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The Intergovernmental Panel on Climate Change Assessment Report 5 (IPCC AR5, 2013) discussed bulk atmospheric temperatures as indicators of climate variability and change. We examine four satellite datasets producing bulk tropospheric temperatures, based on microwave sounding units (MSUs), all updated since IPCC AR5. All datasets produce high correlations of anomalies versus independent observations from radiosondes (balloons), but differ somewhat in the metric of most interest, the linear trend beginning in 1979. The trend is an indicator of the response of the climate system to rising greenhouse gas concentrations and other forcings, and so is critical to understanding the climate. The satellite results indicate a range of near-global (+0.07 to +0.13°C decade−1) and tropical (+0.08 to +0.17°C decade−1) trends (1979-2016), and suggestions are presented to account for these differences. We show evidence that MSUs on National Oceanic and Atmospheric Administration’s satellites (NOAA-12 and −14, 1990-2001+) contain spurious warming, especially noticeable in three of the four satellite datasets. Comparisons with radiosonde datasets independently adjusted for inhomogeneities and Reanalyses suggest the actual tropical (20°S-20°N) trend is +0.10 ± 0.03°C decade−1. This tropical result is over a factor of two less than the trend projected from the average of the IPCC climate model simulations for this same period (+0.27°C decade−1). [ABSTRACT FROM AUTHOR]

We investigated the effect of land use on differences in air temperature. We based our analysis on a decade of weather and energy flux measurements, collected over two contrasting landscapes, an oak savanna and an annual grassland, growing under the same climate conditions. Over the decade, the daily-averaged, potential air temperature above the aerodynamically rougher and optically darker oak savanna was 0.5°C warmer than that above the aerodynamically smoother and optically brighter annual grassland. However, air temperature differences were seasonal. Smallest differences in potential air temperature occurred towards the end of spring, when much of the soil moisture reservoir was depleted. Largest differences in potential air temperature occurred during the winter rain season when the grass was green and transpiring and when the trees were senescent or deciduous. To understand the effect of land use on the local climate, we examined the concomitant changes in net radiation, sensible and latent heat exchange, the aerodynamic roughness (Ra), the surface resistance to water transfer (Rs), aerodynamic surface temperature and the growth of the planetary boundary layer, with measurements and model computations. Overall, these biophysical variables provide us with mechanistic information to diagnose and predict how changes in air temperature will follow changes in land use or management. In conclusion, land use change is responsible for having a marked impact on the local climate of a region. At the local level, the change in the surface energy balance, towards a darker and rougher surface, will produce an additive increment to climate warming induced by a greater greenhouse gas burden in the atmosphere. [ABSTRACT FROM AUTHOR]

The projected rise in temperature in the 21st century will alter forest ecosystem functioning and carbon dynamics. To date, the acclimation of plant photosynthesis to rising temperature has not been adequately considered in earth system models. Here we present a study on regional ecosystem carbon dynamics under future climate scenarios incorporating temperature acclimation effects into a large-scale ecosystem model, the terrestrial ecosystem model (TEM). We first incorporate a general formulation of the temperature acclimation of plant photosynthesis into TEM, and then apply the revised model to the forest ecosystems of the conterminous United States for the 21st century under the future Intergovernmental Panel on Climate Change (IPCC) Special Report on Emissions Scenarios (SRES) climate scenarios A1FI, A2, B1 and B2. We find that there are significant differences between the estimates of carbon dynamics from the previous and the revised models. The largest differences occur under the A1FI scenario, in which the model that considers acclimation effects predicts that the region will act as a carbon sink, and that cumulative carbon in the 21st century will be 35 Pg C higher than the estimates from the model that does not consider acclimation effects. Our results further indicate that in the region there are spatially different responses to temperature acclimation effects. This study suggests that terrestrial ecosystem models should take temperature acclimation effects into account so as to more accurately quantify ecosystem carbon dynamics at regional scales. [ABSTRACT FROM AUTHOR]

This study investigated the potential impact of soil moisture perturbations on the statistical spread of an ensemble forecast for three different synoptic events during the summer of 2006. Soil moisture was perturbed from a control simulation to generate a 12 member ensemble with six drier and six moister soils. The impacts on the near-surface atmospheric conditions and on precipitation were analysed. It was found, as previous studies have confirmed, that soil moisture can change the spatial and temporal distribution of precipitation and of the overlying circulation. It was found that regardless of the conditions in synoptic forcing, temperature, relative humidity and horizontal wind field exhibited a spatial correlation coefficient (R) close to one with respect to the control simulation. Vertical velocity, however, showed a marked decrease in R down to 0.4 as the precipitation activity increased. For vertical velocity, however, this quantity grew to near 1.0 consistent with R near zero and standard deviations very close to that of the control. These results suggested a more complex picture in which soil moisture perturbations played a major role in modifying precipitation and the near-surface circulation but did not broaden the statistical spread of trajectories in phase space of all variables. [ABSTRACT FROM AUTHOR]

The article highlights the weather conditions for April 2008 in the U.S., Alaska and Canada. The author stated that wet conditions persisted in most areas from eastern Plains to the Mississippi Valley with below-normal temperatures. Meanwhile, precipitation in Alaska is above normal with two to six times greater than normal. On the other hand, snow in Canada is not so remarkable and the eastern part has a reprieve from snowstorms.

