Spatial and temporal variability of satellite-derived sea surface temperature in the Barents Sea

The Barents Sea (BS) is an important region for studying climate change. This sea is located on the main pathway of the heat transported from low to high latitudes. Since oceanic conditions in the BS may influence vast areas of the Arctic Ocean, it is important to continue to monitor this region and analyse the available oceanographic data sets. One of the important quantities that can be used to track climate change is the sea surface temperature (SST). In this study, we have analysed the 32 years, (1982–2013) National Oceanic and Atmospheric Administration (NOAA) Optimum Interpolation SST Version 2 data for the BS. Our results indicate that the regionally averaged SST trend in the BS (about 0.03°C year^–1) is greater than the global trend. This trend varies spatially with the lowest values north from 76° N and the highest values (about 0.06°C year^–1) in proximity of Svalbard and in coastal regions near the White Sea. The SST and 2 m air temperature (AT) trends are high in winter months in the open BS region located west from Novaya Zemlya. Such trends can be linked to a significant retreat of sea ice in this area in recent years. In this article, we also documented spatial patterns in the annual cycle of SST in the BS. We have shown that the interannual variability of SST is similar in different regions of the BS and well correlated with the interannual patterns in AT variability.     

Review of:“Conference on Design Methods”. Edited by J. C. JONES and D,G. THOBNLEY. (London: Pergamon Press, 1963.) [Pp. xiii+222.] 50s.

Abstract

This paper describes an experiment in which 1G people each experienced four levels of change in temperature and reported their sensations. Changes were of 0°, 3°, 6° and 9°C and were symmetrical about a center point of 23°C and linear over an exposure period of 6 hours. Changes occurred in both upward and downward directions. Subjects reported their warmth sensations at hourly intervals and gave a summary assessment on 11 semantic differential scales at the end of the period of exposure. The smallest rate of change was reliably detected and changing environments were reported to be less pleasant and more uneven than the steady state. Degree of extraveraion of the subjects and direction of changes in temperature were non-significant variables. A method of estimating the degree of dissatisfaction produced by temperature changes is briefly described.     

Reproducibility of body temperature response to standardized test conditions when assessing clothing

Abstract

The traditional use of core temperature to assess the thermal effects of clothing has recently been questioned. The purpose of this study was to assess the reproducibility of body temperature in five subjects (mean age, 226 ± 1-5 yrs) wearing either athletic clothing or a chemical protective overgarment while exercising at 20°C and at 40°C. The exercise was preceded by a 1 h adaptation period in a controlled environmental chamber. Results indicated that mean group change in rectal temperature (δT_r ) appeared to be reproducible for both garment ensembles at 20°C but not at 40°C. For mean change in oesophageal temperature ( δT_oes ) at 20°C, reproducibility was obtained for the overgarment but not for the athletic garment; at 40°C, mean δT_oes appeared to be reproducible with both garments. However, when individual responses were examined, there was little reproducibility for either δT_r or δT_oes . In addition, these measurements failed to show differences in the types of clothing worn. It was concluded that the use of core temperature to assess heat stress imposed by wearing clothing during exercise may lead to erroneous conclusions.     

An initial validation of Landsat 5 and 7 derived surface water temperature for U.S. lakes,reservoirs, and estuaries

ABSTRACT

The United States Harmful Algal Bloom and Hypoxia Research Control Act of 2014 identified the need for forecasting and monitoring harmful algal blooms (HAB) in lakes, reservoirs, and estuaries across the nation. Temperature is a driver in HAB forecasting models that affects both HAB growth rates and toxin production. Therefore, temperature data derived from the U.S. Geological Survey Landsat 5 Thematic Mapper and Landsat 7 Enhanced Thematic Mapper Plus thermal band products were validated across 35 lakes and reservoirs, and 24 estuaries. In situ data from the Water Quality Portal (WQP) were used for validation. The WQP serves data collected by state, federal, and tribal groups. Discrete in situ temperature data included measurements at 11,910 U.S. lakes and reservoirs from 1980 through 2015. Landsat temperature measurements could include 170,240 lakes and reservoirs once an operational product is achieved. The Landsat-derived temperature mean absolute error was 1.34°C in lake pixels >180 m from land, 4.89°C at the land-water boundary, and 1.11°C in estuaries based on comparison against discrete surface in situ measurements. This is the first study to quantify Landsat resolvable U.S. lakes and reservoirs, and large-scale validation of an operational satellite provisional temperature climate data record algorithm. Due to the high performance of open water pixels, Landsat satellite data may supplement traditional in situ sampling by providing data for most U.S. lakes, reservoirs, and estuaries over consistent seasonal intervals (even with cloud cover) for an extended period of record of more than 35 years.     

