxia Grasslands

Grassland plays an important role in the global carbon cycle and climate regulation. However, there are still large uncertainties in grassland carbon pool and also its role in global carbon cycle due to the lack of measured grassland biomass at regional scale or global scale with a unified survey method, particular for below-ground biomass. The present study, based on a total of 44 grassland sampling plots with 220 quadrats across Ningxia, investigated the characteristics of above-ground biomass （AGB）, below-ground biomass （BGB）, litter biomass （LB）, total biomass （TB） and root：shoot ratios （R：S） for six predominantly grassland types, and their relationships with climatic factors. AGB, BGB, LB and TB varied markedly across different grassland types, the median value ranging from 28.2-692.6 g m-2 for AGB, 130.4-2 036.6 g m-： for BGB, 9.2-82.3 g m2 for LB, and 168.0-2 681.3 g m-： for TB. R：S showed less variation with median values from 3.2 to 5.3 （excluding marshy meadow）. The different grassland types showed similar patterns of biomass allocation, with more than 70% BGB for all types. There is evidence of strong positive effects associated with mean annual precipitation （MAP） and negative effects associated with mean annual temperature （MAT） on AGB, BGB, and LB, although both factors have the opposite effect on R：S.

Evaluating the grassland net primary productivity of southern China from 2000 to 2011 using a new climate productivity model

Grassland is the important component of the terrestrial ecosystems. Estimating net primary productivity （NPP） of grassland ecosystem has been a central focus in global climate change researches. To simulate the grassland NPP in southern China, we built a new climate productivity model, and validated the model with the measured data from different years in the past. The results showed that there was a logarithmic correlation between the grassland NPP and the mean annual temperature, and there was a linear positive correlation between the grassland NPP and the annual precipitation in southern China. Al these results reached a very signiifcant level （P〈0.01）. There was a good correlation between the simulated and the measured NPP, withR2 of 0.8027, reaching the very signiifcant level. Meanwhile, both root mean square errors （RMSE） and relative root-mean-square errors （RRMSE） stayed at a relatively low level, showing that the simulation results of the model were reliable. The NPP values in the study area had a decreasing trend from east to west and from south to north, and the mean NPP was 471.62 g C m？2 from 2000 to 2011. Additionaly, there was a rising trend year by year for the mean annual NPP of southern grassland and the tilt rate of the mean annual NPP was 3.49 g C m？2 yr？1 in recent 12 years. The above results provided a new method for grassland NPP estimation in southern China.

Mismatch between species distribution and climatic niche optima in relation to functional traits

Background:Forecasts of climate change impacts on biodiversity often assume that the current geographical distributions of species match their niche optima.However,empirical evidence has challenged this assumption,suggesting a mismatch.We examine whether the mismatch is related to functional traits along temperature or precipitation gradients.Methods:The observed distributions of 32 tree species in northeast China were evaluated to test this mismatch.Bayesian models were used to estimate the climatic niche optima,i.e.the habitats where the highest species growth and density can be expected.The mismatch is defined as the difference between the actual species occurrence in an assumed niche optimum and the habitat with the highest probability of species occurrence.Species’functional traits were used to explore the mechanisms that may have caused the mismatches.Results:Contrasting these climatic niche optima with the observed species distributions,we found that the distribution-niche optima mismatch had high variability among species based on temperature and precipitation gradients.However,these mismatches depended on functional traits associated with competition and migration lags only in temperature gradients.Conclusions:We conclude that more relevant research is needed in the future to quantify the mismatch between species distribution and climatic niche optima,which may be crucial for future designs of forested landscapes,species conservation and dynamic forecasting of biodiversity under expected climate change.

Study on Ann-Based Multi-Step Prediction Model of Short-Term Climatic Variation

In the context of 1905–1995 series from Nanjing and Hangzhou, study is undertaken of estab-lishing a predictive model of annual mean temperature in 1996–2005 to come over the Changjiang (Yangtze River) delta region through mean generating function and artificial neural network in combination. Results show that the established model yields mean error of 0.45°C for their abso-lute values of annual mean temperature from 10 yearly independent samples (1986–1995) and the difference between the mean predictions and related measurements is 0.156°C. The developed model is found superior to a mean generating function regression model both in historical data fit-ting and independent sample prediction. Key words Climate trend prediction. Mean generating function (MGF) - Artificial neural network (ANN) - Annual mean temperature (AMT)

