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AbstractHuman and climate induced land surface changes resulting from irrigation, snow cover decreases, and greening impact the surface albedo over High Mountain Asia (HMA). Here we use a partial information decomposition approach and remote sensing data to quantify the effects of the changes in leaf area index, soil moisture, and snow cover on the surface albedo in HMA, home to over a billion people, from 2003 to 2020. The study establishes strong evidence of anthropogenic agricultural water use over irrigated lands (e.g., Ganges–Brahmaputra) which causes the highest surface albedo decreases (≤ 1%/year). Greening and decreased snow cover from warming also drive changes in visible and near-infrared surface albedo in different areas of HMA. The significant role of irrigation and greening in influencing albedo suggests the potential of a positive feedback cycle where albedo decreases lead to increased evaporative demand and increased stress on water resources.

A study has been carried out to analyse the temporal and seasonal patterns in the trends of diurnal air temperature range (DTR) and its components in Shaheed Benazir Abad for the time period 1996–2014.The magnitude, the slope and the significance of trends were investigated by using the linear regression method, the trend magnitude, the Mann-Kendall test and the Sen’s estimator of slope. The Mann-Kendall test and Sen's estimator of slope were calculated by using Addinsoft's XLSTAT 2015 software. The hypothesis of Mann-Kendall test was investigated at 95% confidence level for all variables. The result shows that minimum temperature of Shaheed Benazir Abad has increased at the rate of 0.063°C per year during study period while the maximum temperature for all months exhibits no change. This increase of minimum temperature contributed to the decreasing trend of diurnal temperature range. The DTR decreased at the rate of 0.057°C /year in Shaheed Benazir Abad. The investigation of seasonal DTR trends revealed that Summer and Spring seasons also witnessed a decreasing trends at the rate of 0.26 °C/year and 0.047°C/year respectively. Winter and aseasons, on the other hand, have experienced the increasing trends of DTR at the rate of 0.136 °C/year and 0.115 °C/year respectively. It is found by MK test that Tmax (winter), Tmax (Spring) and Tmin (Spring) exhibited the significant positive trends at the rate of 0.21°C/year, 0.368 °C/year and 0.421°C/year respectively. The increasing trends of Tmax of winter and spring indicate that winter and spring are warmer now.

AbstractThis paper will present results of a numerical modelling study on CO2 migration through abandoned wells. Leakage of CO2 through plugged and abandoned wellbores is one of the major concerns for long-term safety and effectiveness of geologic CO2 sequestration. For risk assessment and mitigation, it is not only important to understand and characterize the potential for CO2 leakage through wellbores but also subsequent CO2 migration beyond the primary sequestration reservoir. Subsequent to the leak, CO2 may take a direct path towards the accessible environment or it may migrate in an indirect stair-stepping manner through wellbores/fractures across multiple, shallow permeable strata. In the later case, identification of leak source and application of mitigation strategies may become a challenge.For this study we use data from a site in Alberta, Canada which has reported natural gas leak at surface. Investigations on origin of the gas and potential gas migration path from the original source to the surface at the analog site show that the gas could be moving through multiple wells and across multiple formations. There are multiple wells at the site which were drilled and abandoned without production casing and are completely open between two hydrocarbon bearing zones creating cross-flow across zones through open wellbores. Our study focuses on the deeper formations and potential for leakage for CO2 injected in deeper formation. A complex numerical fluid-flow model is developed for the site in FEHM, LANL’s porous media fluid-flow simulator. The model explicitly accounts for wellbore details such as abandonment plugs, casing, annulus cement, etc. The model was used to perform long-term simulations of CO2 injection and potential migration through abandoned wells. Numerical simulation results show limited migration of CO2 through abandoned wells. Such detailed simulation would be valuable to develop effective abandonment practices as well as mitigation strategies at CO2 sequestration sites.

Mangrove wetlands exist in the transition zone between terrestrial and marine environments and have remarkable ecological and socio-economic value. This study uses climate change downscaling to address the question of non-stationarity influences on mangrove variations (expansion and contraction) within an arid coastal region. Our two-step approach includes downscaling models and uncertainty assessment, followed by a non-stationary and trend procedure using the Extreme Value Analysis (extRemes code). The Long Ashton Research Station Weather Generator (LARS-WG) model along with two different general circulation model (GCMs) (MIRH and HadCM3) were used to downscale climatic variables during current (1968–2011) and future (2011–2030, 2045–2065, and 2080–2099) periods. Parametric and non-parametric bootstrapping uncertainty tests demonstrated that the LARS-WGS model skillfully downscaled climatic variables at the 95 % significance level. Downscaling results using MIHR model show that minimum and maximum temperatures will increase in the future (2011–2030, 2045–2065, and 2080–2099) during winter and summer in a range of +4.21 and +4.7 °C, and +3.62 and +3.55 °C, respectively. HadCM3 analysis also revealed an increase in minimum (∼+3.03 °C) and maximum (∼+3.3 °C) temperatures during wet and dry seasons. In addition, we examined how much mangrove area has changed during the past decades and, thus, if climate change non-stationarity impacts mangrove ecosystems. Our results using remote sensing techniques and the non-parametric Mann–Whitney two-sample test indicated a sharp decline in mangrove area during 1972,1987, and 1997 periods (p value = 0.002). Non-stationary assessment using the generalized extreme value (GEV) distributions by including mangrove area as a covariate further indicated that the null hypothesis of the stationary climate (no trend) should be rejected due to the very low p values for precipitation (p value = 0.0027), minimum (p value = 0.000000029) and maximum (p value = 0.00016) temperatures. Based on non-stationary analysis and an upward trend in downscaled temperature extremes, climate change may control mangrove development in the future.