Modelling long-term C dynamics in croplands in the context of climate change: a case study from Ohio

A simple dynamic model (CBUDGET) was developed to quantify long-term carbon (C) dynamics in croplands. By using independent datasets (on continuous wheat) from the Waite Permanent Rotation Trial (Australia) and from Northwest Ohio, the tests of its performance resulted in R² values of 0.85 and 0.80, respectively, between observed and simulated values. Our model suggests that the rate of residual C addition into the soil is the primary factor that controls soil organic carbon (SOC) storage for Ohio croplands under continuous corn, wheat and oats for the period 1866–1996 and continuous soybean for the period of 1924–1996. The interaction of CO₂-fertilization and a temperature increase of 0.5°C decreased mean SOC levels for the selected crops over the same periods. A multiple linear regression model (MLR) relating carbon dioxide (CO₂) emissions to population growth, affluence and energy intensity with an R² of 0.99 indicates the significance of underlying causes of anticipated climate change. The MLR model thus serves to capture a more complete picture of anthropogenic sources of global climate change than considering agricultural activities only in exploring locally and regionally mitigative and preventive measures towards global climatic stability.     

Recognition of an overspill-induced estuarine frontal system in the Ria do Barqueiro,north-west Spain,using remote sensing techniques

Abstract

Rising tidal waters breach a channel-bounding spit at mid-tide to carry cool, saline waters into the ebb-dominant channel of the Ria do Barqueiro. Foam lines form an evolving pointed and curving pattern bounding more and less saline waters, and mark the surface limits of the intrusive front. Repeated measurement by radiometer demonstrate the initial presence of three thermally identifiable water masses, at I6.5°C, 17.5°C and 19.8°C, and the homogenization of temperature in less than half an hour.     

Remote sensing analysis of the land surface temperature anomaly in the sand-dune region across the Israel-Egypt border

In the sand-dune region across the Israel-Egypt border, an anomalous phenomenon of thermal variation was observed on remote sensing images: the Israeli side with much more vegetation cover has higher surface temperature than the Egyptian side, where bare sand surface prevails. The study intends to examine the phenomenon using NOAA-AVHRR and Landsat TM data. The focus is to analyse the seasonal and spatial change of land surface temperature (LST) in the border region, to verify it through ground truth measurements and to simulate the average LST change on both sides according to surface composition structure. A split window algorithm containing only two parameters (transmittance and emissivity) has been developed for retrieving LST from NOAA-AVHRR data and a mono-window algorithm is proposed for computing LST from the only one thermal band of Landsat TM data. Application of these algorithms to the available AVHRR and Landsat TM data indicates that the LST anomaly does occur not only in one day but almost all the year. In hot dry summer the Israeli side is usually about 2.5-3.5°C hotter. In wet cool winter the LST difference between the sides is not large but the Israeli side still has higher LST. The Egyptian side may have slightly higher LST when surface temperature is below 20°C, several days after heavy rain, which leads to very wet surface conditions. The sharp LST contrast disappears on night-time images. Ground truth measurements indicate that the LST contrast mainly can be attributed to the surface temperature difference on the two typical surface patterns: biogenic crust and bare sand, which have above 3°C difference in surface temperature during summer. Experiments on soil samples from the field indicate that biogenic crust and sand have emissivity values of about 0.972 and 0.954, respectively, in hot dry conditions that match the environment of the region in summer. Surface composition determination based on three methods indicates that more than 72% of the ground on the Israeli side is covered with biogenic crust and more than 80% on the Egyptian side is bare sand. Actually, the LST anomaly can be understood as the direct result of surface composition difference, especially in biogenic crust and sand cover rate. Simulation with this surface composition difference shows that the Israeli side has steadily higher LST when the temperature of the biogenic crust is more than 1°C higher that of the sand surface, which usually occurs at moderate to high temperature levels (>30°C). When temperature is between 15 and 25°C, such as at about midnight, the two sides will have no obvious LST difference. This result is in agreement with the remote sensing observation. Therefore, it can be concluded that the vegetation cover does not contribute much to the LST contrast in comparison to the effect of the biogenic crust and sand cover.     