Stability evaluation of radial growth of Picea schrenkiana in different age groups in response to climate change in the eastern Tianshan Mountains

Global warming causes an unstable response in tree radial growth at high latitudes in the Northern Hemisphere.Additionally,different climatic responses of different age groups of trees have been found due to their different physiological mechanisms.In this study,the response stability and growth trend of three age groups(young<100 a,middle 100-200 a,old≥200 a)of Picea schrenkiana(Schrenk spruce)to climate change and the causes of the different responses in different age groups were analyzed in the relatively dry climate of the eastern Tianshan Mountains.The results showed that:(1)With the abrupt increase in temperature in 1989,the annual mean minimum temperature became the dominant radial growth-limiting factor of the three age groups of Schrenk spruce.(2)The radial growth of the middle and young groups was more sensitive than that of the old group based on growth-climate correlation analysis.(3)The radial growth of the different age groups had different responses to climate factors,and all age groups were unstable on time scales.(4)The trend of the linear regression simulation of the basal area increment(BAI)indicated that the Schrenk spruce had the same growth trends in different age groups with growth first increased and then decreased;however,the decreased growth rate was higher in the middle and young age groups than in the old age group after the abrupt increase in temperature.Therefore,we should pay active attention to the impact of drought on Schrenk spruce in the eastern Tianshan Mountains and should particularly strengthen the conservation and management of the middle and young age groups.

Climate warming over 1961–2019 and impacts on permafrost zonation in Northeast China

In boreal forest ecosystems, permafrost and forest types are mutually interdependent;permafrost degradation impacts forest ecosystem structure and functions. The Xing’an permafrost in Northeast China is on the southern margin of the Eastern Asia latitudinal permafrost body. Under a warming climate, permafrost undergoes rapid and extensive degradation. In this study, the frost-number (Fn) model based on air temperatures and ground surface temperatures was used to predict the distribution of the Xing’an permafrost, and, temporal and spatial changes in air and ground-surface temperatures from 1961 to 2019 are analyzed. The results show that Northeast China has experienced a rapid and substantial climate warming over the past 60 years. The rises in mean annual air and mean annual ground-surface temperatures were higher in permafrost zones than those in the seasonal frost zone. The frost numbers of air and ground-surface temperatures were calculated for determining the southern limit of latitudinal permafrost and for permafrost zonation. The southern limits of discontinuous permafrost, sporadic permafrost, and latitudinal permafrost moved northward significantly. According to the air-temperature frost-number criteria for permafrost zoning, compared with that in the 1960s, the extent of Xing’an permafrost in Northeast China had decreased by 40.6% by the 2010s. With an average rate of increase in mean annual air temperatures at 0.03 ℃ a^(−1), the extent of permafrost in Northeast China will decrease to 26.42 × 10^(4) by 2020, 14.69 × 10^(4) by 2040 and to 11.24 × 10^(4) km^(2) by 2050. According to the ground-surface temperature frost-number criteria, the southern limit of latitudinal permafrost was at the 0.463. From the 1960s to the 2010s, the extent of latitudinal permafrost declined significantly. Due to the nature of the ecosystem-protected Xing’an-Baikal permafrost, management and protection (e.g., more prudent and effective forest fire management and proper logging of forests) of the Xing’an permafrost eco-environment should be strengthened.

Rapid range expansion predicted for the Common Grackle(Quiscalus quiscula)in the near future under climate change scenarios

Background:Climate change due to anthropogenic global warming is the most important factor that will affect future range distribution of species and will shape future biogeographic patterns.While much effort has been expended in understanding how climate change will affect rare and declining species we have less of an understanding of the likely consequences for some abundant species.The Common Grackle(Quiscalus quiscula;Linnaeus 1758),though declining in portions of its range,is a widespread blackbird(Icteridae)species in North America east of the Rocky Mountains.This study examined how climate change might affect the future range distribution of Common Grackles.Methods:We used the R package Wallace and six general climate models(ACCESS1-0,BCC-CSM1-1,CESM1-CAM5-1-FV2,CNRM-CM5,MIROC-ESM,and MPI-ESM-LR)available for the future(2070)to identify climatically suitable areas,with an ecological niche modelling approach that includes the use of environmental conditions.Results:Future projections suggested a significant expansion from the current range into northern parts of North America and Alaska,even under more optimistic climate change scenarios.Additionally,there is evidence of possible future colonization of islands in the Caribbean as well as coastal regions in eastern Central America.The most important bioclimatic variables for model predictions were Annual Mean Temperature,Temperature Seasonality,Mean Temperature of Wettest Quarter and Annual Precipitation.Conclusions:The results suggest that the Common Grackle could continue to expand its range in North America over the next 50 years.This research is important in helping us understand how climate change will affect future range patterns of widespread,common bird species.

