Search

The spread of infectious diseases was further promoted due to busy cities, increased travel, and climate change, which led to outbreaks, epidemics, and even pandemics. The world experienced the severity of the 125 nm virus called the coronavirus disease 2019 (COVID-19), a pandemic declared by the World Health Organization (WHO) in 2019. Many investigations revealed a strong correlation between humidity and temperature relative to the kinetics of the virus's spread into the hosts. This study aimed to solve the riddle of the correlation between environmental factors and COVID-19 by applying RepOrting standards for Systematic Evidence Syntheses (ROSES) with the designed research question. Five temperature and humidity-related themes were deduced via the review processes, namely 1) The link between solar activity and pandemic outbreaks, 2) Regional area, 3) Climate and weather, 4) Relationship between temperature and humidity, and 5) the Governmental disinfection actions and guidelines. A significant relationship between solar activities and pandemic outbreaks was reported throughout the review of past studies. The grand solar minima (1450-1830) and solar minima (1975-2020) coincided with the global pandemic. Meanwhile, the cooler, lower humidity, and low wind movement environment reported higher severity of cases. Moreover, COVID-19 confirmed cases and death cases were higher in countries located within the Northern Hemisphere. The Blackbox of COVID-19 was revealed through the work conducted in this paper that the virus thrives in cooler and low-humidity environments, with emphasis on potential treatments and government measures relative to temperature and humidity. Highlights: • The coronavirus disease 2019 (COIVD-19) is spreading faster in low temperatures and humid area. • Weather and climate serve as environmental drivers in propagating COVID-19. • Solar radiation influences the spreading of COVID-19. • The correlation between weather and population as the factor in spreading of COVID-19. [ABSTRACT FROM AUTHOR]

Mixing layer height (h) is an important parameter for understanding the transport process in the troposphere, air pollution, weather and climate change. Many methods have been proposed to determine h by identifying the turning point of the radiosonde profile. However, substantial differences have been observed in the existing methods (e.g., the potential temperature (ϑ), relative humidity (RH), specific humidity (q) and atmospheric refractivity (N) methods). These differences are associated with the inconsistency of the temperature and humidity profiles in a boundary layer that is not well mixed, the changing measurability of the specific humidity and refractivity with height, the measurement error of humidity instruments within clouds, and the general existence of clouds. This study proposes a method to integrate the information of temperature, humidity and cloud to generate a consistent estimate of h. We apply this method to high vertical resolution (~ 30 m) radiosonde data that were collected at 79 stations over North America during the period from 1998 to 2008; the data are obtained from the Stratospheric Processes and their Role in Climate Data Center (SPARC). The results show good agreement with those from N method as the information of temperature and humidity contained in N; however cloud effects that are included in our method increased the reliability of h. Furthermore, our results agree well with the independent h that was determined from lidar observations. From 1988 to 2008, the climatological h over North America was 1675±303m with a strong east-west gradient: higher values (generally greater than 1800 m) occurred over the Midwest US, and lower values (usually less than 1400 m) occurred over Alaska and the US west coast. [ABSTRACT FROM AUTHOR]

Timber is a widely used material in construction. The moisture content has a significant impact on the mechanical and physical properties of it. This paper studies how the moisture content values are directly connected to the climate conditions, especially temperature and relative humidity, by measuring these factors for a non-renovated historical timber roof for a one-year period, combined with meteorological data for Pécs since 1901. The fluctuation in moisture content values created instability in the water content of the structural elements due to absorption and release of water in order to reach the equivalent moisture content point. This process led to continuous volume increase-decrease of the timber, thus to formation of cracks, discoloration and harmful fungi development. [ABSTRACT FROM AUTHOR]

Copyright of TEME: Casopis za Društvene Nauke is the property of TEME: Casopis za Drustvene Nauke and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Global warming and climate change have increased the frequency of heavy precipitation. Heavy rainfall results in a large amount of water entering roadways within a short time period. Water remains in the pavement system for a certain time period, reduces strengths and moduli of granular bases and subgrades, and induces pavement distresses. Geotextiles are commonly used in roadways for drainage purposes, which require soil saturation. However, soil saturation does not always exist in roadways to enable gravity drainage of water by conventional geotextiles. Wicking geotextile, a new type of woven geotextile, was recently introduced to the market to remove moisture from unsaturated soils. The wicking geotextile includes special hydrophilic and hygroscopic 4 deep groove fibers with multichannel cross sections, which can induce high capillary force to wick water out of moist soil without saturation of soil. The ability and rate of this geotextile to remove water from moist soil depends on several factors, including temperature and relative humidity. In this study, a series of laboratory tests under controlled temperature and relative humidity were conducted to quantify the water removal rate of the wicking geotextile. A half length of the wicking geotextile was submerged in water tanks, and the other half was hung outside of the tanks. The water wicked from the tank into the geotextile evaporated into the air. Such tests were conducted under 12 different test conditions (i.e., different temperatures and relative humidities). Test results demonstrated that the wicking geotextile could remove water from the water tank at a certain rate. Three commonly used methods available in the literature were adopted to quantify the water removal rate of the wicking geotextile based on vapor pressure, temperature, and relative humidity. A new concept of equivalent water evaporation length of a wicking geotextile is proposed in this study. It should be pointed out that the tests presented in this paper aimed to determine the maximum water removal capacity of the geotextile given sufficient water supply. [ABSTRACT FROM AUTHOR]

This paper studies the impact of climate change on the electricity consumption by means of a fuzzy regression approach. The climate factors which have been considered in this paper are humidity and temperature, whereas the simultaneous effect of these two climate factors is considered. The impacts of other climate variables, like the wind, with a minor effect on energy consumption are ignored. The innovation which applies in this paper is the division of the year into two parts by using the temperature-day graph in the year. To index the humidity, data of the minimum humidity per day are used. For temperature, the maximum temperature of the first part of the year (warm days) and the minimum of the second part (cold days) are used. The indicator for the consumption is the daily peak load. The model results show high sensitivity to the temperature but low sensitivity to the humidity. Moreover, it is concluded that the model structure cannot be the same and for the cold par additional variables such as gas consumption should be considered. [ABSTRACT FROM AUTHOR]

