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Land use change is a crucial driving factor in hydrological processes. Understanding its long-term dynamics is essential for sustainable water resources management. This study sought to quantify and analyze land use change between 1985 and 2021 and its impacts on the hydrology of the Sejnane watershed, northern Tunisia. Remote sensing and a SWAT model using the SUFI-2 algorithm to identify the most sensitive parameters were used to achieve this objective. Land use maps were developed for 1985, 2001 and 2021. For the last 37 years, the watershed experienced a slight decrease in forest, scrubland and forage crops, a significant reduction in grassland, and a conspicuous expansion of olive trees and vegetable crops. Given the scarcity of observed discharge data, a SWAT model was calibrated for the period 1997–2010 and validated for 2011–2019. Model performance was good for both calibration (NSE = 0.78, PBIAS = −6.6 and R2 = 0.85) and validation (NSE = 0.70, PBIAS = −29.2 and R2 = 0.81). Changes in land use strongly affected the water balance components. Surface runoff and percolation were the most influenced, showing an increase in runoff and a decrease in percolation by 15.5% and 13.8%, respectively. The results revealed that the construction of the Sejnane dam, the extension of irrigated perimeters and olive tree plantations were the major contributors to changes in hydrology.

Land surface temperature (LST) plays a key role in the surface energy budget computation and land surface process studies. The Moderate Resolution Imaging Spectroradiometer (MODIS) sensors onboard the Aqua and Terra satellites provide comprehensive global LST estimates at a fine spatial resolution. The MODIS products were recently upgraded to Collection 6, and shown to be more accurate than its predecessor Collection 5 products. In this study, LST and its variability have been examined across India from Collection 6 of the Aqua MODIS data at 0.05° spatial resolution for the period of 2003 to 2017. All-India mean LST characteristics show distinctive features as compared to the well-documented mean characteristics of near-surface air temperature. All land cover types except permanent snow and ice, and cold desert areas exhibit bimodal peaks in seasonal variations of daytime LST. The daytime LST over the coldest and high-altitude regions of northern India shows anomalous positive linear relationship with NDVI at a monthly scale. However, monthly domain-mean daytime LST of cropland regions is largely negatively correlated with NDVI as compared to other land cover types. Results reveal that about 17% of the Indian landmass received its hottest LST during 2010 followed by 2016. Linear trend analysis for the 15-year period of mean annual LST shows a decrease in diurnal temperature range over most parts of the country due to rather rapid increase in nighttime LST than daytime LST, similar as changes in near-surface air temperature across the country.

In the current survey, a novel fluorocarbon-based wettability modifier chemical is proposed to alter the wettability of sandstone rock surface from liquid wetting to preferentially gas wetting condition. Several experimental tests describing wettability condition of the rock surface including static contact angle measurements, spontaneous imbibition and dynamic core flooding using water and n-decane fluids were conducted on untreated and treated sandstone rock to investigate the effect of the proposed chemical on surface wetting behavior. Adsorption of fluorinated chemical on sandstone surfaces was characterized using FTIR and SEM. Elemental analysis of rock surface after treatment was determined by EDX analysis and EDX map. After chemical treatment of sandstone thin section, contact angles of water and n-decane in air-liquid-rock system were altered from 0° and 0° to 151° and 101°, respectively. Spontaneous imbibition of water and n-decane as imbibing liquid fluids into the core sample saturated with dry air at room temperature on untreated and treated core showed that the ultimate amounts of liquid imbibitions were decreased to factors of 0.03 and 0.16 PV, demonstrating wettability alteration from strongly condensate-and water-wet to preferentially gas-wet condition, respectively. Also, the results of core flooding experiments demonstrated the improvement of liquid phase mobility as a result of treatment with proposed chemical fluid by factors of 3.85 and 3.5 for water and n-decane, respectively. The outcome of this integrated study proposes that fluorochemical agents can be considered as a promising candidate for possible field applications to alleviate both condensate and water blockage in gas condensate reservoirs by wettability alteration technique.

