Contribution of anthropogenic aerosols to persistent La Niña-like conditions in the early 21st century.

The discrepancy between the observed lack of surface warming in the eastern equatorial Pacific and climate model projections of an El Niño-like warming pattern confronts the climate research community. While anthropogenic aerosols have been suggested as a cause, the prolonged cooling trend over the equatorial Pacific appears in conflict with Northern Hemisphere aerosol emission reduction since the 1980s. Here, using CESM, we show that the superposition of fast and slow responses to aerosol emission change-an increase followed by a decrease-can sustain the La Niña-like condition for a longer time than expected. The rapid adjustment of Hadley Cell to aerosol reduction triggers joint feedback between low clouds, wind, evaporation, and sea surface temperature in the Southeast Pacific, leading to a wedge-shaped cooling that extends to the central equatorial Pacific. Meanwhile, the northern subtropical cell gradually intensifies, resulting in equatorial subsurface cooling that lasts for decades.

CO2-forced Late Miocene cooling and ecosystem reorganizations in East Asia.

In parallel with pronounced cooling in the oceans, vast areas of the continents experienced enhanced aridification and restructuring of vegetation and animal communities during the Late Miocene. Debate continues over whether pCO2-induced global cooling was the primary driver of this climate and ecosystem upheaval on land. Here we present an 8 to 5 Ma land surface temperatures (LST) record from East Asia derived from paleosol carbonate clumped isotopes and integrated with climate model simulations. The LST cooled by ~7 °C between 7.5 and 5.7 Ma, followed by rapid warming across the Miocene-Pliocene transition (5.5 to 5 Ma). These changes occurred synchronously with variations in alkenone and Mg/Ca-based sea surface temperatures and with hydroclimate and ecosystem shifts in East Asia, highlighting a global climate forcing mechanism. Our modeling experiments additionally demonstrate that pCO2-forced cooling would have altered moisture transfer and pathways and driven extensive aridification in East Asia. We, thus, conclude that the East Asian hydroclimate and ecosystem shift was primarily controlled by pCO2-forced global cooling between 8 and 5 Ma.

Measurement and Analysis of Surface Temperature Gradients on Magnetron Sputtered Thin Film Growth Studied Using NiCr/NiSi Thin Film Thermocouples.

In the general analysis of thin-film growth processes, it is often assumed that the temperature of the film growth surface is the same as the temperature of the film growth substrate. However, a temperature gradient exists between the film growth surface and film growth substrate. Using the growth surface of TiO2 thin films as an example, the temperature gradient of the film growth surface is tested and analyzed. A NiCr/NiSi thin-film thermocouple is fabricated using the direct-current pulse magnetron sputtering method. A three-layer NiCr/NiSi thin-film thermocouple temperature measurement system is established to measure the temperature gradient of the film growth surface. The growth surface temperature and substrate temperature of the TiO2 thin films are measured. For a sputtering power density of 0.83 W cm- 2, the temperature difference between the first and second layers is 104.79 °C, while the temperature difference between the second and third layers is 39.92 °C. A standard K-type thermocouple is used to measure the substrate temperature, which is recorded to be 132.05 °C, consistent with common measurements of substrate temperature. The heat conduction on the film growth surface in the vacuum chamber is examined and a model for the temperature measurement device during film growth is constructed.

Pacific salmon in the Canadian Arctic highlight a range-expansion pathway for sub-Arctic fishes.

Rapid climate change is altering Arctic ecosystems at unprecedented rates. These changes in the physical environment may open new corridors for species range expansions, with substantial implications for subsistence-dependent communities and sensitive ecosystems. Over the past 20 years, rising incidental harvest of Pacific salmon by subsistence fishers has been monitored across a widening range spanning multiple land claim jurisdictions in Arctic Canada. In this study, we connect Indigenous and scientific knowledges to explore potential oceanographic mechanisms facilitating this ongoing northward expansion of Pacific salmon into the western Canadian Arctic. A regression analysis was used to reveal and characterize a two-part mechanism related to thermal and sea-ice conditions in the Chukchi and Beaufort seas that explains nearly all of the variation in the relative abundance of salmon observed within this region. The results indicate that warmer late-spring temperatures in a Chukchi Sea watch-zone and persistent, suitable summer thermal conditions in a Beaufort Sea watch-zone together create a range-expansion corridor and are associated with higher salmon occurrences in subsistence harvests. Furthermore, there is a body of knowledge to suggest that these conditions, and consequently the presence and abundance of Pacific salmon, will become more persistent in the coming decades. Our collaborative approach positions us to document, explore, and explain mechanisms driving changes in fish biodiversity that have the potential to, or are already affecting, Indigenous rights-holders in a rapidly warming Arctic.