The paper has examined the impact of variations of Atlantic multidecadal oscillation on the change in air temperature during the summer season on the territory of Montenegro. Starting from the fact that in recent years more and more extreme weather events occur, as well as from the intention to comprehensively consider the temperature conditions in the territory of Montenegro, first analysis is of changes in air temperature in 8 parameters, of which 5 climate indices; connections with Atlantic multidecadal oscillation have also been analyzed. To study changes in temperature extreme indexes proposed by the WMO CCL/CLIVAR are used. Research within the listed topics was realized using data from 23 meteorological stations for the period 1951-2010 and the calculations are done for the summer season. The results show that there is increased number of maximum and minimum daily temperatures of warmer value. The impact assessment Atlantic multidecadal oscillation, teleconnection pattern that is quite distant, showed that its variability affects changes in summer temperatures in Montenegro, both in terms of mean values, and the frequency of extreme actions presented by climate indices. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Kirkuk University for Agricultural Sciences is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this paper, the climate change in Haiyan County in recent decades was analyzed in detail with the methods of moving average, Mann-Kendall non-parametric mutation test and wavelet analysis. According to the variation trend of meteorological factors such as temperature, relative humidity, wind speed, pan evaporation and precipitation in recent decades, the climate of Haiyan County has a tendency of drought, which is becoming more and more serious. From the results of the analysis, the sunshine hours and the air temperature in Haiyan County have an obvious upward trend. The average surface temperature has increased by 2.75 °C from 1976, and its largest increase occurred in the late 1970s and 1980s. At this stage, the average surface temperature increased by 1.37 °C. The relative humidity has a decreasing trend that has decreased by 2.75%. From 1976 to the present, there are two quasi-3a cycles and one quasi-6a cycle. The precipitation and evaporation showed the opposite change trend, in which the trend of precipitation fluctuated upward, while the trend of evaporation showed a fluctuating downward tendency, which led to the serious loss of water in the feeding area. The wind direction in Haiyan County are mainly from west to east, and its wind speed has a trend of slight increase. [ABSTRACT FROM AUTHOR]

This paper summarizes the results from microclimatic monitoring of the impacts related to the construction and exploration phase of a hydroelectric powerplant in the upper Douro River (Portugal). Reference climatic elements for both periods were obtained and the impacts of the reservoir water mass on the region's microclimate were evaluated. For this purpose, Sen's slope estimate non-parametric test was used to detect the meteorological variables' trends over 10 years, considering the division into the construction (2011–2015) and exploration (2016–2020) phases. A network of meteorological stations located close to the dam, in addition to a control station relatively distant from the dam, was used to collect the meteorological data. The control station is still integrated into the same regional climatic context but not exposed to the direct influence of the resulting reservoirs. As a result, temporal differences were determined for temperature and relative humidity. The results show a statistically significant increase in the minimum relative humidity, accompanied by a statistically significant decrease in the daily and seasonal temperature amplitudes between the construction and the exploration phase periods. These outcomes thereby suggest that large reservoirs affect the local climate and may create new microclimates, in the surrounding area, with both positive and negative potential effects. [ABSTRACT FROM AUTHOR]

Copyright of Acta Scientiarum: Human & Social Sciences is the property of Universidade Estadual de Maringa and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper focuses on the primary causes of changes in potential evapotranspiration (ETo) in order to comprehensively understand climate change and its impact on hydrological cycle. Based on modified Penman-Monteith model, ETo is simulated, and its changes are attributed by analyzing the sensitivity of ETo to influence meteorological variables together with their changes for 595 meteorological stations across China during the period 1961–2008. Results show the decreasing trends of ETo in the whole country and in most climate regions except the cold temperate humid region in Northeast China. For China as a whole, the decreasing trend of ETo is primarily attributed to wind speed due to its significant decreasing trend and high sensitivity. Relative humidity is the highest sensitive variable; however, it has negligible effect on ETo for its insignificant trend. The positive contribution of temperature rising to ETo is offset by the effect of wind speed and sunshine duration. In addition, primary causes to ETo changes are varied for differing climate regions. ETo changes are attributed to decreased wind speed in most climate regions mainly distributed in West China and North China, to declined sunshine duration in subtropical and tropical humid regions in South China, and to increased maximum temperature in the cold temperate humid region. [ABSTRACT FROM AUTHOR]

Vector‐borne diseases cause significant financial and human loss, with billions of dollars spent on control. Arthropod vectors experience a complex suite of environmental factors that affect fitness, population growth and species interactions across multiple spatial and temporal scales. Temperature and water availability are two of the most important abiotic variables influencing their distributions and abundances. While extensive research on temperature exists, the influence of humidity on vector and pathogen parameters affecting disease dynamics are less understood. Humidity is often underemphasized, and when considered, is often treated as independent of temperature even though desiccation likely contributes to declines in trait performance at warmer temperatures. This Perspectives explores how humidity shapes the thermal performance of mosquito‐borne pathogen transmission. We summarize what is known about its effects and propose a conceptual model for how temperature and humidity interact to shape the range of temperatures across which mosquitoes persist and achieve high transmission potential. We discuss how failing to account for these interactions hinders efforts to forecast transmission dynamics and respond to epidemics of mosquito‐borne infections. We outline future research areas that will ground the effects of humidity on the thermal biology of pathogen transmission in a theoretical and empirical framework to improve spatial and temporal prediction of vector‐borne pathogen transmission. [ABSTRACT FROM AUTHOR]

In light of current climate change projections in recent years, there has been an increasing interest in the assessment of indoor overheating in domestic environments in previously heating-dominated climates. This paper presents a monitoring study of overheating in 122 London dwellings during the summers of 2009 and 2010. Dry Bulb Temperature and Relative Humidity in the main living and sleeping area were monitored at 10 min intervals. The ASHRAE Standard 55 adaptive thermal comfort method was applied, which uses outdoor temperature to derive the optimum indoor comfort temperature. It was found that 29% of all living rooms and 31% of all bedrooms monitored during 2009 had more than 1% of summertime occupied hours outside the comfort zone recommended by the standard to achieve 90% acceptability. In 2010, 37% of monitored living rooms and 49% of monitored bedrooms had more than 1% of summertime occupied hours outside this comfort zone. The findings of this study indicate that London dwellings face a significant risk of overheating under the current climate. Occupant exposure to excess indoor temperatures is likely to be exacerbated in the future if climate change adaptation strategies are not incorporated in Building Regulations, building design and retrofit. [ABSTRACT FROM AUTHOR]

