Cumulative Anomalies Research Articles

Trends of the Intra‐Annual Onset and End of Humid Heatwaves in the Northern Hemisphere

AbstractHumid heatwaves negatively affect human health due to the integrating effect of temperature and humidity, and thus the early warning and timely mitigating on climate extremes are essential. Yet, systematic assessment on the intra‐annual onset and end of humid heatwaves, which is associated to the occurrence of first and last humid heatwaves, are missing globally. Using a new station‐based data set of daily maximum wet‐bulb temperature, the start and end dates, cumulative anomaly and extremely humid heat of the first and last humid heatwaves in the Northern Hemisphere were explored. It was found that at 91.54% of stations, humid heatwaves started earlier or ended later in the period of 2001–2020 compared to 1981–2000. High cumulative anomalies of the first or last humid heatwaves were found in the mid‐ and high‐latitude regions. Average difference between all humid heatwaves and the first humid heatwaves in cumulative anomalies increased steadily at stations north of 35°N. At regional scales, South East Asia had become the most prominent area with intensification of intra‐annual onset and end of humid heatwaves and will experience more frequent extreme events by 2100. Our findings demonstrated more intensified characteristics of the intra‐annual onset and end of humid heatwaves, calling for global awareness.

Spatiotemporal Distribution Characteristics of Actual Evapotranspiration in the Qinghai–Tibet Plateau

Evapotranspiration is a key part of the water cycle between the atmosphere and the land surface, and it is an important parameter for studying the land–atmosphere system. Change and evolution have important implications. Therefore, the understanding and research of actual evapotranspiration (AET) can profoundly affect water use, ecological environment, temperature, and precipitation. In this paper, the single-layer monthly average reanalysis meteorological data of the Qinghai–Tibet Plateau from 1981 to 2020 was used to study and calculate the actual evapotranspiration in the Qinghai–Tibet Plateau, and the temporal and spatial variation characteristics, variation laws, and changes were analyzed by methods such as cumulative anomalies and the Mann–Kendall trend test. The results showed the following: (1) The evapotranspiration gradually decreased from southeast to northwest. The evapotranspiration in the southeastern region is strong, and the maximum value appears in the Hengduan Mountains. (2) The evapotranspiration was the largest in summer and gradually decreased from southeast to northwest; the evapotranspiration in spring and autumn was relatively uniform, with little overall difference, and the evapotranspiration was the lowest in winter. (3) There were mainly three spatial distribution modes of evapotranspiration in the Qinghai–Tibet Plateau, which were characterized by a significant and consistent change centered on the Tibet region, an east–west reverse type, and an east–west “negative-positive-negative” of the distributed three-pole space. The corresponding time coefficients characterized the interdecadal and interannual variation, and the decadal variation characteristics are more significant than the annual variation characteristics. (4) The actual evapotranspiration had step change; the step change years were 1989, 2002, 2011, and 2015, and there was an interval of about 5 years.

Season Onset Prediction Based on Statistical Model for Malang Regency, East Java

Prediction of season onset is important for many sectors, particularly on agricultural practices, as its usage for reducing climate risk and planning activities. Current knowledge on season onset prediction mainly focused on large area, which remains research challenge for local level. This research developed model prediction of season onset for Malang Regency, East Java based on global climate data. The research specifically aimed to: (i) determine the onset date of rainy and dry season, (ii) generate equation for onset date prediction using principal component regression (PCR) approach, and (iii) evaluate the model performance. We depend on statistical model based on a combine of domain time and principal component analysis (PCA) for atmospheric variables, namely sea level pressure, outgoing longwave radiation, and zonal wind. We used the Tropical Rainfall Measuring Mission (TRMM) data for model evaluation, especially for determination of onset date. Based on cumulative anomalies rainfall, the onset date for dry season occurred in the early May, whereas for rainy season it was in early November. The results showed that regression models of the principal components had a good skill to predict onset date for both seasons. It has been confirmed by a low error and a high correlation. Visually, the dynamic of onset dates from model was mostly identical to the observation. The predictive model for rainy season had higher performance compared to the model for dry season. This finding was confirmed by insignificant difference resulted from the independent t-test between model and observed onset dates. The best model for dry season was conducted by domain time of February, whereas for rainy season was domain time of August. This research can be used to complement previous studies regarding season onset prediction in Indonesia.

Effects of climate changes and road exposure on the rapidly rising legionellosis incidence rates in the United States.