Even cooler insights: On the power of forests to (water the Earth and) cool the planet.

Scientific innovation is overturning conventional paradigms of forest, water, and energy cycle interactions. This has implications for our understanding of the principal causal pathways by which tree, forest, and vegetation cover (TFVC) influence local and global warming/cooling. Many identify surface albedo and carbon sequestration as the principal causal pathways by which TFVC affects global warming/cooling. Moving toward the outer latitudes, in particular, where snow cover is more important, surface albedo effects are perceived to overpower carbon sequestration. By raising surface albedo, deforestation is thus predicted to lead to surface cooling, while increasing forest cover is assumed to result in warming. Observational data, however, generally support the opposite conclusion, suggesting surface albedo is poorly understood. Most accept that surface temperatures are influenced by the interplay of surface albedo, incoming shortwave (SW) radiation, and the partitioning of the remaining, post-albedo, SW radiation into latent and sensible heat. However, the extent to which the avoidance of sensible heat formation is first and foremost mediated by the presence (absence) of water and TFVC is not well understood. TFVC both mediates the availability of water on the land surface and drives the potential for latent heat production (evapotranspiration, ET). While latent heat is more directly linked to local than global cooling/warming, it is driven by photosynthesis and carbon sequestration and powers additional cloud formation and top-of-cloud reflectivity, both of which drive global cooling. TFVC loss reduces water storage, precipitation recycling, and downwind rainfall potential, thus driving the reduction of both ET (latent heat) and cloud formation. By reducing latent heat, cloud formation, and precipitation, deforestation thus powers warming (sensible heat formation), which further diminishes TFVC growth (carbon sequestration). Large-scale tree and forest restoration could, therefore, contribute significantly to both global and surface temperature cooling through the principal causal pathways of carbon sequestration and cloud formation.

Long-term effects of climate change on juvenile bull shark migratory patterns.

Seasonal variability in environmental conditions is a strong determinant of animal migrations, but warming temperatures associated with climate change are anticipated to alter this phenomenon with unknown consequences. We used a 40-year fishery-independent survey to assess how a changing climate has altered the migration timing, duration and first-year survival of juvenile bull sharks (Carcharhinus leucas). From 1982 to 2021, estuaries in the western Gulf of Mexico (Texas) experienced a mean increase of 1.55°C in autumn water temperatures, and delays in autumn cold fronts by ca. 0.5 days per year. Bull shark migrations in more northern estuaries concomitantly changed, with departures 25-36 days later in 2021 than in 1982. Later, migrations resulted in reduced overwintering durations by up to 81 days, and the relative abundance of post-overwintering age 0-1 sharks increased by >50% during the 40-year study period. Yet, reductions in prey availability were the most influential factor delaying migrations. Juvenile sharks remained in natal estuaries longer when prey were less abundant. Long-term declines in prey reportedly occurred due to reduced spawning success associated with climate change based on published reports. Consequently, warming waters likely enabled and indirectly caused the observed changes in shark migratory behaviour. As water temperatures continue to rise, bull sharks in the north-western Gulf of Mexico could forgo their winter migrations in the next 50-100 years based on current trends and physiological limits, thereby altering their ecological roles in estuarine ecosystems and recruitment into the adult population. It is unclear if estuarine food webs will be able to support changing residency patterns as climate change affects the spawning success of forage species. We expect these trends are not unique to the western Gulf of Mexico or bull sharks, and migratory patterns of predators in subtropical latitudes are similarly changing at a global scale.

Environmental drivers of global variation in home range size of terrestrial and marine mammals.