Global warming can cause deep and extensive changes in the Earth's climate and changes in the time and place of climatic phenomena. The present trend analysis study assesses cold stress using the thermo-hygrometric index (THI) in the two seasons of autumn and winter in outdoor environments in Iran. The data related to the average of the two variables of daily air temperature and relative humidity from 60 synoptic meteorological stations for a statistical period of 30 years were obtained from the Iranian Meteorological Organization. The THI index was calculated for autumn and winter, and the level of thermal discomfort was determined for each station. The Mann–Kendall statistical test with the help of Minitab ver17.1.0 software was also used to investigate the changes in air temperature, relative humidity and THI index. The THI for autumn increased in 68% of the stations, and this increasing trend is statistically significant in 51% of these stations. The THI for winter increased in 83% of the stations, and this increasing trend is statistically significant in 51% of these stations. In autumn, 53% of the stations were in the range of thermal discomfort, and in winter only 5% were in the range of thermal comfort. The decreasing trend in THI in some climatic types, along with the increasing trend in air temperature, can indicate the decrease in relative humidity in the monitored stations during the studied years. It is recommended to know the temporal and spatial distribution and the probability of occurrence of cold stress through the use of THI in order to adopt preventive measures and policies in the outdoors in Iran. [ABSTRACT FROM AUTHOR]

Background: Climatic change is an inescapable fact that implies alterations in seasons where weather occurrences have their schedules shift from the regular and magnitudes intensify to more extreme variations over a multi-year period. Southeast Asia is one of the many regions experiencing changes in climate and concurrently still has endemicities of malaria. Given that previous studies have suggested the influence of climate on malaria’s vector the Anopheles mosquitoes and parasite the Plasmodium group, this study was conducted to review the evidence of associations made between malaria cases and climatic variables in Southeast Asia throughout a multi-year period. Methods: Our systematic literature review was informed by the PRISMA guidelines and registered in PROSPERO: CRD42022301826 on 5 th February 2022. We searched for original articles in English and Indonesian that focused on the associations between climatic variables and malaria cases. Results: The initial identification stage resulted in 535 records of possible relevance and after abstract screening and eligibility assessment we included 19 research articles for the systematic review. Based on the reviewed articles, changing temperatures, precipitation, humidity and windspeed were considered for statistical association across a multi-year period and are correlated with malaria cases in various regions throughout Southeast Asia. Conclusions: According to the review of evidence, climatic variables that exhibited a statistically significant correlation with malaria cases include temperatures, precipitation, and humidity. The strength of each climatic variable varies across studies. Our systematic review of the limited evidence indicates that further research for the Southeast Asia region remains to be explored.

Recent work attributing decadal regime changes in temperature to radiative forcing is extended to atmospheric moisture. Temperature, and specific and relative humidity (T, q, RH) from the HadISDH data set were analyzed for regime shifts using the bivariate test. Most shifts in q and T for global and northern hemisphere (NH), and tropical land occurred within a year of each other. Only one shift of q was recorded in the southern hemisphere (SH). RH increased in the NH in 1990–91 and decreased in a series of shifts from the late 1990s, while in the SH decreased from 2001. The tropics have remained neutral, shifting negative over land and positive over the ocean. The global decreases in 2001 and 2011 was −0.56%. Global RH from 32 climate models from the CMIP5 RCP4.5 archive all contained regime shifts but only 4 reached or exceeded the observed decreases by 2100, the earliest in 2056. Regime shifts in RH and fire danger over Australia are consistent with the SH decreases in RH, shifting within one year of global fire season length in 2002, showing that impacts are also being underestimated by current analyses. Methods for nonlinear attribution and the contributing processes for nonlinear change are discussed. These results show that developing a better understanding of nonlinear change in moisture-related climate risk is an urgent task. [ABSTRACT FROM AUTHOR]

Sub-daily extreme precipitation in Jakarta exhibits trends that are related to local temperature, seasonal tropical monsoon circulations, and other environmental drivers. An analysis of 81 years of hourly rainfall between 1900 and 2010 shows a significant increase of about doubling the number of short-duration rainfall events in the wet season. In recent decades, rainfall is found to be higher in intensity and shorter in duration relative to preceding decades. These short-duration rain showers develop typically between afternoon and late night or during early morning hours. Changing short-duration rainfall characteristics throughout the last century are partly attributed to changes in the surface environment of urban Jakarta. A recent temperature increase and land surface drying in the city, in combination with a small increase in the atmospheric moisture content, promote intensified atmospheric convection. A combination of rain gauge data with upper-air observations collected during 2002 -- 2016 reveals that surface warming in the urbanized city accompanied by enhanced availability of moisture results in an increase in convective available potential energy, which contributes to enhanced intense precipitation. Super Clausius--Clapeyron scaling (CC) of high-intensity rainfall is attributed to high near-surface temperature and atmospheric moisture content in the morning. This super-CC scaling is present in a relatively small range of surface temperature values. Results of this study are in agreement with earlier findings exploring the intensification of extreme morning precipitation and a temporal shift of the diurnal convective maximum from late afternoon to late night/early morning in response to local warming. For a delta city such as Jakarta with abundant convection and heavy precipitation, a well-maintained rainfall database is crucial to assist urban flood early warning. [ABSTRACT FROM AUTHOR]

Seppä, H., Birks, H. J. B., Bjune, A. E. & Nesje, A. 2010: Current continental palaeoclimatic research in the Nordic region (100 years since Gunnar Andersson 1909) - Introduction. Boreas, Vol. 39, pp. 649-654. 10.1111/j.1502-3885.2010.00170.x. ISSN 0300-9483. [ABSTRACT FROM AUTHOR]

The natural hydration of obsidian was first proposed as a dating technique for young geological and archaeological specimens by Friedman and Smith (1960), who noted that the thickness of the hydrated layer on obsidian artifacts increases with time. This approach is, however, sensitive to temperature and humidity under earth-surface conditions. This has made obsidian hydration dating more difficult, but potentially provides a unique tool for paleoclimatic reconstructions. In this paper we present the first successful application of this approach, based on combining laboratory-based experimental calibrations with archaeological samples from the Chalco site in the Basin of Mexico, dated using stratigraphically correlated 14C results and measuring hydration depths by secondary ion mass spectrometry. The resultant data suggest, first, that this approach is viable, even given the existing uncertainties, and that a cooling trend occurred in the Basin of Mexico over the past 1450 yr, a result corroborated by other paleoclimatic data. [ABSTRACT FROM AUTHOR]

