The method of the medium-range forecast of air temperature in the area of the “Baikonur” cosmodrome

The statistical model of the forecast (complex postprocessing) of surface air temperature with the lead time up to eight days is constructed using the results of the integration of hydrodynamic atmospheric models. The model is adapted to the area of the “Baikonur” using the method of central typing that allows increasing the accuracy of operational forecasts. The analysis of climate characteristics needed for constructing the proper statistical model for this area is given using both observational data for recent 25 years and the data of WMO (from the All-Russian Research Institute of Hydro-meteorological Information-World Data Center). Computed are the estimates of the accuracy of operational forecasts.     

Near-term increase in frequency of seasonal temperature extremes prior to the 2°C global warming target

Given current international efforts to reduce greenhouse gas emissions and limit human-induced global-mean near-surface temperature increases to 2°C, relative to the pre-industrial era, we seek to determine the impact such a temperature increase might have upon the frequency of seasonal-mean temperature extremes; further we seek to determine what global-mean temperature increase would prevent extreme temperature values from becoming the norm. Results indicate that given a 2°C global mean temperature increase it is expected that for 70–80% of the land surface maximum seasonal-mean temperatures will exceed historical extremes (as determined from the 95th percentile threshold value over the second half of the 20th Century) in at least half of all years, i.e. the current historical extreme values will effectively become the norm. Many regions of the globe—including much of Africa, the southeastern and central portions of Asia, Indonesia, and the Amazon—will reach this point given the “committed” future global-mean temperature increase of 0.6°C (1.4°C relative to the pre-industrial era) and 50% of the land surface will reach it given a future global-mean temperature increase of between 0.8 and 0.95°C (1.6–1.75°C relative to the pre-industrial era). These results suggest substantial fractions of the globe could experience seasonal-mean temperature extremes with high regularity, even if the global-mean temperature increase remains below the 2°C target.     

Decadal oscillations in rainfall and air temperature in the Paute River Basin—Southern Andes of Ecuador

In the Andes environment, rainfall and temperature can be extremely variable in space and time. The determination of climate variability and climate change needs a special assessment for water management. This paper examines the anomalies of observed monthly rainfall and temperature data from 25 to 16 stations, respectively, from the early 1960s to the 1990s. The stations are located in the Rio Paute Basin in the Ecuador’s Southern Andes. All stations are within the elevation band 1,800 and 4,200?m?a.s.l. and affected by the Tropical Pacific, Amazon, and Tropical Atlantic climate. Anomalies in quantiles were determined for each station and their significance tested. In addition, their correlations with different external climatic influences were studied for anomalies in annual and 3-month seasonal block periods. The results show similar temperature variations for the entire region, which are highly influenced by the El Ni?o–Southern Oscillation, especially during the December–February season. During June–August, the correlation is weaker showing the influence of other climate factors. Higher temperature anomalies are found at the high elevation sites while at deep valley sites the anomalies are less significant. Rainfall variations depend, in addition to elevation, on additional factors such as the aspect orientation, slope, and hydrological regime. The highest and most significant rainfall anomalies are found in the eastern sites.     

Peculiarities of surface air temperature variations over the Far East regions in 1976–2005

Peculiarities are investigated of the air temperature variation tendencies at some stations of the Far East in 1976–2005. The estimate of linear trend equation coefficients is computed according to the air temperature observation data using the least squares method. It is demonstrated that the air temperature trend in northern regions possesses a small probability at small values of residual variability. In the southern regions, the trend significance increases for almost all seasons at small values of residual variability. At midlatitude stations, the trend significance in January and February decreases considerably due to the large values of residual variability.     

The Warming of the Tibetan Plateau in Response to Transient and Stabilized 2.0°C/1.5°C Global Warming Targets

As "the third pole", the Tibetan Plateau (TP) is sensitive to climate forcing and has experienced rapid warming in recent decades. This study analyzes annual and seasonal near-surface air temperature changes on the TP in response to transient and stabilized 2.0°C/1.5°C global warming targets based on simulations of the Community Earth System Model (CESM). Elevation-dependent warming (EDW) with faster warming at higher elevations is predicted. A surface energy budget analysis is adopted to uncover the mechanisms responsible for the temperature changes. Our results indicate a clear amplified warming on the TP with positive EDW in 2.0°C/1.5°C warmer futures, especially in the cold season. Mean TP warming relative to the reference period (1961–90) is dominated by an enhanced downward longwave radiation flux, while the variations in surface albedo shape the detailed pattern of EDW. For the same global warming level, the temperature changes under transient scenarios are ~0.2°C higher than those under stabilized scenarios, and the characteristics of EDW are broadly similar for both scenarios. These differences can be primarily attributed to the combined effects of differential downward longwave radiation, cloud radiative forcing, and surface sensible and latent heat fluxes. These findings contribute to a more detailed understanding of regional climate on the TP in response to the long-term climate goals of the Paris Agreement and highlight the differences between transient and stabilized warming scenarios.     