As animal home range size (HRS) provides valuable information for species conservation, it is important to understand the driving factors of HRS variation. It is widely known that differences in species traits (e.g. body mass) are major contributors to variation in mammal HRS. However, most studies examining how environmental variation explains mammal HRS variation have been limited to a few species, or only included a single (mean) HRS estimate for the majority of species, neglecting intraspecific HRS variation. Additionally, most studies examining environmental drivers of HRS variation included only terrestrial species, neglecting marine species. Using a novel dataset of 2800 HRS estimates from 586 terrestrial and 27 marine mammal species, we quantified the relationships between HRS and environmental variables, accounting for species traits. Our results indicate that terrestrial mammal HRS was on average 5.3 times larger in areas with low human disturbance (human footprint index [HFI] = 0), compared to areas with maximum human disturbance (HFI = 50). Similarly, HRS was on average 5.4 times larger in areas with low annual mean productivity (NDVI = 0), compared to areas with high productivity (NDVI = 1). In addition, HRS increased by a factor of 1.9 on average from low to high seasonality in productivity (standard deviation (SD) of monthly NDVI from 0 to 0.36). Of these environmental variables, human disturbance and annual mean productivity explained a larger proportion of HRS variance than seasonality in productivity. Marine mammal HRS decreased, on average, by a factor of 3.7 per 10°C decline in annual mean sea surface temperature (SST), and increased by a factor of 1.5 per 1°C increase in SST seasonality (SD of monthly values). Annual mean SST explained more variance in HRS than SST seasonality. Due to the small sample size, caution should be taken when interpreting the marine mammal results. Our results indicate that environmental variation is relevant for HRS and that future environmental changes might alter the HRS of individuals, with potential consequences for ecosystem functioning and the effectiveness of conservation actions.

Infrared-A to improve mood: an exploratory study of water-filtered infrared-A (wIRA) exposure.

Diurnal preference to eveningness might predispose to depression. There is preliminary evidence of infrared-A (IR-A) induced whole-body hyperthermia (WBH) in the treatment of depression. In this exploratory study with 19 adults, we investigated the effects of a 20-min exposure of water-filtered IR-A (wIRA) to the skin of back and buttock area, without inducing WBH, on mood and assessed the outcome by diurnal preference (#R19047, approval on 7 May 2019). The skin received irradiation with an integrated power of 102.4 W in the wavelength region of 550-1350 nm and a total dose of 123 kJ over the total area of 0.0483 m2. The diurnal preference was assessed with a 6-item version of the Morningness-Eveningness Questionnaire (mMEQ). The 40-item Profile of Mood States (POMS) questionnaire was used to assess total mood disturbance (TMD). Core temperature was measured 30 min before, during and 30 min after the irradiation. Skin surface temperature was measured on baseline and every two minutes during the irradiation. The TMD improved immediately after the exposure, and this positive effect lasted for 24 h (p = 0.001) as well as for 2 weeks (p = 0.02). Concerning the diurnal preference, the positive effect on mood was immediate and lasted for 24 h in evening types (p = 0.02) and for 2 weeks in morning types (p = 0.04). During the exposure, core body temperature was constantly lower in morning types compared to evening types. This study gives us new information on the effects of near-infrared radiation, without inducing WBH, through the skin on mood.

Unraveling the Influence of Satellite-Observed Land Surface Temperature on High-Resolution Mapping of Ground-Level Ozone Using Interpretable Machine Learning.

Accurately mapping ground-level ozone concentrations at high spatiotemporal resolution (daily, 1 km) is essential for evaluating human exposure and conducting public health assessments. This requires identifying and understanding a proxy that is well-correlated with ground-level ozone variation and available with spatiotemporal high-resolution data. This study introduces a high-resolution ozone modeling method utilizing the XGBoost algorithm with satellite-derived land surface temperature (LST) as the primary predictor. Focusing on China in 2019, our model achieved a cross-validation R2 of 0.91 and a root-mean-square error (RMSE) of 13.51 µg/m3. We provide detailed maps highlighting ground-level ozone concentrations in urban areas, uncovering spatial variations previously unresolved, along with time series aligning with established understandings of ozone dynamics. Our local interpretation of the machine learning model underscores the significant contribution of LST to spatiotemporal ozone variations, surpassing other meteorological, pollutant, and geographical predictors in its influence. Validation results indicate that model performance decreases as spatial resolution becomes coarser, with R2 decreasing from 0.91 for the 1 km model to 0.85 for the 25 km model. The methodology and data sets generated by this study offer new insights into ground-level ozone variability and mapping and can significantly aid in exposure assessment and epidemiological research related to this critical environmental challenge.