The United States is continuing on the trajectory to be a racially and ethnically diverse society where non-Hispanic Whites are projected to become the largest group for the next four decades. Whilst the majority becomes the minority and vice versa, the same trend is not reflected in the Science, Technology, Engineering, and Mathematics (STEM) degree attainment or the STEM workforce. A recent report by the National Academies of Sciences, Engineering, and Medicine describes how minority-serving institutions are not widely targeted and highly utilized in the production of future STEM workers. The NSF reported that 22% of all science and engineering bachelor's degrees were awarded to underrepresented minorities. The distribution of bachelor's degrees consisted of Hispanics or Latinos receiving 13.5% of science and 10% of engineering degrees; Black or African Americans, 9% and 4%; and American Indians or Alaska Natives, 0.5% and 0.3%, respectively. From years 2004 to 2014, there has been a 11.6% decline of underrepresented minorities earning science and engineering bachelor's degree at high Hispanic enrollment institutions and a 26.5% decline at historically black colleges or universities. The NSF also reported that in 2015, African-American and Hispanic scientists and engineers working in science and engineering occupations were only five and six percent, respectively. Although studies have found modest gains in geoscience bachelor's degree recipients among women, the number of underrepresented minorities recipients is at 12% or less. Additionally, other studies reported that according to the Bureau of Labor Statistics, in 2017 underrepresented minorities comprised only a tenth of the geoscience workforce in the United States, and women comprised approximately a third of environmental scientists and geoscientists and a fifth of the four-year geoscience faculty. It is clear that for too long the geosciences (and STEM in general) has struggled to address issues of diversity, equity, and inclusion. At the Center for Remote Sensing and Earth System Sciences (ReSESS) at the New York City College of Technology, the catalyst of Service-Learning via Remote Sensing Research in underserved communities and with underrepresented minority students was used as a means of attracting and engaging students in remote sensing research. Results show that the DEI-service learning-remote sensing nexus increased awareness and, understanding in the geosciences, and it motivated underrepresented students to share their newfound knowledge with local citizens in environmental sustainability initiatives. Both students and citizens were enthralled by the engagement of remote sensing at the neighborhood scale.

Summary Advantage of CWI over WI and CO2 injection for an Iranian heavy oil reservoir, is studied through core flooding experiments. Five different experiments were conducted in different wettability states using secondary and tertiary injection scenarios. The results showed that CWI is more beneficial than WI and CO2 injection. Higher sweep efficiency, more stable front, CO2 diffusion to oil and subsequent oil viscosity reduction and swelling are the reasons for better CWI performance. Moreover, due to the lower sweep efficiency of WI and low resistance channels created along the flow axis, tertiary CWI is not capable to recover all the bypassed oil, so its recovery is less than secondary CWI. The results of aged experiments indicated that by shifting wettability toward mixed wet, CWI performance decreased in both WI and secondary CWI. In mixed wet wettability several pores which were accessible for injection fluid in clean sand, are not reachable in aged sand anymore which accelerated injection fluid breakthrough and decreased ultimate recovery. Besides, it was observed that the proportion of recovery after breakthrough to the total recovery was increased for SCWI while decreased for WI, this is attributed to the acidic nature of carbonated water and consequent wettability alteration.

Globally, soils store two to three times as much carbon as currently resides in the atmosphere, and it is critical to understand how soil greenhouse gas (GHG) emissions and uptake will respond to ongoing climate change. In particular, the soil‐to‐atmosphere CO2 flux, commonly though imprecisely termed soil respiration (R S), is one of the largest carbon fluxes in the Earth system. An increasing number of high‐frequency R S measurements (typically, from an automated system with hourly sampling) have been made over the last two decades; an increasing number of methane measurements are being made with such systems as well. Such high frequency data are an invaluable resource for understanding GHG fluxes, but lack a central database or repository. Here we describe the lightweight, open‐source COSORE (COntinuous SOil REspiration) database and software, that focuses on automated, continuous and long‐term GHG flux datasets, and is intended to serve as a community resource for earth sciences, climate change syntheses and model evaluation. Contributed datasets are mapped to a single, consistent standard, with metadata on contributors, geographic location, measurement conditions and ancillary data. The design emphasizes the importance of reproducibility, scientific transparency and open access to data. While being oriented towards continuously measured R S, the database design accommodates other soil‐atmosphere measurements (e.g. ecosystem respiration, chamber‐measured net ecosystem exchange, methane fluxes) as well as experimental treatments (heterotrophic only, etc.). We give brief examples of the types of analyses possible using this new community resource and describe its accompanying R software package., Here we describe the lightweight, open source COSORE (COntinuous SOil REspiration) database and software. COSORE focuses on automated, continuous and long‐term greenhouse gas flux datasets, and is intended to serve as a community resource for earth sciences, climate change syntheses and model evaluation.