We modeled soil temperatures at 50-cm depth, using 1951–2000 air temperature and precipitation data from 194 National Weather Service stations in Wisconsin and Michigan. The accuracy and bias of the physical model used in this study were validated by comparing its output data to 22,401 actual soil temperature readings taken from sandy soils at thirty-nine forested sites throughout northern Michigan; the model was shown to have almost no temperature bias. Although mean annual air temperatures across the region show no strong spatial or temporal trends over the fifty-year period, at many sites, especially in Wisconsin, wintertime air temperatures have been increasing slightly in recent years. Conversely, mean annual soil temperatures have been decreasing at most sites in the region, some by more than 0.5°C. Likewise, wintertime soil temperatures are also decreasing, especially at sites downwind from the Great Lakes—many of which are in snowbelt locations. Increasing wintertime air temperatures over the past fifty years coincide with (and probably have led to) more variable and thinner snowpacks, lessening their insulating impact and contributing to decreasing wintertime soil temperatures that our model show are occurring in the eastern and northern parts of the region. These findings illustrate the complex response of natural systems to slow atmospheric warming, and draw attention to the potential changes that are occurring in growing season characteristics, phenology, and spring runoff characteristics in the Great Lakes region. [ABSTRACT FROM AUTHOR]

The article focuses on the weather condition in the U.S. for the month of May in 2007. The temperatures averaged at least 5°Fahrenheit above normal in parts of the Midwest and at several Western areas. The month brought wet condition across the central one-third of the country and unusual dryness in the West and Southeast. Wildfires in and near the Okefenokee Swamp of southern Georgia and northern Florida started during windstosm on the 16th of the month. Rainfall totaled less than quarter an inch of rain in several states.

The article reports on the weather of the U.S. for April 2007. Monthly record lows have been established on April 7-8 in some locations that have experienced their warmest March. The state of Oklahoma, which has experienced its warmest March on record, has been hit by April freezes that stretched from the central and southern Plains into the Southeast. The month's most significant weather development has been the continuation of locally heavy precipitation across the central and southern Plains.

The article reports on the weather condition in the U.S. in October 2006. Temperature decreased beyond the normal in most parts while southern Texas experienced warmth with a recorded average temperature of 37°F. Continual rains in the Ohio Valley and the lower Great Lakes region resulted to lowland flooding. Temperatures in Daytona Beach, Florida reached 90°F which lasted for 5 days. Buffalo, New York was covered with 22.6 inches of snow from October 12 to 13. October 2006 was the 29th coolest October recorded.

The article reports on the weather in the U.S. in September 2005. Hurricane Rita had caused property damages across Texas and Louisiana. The average temperature in California was recorded as 57°F. According to the Storm Prediction Center, there were a total of 131 tornadoes in the country with 86 of them attributed to Hurricane Rita.

Focuses on the weather condition in the U.S. in May 2004. Damage and fatalities caused by tornadoes and storms; Occurrence of rain and snowfall in the midwestern part of the country; Development of high temperature in the Western parts of the country.

Focuses on the role of temperature and weather in Florida in the production of fresh fruits such as blueberries. Importance of winds and temperature inversions during Florida freezes; Methods implemented by growers to protect blueberries from freezes; Temperature required for blueberry flowers and fruit.

Ultrafine particles (diameter <0.1 μm) have been suggested as a possible causative agent for the observed increases in mortality and morbidity with increases in particulate matter (PM) concentration. Zhu et al. conducted systematic measurements of the concentration and size distribution of ultrafine particles in the vicinity of Interstate 405 (mostly gasoline traffic) and Interstate 710 (large proportion of heavy-duty diesel traffic) in Los Angeles during the summer of 2001. The present study compares these measurements with those made at the same locations in the winter of 2001-2002. Particle number concentration and size distribution in the size range from 6 to 220 nm were measured by a condensation particle counter (CPC) and a scanning mobility particle sizer (SMPS). Measurements were taken at five distances downwind from the freeway. At each sampling location, concentrations of carbon monoxide (CO) and black carbon (BC) were also measured by a Dasibi CO monitor and an aethalometer, respectively. Average temperatures were about 7 degrees Celsius higher in summer than in winter. Wind directions are the same for both seasons, wind speeds are slightly higher in summer. Traffic densities were not statistically different between summer and winter for both the 405 and 710 freeways. The decay rates of CO and BC are slightly greater in summer than in winter for both freeways, suggesting a weaker atmospheric dilution effect in winter. Particle number concentration in the size range of 6-12 nm is significantly higher in winter than in summer. The associated concentration in that size range decreased at a slower rate in winter than in summer. The surface area concentrations in the size range of 6-220 nm are consistently higher in summer for all sampling locations. These results suggest that wintertime conditions favor greater particle formation, possibly due to increased condensation of organic vapors. These data may be useful to estimate exposure to ultrafine particles in the vicinity of major highways for epidemiological studies and to evaluate the adverse health effects of such particles. [ABSTRACT FROM AUTHOR]