Legionellosis is an infection acquired through inhalation of aerosols that are contaminated with environmental bacteria Legionella spp. The bacteria require warm temperature for proliferation in bodies of water and moist soil. The legionellosis incidence in the United States has been rising rapidly in the past two decades without a clear explanation. In the meantime, the US has recorded consecutive years of above-norm temperature since 1997 and precipitation surplus since 2008. The present study analyzed the legionellosis incidence in the US during the 20-year period of 1999 to 2018 and correlated with concurrent temperature, precipitation, solar ultraviolet B (UVB) radiation, and vehicle mileage data. The age-adjusted legionellosis incidence rates rose exponentially from 0.40/100,000 in 1999 (with 1108 cases) to 2.69/100,000 in 2018 (with 9933 cases) at a calculated annual increase of 110%. In regression analyses, the rise correlated with an increase in vehicle miles driven and with temperature and precipitation levels that have been above the 1901–2000 mean since 1997 and 2008, respectively, suggesting more road exposure to traffic-generated aerosols and promotive effects of anomalous climate. Remarkably, the regressions with cumulative anomalies of temperature and precipitation were robust (R2 ≥ 0.9145, P ≤ 4.7E-11), implying possible changes to microbial ecology in the terrestrial and aquatic environments. An interactive synergy between annual precipitation and vehicle miles was also found in multiple regressions. Meanwhile, the bactericidal UVB radiation has been decreasing, which also contributed to the rising incidence in an inverse correlation. The 2018 legionellosis incidence peak corresponded to cumulative effects of the climate anomalies, vast vehicle miles (3,240 billion miles, 15904 km per capita), record high precipitation (880.1 mm), near record low UVB radiation (7488 kJ/m2), and continued above-norm temperature (11.96°C). These effects were examined and demonstrated in California, Florida, New Jersey, Ohio, and Wisconsin, states that represent diverse incidence rates and climates. The incidence and above-norm temperature both rose most in cold Wisconsin. These results suggest that warming temperature and precipitation surplus have likely elevated the density of Legionella bacteria in the environment, and together with road exposure explain the rapidly rising incidence of legionellosis in the United States. These trends are expected to continue, warranting further research and efforts to prevent infection.

Ocean‐Induced Melt Triggers Glacier Retreat in Northwest Greenland

AbstractIn recent decades, tidewater glaciers in Northwest Greenland contributed significantly to sea level rise but exhibited a complex spatial pattern of retreat. Here we use novel observations of bathymetry and water temperature from NASA's Ocean Melting Greenland mission to quantify the role of warm, salty Atlantic Water in controlling the evolution of 37 glaciers. Modeled ocean‐induced undercutting of calving margins compared with ice advection and ice front retreat observed by satellites from 1985 to 2015 indicate that 35 glaciers retreated when cumulative anomalies in ocean‐induced undercutting rose above the range of seasonal variability of calving‐front positions, while two glaciers standing on shallow sills and colder water did not retreat. Deviations in the observed timing of retreat are explained by residual uncertainties in bathymetry, inefficient mixing of waters in shallow fjords, and the presence of small floating sections. Overall, warmer ocean temperature triggered the retreat, but calving processes dominate ablation (71%).

Recent speed‐up of an alpine rock glacier: an updated chronology of the kinematics of outer hochebenkar rock glacier based on geodetic measurements

Surface velocities have been regularly monitored at the rock glacier in Outer Hochebenkar, Ötztal Alps, Austria since the early 1950s. This study provides an update to previously published surface velocity time series, showing mean profile velocities of four cross profiles since the beginning of the measurements (1951,1954, 1997; depending on the profile), as well as single block displacements from 1998 to 2015. Profiles P1, P2 and P3 have moved between 42 and 90 m, at mean velocities between 0.70 and 1.48 m yr–1, since they were first established in the early 1950s (1951/54). Profile P0, established in 1997, has since moved 13 m or 0.75 m yr–1. An acceleration can be observed at all profiles since the late 1990s, with a particularly sharp velocity increase since 2010. All profiles reached a new maximum velocity in 2015, with 1.98 m yr–1 at the slowest profile (P0) and 6.37 m yr–1 at the fastest profile (P1). Year‐to‐year variations in profile velocities cannot be clearly attributed to inter‐annual variations of climatic parameters like mean annual air temperature, summer temperature, positive degree days, or precipitation. However, higher correlation is found between velocities and cumulative anomalies of air temperature (mean annual air temperature and positive degree days) and summer precipitation, suggesting that these parameters play a key role for the movement of the rock glacier. The lower profiles (P0, P1) show more pronounced year‐to‐year variations than the upper profiles (P2, P3). It is considered likely that processes other than climatic forcing (e.g. sliding, topography) contribute to the different velocity patterns at the four profiles.