Stabilizing global mean surface temperature: A feedback control perspective

In this paper, we develop a discrete time, state variable feedback control regime to analyze the closed-loop properties associated with stabilizing the global mean surface temperature anomaly at 2 °C within a sequential decision making framework made up of 20 year review periods beginning in 2020. The design of the feedback control uses an optimal control approach that minimizes the peak deceleration of anthropogenic CO₂ emissions whilst avoiding overshooting the 2 °C target. The peak value for emissions deceleration that satisfies the closed-loop optimization was found to be linearly related to climate sensitivity and a climate sensitivity of 3.5 °C gave a deceleration of ?1.9 GtC/a/20 years². In addition to accounting for the predicted climate dynamics, the control system design includes a facility to emulate a robust corrective action in the face of uncertainty. The behavior of the overall control action is evaluated using an uncertainty scenario for climate model equilibrium sensitivity.     

Annual anomalies and trends for TOMS reflectivities (1978–2005) in the Southern Hemisphere

Annual anomalies of Lambertian equivalent reflectivity (LER) retrieved from the total ozone mapping spectrometer spanning the period November 1978–November 2005 were studied in the Southern Hemisphere, in a region bounded by 0° S and 60° S, and their trends were estimated. With the exception of few regions where the variable may represent the contribution of both cloudiness and snow, trends in LER anomalies provided an evolution of total cloudiness. On average, the study region experienced a net increase in LER values of 0.78 reflectivity units (RU) decade^?1; if only significant trend values are considered this figure increased to 1.18 RU decade^?1. The region that showed the largest upward trend, up to 4 RU decade^?1, was located over the eastern Pacific, off the coasts of Chile and Peru, where the presence of marine stratocumulus is frequent. Despite the overall positive trend there were regions that yielded a negative one, most notably the tropical latitudes of South America and Africa. The yearly zonal means also showed a positive trend at all latitudes, but significance occurred beyond 20° S only. Correlation maps between LER anomalies and five different circulation indices were also introduced. The indices with the highest and lowest number of significant correlation values were the Madden–Julian oscillation at 70° E and the quasi-biennial Oscillation, respectively.     

Comparison of two different cooling systems in alleviating thermal and physiological strain during prolonged exercise in the heat

Abstract

This study compared the efficacy of an ice vest comprising of water (WATER) or a water-carbon (CARBON) emulsion on thermophysiological responses to strenuous exercise in the heat. Twelve male cyclists completed three 50-minute constant workload trials (55% of peak power output, ambient temperature 30.4?±?0.6°C) with WATER, CARBON, and without ice vest (CONTROL), respectively. The increase in core body temperature (Tcore) was lower in WATER at 40 (?0.49?±?0.34 °C) and 50?minutes (?0.48?±?0.48 °C) and in CARBON at 30 (?0.41?±?0.48 °C), 40 (?0.54?±?0.51 °C), and 50?minutes (?0.67?±?0.62 °C) as compared to CONTROL (p?<?0.05, ES > 0.8). While heart rate and blood lactate kinetics did not differ between the conditions, statistical main effects in favour of both WATER and CARBON were found for thermal sensation (condition p?<?0.001 and interaction p?<?0.01) and rating of perceived exertion (condition p?<?0.05). Per-cooling with CARBON and WATER similarly reduced Tcore but not physiological strain during prolonged exercise in the heat.

Practitioner Summary: Exercise in the heat is characterised by increases in thermophysiological strain. Both per-cooling with a novel carbon-based and a conventional water-based ice vest were shown to reduce core temperature significantly. However, due to its lower mass, the carbon-based system may be recommended especially for weight-bearing sports.     