To support their Integrated Water Supply Grid, Wessex Water recognized the need for a sophisticated control system. The Servelec Technologies pump optimization system OptiMISER was identified as the best tool for this function and has been in use in the Control Room since September 2014. Since then it has been controlling pumps and valves across the Warminster area, ensuring pro-active optimal management of that part of the network, as a precursor to full implementation over the Grid.

Fire danger indices are descriptors of fire potential in a large area, and combine a few variables that affect the initiation, spread and control of forest fires. The Canadian Fire Weather Index (FWI) is one of the most widely used fire danger indices in the world, and it is built upon instantaneous values of temperature, relative humidity and wind velocity at noon, together with 24 hourly accumulated precipitation. However, the scarcity of appropriate data has motivated the use of daily mean values as surrogates of the instantaneous ones in several studies that aimed to assess the impact of global warming on fire. In this paper we test the sensitivity of FWI values to both instantaneous and daily mean values, analyzing their effect on mean seasonal fire danger (seasonal severity rating, SSR) and extreme fire danger conditions (90th percentile, FWI90, and FWI>30, FOT30), with a special focus on its influence in climate change impact studies. To this aim, we analyzed reanalysis and regional climate model (RCM) simulations, and compared the resulting instantaneous and daily mean versions both in the present climate and in a future scenario. In particular, we were interested in determining the effect of these datasets on the projected changes obtained for the mean and extreme seasonal fire danger conditions in future climate scenarios, as given by a RCM. Overall, our results warn against the use of daily mean data for the computation of present and future fire danger conditions. Daily mean data lead to systematic negative biases of fire danger calculations. Although the mean seasonal fire danger indices might be corrected to compensate for this bias, fire danger extremes (FWI90 and specially FOT30) cannot be reliably transformed to accommodate the spatial pattern and magnitude of their respective instantaneous versions, leading to inconsistent results when projected into the future. As a result, we advocate caution when using daily mean data and strongly recommend the application of the standard definition for its calculation as closely as possible. Threshold-dependent indices derived from FWI are not reliably represented by the daily mean version and thus can neither be applied for the estimation of future fire danger season length and severity, nor for the estimation of future extreme events. The research leading to these results has received funding from the European Union's Seventh Framework Programme (FP7/2007-2013) under grant agreement 243888 (FUME Project). J.F. acknowledges nancial support from the Spanish R&D&I programme through grant CGL2010-22158-C02 (CORWES project). The ESCENA project (200800050084265) of the Spanish \Strategic action on energy and climate change" provided the WRF RCM simulation used in this study. We acknowledge three anonymous referees for their useful comments that helped to improve the original manuscript.

Natural ventilation performance is one of the key climate control parameters for Canary type greenhouses, which are rapidly expanding along the Atlantic coast in Morocco. The use of insect screens significantly reduces airflow and increases thermal gradients inside the greenhouse. The aim of this study was to analyze the natural ventilation performances in real cultural conditions of a large-scale Canary type tomato greenhouse (1.1 ha) equipped with insect screens on the vent openings. A global energy balance of the greenhouse was used, allowing for the determination of air exchange rates. The greenhouse ventilation performance was compared with those of other greenhouses types and discussed with respect to the improvement of greenhouse vent design, insect screen types, and ridge and crop row orientation. The results confirm the strong dependence of greenhouse ventilation rate on wind speed and ventilation opening location. In addition, results show a significant reduction of the ventilation rate compared with other greenhouse types: the insect screen reduced the greenhouse ventilation rate by 46%, and the tomato rows that were oriented perpendicular to the prevailing air movement through the greenhouse reduced the ventilation rate by 50%. From this analysis, practical improvements are proposed and discussed in the context of protected crop production in the coastal area of Morocco.

Water scarcity is a worldwide concern considering that water is a limited resource and essential for life. In Brazil, approximately 30% of its population lives in a semi-arid region covering about 20% of the country’s territorial extension, which is one of the areas that most suffers from a lack of water. The lack of water, mainly in the northeast of the country, has been a problem for years, as people who live in this territory suffer for months from the poor distribution of this resource, which increases the degree of inequality between the regions of the country. The research aims to show the effect of the hydrological cycle on the quality of vegetation and how such processing can end up affecting people’s lives and the environment. This study carried out a temporal analysis from 1961 to 2021. The hydrological model system used to assess water availability was the Pernambuco Hydrological Response Units SUPer-System. UAV (Unmanned Aerial Vehicles) was used to view the relationship between living and environmental conditions. The results showed a difference between the water balance today and in the future due to climate change. Thus, it is concluded that climate change will have different impacts at a small scale as well as on people’s living conditions as a result of different characteristics of the environment. It is very important to carry out studies on a detailed scale to provide better public policies for mitigating the effects of climate change on people’s lives.