SchoolHEAT: Racial and Ethnic Inequity in School Temperature.

Exposure to high environmental temperature is detrimental to health through multiple pathways. This paper describes disparities in school-based high-temperature exposure at metropolitan schools in the United States. Using school location and sociodemographic data from the National Center for Education Statistics, neighborhood data from the US Census Bureau, and land surface temperature (LST) data from the Aqua Earth-observing satellite mission, we find that for every 10% more Black or Hispanic residents in the neighborhood, schools have LST 0.25 °C and 0.38 °C hotter, respectively. When the Black or Hispanic student population is greater than the neighborhood population, LST is an additional 0.20 °C and 0.40 °C for each 10% increase in students over neighborhood population, respectively. Black and Hispanic students are overrepresented in the hottest schools, making up 58.7% of students in the hottest 20% of schools, compared to only 30.0% of students in the coolest 20% of schools.

Summer Heat, Historic Redlining, and Neighborhood Walking among Older Adults: 2017 National Household Travel Survey.

No known studies have examined the relationships between urban heat islands, historic redlining, and neighborhood walking in older adults. We assessed whether (1) individual and neighborhood characteristics (including redlining score) differ by neighborhood summer land surface temperature (LST); (2) higher LST is associated with less neighborhood walking, and whether associations differ by historic redlining score; and (3) neighborhoods with discriminatory redlining scores have greater LSTs. We used data on 3982 ≥ 65 years old from the 2017 National Household Travel Survey. Multivariable negative binomial and linear regressions tested associations between LST z-score (comparing participant's neighborhood LST to surrounding region's LST) and self-reported neighborhood walking and the association between living in neighborhoods redlined as "definitely declining" or "hazardous" (versus "still desirable"/"best") and LST z-score. LSTs were higher for those in neighborhoods with higher area deprivation scores and more African American/Black residents. Older adults living in neighborhoods with higher summer LST z-scores had fewer minutes of neighborhood walking/day. This association seemed limited to individuals with neighborhood redlining scores of "still desirable"/"best." Neighborhood redlining scores of "definitely declining" or "hazardous" (versus "still desirable" and "best") were associated with greater neighborhood summer LSTs. Overall, these findings suggest that historically redlined neighborhoods may experience urban heat island effects more often. While older adults living in hotter neighborhoods with "still desirable" or "best" redlining scores may less often engage in neighborhood walking, those in neighborhoods with redlining scores of "definitely declining" and "hazardous" do not seem to decrease neighborhood walking with higher LSTs. Future work is needed to elucidate the impact of extreme heat on health-promoting behaviors such as walking and the types of interventions that can successfully counteract negative impacts on historically disadvantaged communities.

Association of neighborhood-level socioeconomic status and urban heat in China: Evidence from Hangzhou.

The escalating contradiction between global urban development and thermal environments has become increasingly apparent, underscoring the imperative to address social inequality in heat exposure and advocate for environmental justice (EJ) in the pursuit of sustainable urban development. To bridge the research gap in this domain, a comprehensive study was conducted to examine the correlation mechanism linking the thermal environment with the socioeconomic status (SES) of Chinese cities, employing Hangzhou as a representative case-a pivotal city among China's "four fire stoves". The investigation involved analyzing the spatial distribution pattern of diurnal Land Surface Temperature (LST) during the summer months spanning 2016 to 2018 (July to September). For SES characterization, a holistic indicator was established. Community-level LST variables were derived from LST surfaces obtained through the Terra and Aqua satellite MODIS sensors, with the community serving as the fundamental unit of analysis. The relationship between SES and LST was explored using random forest regression (RF), eXtreme Gradient Boosting (XGBoost), and support vector regression (SVR) to assess socioeconomic inequality in urban heat. The findings reveal that (1) RF exhibits the highest fitting accuracy and adeptly elucidates the nonlinear relationship and marginal effects between LST variables and SES. (2) Community SES in the Hangzhou metropolitan area exhibits spatial clustering. (3) Residents of low and middle SES communities experience heightened heat inequality. (4) A complex nonlinear relationship exists between daytime and nighttime LST and SES, with significant social disparities in urban heat within specific temperature thresholds. When deciding on measures to advance thermal environmental justice, it is crucial to prioritize both relatively disadvantaged groups and specific temperature intervals. This study departs from conventional approaches, exploring the nonlinear relationship between SES and urban heat at a fine scale, thereby assisting urban planners in developing effective strategies.