For too many undergraduate minority students, remote sensing and its plethora of applications to geophysics yet remain new, foreign, and mysterious. These students, even with the requisite STEM backgrounds, lack the exposure, the awareness, the understanding, and the engagement into the foray of remote sensing and the unique lens it provides to probe and unearth new ways of gaining knowledge about the environment. To strengthen undergraduate education, to adequately prepare candidates to become the next generation of geoscientists, and to assist in replenishing the geoscience workforce, unique paradigms of teaching and learning about remote sensing are needed. At the Center for Remote Sensing and Earth System Sciences (ReSESS) at the New York City College of Technology, the catalyst of Service-Learning within a local community was used as a means of attracting and engaging students in remote sensing research. Results show that the service learning-remote sensing nexus increased awareness and, understanding in the geosciences, and it motivated students to share their newfound knowledge with local citizens in environmental sustainability initiatives. Both students and citizens were enthralled by the engagement of remote sensing at the neighborhood scale.

International audience

Accurate estimates of long-term land surface temperature (Ts) and near-surface air temperature (Ta) at finer spatio-temporal resolutions are crucial for surface energy budget studies, for environmental applications, for land surface model data assimilation, and for climate change assessment and its associated impacts. The Atmospheric Infrared Sounder (AIRS) and Moderate Resolution Imaging Spectroradiometer (MODIS) sensors onboard the Aqua satellite provide a unique opportunity to estimate both temperatures twice daily at the global scale. In this study, differences between Ta and Ts were assessed locally over regions of North America from 2009 to 2013 using ground-based observations covering a wide range of geographical, topographical, and land cover types. The differences between Ta and Ts during non-precipitating conditions are generally 2–3 times larger than precipitating conditions. However, these differences show noticeable diurnal and seasonal variations. The differences between Ta and Ts were also investigated at the global scale using the AIRS estimates under clear-sky conditions for the period 2003–2015. The tropical regions showed about 5–20 °C warmer Ts than Ta during the day-time, whereas opposite characteristics (about 2–5 °C cooler Ts than Ta) are found over most parts of the globe during the night-time. Additionally, Ts estimates from the AIRS and the MODIS sensors were inter-compared. Although large-scale features of Ts were essentially similar for both sensors, considerable differences in magnitudes were observed (> 6 °C over mountainous regions). Finally, Ta and Ts estimates from the AIRS and MODIS sensors were validated against ground-based observations for the period of 2009–2013. The error characteristics notably varied with ground stations and no clear evidence of their dependency on land cover types or elevation was detected. However, the MODIS-derived Ts estimates generally showed larger biases and higher errors compared to the AIRS-derived estimates. The biases and errors increased steadily when the spatial resolution of the MODIS estimates changed from finer to coarser. These results suggest that representativeness error should be properly accounted for when validating satellite-based temperature estimates with point observations.

Summary In the current survey, the time required to rupture the water film shielding the oil as a result of oil swelling caused by the diffusion of dissolved gas in the water phase and trapped oil behind it has been investigated in porous medium at high pressure and temperature. To study the active mechanisms, the experiments have been conducted with two different types of injectants: carbon dioxide (CO2) and methane (with different solubility in water), under different miscibility conditions at equal reduced pressures. Experimental observations have been interpreted using theoretical studies. Furthermore, the time of water-film rupture has been identified in production data and matched by an analytical model. This time and its monitoring during various gas-injectant types and regimes under reservoir conditions have not been previously addressed. The results show that water film reduces the performance of oil recovery by limiting the interface of oil and gas phases. Under such a condition, the best scenario is miscible gas injection because the gas can effectively swell the oil and rupture the water shield. At miscible and near-miscible conditions, the time required to eliminate the water film increases as the injectant solubility in water decreases; however, there is a negligible difference at the immiscible regime. The trend of oil-recovery curves after rupture of the water film shows that oil swelling is one of the main mechanisms involved in water-trapped oil recovery. These results suggest practical guidelines to better understand the effect of the water-shielding phenomenon in the field of tertiary gas injection. The outcome of this integrated study could effectively increase the knowledge of shielded oil recovery using different gas-injectant types under various miscibility conditions and could prepare the required basis for compositional simulation of waterflooded oil production during tertiary gas injection.