Answers several questions about weather conditions in the U.S. Cause of an unusual cloud formation in Charlotte, North Carolina; Information on the cloud streets in Houston, Texas; Reason behind the difference between the summer temperatures in San Francisco, California and Seattle, Washington.

Presents weather-related updates in the United States as of September/October 2001. Average monthly temperatures in the Midwest and Southeast regions; Total rainfall in Texas during Tropical Storm Allison; Precipitation level in Tampa, Florida.

Presents weather-related updates in the United States as of September/October 2001. Average height of snowfall posted in Cheyenne, Wyoming and Colorado Springs, Colorado from April 19-21; Temperature drop in Pueblo, Colorado on the afternoon of May 20; Precipitation level posted by Alaska.

Presents statistical information on the temperatures experienced by the United States during 2000. Daily national minimums and maximums; Greatest temperature range on January 18; Reflections. INSET: Memorable Highs and Lows of the Last 20 Years.

Focuses on the United States weather temperature in 1998. Information on the nation's daily minimum and maximum temperatures; Temperatures during September; Weather condition in different states.

Discusses the extremes in atmospheric temperatures in the United States in 1995. Maximums; Minimums; Distribution; Comparison with past temperature records.

Describes the winter season in the U.S. during 1985. Comparison of temperature changes and weather for various months; Occurrence of snowstorms; Area covered by snow; Estimation of lake-effect snows; Snowfall; Temperature and moisture conditions conducive to heavier-than-normal snowfall; Variation in the amount of snow depending of geographical location and elevation.

Discusses several weather events experienced in the U.S. and Canada in August 1985. Hurricanes; Cloudburst; Percentage of normal precipitation; Departure of average temperature from normal; Highest and lowest temperature; Greatest number of sunshine hours.

Analyzes the weather patterns in the U.S. in February 1985. Anticyclone extending from Oregon to the central Appalachians; Percentage of normal precipitation; Warmest and coldest mean temperature; Atmospheric circulation; Cold and tropical airstream.

Analyzes the weather patterns in the U.S. in January 1985. Cold outbreak from the Arctic Circle; Lowest temperatures recorded in each state; Cyclonic activity; Buildup of high pressure over the northern Rocky Mountains on January 11; Percentage of normal precipitation; Snowfall; Warmest temperatures recorded.

Presents guidelines for displaying the normal atmospheric temperature in the almanac programs. Determination of the normal daily maximum, minimum, and average temperatures; Lines to be added to the main almanac program to display the normal temperature of the date; Constants for representative locations in the U.S. and Canada; Calculation of normal temperatures.

Asserts that the tale of weather in the United States in 1993 is told in part by the nation's temperature extremes. Listing of top hot spots in 1993; Top cold spots in 1993; The daily national high; Extremes in Alaska and Death Valley.

Analyzes the temperature extremes in the U.S. during the 1986 season. Recording of the hottest and coldest temperatures each day; Average low temperature for 1986; Average high temperature; Daily temperature extremes; Top cold and hot spots; Comparison of national maximum and minimum extremes for 1985 and 1986.

Explains the effects of urbanization on the local weather patterns in Phoenix, Arizona. Rate of population growth in the area; Increase in volume of smog over the city; Increase in local temperatures due to the development of an urban heat island; Perception of increased humidity among local residents; Factors driving increasing temperatures in the Phoenix's desert environment; Potential impact of increasing weather stress on future planning and development.

Describes temperature variations and weather conditions during 1985 in the U.S. Top hot spots and cold spots across the globe; National maximum and minimum temperature extremes; Geographical distributions and changes in temperature; Effects of geographical location on temperature; Analysis of temperature extremes; Recorded temperatures for various states; Factors influencing temperature and weather patterns; Comparison of recorded temperatures with previous years prior to 1985; Effects of global temperature changes.

Explores why many local meteorologist doubt the accuracy of the maximum atmospheric temperature record taken in Bennett, Colorado on July 11, 1988. State climatological records; Official maximum temperature taken in Denver on July 11, 1988; Unusual temperature differences between Bennett and Denver; Basic atmospheric thermodynamics and hydrostatics; Relationship between surface elevation and maximum surface temperature within Colorado.