The importance of remote sensing from space to the Indian subcontinent

Abstract

The Indian subcontinent is the region lying between about 60 and 100°E longitudes and the equator and 40°N latitudes. About one-quarter of the world's population live in this region, with an average population density of about 400 persons per square mile. This region has a belt of fold mountains, including the highest, the Himalayas, a chain of islands, large desert areas, evergreen tropical forests and low-lying plains fed by perennial rivers. It has every type of climate, soil and vegetation ranging from frozen tundra to dense rain forests. The region is endowed with natural resources, but is, however, economically poor and deficient in food and usable fresh water. The immediate problems are timely assessment of crops and their conditions such as drought, the spread of pests and diseases which if detected and remedied in time would result in the saving of crops. The desert areas also need continuous observation to help derive effective methods of arresting the spread of deserts. Because of the presence of perennial rivers there is good potential for having major irrigation and hydroelectric power projects, and studies over vast command and catchment areas are necessary. Floods in these rivers pose a big problem and flood plain mapping is of utmost importance. Forest wealth has been dwindling fast and proper assessment of present day land use and encroachment on forest land has to be detected and checked. Thus remote sensing has a great potential as an important tool for providing a mass of data which could then be used for solving the problems of backwardness of this region. These problems of the Indian subcontinent and how remote sensing can help is discussed in detail.     

Quantifying how landscape composition and configuration affect urban land surface temperatures using machine learning and neutral landscapes

The urban heat island effect is an important 21st century issue because it intersects with the complex challenges of urban population growth, global climate change, public health and increasing energy demand for cooling. While the effects of urban landscape composition on land surface temperature (LST) are well-studied, less attention has been paid to the spatial arrangement of land cover types especially in smaller, often more diverse cities. Landscape configuration is important because it offers the potential to provide refuge from excessive heat for both people and buildings.We present a novel approach to quantifying how both composition and configuration affect LST derived from Landsat imagery in Southampton, UK. First, we trained a machine-learning (generalized boosted regression) model to predict LST from landscape covariates that included the characteristics of the immediate pixel and its surroundings. The model achieved a correlation between predicted and measured LST of 0.956 on independent test data (n = 102,935) and included predictors for both the immediate and adjacent land use. In contrast to other studies, we found adjacency effects to be stronger than immediate effects at 30 m resolution. Next, we used a landscape generation tool (Landscape Generator) to alter landscape configuration by varying natural and built patch sizes and arrangements while holding composition constant. The generated neutral landscapes were then fed into the machine learning model to predict patterns of LST.When we manipulated landscape configuration, the average city temperature remained the same but the local minima varied by 0.9 °C and the maxima by 4.2 °C. The effects on LST and heat island metrics correlated with landscape fragmentation indices. Moreover, the surface temperature of buildings could be reduced by up to 2.1 °C through landscape manipulation.We found that the optimum mix of land use types is neither at the land-sharing nor land-sparing extremes, but a balance between the two. In our city, maximum cooling was achieved when ~60% of land was left natural and distributed in 7–8 patches km⁻² although this could be location dependent and further work is needed. Opportunities for urban cooling should be required in the planning process and must consider both composition and configuration at the landscape scale if cities are to build capacity for a growing population and climate change.     

The influence of temperature and precipitation climate regimes on vegetation dynamics in the US Great Plains: a satellite bioclimatology case study

Advanced Very High Resolution Radiometer (AVHRR)‐derived Normalized Difference Vegetation Index (NDVI) data are widely used in global‐change research, yet relationships between the NDVI and ecoclimatological variables are not fully understood. This study attempts to model climate‐driven vegetation dynamics through the integration of satellite‐derived NDVI data with climate data collected from ground‐based meteorological stations in the US Great Plains. Monthly maximum value composites of NDVI data (8‐km resolution) and monthly temperature and precipitation records from 305 stations were collected from 1982 to 2001. Analyses involving deseasonalized datasets supported temperature as the dominant climate regime, demonstrating a higher average NDVI–temperature correlation (r = 0.73) than the NDVI–precipitation relationship (r = 0.38). Cluster analysis was used to develop a climate regionalization scheme based primarily on temperature, and NDVI characteristics of each subregion were compared. In the context of global climate change, findings from this study emphasize the influence of temperature and precipitation variability over vegetation cover in the Great Plains region.     

Core temperature and heart rate response to repeated bouts of firefighting activities

During live-fire firefighting operations and training evolutions, firefighters often consume multiple cylinders of air and continue to wear their personal protective equipment even after fire suppression activities have ceased. However, most studies have only reported core temperature changes during short-term firefighting activities and have shown a very modest increase in core temperature. Therefore, the purpose of this study is to evaluate core temperature and heart rate (HR) during repeated bouts of firefighting activity over ～3 h. The results of this study show that core temperatures increase by an average of 1.9°C – to a larger magnitude than previously reported – and continue to increase during subsequent work cycles (38.4 vs. 38.7) even after long breaks of more than 30 min. The rate of core temperature increase during work continues to increase later in the training exercise (from 0.036 to 0.048°C/min), increasing the risk for exertional heat stress particularly if long-duration firefighting activity is required at these later times.