We analyze how winter thaw events (TE; T > 0°C) are changing on the summit of Mount Washington, New Hampshire, using three metrics: the number of TE, number of thaw hours, and number of thaw degree-hours for temperature and dewpoint for winters from 1935/36 to 2019/20. The impact of temperature-only TE and dewpoint TE on snow depth are compared to quantify the different impacts of sensible-only heating and sensible-and-latent heating, respectively. Results reveal that temperature and dewpoint TE for all metrics increased at a statistically significant rate (p < 0.05) over the full time periods studied for temperature (1935/36–2019/20) and dewpoint (1939/40–2019/20). Notably, around 2000/01, the positive trends increased for most variables, including dewpoint-thaw degree-hours that increased by 82.11 degree-hours decade−1 during 2000–20, which is approximately 5 times as faster as the 1939–2020 rate of 17.70 degree-hours decade−1. Furthermore, a clear upward shift occurred around 1990 in the lowest winter values of thaw hours and thaw degree-hours—winters now have a higher baseline amount of thaw than before 1990. Snow-depth loss during dewpoint TE (0.36 cm h−1) occurred more than 2 times as fast as temperature-only TE (0.14 cm h−1). With winters projected to warm throughout the twenty-first century in the northeastern United States, it is expected that the trends in winter thaw events, and the sensible and latent energy that they bring, will continue to rise and lead to more frequent winter flooding, fewer days of good quality snow for winter recreation, and changes in ecosystem function. [ABSTRACT FROM AUTHOR]

Characteristics of temperature inversions (TIs) and specific humidity inversions (SHIs) and their relationships in three of the latest global reanalyses—the European Centre for Medium-Range Weather Forecasts Interim Reanalysis (ERA-I), the Japanese 55-year Reanalysis (JRA-55), and the ERA5—are assessed against in situ radiosonde (RS) measurements from two expeditions over the Arctic Ocean. All reanalyses tend to detect many fewer TI and SHI occurrences, together with much less common multiple TIs and SHIs per profile than are seen in the RS data in summer 2008, winter 2015, and spring 2015. The reanalyses generally depict well the relationships among TI characteristics seen in RS data, except for the TIs below 400 m in summer, as well as above 1000 m in summer and winter. The depth is simulated worst by the reanalyses among the SHI characteristics, which may result from its sensitivity to the uncertainties in specific humidity in the reanalyses. The strongest TI per profile in RS data exhibits more robust dependency on surface conditions than the strongest SHI per profile, and the former is better presented by the reanalyses than the latter. Furthermore, all reanalyses have difficulties simulating the relationships between TIs and SHIs, together with the correlations between the simultaneous inversions. The accuracy and vertical resolution in the reanalyses are both important to properly capture occurrence and characteristics of the Arctic inversions. In general, ERA5 performs better than ERA-I and JRA-55 in depicting the relationships among the TIs. However, the representation of SHIs is more challenging than TIs in all reanalyses over the Arctic Ocean. [ABSTRACT FROM AUTHOR]

The human impacts of changes in heat events depend on changes in the joint behavior of temperature and humidity. Little is currently known about these complex joint changes, either in observations or projections from general circulation models (GCMs). Further, GCMs do not fully reproduce the observed joint distribution, implying a need for simulation methods that combine information from GCMs with observations for use in impact studies. We present an observation-based, conditional quantile mapping approach for the simulation of future temperature and humidity. A temperature simulation is first produced by transforming historical temperature observations to include projected changes in the mean and temporal covariance structure from a GCM. Next, a humidity simulation is produced by transforming humidity observations to account for projected changes in the conditional humidity distribution given temperature, using a quantile regression model. We use the Community Earth System Model Large Ensemble (CESM1-LE) to estimate future changes in summertime (June–August) temperature and humidity over the continental United States (CONUS), and then use the proposed method to create future simulations of temperature and humidity at stations in the Global Summary of the Day dataset. We find that CESM1-LE projects decreases in summertime humidity across CONUS for a given deviation in temperature from the forced trend, but increases in the risk of high dewpoint on historically hot days. In comparison with raw CESM1-LE output, our observation-based simulation largely projects smaller changes in the future risk of either high or low humidity on days with historically warm temperatures. [ABSTRACT FROM AUTHOR]

Buildings are subjected to the indoor environment, especially in non-controlled climates. Temperature and humidity variations might effect or even damage materials sensitive to moisture. For this reason, it is important to understand the response of hygroscopic materials to variable indoor environmental conditions. Existing methods looked into the dynamic sorption capacity of materials, by analysing the impact of only humidity fluctuations, with temperature usually considered non-influential or non variable. However, temperature fluctuations may impact the moisture capacity of the materials, as materials properties might substantially vary with temperature. Moreover, in existing protocols, the humidity variations are considered to be varying under square wave fluctuations, which may not be applicable in environments, where the indoor is influenced by daily and seasonal climate variations, which presents more complex fluctuation. In this study, a simulation method that can predict the impact of environmental condition on materials under simultaneous temperature and humidity fluctuations was developed. Clay and gypsum plaster were analysed in the numerical model and results were then validated with experimental data. Materials were subjected to either sinusoidal and triangular temperature and RH variations and different cycle time intervals. The investigation of sinusoidal and triangular environmental variations pushed to a better understanding of materials response to different environments and to the improvement of the simplified model. The development of a simplified model can realistically predict the potential future impact of climate changes on buildings without the use of complex and memory demanding computational methods. [ABSTRACT FROM AUTHOR]

This paper summarizes the results from microclimatic monitoring of the impacts related to the construction and exploration phase of a hydroelectric powerplant in the upper Douro River (Portugal). Reference climatic elements for both periods were obtained and the impacts of the reservoir water mass on the region’s microclimate were evaluated. For this purpose, Sen’s slope estimate non-parametric test was used to detect the meteorological variables’ trends over 10 years, considering the division into the construction (2011–2015) and exploration (2016–2020) phases. A network of meteorological stations located close to the dam, in addition to a control station relatively distant from the dam, was used to collect the meteorological data. The control station is still integrated into the same regional climatic context but not exposed to the direct influence of the resulting reservoirs. As a result, temporal differences were determined for temperature and relative humidity. The results show a statistically significant increase in the minimum relative humidity, accompanied by a statistically significant decrease in the daily and seasonal temperature amplitudes between the construction and the exploration phase periods. These outcomes thereby suggest that large reservoirs affect the local climate and may create new microclimates, in the surrounding area, with both positive and negative potential effects.