While foam propagation, foam–oil interaction and foam oil recovery performance have been investigated by numerous research studies, most of previous works were performed on short porous media with the maximum length of 30 cm. Therefore, their results mostly represent foam behavior in the vicinity of the injection well and may not represent the foam propagation, quality and oil recovery potential at large distances from the injection well. In this study, by using a high-pressure and high-temperature rig equipped with a 12-m long porous medium and microscopic visualization facilities, foam stability in the presence and absence of a reservoir crude oil, foam propagation, foam–oil interaction, and finally foam oil recovery potential at large distances from the injection well were investigated. The oil recovery behavior of four tertiary scenarios, including Sodium Dodecyl Sulfate (SDS) foam, Alpha-Olefin Sulfonate (AOS) foam, gas, and simultaneous water alternating gas (SWAG) injection, were investigated. According to results, pressure presented a positive impact on the foam stability. The extent of this impact was a function of the surfactant type. Compared to gas and SWAG injection, in the 12-m long porous medium, foam flooding scenarios presented much stronger oil recovery potentials. This reveals the strong potential of foam flooding in producing the oil trapped in areas deep into the reservoir and far from the injection well. Based on this study, by using a suitable surfactant solution and optimum gas fractional flow, even in the presence of oil, foam can propagate to large distances from the injection well and leads to extra oil recovery.

Accurate estimation of passive microwave land surface emissivity (LSE) is crucial for numerical weather prediction model data assimilation, for microwave retrievals of land precipitation and atmospheric profiles, and for a better understanding of land surface and subsurface characteristics. In this study, global instantaneous LSE is estimated for a 9-yr period from the Advanced Microwave Scanning Radiometer for Earth Observing System (AMSR-E) and for a 5-yr period from the Advanced Microwave Scanning Radiometer 2 (AMSR2) sensors. Estimates of LSE from both sensors were obtained by using an updated algorithm that minimizes the discrepancy between the differences in penetration depths from microwave and infrared remote sensing observations. Concurrent ancillary datasets such as skin temperature from the Moderate Resolution Imaging Spectroradiometer (MODIS) and profiles of air temperature and humidity from the Atmospheric Infrared Sounder are used. The latest collection 6 of MODIS skin temperature is used for the LSE estimation, and the differences between collections 6 and 5 are also comprehensively assessed. Analyses reveal that the differences between these two versions of infrared-based skin temperatures could lead to approximately a 0.015 difference in passive microwave LSE values, especially in arid regions. The comparison of global mean LSE features from the combined use of AMSR-E and AMSR2 with an independent product—Tool to Estimate Land Surface Emissivity from Microwave to Submillimeter Waves (TELSEM2)—shows spatial pattern correlations of order 0.92 at all frequencies. However, there are considerable differences in magnitude between these two LSE estimates, possibly because of differences in incidence angles, frequencies, observation times, and ancillary datasets.

Summary Following the launch of the Global Precipitation Measurement (GPM) Core Observatory, two advanced high resolution multi-satellite precipitation products namely, Integrated Multi-satellitE Retrievals for GPM (IMERG) and Global Satellite Mapping of Precipitation (GSMaP) version 6 are released. A critical evaluation of these newly released precipitation data sets is very important for both the end users and data developers. This study provides a comprehensive assessment of IMERG research product and GSMaP estimates over India at a daily scale for the southwest monsoon season (June to September 2014). The GPM-based precipitation products are inter-compared with widely used TRMM Multi-satellite Precipitation Analysis (TMPA), and gauge-based observations over India. Results show that the IMERG estimates represent the mean monsoon rainfall and its variability more realistically than the gauge-adjusted TMPA and GSMaP data. However, GSMaP has relatively smaller root-mean-square error than IMERG and TMPA, especially over the low mean rainfall regimes and along the west coast of India. An entropy-based approach is employed to evaluate the distributions of the selected precipitation products. The results indicate that the distribution of precipitation in IMERG and GSMaP has been improved markedly, especially for low precipitation rates. IMERG shows a clear improvement in missed and false precipitation bias over India. However, all the three satellite-based rainfall estimates show exceptionally smaller correlation coefficient, larger RMSE, larger negative total bias and hit bias over the northeast India where precipitation is dominated by orographic effects. Similarly, the three satellite-based estimates show larger false precipitation over the southeast peninsular India which is a rain-shadow region. The categorical verification confirms that these satellite-based rainfall estimates have difficulties in detection of rain over the southeast peninsula and northeast India. These preliminary results need to be confirmed in other monsoon seasons in future studies when the fully GPM-based IMERG retrospectively processed data prior to 2014 are available.