Practitioner Summary: To date, core temperature and HR changes during firefighting have been reported for short-term studies, which may significantly underestimate the physiological burden of typical firefighting activities. Firefighter core temperatures are shown to increase to a larger magnitude than previously observed and the rate of rise in core temperature increases during subsequent firefighting activities.     

The Measurement of Fatigue in Hot Working Conditions

Abstract

The N.S.W. Division of Occupational Health was requested to provide information to assist a Mines Rescue Station to choose a type of self-contained breathing apparatus which would be likely to permit the greatest duration of exposure of Mines Rescue personnel to hot and humid environment whilst performing heavy work, without collapse.

A number of subjects were tested in a heat chamber, performing a work cycle of 2 minutes duration, followed by a 3-minute rest period, at temperatures of 30°c, 35°c, 38°C and 4l°c Dry Bulb with a Wet Bulb temperature about 1° lower in each case, until the subject was either unable to continue or until the rectal temperature reached 38·8°c to 38·9°c.

Pulse rates, skin temperature, and sweat losses were also recorded.

The experiments confirmed that a rectal temperature of 38·8°c to 38·9° will, in most cases, coincide closely with the onset of exhaustion.

Sweat loss and pulse rate were found to be unreliable methods of measuring fatigue and that skin temperature was completely unreliable as an index of fatigue except when the temperature and humidity were high.     

Seasonal and inter-annual variation in surface energy fluxes and forcing parameters in agro-climatic regions of India

Understanding changes in monsoon variability over a decade requires thorough knowledge of the seasonal and inter-annual variability in surface energy flux and its forcing parameters (land surface and meteorology) in response to climate change. In the present study, the Moderate Resolution Imaging Spectroradiometer (MODIS) Aqua climate model gridded global products (0.05° × 0.05° spatial resolution) of land surface temperature (LST; T_s), normalized difference vegetation index (NDVI), and surface albedo (α) were used to generate seasonal (June–September) and inter-annual (2003–2012) variation in surface energy flux and its forcing parameters over different agro-climatic regions (ACRs) of India. Energy fluxes were retrieved using a single-source surface energy balance model (here vegetation and soil is considered as a single unit). Energy flux observations over different ACRs allowed comparison of the seasonal transition of latent heat flux (LE), net radiation (R_n), soil heat flux (G), available energy (Q = R_n – G), and evaporative fraction (EF) as terrestrial links to the atmosphere. The seasonal and inter-annual variation in EF was investigated by plotting against the soil moisture information retrieved from the Advanced Microwave Scanning Radiometer-EOS (AMSR-E) global monthly data product (1° × 1° spatial resolution). Decadal and seasonal analysis showed that energy fluxes vary widely in time and space due to variability in surface radiation parameters (T_s, α), vegetation cover, soil moisture, and air temperature (T_a), which influence the seasonal transition of monsoon through LE and EF. Among the ACRs, LE and EF were found lowest in the Western Dry Region (WDR) and highest in the Western Himalayan Region (WHR). The spatiotemporal depiction of MODIS LE and MODIS EF over a span of 10 years can identify the hotspots and monsoon intensity over different ACRs. Climatic parameters that are susceptible to changes resulting from climate change are thoroughly studied in the present analysis.     

Characterizing 40 years of natural Pinus sylvestris var. mongolica carbon stocks in Northeast China using stand age from remote sensing time series