The article focuses on study "Impacts of climate change and extreme weather on U.S. agricultural productivity: evidence and projection" from National Bureau of Economic Research. It mentions authors use 1941–70 historical weather data to create a temperature–humidity index and an Oury index. It mentions THI combines temperature and humidity to measure the degree of discomfort experienced during warm weather.

In recent decades, the land surface has warmed substantially more than the ocean surface, and relative humidity has fallen over land. Amplified warming and declining relative humidity over land are also dominant features of future climate projections, with implications for climate-change impacts. An emerging body of research has shown how constraints from atmospheric dynamics and moisture budgets are important for projected future land-ocean contrasts, but these ideas have not been used to investigate temperature and humidity records over recent decades. Here we show how both the temperature and humidity changes observed over land between 1979 and 2016 are linked to warming over neighboring oceans. A simple analytical theory, based on atmospheric dynamics and moisture transport, predicts equal changes in moist static energy over land and ocean and equal fractional changes in specific humidity over land and ocean. The theory is shown to be consistent with the observed trends in land temperature and humidity given the warming over ocean. Amplified land warming is needed for the increase in moist static energy over drier land to match that over ocean, and land relative humidity decreases because land specific humidity is linked via moisture transport to the weaker warming over ocean. However, there is considerable variability about the best-fit trend in land relative humidity that requires further investigation and which may be related to factors such as changes in atmospheric circulations and land-surface properties. [ABSTRACT FROM AUTHOR]

The article describes activities engaging middle school students on climate change topics, as part of National Science Foundation, Innovative Technology Experiences for Students and Teachers grant-funded project. Topics include student's understanding of temperature, precipitation and humidity; use of probeware for measuring and analyzing weather parameters such as relative humidity, and wind speed; and a wildlife quiz game.

The long-term dynamics of both urban heat island (UHI) and urban dry island (UDI) intensities over the city of Moscow, Russia, has been analyzed for the period from the end of the nineteenth century until recent years using data of the ground meteorological network. Besides traditional maximum heat/dry island intensity, an additional parameter-station-averaged intensity as a mean difference between the data of all urban and rural stations-has been used. The traditional maximum (mean annual) UHI intensity in Moscow was nearly 1.0°C at the end of the nineteenth century, 1.2°C one century ago, 1.5°-1.6°C both in the middle and at the end of the twentieth century, and 2.0°C in recent years. The station-averaged UHI intensity was equal to 0.7°-0.8°C in the second half of the twentieth century and increased up to 1.0°C in recent years. It is probable that stabilization of both parameters from the 1950s to the 1990s was connected with the extensive city growth at that time (mass resettlement of inhabitants from the overpopulated city center to the new urban periphery since the 1960s). The new increase of UHI intensities is the result of the new intensive city growth. The relative humidity in Moscow significantly decreased during the last 146 years (mostly because of warming), unlike water vapor pressure. The UDI is closely connected with the UHI; the absolute value (modulus) of its intensity is increasing in time from −4% at the end of the nineteenth century to −9% now. During the last two decades, the UDI as well as the UHI became much stronger than before. [ABSTRACT FROM AUTHOR]

The design characteristics of street canyons were investigated in Guangzhou in the hot-humid area of China, and the effects of the design factors and their interactions on pedestrian thermal comfort were studied by numerical simulations. The ENVI-met V4.0 (BASIC) model was validated by field observations and used to simulate the micrometeorological conditions and the standard effective temperature (SET) at pedestrian level of the street canyons for a typical summer day of Guangzhou. The results show that the micrometeorological parameters of mean radiant temperature (MRT) and wind speed play key roles in pedestrian thermal comfort. Street orientation has the largest contribution on SET at pedestrian level, followed by aspect ratio and greenery, while surface albedo and interactions between factors have small contributions. The street canyons oriented southeast-northwest or with a higher aspect ratio provide more shade, higher wind speed, and better thermal comfort conditions for pedestrians. Compared with the east-west-oriented street canyons, the north-south-oriented street canyons have higher MRTs and worse pedestrian thermal comfort due to their wider building spacing along the street. The effects of greenery change with the road width and the time of the day. Street canyon design is recommended to improve pedestrian thermal comfort. This study provides a better understanding of the effects of street canyon design on pedestrian thermal comfort and is a useful guide on urban design for the hot-humid area of China. [ABSTRACT FROM AUTHOR]

Climate change, epidemiology, fungi, humidity, plant health, temperature, weather, oomycota Keywords: climate change; epidemiology; fungi; humidity; oomycota; plant health; temperature; weather EN climate change epidemiology fungi humidity oomycota plant health temperature weather 1557 1558 2 05/02/22 20220601 NES 220601 A comment on Romero et al. (2022) 'Humidity and high temperature are important for predicting... In a Letter published in this issue of I New Phytologist i , Romero I et al i . Weather does influence fungal and oomycete crop disease outbreaks, but ProMED-mail reports don't prove it. [Extracted from the article]

A method for estimating the occurrence of freezing rain (FZRA) in gridded atmospheric data sets was evaluated, calibrated against SYNOP weather station observations, and applied to the ERA-Interim reanalysis for climatological studies of the phenomenon. The algorithm, originally developed at the Finnish Meteorological Institute for detecting the precipitation type in numerical weather prediction, uses vertical profiles of relative humidity and temperature as input. Reanalysis data in 6 h time resolution were analysed over Europe for the period 1979-2014. Mean annual and monthly numbers of FZRA events, as well as probabilities of duration and spatial extent of events, were then derived. The algorithm was able to accurately reproduce the observed, spatially averaged interannual variability of FZRA (correlation 0.90) during the 36-year period, but at station level rather low validation and cross-validation statistics were achieved (mean correlation 0.38). Coarse-grid resolution of the reanalysis and misclassifications to other freezing phenomena in SYNOP observations, such as ice pellets and freezing drizzle, contribute to the low validation results at station level. Although the derived gridded climatology is preliminary, it may be useful, for example, in safety assessments of critical infrastructure. [ABSTRACT FROM AUTHOR]