Assessing the strength of regional changes in near-surface climate associated with a global warming of 2°C

In this study, the strength of the regional changes in near-surface climate associated with a global warming of 2°C with respect to pre-industrial times is assessed, distinguishing between 26 different regions. Also, the strength of these regional climate changes is compared to the strength of the respective changes associated with a markedly stronger global warming of 4.5°C. The magnitude of the regional changes in climate is estimated by means of a normalized regional climate change index, which considers changes in the mean as well as changes in the interannual variability of both near-surface temperature and precipitation. The study is based on two sets of four ensemble simulations with the ECHAM5/MPI-OM coupled climate model, each starting from different initial conditions. In one set of simulations (1860–2200), the greenhouse gas concentrations and sulphate aerosol load have been prescribed according to observations until 2000 and according to the SRES A1B scenario after 2000. In the other set of simulations (2020–2200), the greenhouse gas concentrations and sulphate aerosol load have been prescribed in such a way that the simulated global warming does not exceed 2°C with respect to pre-industrial times. The study reveals the strongest changes in near-surface climate in the same regions for both scenarios, i.e., the Sahara, Northern Australia, Southern Australia and Amazonia. The regions with the weakest changes in near-surface climate, on the other hand, vary somewhat between the two scenarios except for Western North America and Southern South America, where both scenarios show rather weak changes. The comparison between the magnitude of the regional changes in near-surface climate for the two scenarios reveals relatively strong changes in the 2°C-stabilization scenario at high northern latitudes, i.e., Northeastern Europe, Alaska and Greenland, and in Amazonia. Relatively weak regional climate changes in this scenario, on the other hand, are found for Eastern Asia, Central America, Central South America and Southern South America. The ratios between the regional changes in the near-surface climate for the two scenarios vary considerably between different regions. This illustrates a limitation of obtaining regional changes in near-surface climate associated with a particular scenario by means of scaling the regional changes obtained from a widely used “standard” scenario with the ratio of the changes in the global mean temperature projected by these two scenarios.     

A Study of the Impacts of the Spatial Differences in Climate Engineering Programs on the Extreme Intensities of High-Temperature Events in China Under A 1.5°C Temperature Control Target

Based on the daily maximum temperature data and average temperature data prediction for the period ranging from 2020 to 2099 under the scenario of BNU-ESM climate engineering (G4 test) and non-climate engineering (RCP4.5), the regional differences in the extreme high-temperature intensities in China during the implementation of climate engineering programs (2020 to 2069) and after the implementation of those programs (2070 to 2099) were analyzed using a Weibull Distribution Theory. The results indicated the following: (1) The results of this study’s comparison between the two scenarios had shown that climate engineering had not fundamentally changed the spatial features of the high and low differentiations for the extreme high-temperature intensities with the different recurrence periods in China. It was found that in both scenarios, the extreme high-temperature intensities were characterized by the spatial differentiations of low-temperature intensities on the Qinghai-Tibet Plateau, and high-temperature intensities in the eastern and northwestern region; (2) This study’s comparison results of the two scenarios had indicated that the climate engineering processes during the two study periods could potentially help mitigate the extreme high-temperature intensities with different recurrence periods in China. Furthermore, the mitigation effects during the implementation period would be significantly higher than those after the implementation; (3) This study’s results of the comparison between the periods ranging from 2020 to 2069 and 2070 to 2099 under the proposed climate engineering scenarios suggested that there would be no strong rebounding of the extreme high-temperatures following the implementation of climate engineering programs, and the mitigation effects on the extreme high-temperature intensities during the implementation of the climate engineering programs would be significantly higher than after the implementation of the programs; (4) When comparisons were made of the changes of the average temperatures in China before and after the implementation of climate engineering programs, the results had shown that the average temperature in China had been reduced by at least 1.25℃ as a result of climate engineering, which would effectively alleviate the global warming trend, and could also be conducive to the realization of a temperature control target of 1.5℃ in accordance with the Paris Agreement.     

Changes in Extreme Maximum Temperature Events and Population Exposure in China under Global Warming Scenarios of 1.5 and 2.0°C: Analysis Using the Regional Climate Model COSMO-CLM

We used daily maximum temperature data (1986–2100) from the COSMO-CLM (COnsortium for Small-scale MOdeling in CLimate Mode) regional climate model and the population statistics for China in 2010 to determine the frequency, intensity, coverage, and population exposure of extreme maximum temperature events (EMTEs) with the intensity–area–duration method. Between 1986 and 2005 (reference period), the frequency, intensity, and coverage of EMTEs are 1330–1680 times yr^–1, 31.4–33.3°C, and 1.76–3.88 million km², respectively. The center of the most severe EMTEs is located in central China and 179.5–392.8 million people are exposed to EMTEs annually. Relative to 1986–2005, the frequency, intensity, and coverage of EMTEs increase by 1.13–6.84, 0.32–1.50, and 15.98%–30.68%, respectively, under 1.5°C warming; under 2.0°C warming, the increases are 1.73–12.48, 0.64–2.76, and 31.96%–50.00%, respectively. It is possible that both the intensity and coverage of future EMTEs could exceed the most severe EMTEs currently observed. Two new centers of EMTEs are projected to develop under 1.5°C warming, one in North China and the other in Southwest China. Under 2.0°C warming, a fourth EMTE center is projected to develop in Northwest China. Under 1.5 and 2.0°C warming, population exposure is projected to increase by 23.2%–39.2% and 26.6%–48%, respectively. From a regional perspective, population exposure is expected to increase most rapidly in Southwest China. A greater proportion of the population in North, Northeast, and Northwest China will be exposed to EMTEs under 2.0°C warming. The results show that a warming world will lead to increases in the intensity, frequency, and coverage of EMTEs. Warming of 2.0°C will lead to both more severe EMTEs and the exposure of more people to EMTEs. Given the probability of the increased occurrence of more severe EMTEs than in the past, it is vitally important to China that the global temperature increase is limited within 1.5°C.