Probable effects of heat advection on the adjacent environment during oil production at Prudhoe Bay, Alaska

The latest available data for mean annual air temperature at sites away from the Arctic coast in both Alaska and the Yukon Territory show no significant warming in the last 30-50 years. However, around the Arctic coast of northwest North America centered on Prudhoe Bay, the weather stations show significant warming of both the air and the ocean water, resulting in substantial losses in sea ice west of Prudhoe Bay. These changes appeared shortly after the commencement of shipment of oil through the Trans-Alaska Pipeline in 1977, but have now reached a quasi-stable thermal state. Since more than 17 trillion barrels of oil have passed through the pipeline after being cooled by the adjacent air, which in turn, can then result in the melting of the adjacent sea ice, there appears to be a very strong relationship between these events, and a marked lack of correlation with the changes of the content of greenhouse gases in the atmosphere. This contrasts with the IPCC interpretation of the available climatic data, which assumes that the maximum climatic warming at Prudhoe Bay is typical of the entire region and is the result of increasing greenhouse gases. Engineers need to consider heat advection by oil or gas from underground when designing pipeline facilities, and to take account of the potential environmental con-sequences that they may cause.

Response of Permafrost Thermal Regime to Climate Change over Northern Hemisphere in the 21st Century

Based on the CMIP5 simulation and numerical model, the permafrost thermal regimes over Northern Hemisphere land during the early (2016-2035), middle (2046-2065) and late (2080-2099) period of 21st century are projected, and its relationship with climate change is also analyzed. The results show that, relative to the reference period of 1986-2005, the mean annual ground temperature (MAGT) over Northern Hemisphere shows an increasing trend, with a decreasing trend of the depth of zero annual amplitude (DZAA), and the most significant changes occur in Siberia, Tibetan Plateau, Canada arctic and Alaska, and the changes in MAGT and DZAA grow larger with time and emission, especially during the LP for RCP8.5, MAGT will increase by 4 and DZAA decreases by 1.5 m (the relative change exceeds 20%) in most regions. The changes of permafrost in the 21st century mainly depend on the changes of cold permafrost. The relationship between MAGT and air temperature as well as that between DZAA and air temperature suggests that the increase of MAGT and the decrease of DZAA are related to the increase of air temperature in winter, especially in January. However, the rate of change in MAGT and DZAA gradually declines, with the temperature increasing.

Late Pleistocene spore-pollen record and climatic change at the Chongphadae Cave Site,Democratic People's Republic of Korea

We present a detailed pollen record and interpretations of late Pleistocene climatic change at the Chongphadae Cave Site, Democratic People's Republic of Korea. The mean annual paleotemperature and mean annual paleoprecipitation of the site were calculated using the temperature index and precipitation index based on ecological features and geographical distribution of each taxon. Temperature index and precipitation index range from 8.8℃ to 10.4℃ and from 805.0 mm to 963.1 mm, respectively. Four dates(radiocarbon, uranium series, fission track, and paleomagnetic excursion dating) of the deposit profile investigated yield a range of ~21.3 ka BP to ~117 ka BP, geochronologically corresponding to the late Pleistocene, and extend from the last interglacial highstand through the Last Glacial Maximum. Our results are thus consistent with the climatic shift from interglacial to glacial conditions, provide evidence that the environments of the region, which was reconstructed from the paleoclimatic index, changed from a mild and humid to a cool and dry climate during the late Pleistocene, and suggest trends similar to those of several parts of the Northern Hemisphere which lie in the same latitudinal zone as our study area.