Background: Global climate change is one of the most serious environmental issues faced by humanity, and the resultant change in frequency and intensity of heat waves and cold spells could increase mortality. The influence of temperature on human health could be immediate or delayed. Latitude, relative humidity, and air pollution may influence the temperature-mortality relationship. We studied the influence of temperature on mortality and its lag effect in four Chinese cities with a range of latitudes over 2008-2011, adjusting for relative humidity and air pollution.Methods: We recorded the city-specific distributions of temperature and mortality by month and adopted a Poisson regression model combined with a distributed lag nonlinear model to investigate the lag effect of temperature on mortality.Results: We found that the coldest months in the study area are December through March and the hottest months are June through September. The ratios of deaths during cold months to hot months were 1.43, 1.54, 1.37 and 1.12 for the cities of Wuhan, Changsha, Guilin and Haikou, respectively. The effects of extremely high temperatures generally persisted for 3 days, whereas the risk of extremely low temperatures could persist for 21 days. Compared with the optimum temperature of each city, at a lag of 21 days, the relative risks (95 % confidence interval) of extreme cold temperatures were 4.78 (3.63, 6.29), 2.38 (1.35, 4.19), 2.62 (1.15, 5.95) and 2.62 (1.44, 4.79) for Wuhan, Changsha, Guilin and Haikou, respectively. The respective risks were 1.35 (1.18, 1.55), 1.19 (0.96, 1.48), 1.22 (0.82, 1.82) and 2.47 (1.61, 3.78) for extreme hot temperatures, at a lag of 3 days.Conclusions: Temperature-mortality relationships vary among cities at different latitudes. Local governments should establish regional prevention and protection measures to more effectively confront and adapt to local climate change. The effects of hot temperatures predominantly occur over the short term, whereas those of cold temperatures can persist for an extended number of days. [ABSTRACT FROM AUTHOR]

Temperature data from radiosondes over Germany have been homogenized manually. The method makes use of the different radiosonde (RS) networks existing in East and West Germany until 1990. The largest temperature adjustments, up to 2.5 K, apply to Freiberg sondes used in the east in the 1950s and 1960s. Adjustments for Graw Hamburg 1948 (H48), 1950 (H50), and Munich 1960 (M60) sondes, used in the west from the 1950s to the late 1980s, and for RKZ sondes, used in the east in the 1970s and 1980s, are also significant: 0.3-0.5 K. Small differences between Vaisala RS80 and RS92 sondes used throughout Germany since 1990 and ~2004, respectively, were not corrected for at levels from the ground to 300 hPa. Comparison of the homogenized data with other datasets-Radiosonde Innovation Composite Homogenization (RICH) and Hadley Centre Atmospheric Temperature, version 2 (HadAT2)-and with Microwave Sounding Unit satellite data shows generally good agreement. HadAT2 data exhibit a few suspicious spikes in the 1970s and 1980s and some suspicious offsets up to 1 K after 1995. Compared to RICH, the homogenized data show slightly different temperatures, by less than ~0.4 K, in the 1960s and 1970s. As reported in other studies, the troposphere over Germany has been warming by 0.2 ± 0.1 K decade−1 from ~1950 to 2013, and the stratosphere has been cooling. The stratospheric trend increases from almost no change near 230 hPa (the tropopause) to −0.4 ± 0.2 K decade−1 near 50 hPa. Trends from the homogenized data are more positive by about 0.1 K decade−1 compared to the original data, both in the troposphere and stratosphere. [ABSTRACT FROM AUTHOR]

In present research work the effect of climate change over the humidex in Iran is analyzed. From this research, we can conclude that the PD index showed a special sensibility to changes in temperature and relative humidity, hence, it can be an interesting tool, may be even better than the humidex to show the expected effect of climate change in perception of air quality. Thus, it was found that the humidex expected in the future will be more elevated than that in the preceding period and, on the other hand, the PD has clearly reached a lower value than in the preceding period. The same effects, other than those using the earlier indexes in a more detailed manner, were observed with the PD. This index showed a higher sensitivity to variations in temperature and relative humidity, than the humidex. Finally, the main results obtained must be considered at the time of design and during construction of future buildings, since buildings that are being constructed today will be occupied in the future years of the 2100s. [ABSTRACT FROM AUTHOR]

Thirty-year periods are treated in climatology as spans with relatively representative and stable climatic patterns, which can be used for calculating climate normals. Annual and seasonal series of circulation types were used to compare two 30-year sub-periods, 1961–1990 and 1991–2020, the second one being strongly influenced by recent global warming. This analysis was conducted according to the objective classification of circulation types and the climatic characteristics of sunshine duration, temperature, humidity, precipitation, and wind speed as calculated for the territory of the Czech Republic during the 1961–2020 period. For both sub-periods, their statistical characteristics were calculated, and the statistical significance of differences between them was evaluated. There was a statistically significant increase in the annual frequencies of anticyclonic circulation types and a significant decrease in cyclonic circulation types during 1991–2020 compared with 1961–1990. Generally, in both 30-year periods, significant differences in means, variability, characteristics of distribution, density functions, and linear trends appear for all climatic variables analysed except precipitation. This indicates that the recent 30-year "normal" period of 1991–2020, known to be influenced more by recent climate change, is by its climatic characteristics unrepresentative of the stable climatic patterns of previous 30-year periods. [ABSTRACT FROM AUTHOR]

Outdoor temperature has been reported to have a significant influence on the seasonal variations of stroke mortality, but few studies have investigated the effect of high temperature on the mortality of ischemic and hemorrhagic strokes. The main study goal was to examine the effect of temperature, particularly high temperature, on ischemic and hemorrhagic strokes. We investigated the association between outdoor temperature and stroke mortality in four metropolitan cities in Korea during 1992-2007. We used time series analysis of the age-adjusted mortality rate for ischemic and hemorrhagic stroke deaths by using generalized additive and generalized linear models, and estimated the percentage change of mortality rate associated with a 1°C increase of mean temperature. The temperature-responses for the hemorrhagic and ischemic stroke mortality differed, particularly in the range of high temperature. The estimated percentage change of ischemic stroke mortality above a threshold temperature was 5.4 % (95 % CI, 3.9-6.9 %) in Seoul, 4.1 % (95 % CI, 1.6-6.6 %) in Incheon, 2.3 % (−0.2 to 5.0 %) in Daegu and 3.6 % (0.7-6.6 %) in Busan, after controlling for daily mean humidity, mean air pressure, day of the week, season, and year. Additional adjustment of air pollution concentrations in the model did not change the effects. Hemorrhagic stroke mortality risk significantly decreased with increasing temperature without a threshold in the four cities after adjusting for confounders. These findings suggest that the mortality of hemorrhagic and ischemic strokes show different patterns in relation to outdoor temperature. High temperature was harmful for ischemic stroke but not for hemorrhagic stroke. The risk of high temperature to ischemic stroke did not differ by age or gender. [ABSTRACT FROM AUTHOR]