Monitoring of wetland turbidity using multi-temporal Landsat-8 and Landsat-9 satellite imagery in the Bisalpur wetland, Rajasthan, India.

Satellite imagery has emerged as the predominant method for performing spatial and temporal water quality analyses on a global scale. This study employs remote sensing techniques to monitor the water quality of the Bisalpur wetland during both the pre and post-monsoon seasons in 2013 and 2022. The study aims to investigate the prospective use of Landsat-8 (L8) and Landsat-9 (L9) data acquired from the Operational Land Imager (OLI) and Thermal Infrared Sensor (TIRS) for the temporal monitoring of turbidity. Concurrently, the study examines the relationship of turbidity with water surface temperature (WST) and chlorophyll-a (Chl-a) concentrations. We utilized visible and near-infrared (NIR) bands to conduct a single-band spectral response analysis of wetland turbidity. The results reveal a notable increase in turbidity concentration in May 2022, as this timeframe recorded the highest reflectance (0.28) in the NIR band. Additionally, the normalized difference turbidity index (NDTI) formula was used to assess the overall turbidity levels in the wetland. The results indicated that the highest concentration was observed in May 2013, with a value of 0.37, while the second-highest concentration was recorded in May 2022, with a value of 0.25. The WST was calculated using thermal band-10 in conjunction with Chlorophyll-a, utilizing the normalized difference chlorophyll index (NDCI). The regression analysis shows a positive correlation between turbidity and WST, as indicated by R2 values of 0.41 in May 2013 and 0.40 in May 2022. Furthermore, a robust positive relationship exists between turbidity and Chl-a, with a high R2 value of 0.71 in May 2022. These findings emphasize the efficacy of the L8 and L9 datasets for conducting temporal analyses of wetland turbidity, WST, and Chl-a. Additionally, this research underscores the critical role of satellite imagery in assessing and managing water quality, particularly in situations where in-situ data is lacking.

Fresh and recirculated submarine groundwater discharge zones along the central west coast of India.

The study area receives an average of 2840.0 mm of rainfall within four months every year. A portion of the rainwater is flown to the sea as surface water, and the other part is percolated into the bottom as groundwater. In coastal aquifers, the groundwater is transported to the sea due to a hydraulic gradient, and it contains a significant quantity of dissolved materials and nutrients. SGD processes impact the ocean productivity, mangrove and coral growth, local acidification and many. To isolate the SGD on the central west coast of India, different data was referred. The GWL concerning MSL contributed significantly to demarcating the SGD zones by considering the positive (>0 m) and negative (<0 m) values of GWL concerning above MSL. Thermal images for SST of pre-monsoon and post-monsoon periods of 2020 exhibit cooler surrounded by warmer, which might be the SGD buffering zones in the off-central west coast of India. By considering the results from GWL and SST, 8 SGD beach sites were identified for the further particularized study. The water samples were collected in March 2022, and analyzed using standard procedures and instruments. Fresh and mixing (recirculated) zones have been isolated by piper, hydrochemical facies evolution, and Ca2++Mg2+/K++Na + Vs log Cl- ionic ratio plots. The aquifer water chemical elements are converting possibly due to ionic exchange processes. The decrease in salinity and conductivity observed in the pore water just below the seawater might be due to the influence of freshwater inputs, helping to isolate the fresh SGD and recirculated SGD zones in the study area. Among 8 sites, 3 were found to be fresh SGD sites and 5 were noticed to be mixing/recirculated SGD sites. Most of these Beaches are bounded by hills, which helps to lead the SGD along the central west coast of India.

Regional differences in the effects of various Stokes drifts on the cooling of the marine environment under different wave conditions.