ABSTRACT

Remote sensing (RS)-assisted estimates of forest carbon stocks are essential for modelling carbon budgets at large scales. Research on the dynamic variations in forest biomass and carbon stocks is important to improve the sustainable use of forest resources and understand forest carbon budgets in China. The Honghuaerji region of the Inner Mongolia Autonomous Region is where Pinus sylvestris var. mongolica Litv. (MP) originated. MP forests contained the most important coniferous silvicultural tree species and were later introduced to the desert regions of northern China. However, there has been very little research on carbon stocks (vegetation and soil carbon) over time in the original MP forests. Our goal was to estimate the changes in the carbon stocks of the natural MP forests in the Honghuaerji region using a 40-year RS time series, forest survey data and laboratory data. First, we mapped MP forests and estimated forest ages based on Key Hole 9 and Landsat time series stacks from 1975 to 2015, and the estimated forest ages were shown to be consistent with the surveyed tree ages with a coefficient of determination (R²) of 0.96. Second, fifteen vegetation indices were evaluated as indicators of diameter at breast height (DBH). Of these, tasselled cap greenness provided the best relationships, and an RS-based DBH equation was constructed with an R² of 0.65. Third, the carbon densities in the different ages of MP forests were obtained at regional scales. Finally, the dynamics of the carbon stocks in the natural MP forest ecosystem (including stems, branches, leaves, roots and soils) over 40 years were obtained. The results of this study indicated that the total MP forest ecosystem carbon stocks increased significantly from 7.36 ± 1.92 Tg C in 1975 to 11.52 ± 2.51 Tg C in 2015 at a rate of 1.42% year^–1, among which vegetation carbon stocks increased 5.54% year^–1 and soil carbon stocks increased 0.45% year^–1. The results reveal a notable carbon increase in the MP forests in the Honghuaerji region over the past four decades and provide information on the role of natural forest conservation and management in China in mitigating global climate change.     

Microwave brightness temperature as an indicator of near-surface air temperature over snow in Canadian northern regions

During the past 50 years, winter temperatures have risen more rapidly than in summer in northern high latitudes. However, there are relatively few meteorological stations in these areas, and a better characterization of this trend is needed. This article investigates whether satellite microwave brightness temperature can be used as an indicator of near-surface air temperature over snow. The Helsinki University of Technology (HUT) snow emission model is used to generate a dry snow emissivity relationship between 19 and 37 GHz under the assumption that the air–snow interface temperatures and air temperatures (T_air ) are similar. This relationship allows the development of a near-surface air temperature retrieval model. A second empirical linear correction is also applied to reduce the residual observed bias. The comparison between retrieved near-surface air temperature and in situ air temperature for the Canadian northern regions shows a significant correlation (R ² of 0.76) but with a root mean square error (RMSE) of 4.94°C. Results also show that the satellite-derived temperatures can be compared to the thermal infrared skin temperature (RMSE of 5.9°C). The proposed approach gives better results than the direct correlation between brightness temperature (T _b) and in situ air temperature (RMSE reduced by 50%).     

Cooling vests with phase change material packs: the effects of temperature gradient,mass and covering area

Phase change material (PCM) absorbs or releases latent heat when it changes phases, making thermal-regulated clothing possible. The objective of this study was to quantify the relationships between PCM cooling rate and temperature gradient, mass and covering area on a thermal manikin in a climatic chamber. Three melting temperatures (24, 28, 32°C) of the PCMs, different mass, covering areas and two manikin temperatures (34 and 38°C) were used. The results showed that the cooling rate of the PCM vests tested is positively correlated with the temperature gradient between the thermal manikin and the melting temperature of the PCMs. The required temperature gradient is suggested to be greater than 6°C when PCM vests are used in hot climates. With the same temperature gradient, the cooling rate is mainly determined by the covering area. The duration of the cooling effect is dependent on PCM mass and the latent heat.

Statement of Relevance: The study of factors affecting the cooling rate of personal cooling equipment incorporated with PCM helps to understand cooling mechanisms. The results suggest climatic conditions, the required temperature gradient, PCM mass and covering area should be taken into account when choosing personal PCM cooling equipment.     

Studies of polymer deformation and recovery in micro hot embossing

In large areas of micro hot embossing, process temperature plays a critical role to both the local-area fidelity and global uniformity of microstructure formation. Higher embossing temperature could improve structure fidelity, however, at the expense of demoulding easiness. Micro embossing at the lowest possible temperature with acceptable fidelity can improve global flatness after demoulding. This study focuses on polymer deformation and recovery in micro embossing when the process temperature is below the polymer glass transition temperature (Tg). PMMA (Polymethyl Methacrylate) substrates (Tg = 105°C) were employed with the process temperature ranging from 25°C to its Tg. At temperature below Tg −55°C, significant recovery occurred after processing, but permanent structures could still be formed with sufficiently high applied stress. With an increase in temperature, plastic deformation increased and was the dominant polymer deformation mode for permanent cavities formation. However, the formation of protrusive structures was not complete since there was little polymer flow. The polymer will lose its storage modulus at an even higher temperature and microstructures could be formed with high fidelity. A compromise between local fidelity of embossed patterns and global flatness of substrate has to be reached in micro hot embossing.