New York City College of Technology has created a year-round geoscience workforce preparation and geoscience career mentoring program for nongeoscience, minority science, technology, engineering, and math (STEM) students beginning at the critical juncture of their junior year. The overall goal of the program is to create a viable pathway to the geoscience workforce by tapping into a nontraditional pool of students. Each year 12 students are recruited to participate in a structured geoscience workforce model program that consists of geoscience exposure, preparation, apprenticeship, and experience. The students not only receive support with cohort-building activities, but they also participate in two geoscience internship programs that equip them with geoscience knowledge; geoscience workforce skills; summer internships at a federal, local, or private geoscience facilities; mentoring by geoscience practitioners; and networking opportunities with geoscience companies and geoscience professional societies. The expectation through this unique initiative is that many students who would otherwise not pursue a geoscience career may now choose to follow a geoscience corridor that could lead to lucrative geoscience careers. This paper focuses on the 4-day geoscience workforce skills training and enrichment component of the program. This important enrichment component pivots students from the geoscience theory taught in class to geoscience applications and workforce preparedness. The 4-day program may serve as a model and best practice for preparing nongeoscience STEM students with the skills needed for the geoscience workforce. Preliminary results show that the nongeoscience STEM student participants increased their geoscience awareness, knowledge, and skills competencies and their interest in the geosciences was heightened.

At all academic levels, recruiting, retaining, and graduating minority students in sufficient numbers within the geosciences remain a monumental and failed task of the geoscience community. This continued dismal failure culminates in the persistence of an ethnic (and far too often gender) homogeneity among the community’s participants. The paucity of diversity in the geosciences does not bode well for the sustainability, the vitality, and the global reach of the field. Inclusiveness and accessibility in the geosciences are critical, and innovative approaches/methodologies are urgently needed to ameliorate this vexing problem. Results from a pioneering program in New York City show that a rigorous and exciting introduction to satellite and ground-based remote sensing can be successfully used to attract, to raise geoscience awareness, and to engage non-geoscience, underrepresented minority students majoring in Science, Technology, Engineering, and Mathematics (STEM) in productive geoscience participation: research, peer-reviewed publications, conference presentations, and workforce and graduate school entrances. The results also show that program participants: a) developed a deeper interest in the geosciences; b) became more aware of remote sensing as a research tool, and c) connected remote sensing to a host of real world, geophysical phenomena and applications.

In gas condensate reservoirs, when fluid pressure decreases below its dew point pressure, it contributes to condensate build-up around the wellbore. Due to liquid condensation, gas and condensate relative permeability and mobility significantly drop and well productivity is considerably decreased. Several approaches have been recommended to mitigate condensate banking. Wettability alteration of the reservoir rock surface towards gas-wet is considered as one of the promising techniques for alleviating condensate banking. In this communication, a fluoro-chemical foam treatment technique is introduced to alleviate the condensate banking. To evaluate the effectiveness of the foam injection technique for the gas-wetting alteration of sandstone and carbonate cores, the contact angle measurement, liquid imbibition, and core displacement tests were conducted in the gas-liquid-core system. The adsorption of the fluoro-chemical solution on sandstone and carbonate samples was verified by surface analysis techniques including SEM, FTIR, and EDXS. The results show that the contact angles of brine and hexadecane droplets on the treated sandstone substrate increased from 0° and 0° to to135° and 103°, respectively. Moreover, treatment of carbonate substrate with fluoro-chemical solution resulted in an increase of 0° to 130° and 0° to 123° for brine and hexadecane contact angles, respectively. After treatment, the imbibition of brine and hexadecane liquids into the cores decreased significantly. Finally, the results of dynamic two-phase core flooding in sandstone and carbonate cores show that the chemical foam treatment can improve the end-point gas relative permeabilities by the factors of 1.704 and 1.69 for sandstone and carbonate cores, respectively.