The WAVEWATCHIII model is employed to simulate Stokes drift, utilizing four distinct schemes integrated into the SBPOM circulation model. Deviations between simulated values and observations from the Optimum Interpolation Sea Surface Temperature (OISST) dataset unveil significant variations, particularly in regions characterized by pronounced swell. The northern hemisphere exhibits the highest deviations, reaching up to 0.3 °C during the March-April-May (MAM) and December-January-February (DJF) periods, while the Antarctic Circumpolar Current (ACC) consistently displays smaller deviations of approximately 0.1 °C. Deviations from Argo buoy measurements hover around 0.1 °C, except in the northern hemisphere where they escalate to approximately 1.5 °C. A comparative analysis of simulation results and Argo buoy measurements reveals an increasing deviation trend with a higher proportion of swell in specific sea areas, particularly evident in simulations utilizing approximate parameterization schemes. Notably, the Phillips profile scheme exhibits optimal performance, while the monochromatic profile scheme peaks with a simulated deviation of 0.13 °C. In contrast, the wave spectrum profile scheme consistently demonstrates applicability across diverse wave conditions and accurately captures the mixed layer at various depths. This study highlights the importance of the coupled WAVEWATCHIII-SBPOM model in accurately modeling future ocean conditions, providing valuable insight into the field of environmental science.

The influence of climate and human factors on a regional heat island in the Zhengzhou metropolitan area, China.

The development of urbanization and the establishment of metropolitan areas causes the urban heat island to cross the original single-city scale and form a regional heat island (RHI) with a larger influence range. Due to the decreasing distance between cities, there is an urgent need to reevaluate RHI for urban agglomerations, considering all cities instead of a conventional single-city perspective. The impact of climatic conditions and human factors on heat islands still lacks a general method and framework for systematic evaluation. Therefore, we used land and night light data as background conditions to study the diurnal and seasonal changes of heat islands in the Zhengzhou metropolitan area, China. Pearson correlation analysis and random forest regression analysis were then used to explore the influence of climatic conditions and human factors on RHI and its internal relationship. We found that the daytime RHI had strong spatial heterogeneity and seasonal differences from 2001 to 2020. The daytime RHI was stronger than nighttime in spring, summer, and autumn, and the nighttime RHI was stronger than daytime in winter. From spring to winter, RHI increased first and then decreased during the daytime, while the opposite was observed at night. In this study, temperature has a greater effect on daytime RHI; CO2 and NL have a greater effect on nighttime RHI. There was strong spatial heterogeneity in the effects of climatic conditions and human factors on the RHI, with climatic conditions contributing more to the daytime RHI in the northern mountainous areas, while human factors had a greater impact on the nighttime RHI in the main urban areas of each location. The results of this study highlight more targeted and informed strategies for RHI mitigation in the Zhengzhou metropolitan area and provide helpful insights into RHI evaluation in other urban agglomerations.

Sensing the dependable surficial signatures of temporal groundwater variations in arid coastal regions through geospatial techniques with respect to microclimate changes.

Reports on Groundwater level variations and quality changes have been a critical issue, especially in arid regions. An attempt has been made in this study to determine the surface manifestations of groundwater variations through processing imageries for determining the changes in land use, Normalized Differential Building Index (NDBI), Normalized Difference Vegetation Index (NDVI), Land Surface Temperature (LST), along with Groundwater level (GWL) and Electrical conductivity (EC). Decadal variation between these parameters for 2013 and 2023 shows that the average water level had increased by 1.03amsl, while the EC values of groundwater decreased by 418 µS/cm. The decrease in EC values indicates freshwater recharge, promoting natural vegetation, thus reducing the LST values by 3.28 °C. In addition, urban landscaping and relatively lesser emissivity from built-up surfaces than the sandy desert have further reduced the LST. The interrelationship of the parameters indicates that an increase in LST correlates with an increase in NDBI and with less significant changes in NDVI. The lowering of the LST along the coastal regions was inferred to be due to the influence of Sea breeze, adjacent moisture from the ocean, shallow water level, and the shadow effect of the buildings. Further, the increase in water level was mainly attributed to the recent increase in rainfall and the extreme event in 2018. The higher EC in the lesser NDBI regions is attributed to the anthropogenic contamination from agriculture and landfill leachates. Though there was an increase in NDBI, the LST of the region was inferred to be reduced mainly due to the increase in water level and reduction of emission from desert sand by recent urban developments.