Background: Climate change may affect Plasmodium vivax malaria transmission in a wide region including both subtropical and temperate areas. Objectives: We aimed to estimate the effects of climatic variables on the transmission of P. vivax in temperate regions. Methods: We estimated the effects of climatic factors on P. vivax malaria transmission using data on weekly numbers of malaria cases for the years 2001.2009 in the Republic of Korea. Generalized linear Poisson models and distributed lag nonlinear models (DLNM) were adopted to estimate the effects of temperature, relative humidity, temperature fluctuation, duration of sunshine, and rainfall on malaria transmission while adjusting for seasonal variation, between-year variation, and other climatic factors. Results: A 1°C increase in temperature was associated with a 17.7% [95% confidence interval (CI): 16.9, 18.6%] increase in malaria incidence after a 3-week lag, a 10% rise in relative humidity was associated with 40.7% (95% CI:-44.3, -36.9%) decrease in malaria after a 7-week lag, a 1°C increase in the diurnal temperature range was associated with a 24.1% (95% CI: -26.7, -21.4%) decrease in malaria after a 7-week lag, and a 10-hr increase in sunshine per week was associated with a 5.1% (95% CI: -8.4,-1.7%) decrease in malaria after a 2-week lag. The cumulative relative risk for a 10-mm increase in rainfall (≤ 350 mm) on P. vivax malaria was 3.61 (95% CI: 1.69, 7.72) based on a DLNM with a 10-week maximum lag. Conclusions: Our findings suggest that malaria transmission in temperate areas is highly dependent on climate factors. In addition, lagged estimates of the effect of rainfall on malaria are consistent with the time necessary for mosquito development and P. vivax incubation. [ABSTRACT FROM AUTHOR]

The knowledge of the climatic conditions of a region is crucial for its agricultural development. It is also extremely important for understanding the fact that certain cultures have to develop under prevailing temperature and humidity conditions and assist in the adoption of a suitable irrigation technique, as well as its management and operationalization. The Köppen system of climate classification is widely used for the identification of homogeneous climate zones as it considers only rainfall and temperature as the meteorological elements for classification. For this study, we used climatic databases of rainfall and temperature in a raster format, with a spatial resolution of 30″ of arc (an approximate area of 0.86 km pixel), from 1961 to 1990. Through geoprocessing techniques, we obtained a map of climatic classification for the state of Minas Gerais. We found that the state has the following three major climatic groups: A, B and C, which correspond to tropical rainy, dry and warm temperate climates, respectively. The climate classes obtained were Aw, Am, BSh, Cwa and Cwb, with Aw, Cwa and Cwb classes occupying 99.89% of the territorial area of the state. The validation of the results showed a satisfactory agreement, with 93.75% reliability. [ABSTRACT FROM AUTHOR]

The present study tends to describe the survey of climatic changes in the case of the eastern and central areas of Iran and, to some extent, the northern parts. The monthly and yearly change trends in the minimum, maximum and mean temperatures, relative humidity, and the precipitation were surveyed for 26 synoptic stations in Iran during a 55-year period. The study was carried out by using the τ-Kendall test. The results showed the same temperature changes for the centrally located stations as the eastern and northern ones. Most of the stations in Zagros showed no significant temperature changes. A significant decrease in the precipitation was seen in summer in different stations. Most of the eastern and centrally located stations showed a decrease in relative humidity trend, while this condition was not recorded in Zagros and northern part of Iran. The present results also showed that the upward trend of minimum air temperature had an effect in increasing the mean air temperature in the stations with temperature ascending trend. This effect of minimum temperature was significantly more than that of the maximum temperature, which could be the result of increasing the amount of greenhouse gases and the reflection of received thermal energies, from land through the night. This increase in the temperature and a decrease in relative humidity would cause an increase in the evaporation of the received precipitation. [ABSTRACT FROM AUTHOR]

A number of different methodologies are developed for examining the sensitivities of an index. These methodologies are applied to examine the characteristics of the Canadian Fire Weather Index FWI and the McArthur Forest Fire Danger Index FFDI using 8 years of gridded data throughout Australia. Percentile changes in input conditions show that the indices are similar to each other in that they are both most sensitive to wind speed, then secondly to relative humidity and thirdly to temperature. On a finer scale, a combination of the relationship between the indices and their partial derivatives shows that the FFDI is relatively less sensitive to wind speed and rainfall, and more sensitive to temperature and relative humidity, than the FWI. A method based on equilibrium values of the indices shows that the FFDI has a temperature threshold set by recent rainfall above which its sensitivity increases, resulting in some nonlinearity in its relationship with the FWI. The sensitivity differences between the indices mean that the indices are complementary in that they each respond to a somewhat different set of conditions, as is shown by examining a number of recent fire events. The fire events also reveal that index values associated with dangerous fire behaviour can vary greatly between different regions. Methods to reduce the consequences of this variation are examined, including the use of index percentiles. Copyright © 2009 Royal Meteorological Society [ABSTRACT FROM AUTHOR]

Air humidity is an element that plays an important role among meteorological processes within the atmosphere; however, the variety of humidity indices makes the global view of air moisture changes difficult. Long-term variability of air humidity in Kraków was examined by time-series (1901–2000) analysis of vapour pressure and saturation deficit values and their characteristic days with the background of temperature and saturated vapour pressure changes. Long-term variability of air humidity in Kraków has been visible above all in variations of saturation deficit. It should be connected with the contemporary temperature growth and the city development as the atmospheric water vapour content (described by vapour pressure) becomes relatively stable (with no significant tendencies). The parameter showed well-marked trends over the examined period. The growth of saturation deficit values predominated in the warm half of a year (above all in August: an increase in SD value by 3.0 hPa per century). Apart from atmospheric circulation variability, gradual rise in the number of inhabitants and higher development density contributed to the decline in the city’s air humidity; however, the causes of changes in air humidity should be also attributed to natural factors, mainly to variation of air circulation reinforced by the operation of anthropogenic factors. Using air humidity as the indicator, the results that confirm climatic fluctuations in central Europe in the twentieth century obtained earlier were verified and some new aspects of present climate change were given. [ABSTRACT FROM AUTHOR]