Climatic effects on soil organic nitrogen fractions and amino acid chirality in paddy soils

Soil organic nitrogen(ON)accounts for more than 90%of the total nitrogen(TN)in paddy soils.Inadequate understanding of the different ON fractions in paddy soils and their corresponding bioavailability under different climatic conditions has constrained the development of appropriate nutrient management strategies for rice production.In this study,we applied a modified Bremner method coupled with high-performance liquid chromatography to characterize how soil ON fractions and amino acid chirality varied under different climatic conditions at five typical rice production sites along a latitudinal gradient.According to the results,climate had no obvious influence on TN,nitrogen(N)form,and individual amino acid contents.However,the proportions of various N forms in TN had linear relationships with annual mean temperature(AMT),with high correlation coefficient(r)values.Amino acid components also exhibited similar trends,with r as high as 0.85.Most notably,consistent linear relationships were observed between the D/L ratios of several amino acids and AMT in paddy soils(r=0.18–0.92).Findings of this study provide insights into ON and amino acid dynamics in paddy soil systems under intensive production along climate gradients.

Variations of root and heterotrophic respiration along environmental gradients in China’s forests

Aims Root and heterotrophic respiration may respond differently to environmental variability,but little evidence is available from largescale observations.Here we aimed to examine variations of root and heterotrophic respiration across broad geographic,climatic,soil and biotic gradients.Methods We conducted a synthesis of 59 field measurements on root and heterotrophic respiration across China’s forests.Important Findings Root and heterotrophic respiration varied differently with forest types,of which evergreen broadleaf forest was significantly different from those in other forest types on heterotrophic respiration but without statistically significant differences on root respiration.The results also indicated that root and heterotrophic respiration exhibited similar trends along gradients of precipitation,soil organic carbon and satellite-indicated vegetation growth.However,they exhibited different relationships with temperature:root respiration exhibited bimodal patterns along the temperature gradient,while heterotrophic respiration increased monotonically with temperature.Moreover,they showed different relationships with MOD17 GPP,with increasing trend observed for root respiration whereas insignificant change for heterotrophic respiration.In addition,root and heterotrophic respiration exhibited different changes along the age sequence,with insignificant change for root respiration and decreasing trend for heterotrophic respiration.Overall,these results suggest that root and heterotrophic respiration may respond differently to environmental variability.Our findings could advance our understanding on the different environmental controls of root and heterotrophic respiration and also improve our ability to predict soil CO_(2) flux under a changing environment.

Changes in fine root biomass of Picea abies forests:predicting the potential impacts of climate change

Aims the impact of global warming on belowground processes,espe-cially on fine root production,is poorly understood in comparison with its aboveground counterpart.Methods Here,we compiled 227 measurements to assess the influence of temperature and precipitation on fine root biomass of Norway spruce(Picea abies[L.]Karst)forest ecosystems in the Eurasia boreal region.Important Findings We found that fine root biomass decreased significantly with lati-tudes.there was a biomass increase of 0.63 Mg ha−1 and 0.32 Mg ha−1 for fine roots<2 and<1 mm in diameter,respectively,with 1°C increase of mean annual temperature.there was an increase of 0.5 and 0.1 Mg ha−1 per 100 mm year−1 precipitation for the two size classes of fine roots.If the adaption of root production can match the pace of global warming and water is not a limiting factor for plant growth,fine root biomass would be expected to increase by 40-140%in response to the predicted increase in tem-perature(3-10°C)over the next century.Our analyses highlighted the strongly positive influences of temperature and precipitation on belowground function,suggesting that predicted future climate change could substantially enhance belowground biomass in the boreal region where the greatest warming is anticipated.this potential increase of belowground biomass,coupled with aboveground biomass,may provide a better understanding of climate-ecosystem feedbacks.

Simulation of permafrost changes on the Qinghai–Tibet Plateau, China, over the past three decades

Permafrost is one of the largest elements of the terrestrial cryosphere and is extremely sensitive to climate change.Based on mean annual ground temperature(MAGT)data from 189 boreholes on the Qinghai–Tibet Plateau(QTP),terrain factors,and climate data from China Meteorological Forcing Dataset,we propose a new mean annual ground air temperature(MAGAT)statistical model between meteorological parameters with subsurface temperatures to simulate permafrost distribution and variation of MAGT on the QTP over the past three decades(1981–2010).Validation of the model with MAGT data from 13 boreholes and permafrost maps of the QTP indicated that the MAGAT model is applicable to simulate the distribution and evolution of permafrost on the QTP.Simulation results show that the spatiotemporal MAGT of permafrost significantly increased by 0.37℃,or 0.25℃/10 yr,and the total area of permafrost decreased by 2.48×10^(5)km^(2) on the QTP over the past three decades.Regionally,the changes of permafrost in the southwestern QTP were greater than other regions of the QTP.