Capturing temperature changes on the ocular surface along with estrus and ovulation using infrared thermography in Japanese Black cows.

Pre-ovulatory follicles are cooler than the neighboring reproductive organs in cows. Thus, measuring the temperature of reproductive organs could be a useful method for predicting estrus and ovulation in cows, and the establishment of a non-invasive technique is required. In this study, we used infrared thermography (IRT) to measure ocular surface temperature as a potential surrogate for reproductive organ temperature. Five Japanese Black cows with synchronized estrus were subjected to temperature measurements in five regions of the ocular surface, including the nasal conjunctiva, nasal limbus, center cornea, temporal limbus, and temporal conjunctiva, twice a day (0800 h and 1600 h) during the experimental period. The temperatures in the five regions significantly declined in cows from estrus to ovulation. To the best of our knowledge, this study is the first to use IRT to show a temperature decrease in the ocular surface along with estrus to ovulation in Japanese Black cows.

Evaluation of therapeutic efficacy of Emustil drops for ocular discomfort and tear film osmolarity using different treatment management modes under dry environmental conditions.

BACKGROUND: We aimed to check the efficacy of Emustil (oil in water emulsion) drops on tear film index and ocular surface dynamics in dry environments through protection and relief treatment modalities. METHODS: The subjects were exposed to a dry environment using a Controlled Environment Chamber (CEC) where the relative humidity (RH) was 5% and the temperature was 21 °C and screened for ocular symptoms, tear osmolarity, ocular surface temperature (OST) and tear production using ocular Surface Disease Index questionnaire (OSDI), OcuSense TearLab Osmometer, FLIR System ThermaCAM P620 and Schirmer strips/phenol red test respectively. Tear production was calculated by the Tear Function Index test (TFI). RESULTS: The mean tear film osmolarity decreased significantly from 296.8 mOsm/l at 40% RH to 291 mOsm/l at 5%. (p = 0.01). Instillation of Emustil resulted in a significant increase in tear osmolarity in the relief method compared with osmolarity seen at 5% RH when no drop was used. The mean PRT value decreased from 26 ± 9 in normal conditions (40% RH) to 22 ± 4 mm in dry conditions (5% RH). Emustil drops did not induce any significant change in tear production in the PRT test. No significant change was found in OST following exposure to 5% RH. OST did not show a statistically significant change with the emulsion when used for relief (p > 0.05). The mean score of ocular discomfort observed was 70 at 5% RH. Still, the instillation of the oil-in-water emulsion (Emustil) resulted in a noticeable decrease in visual discomfort to 37 (p = 0.00) in protection and 59 in relief (p = 0.05). Emustil drops substantially improved tear film parameters under a desiccating environment, however, tear film parameters respond differently to the management modalities. In the protection method, tear film osmolarity was protected against a dry environment, while in the relief mode, tear production was improved. CONCLUSION: CEC allows for a thorough evaluation of tear film parameters and dry eye treatment protocols in labs, providing greater confidence when applying them to patients. In addition, our study showed that Emustil not only provides protection and relief for dry eyes but also helps to maintain ocular homeostasis in desiccating environments. This indicates a promising potential for improving dry eye treatment protocols.

Sea spray aerosol concentration modulated by sea surface temperature.

Natural aerosols in pristine regions form the baseline used to evaluate the impact of anthropogenic aerosols on climate. Sea spray aerosol (SSA) is a major component of natural aerosols. Despite its importance, the abundance of SSA is poorly constrained. It is generally accepted that wind-driven wave breaking is the principle governing SSA production. This mechanism alone, however, is insufficient to explain the variability of SSA concentration at given wind speed. The role of other parameters, such as sea surface temperature (SST), remains controversial. Here, we show that higher SST promotes SSA mass generation at a wide range of wind speed levels over the remote Pacific and Atlantic Oceans, in addition to demonstrating the wind-driven SSA production mechanism. The results are from a global scale dataset of airborne SSA measurements at 150 to 200 m above the ocean surface during the NASA Atmospheric Tomography Mission. Statistical analysis suggests that accounting for SST greatly enhances the predictability of the observed SSA concentration compared to using wind speed alone. Our results support implementing SST into SSA source functions in global models to better understand the atmospheric burdens of SSA.