Background: It is widely accepted that assessing the impact of heat on populations is an important aspect of climate change research. However, this raises questions about how best to measure people's exposure to heat under everyday living conditions in more detail than is possible by relying on nearby sources of meteorological data. Objective: This study aimed to investigate practical and viable approaches to measuring air temperature and humidity within a population, making comparisons with contemporaneous external data sources. This was done in a rural South African population during the subtropical summer season. Results: Air temperature and humidity were measured indoors and outdoors at three locations over 10 days and the datalogger technology proved reliable and easy to use. There was little variation in measurements over distances of 10 km. Conclusions: Small battery-powered automatic dataloggers proved to be a feasible option for collecting weather data among a rural South African population. These data were consistent with external sources but offered more local detail. Detailed local contemporary data may also allow post hoc modelling of previously unmeasured local weather data in conjunction with global gridded climate models. [ABSTRACT FROM AUTHOR]

The article focuses on measurement of species' distributional responses to seasonal temperature gradients through a mechanistic niche model. Niche theory helps to understand climate change and response of species towards it geographically. The niche is defined in a biological community, physiology and geographic space. It was observed that the distribution of species were controlled by factors like resource availability, relative humidity, physical barriers to dispersal and biotic interactions. In this study, lethal physiological temperatures were used to parameterize the model for bird species in North and South America. The results showed that broad thermal tolerances are possessed by most bird species.

High-resolution model simulations were performed with the quadruple-nested version of the mesoscale model KAMM to investigate the impact of the new storage lake ‘Embalse Puclaro’ on the arid environment. The storage lake covers an area of 1 to 2 km in width and about 7 km in length. Model simulations were performed for a summer and a winter day. Due to a change in the surface properties, the installation of the storage lake resulted in a modification of the energy balance. Above the lake area, a stably stratified atmosphere establishes during the day and unstable stratification during the night. During the day, the latent heat flux is similar to that of the replaced cultivated ground, but is higher at the night. The influence of the storage lake on temperature and humidity can be seen to a height of about 300 m above ground level. During the night, water vapour accumulation results in relative humidity values of 100%, as a result a greater number of days with fog above the storage lake is likely when compared to the surrounding area. The storage lake does not produce its own lake breeze during the day, because the larger-scale up-valley wind is too dominant. However, a significant modification of the nocturnal down-valley wind above the lake area can be observed, especially in summer. As a consequence of the larger-scale valley wind system, the influence of the storage lake on the temperature, humidity, and wind field can be identified up to about 4 km on the downwind side. [ABSTRACT FROM AUTHOR]

ABSTRACT An approach to identifying climate changes is presented that does not hinge on simulations of natural climate variations or anthropogenic changes. Observed interdecadal climate variations are decomposed into several discriminants, mutually uncorrelated spatiotemporal components with a maximal ratio of interdecadal-to-intradecadal variance. The dominant discriminants of twentieth-century variations in surface temperature exhibit large-scale warming in which, particularly in the Northern Hemisphere summer months, localized cooling is embedded. The structure of the large-scale warming is consistent with expected effects of increases in greenhouse gas concentrations. The localized cooling, with maxima on scales of 1000-2000 km over East Asia, eastern Europe, and North America, is suggestive of radiative effects of anthropogenic sulfate aerosols. [ABSTRACT FROM AUTHOR]

Chronic obstructive pulmonary disease (COPD) is one of the greatest global public health challenges. Acute exacerbations of COPD lead to the accelerated deterioration of lung function, reduced quality of life, a higher number of hospitalizations, and increased mortality. The factor causing the exacerbation is usually an infectious agent, but the impact of environmental factors is being studied more thoroughly. Among them, meteorological factors are the least examined. Multiple studies have shown that lower temperatures during the cold season, as well as sudden temperature changes regardless of the season, have the most significant negative effect on patients with COPD. However, higher temperatures, especially during summer heatwaves, can also cause COPD exacerbation and it is expected that this will be an even more important health problem in the future considering climate changes. The effects of other meteorological factors on acute exacerbation of COPD, such as atmospheric pressure, solar radiation, rainfall, wind speed, and humidity are far less investigated and opposing results have been obtained in different studies. Thus, there is a need for further research in this area that would result in clinical recommendations and public health interventions that could decrease the global burden of COPD. [ABSTRACT FROM AUTHOR]

Climatological annual and seasonal dewpoint, specific humidity, and relative humidity maps for the United States are presented using hourly data from 188 first-order weather stations for the period 1961--90. Separate climatologies were calculated for daytime (three observations per day between 0800 and 1600 LST), nighttime (three observations per day between 2000 and 0400 LST), and the full day (eight observations per day, every 3 h). With extended datasets for the period 1961--95, trends in these same variables and temperature are calculated for each of 170 stations and for eight regions of the country. The data show increases in specific humidity of several percent per decade, and increases in dewpoint of several tenths of a degree per decade, over most of the country in winter, spring, and summer. Nighttime humidity trends are larger than daytime trends. The specific humidity increases are consistent with upward temperature trends. The upward temperature and humidity trends are also consistent with upward trends in apparent temperature, a measure of human comfort based on temperature and humidity. Relative humidity trends are weaker than the specific humidity trends, but they do show evidence of increases, especially in winter and spring. The possibility that the detected trends may be artifacts of changes in instrumentation was examined, but several lines of reasoning suggest that they are not. Anthropogenic water vapor produced from fossil fuel consumption, both locally and globally, is too small a source to explain the observed trends. [ABSTRACT FROM AUTHOR]

An objective approach to regionalizing climatic characteristics affecting wildfire ignition potential is useful in fire control strategies. Temperature and humidity observations statistically predict equilibrium moisture content characteristics providing a first approximation to the moisture content of dead, fine fuels. Principal component and cluster analysis grouped fuel moisture attributes for seven locations on a mountain ridge spanning nearly 1000 m in elevation difference on two aspects and within a maximum separation distance of 5 km. The final three groupings showed a dominance of neither elevation nor aspect influences but, rather, a mixture of both. [ABSTRACT FROM AUTHOR]