A satellite-based terrestrial water storage indicator to assess the severity of a heatwave

The emergence and development of improved tools for monitoring the occurrence, timing and duration of droughts and heatwaves are very important for water security purposes, with further implications for food security, water quality and hydropower production, among others. Unlike conventional studies that use climate and ecosystem data to assess the impact of droughts and heatwaves on land surface processes occurring at the terrestrial surface (precipitation, temperature and vegetation indexes) or in the shallow layers of the subsurface (soil water content), recent studies have characterized the severity of droughts over large regions (>100 000 km2) based on satellite observations of terrestrial water storage variations (Houbourg et al. 2012, Thomas et al. 2014). Such indicators can be used as a proxy to estimate the duration and magnitude of water deficit events. This work proposes a new methodology aimed at describing the variability of water storage deficits over space and time in three regions that suffered prominent dry spells over the last decade: Eastern Russia, the Middle East and the Western Sahel (Fig. 1). To accomplish this objective, we investigate the impact of the 2010 Northern Hemisphere summer heatwave on cumulative terrestrial water storage anomalies detected by the Gravity Recovery and Climate Experiment (GRACE) followed by a space–time aggregation. The concept of water storage deficit as defined by Thomas et al. (2014) is estimated and a deficit–duration–area curve is built for each region.

Changes in Arctic melt season and implications for sea ice loss

AbstractThe Arctic‐wide melt season has lengthened at a rate of 5 days decade−1 from 1979 to 2013, dominated by later autumn freezeup within the Kara, Laptev, East Siberian, Chukchi, and Beaufort seas between 6 and 11 days decade−1. While melt onset trends are generally smaller, the timing of melt onset has a large influence on the total amount of solar energy absorbed during summer. The additional heat stored in the upper ocean of approximately 752 MJ m−2 during the last decade increases sea surface temperatures by 0.5 to 1.5 °C and largely explains the observed delays in autumn freezeup within the Arctic Ocean's adjacent seas. Cumulative anomalies in total absorbed solar radiation from May through September for the most recent pentad locally exceed 300–400 MJ m−2 in the Beaufort, Chukchi, and East Siberian seas. This extra solar energy is equivalent to melting 0.97 to 1.3 m of ice during the summer.

Soil gas composition above gas deposits and perspective structures of the Carpathian Foredeep, SE Poland

Abstract In 2001 a surface geochemical survey was carried out in the Carpathian Foredeep, in the area between Jaroslaw and Radymno (SE Poland) where multihorizon gas deposits were discovered. These deposits accumulate microbial CH 4 with small amounts of N 2 and higher molecular weight gaseous hydrocarbons. Soil–gas composition in the hydrocarbon fields in the study area is relatively different from the original composition of natural gas occurring in the subsurface reservoir. In 449 analyzed soil gas samples collected from 1.2 m depth relatively low concentrations were found for CH 4 (median value 2.2 ppm) and its homologues (median value of total alkanes C 2 –C 4 – 0.02 ppm). Alkenes were encountered in 36.3% of the analyzed samples (mean value of total alkenes C 2 –C 4 – 0.015 ppm) together with distinctly higher concentrations of H 2 (maximum value – 544 ppm, mean value – 42 ppm) and CO 2 (maximum value – 10.26 vol.%, mean value – 2.27 vol.%). Individual, very high concentrations of CH 4 (up to about 35 vol.%) resulted from sub-surface biochemical reactions whereas higher alkanes detected in soil gases (up to about 68 ppm) originated from deep gas accumulations. Both the H 2 and alkenes may be indirect indicators of deep hydrocarbon accumulations. Carbon dioxide may also be useful for hydrocarbon exploration, revealing increased concentrations in those sampling sites where CH 4 concentrations are strongly depleted, presumably due to bacterial oxidation. These relationships are valid only for the study area and should not be extended as an universal principle. The interpreted zones of cumulative anomalies of CH 4 , higher molecular weight gaseous hydrocarbons, H 2 and CO 2 related to the results of geological and geophysical studies directly or indirectly point to the presence of undiscovered, deep gas accumulations and suggest larger sizes for known deposits. The character of the anomalies along with the relationships between the components of soil gases support the opinion that gas accumulations occur at various depths. Moreover, the results indicate that the surface geochemical pattern is significantly influenced by tectonic discontinuities.

Long term variability of the annual hydrological regime and sensitivity to temperature phase shifts in Saxony/Germany

Abstract. Recently, climatological studies report observational evidence of changes in the timing of the seasons, such as earlier timing of the annual cycle of surface temperature, earlier snow melt and earlier onset of the phenological spring season. Also hydrological studies report earlier timing and changes in monthly streamflows. From a water resources management perspective, there is a need to quantitatively describe the variability in the timing of hydrological regimes and to understand how climatic changes control the seasonal water budget of river basins. Here, the timing of hydrological regimes from 1930–2009 was investigated in a network of 27 river gauges in Saxony/Germany through a timing measure derived by harmonic function approximation of annual periods of runoff ratio series. The timing measure proofed to be robust and equally applicable to both mainly pluvial river basins and snow melt dominated regimes. We found that the timing of runoff ratio is highly variable, but markedly coherent across the basins analysed. Differences in average timing are largely explained by basin elevation. Also the magnitude of low frequent changes in the seasonal timing of streamflow and the sensitivity to the changes in the timing of temperature increase with basin elevation. This sensitivity is in turn related to snow storage and release, whereby snow cover dynamics in late winter explain a large part of the low- and high-frequency variability. A trend analysis based on cumulative anomalies revealed a common structural break around the year 1988. While the timing of temperature shifted earlier by 4 days, accompanied by a temperature increase of 1 K, the timing of runoff ratio within higher basins shifted towards occurring earlier about 1 to 3 weeks. This accelerated and distinct change indicates, that impacts of climate change on the water cycle may be strongest in higher, snow melt dominated basins.

Climatic fluctuations in southern Italy since the 17th century: reconstruction with precipitation records at Benevento

This work analyses the climatic information of 607 weather anomalies belonging to a large documentary sources heritage of the continental southern Italy during the period 1675–1868. The collected information, mainly originating in Samnium River Region (SRR), were codified to obtain quantitative indices representative of a preliminary reconstruction of the precipitation anomalies. Historical written records of weather conditions that affect agriculture and living conditions have been taken as a proxy for instrumental observations of the relative wetness and dryness. As a consequence a numerical index was established to characterize the rainfall regime and its evolution. So, for the first time a series of the precipitation anomalies in SRR–continental southern Italy during the second half of the Little Ice Age was generated, and subsequently jointed to the instrumental series (1869–2002). Afterwards, in order to identify possible climatic change situations from 1675 today Normalized Cumulative Anomalies (NCA)–serie's and Climograms were produced. This historical period offered a sufficient range of natural variability in climate and circulation together with their relationships. Wettest period were detected in the 19th century, while that driest in the 18th century. However, the Mediterranean climate appearing from our study is far more complex than can be captured by a simple classification. In this way, the final picture is one switching between significantly different climate modes becoming apparent on several space-time-scales during the Late Little Ice Age.

Assessment and mechanism of variations in pubertal timing in internationally adopted children: a developmental hypothesis

During the past decades, children migrating for international adoption have increased in number, creating an original condition of dramatic environmental change during development. In several countries, cohorts of these subjects have been shown to experience a global advancement in age at the onset of puberty, and sexual precocity is seen more frequently than in other conditions. Such early or precocious development has been assessed in relatively small cohorts or individual patients using well-defined physical indicators in comparison with updated references in the foster country. Family and adolescent evaluation of pubertal timing could allow for the study of large series of internationally adopted subjects. Also, this type of assessment integrates the physical changes of puberty with the adolescent changes in psychological and social functioning. The pathophysiological mechanisms leading to advancement of puberty in migrating children are still unclear and possibly involve several factors. In the present paper, we hypothesize that the sexual precocity in children migrating for international adoption could represent a developmentally programmed disorder resulting from cumulative anomalies in early remodeling of the central nervous system by communicational, social, nutritional, and hormonal inputs. There is some evidence that the deviations in those inputs can result in altered brain structure, particularly in the limbic system. We discuss the possible association with further disorders of developmental functions, such as cognitive, psychosocial, and sexual maturation. Along this hypothesis, some forms of idiopathic sexual precocity could result from dysfunction of one or several of the environmental programming factors, while other forms may involve predominantly genetic or familial factors.

Observed climatic changes in Shanghai during 1873–2002

Variation characteristics of temperature and precipitation in January and July and annual mean temperature and annual precipitation are analyzed with the help of cumulative anomalies, Mann-Kendall analysis and wavelet analysis. The research results indicate that January precipitation presents an increasing trend after 1990, wavelet analysis result suggests that this increasing trend will continue in the near future. The changes of July precipitation present different features. During 1900–1960, July precipitation is in a rising trend, but is in a declining trend after 1960. Wavelet analysis shows that this declining trend will go on in the near future. Temperature variations in Shanghai are in fluctuations with 2 to 3 temperature rising periods. Mann-Kendall analysis indicates that temperature variations have the obvious abrupt change time when compared with precipitation changes in Shanghai during the past 100 years. The abrupt change time of January temperature lies in 1985, and that of July temperature lies in 1931–1933 and annual mean temperature has the abrupt change time in 1923–1930. Except July precipitation, the precipitation in January, temperature in January, July and annual mean temperature, and annual precipitation are also in a rising trend in the near future. The research results in this paper may be meaningful for future further climatic changes of Shanghai and social mitigation of climatic disasters in the future.