The article discusses several weather-related topics in the U.S. These include the findings of a study published in the "Bulletin of American Meteorological Society" magazine about cloud seeding, the compilation of daily temperature readings and weather observations at the Mohonk Preserve weather station and the high-speed video captured by researchers in the Mediterranean. According to the video, elves prefer storms at sea to those over land.

This article states that some scientists are saying that a recent trend of increasingly hot summer nights, which do not allow the human body to recover during normal night cooling, is a sign of human-generated global warming. According to the National Climatic Data Center, an average of about 30 percent of the U.S. had "much above normal" average summertime minimum temperatures between 2001 and 2005. "Much above normal" is defined as the highest 10 percent of low temperatures on record. Normally, about 10 percent of the U.S. should experience much above normal summer night lows in any given year. However, in 2003 and 2005, 36 percent of the country had much above normal summer minimum temperatures, while in 2002, 37 percent of the nation experienced such minimums.

The article explains the causes behind the winter-like weather patterns in the U.S. in mid-May 2006. The dreary weather and 50°F temperatures, could have driven north into Quebec and emerged into bright, summer-like conditions. This pattern was caused by a very large low pressure area that was more typical of something seen in March. It had already stalled in the Great Lakes area for two days and was not expected to occur for almost a week.

The article features the Monument Valley in the Arizona-Utah border. The formations of the valley are a result of the atmosphere. During summer, the valley hosts the Arizona Monsoon weather pattern. Its average minimum temperature is 24.6°F in January.

Focuses on the daily average temperature during spring in the U.S. Statistics given by weather forecasters; Factors that contribute to the short-term variability in temperature; Impact of shallow fronts on temperature forecasting.

Reports on the results of a research released by the U.S. National Center for Atmospheric Research regarding an increase in the occurrence of drought as of March 2005. Places where there are an increase in drought; Remarks from Aiguo Dai, author of the study, on the effect of global temperatures on the spread of drought; Importance of monitoring climatic changes.

Presents information on weather conditions in Alaska as of July 2002. Estimated number of lightning strikes detected between July 16 and July 21, 2002; Temperature records set by Anchorage; Precipitation level in Petersburg.

Discusses how geraniums bloomed in Pennsylvania in November 2001. Connection between the pressure surface and the blossoming of the plants; Simulation of a cold air column; Explanation of the balloon analogy to the real atmosphere.

Deals with a study that examined the link between regional climate change and a major change in temperate forest cover in the United States. Percentage of Midwest land under cultivation; Temperature differences between the Midwest and Eastern region

Focuses on the Texas Blue Norther phenomenon which brings cold weather to the state and is known for its sudden drop in temperature and its hazy blue color. Description of the norther, weather conditions that herald the arrival of sharply colder temperatures, and changes from record highs to record lows; Examples of significant northers which include the devastating freeze that affected Florida and extreme south Texas during December in 1983; Description of the Great Texas Freeze of 1899.

Discusses the meteorological event recorded in Texas in March 27, 1984 where temperatures are over 100 degrees fahrenheit in the south and 30 degrees in the north, providing a perfect example of the variety of the state's weather. Deep low pressure system centered 500 miles north of Brownsville in the afternoon of March 27; Air flow pattern; Katabatic warming caused by the downslope flow of the air; Factors that contributed to the varying temperatures.

This article states that the San Diego Supercomputer Center is working with Lawrence Livermore National Laboratory and Colorado State University to develop a more accurate worldwide forecast system by using computational power to thoroughly describe and model the role of clouds and other atmospheric phenomena. SDSC's collaboration with Lawrence Livermore, which began in 2005, uses scientific data management to study global climate modeling and cosmology situations of the early universe. SDSC will be responsible in part for using its computers to translate the data and for making the high-resolution results from the model available to research and education communities.

Features the nowCOAST Web site of the U.S. National Oceanic and Atmospheric Administration. Address of the Web site; Variables that a user can use to access information about the weather, including air temperature.

Provides information on the weather condition across the U.S. in May 2004. Dew point temperature; Result of buoyant air; Analysis of atmospheric temperature.

Presents a list of weather temperature records in the U.S. from July to August 2003.

Presents information on weather conditions in Alaska as of August 2002. Rainfall measurement; Highest temperature recorded; Lowest average temperature recorded; Precipitation level recorded in Port Alexander.

Describes the weather condition in Alaska in December 2001. Highest temperature; Lowest average temperature; Most and least precipitation.

Describes the weather in Alaska in November 2001. Highest temperature; Lowest average temperature; Most and least precipitation.

Looks at the heat wave map in the Southwest region of the United States in July 2001. Level of temperatures posted by Fresno, California and Phoenix, Arizona; Number of weather stations which checked in with temperatures of 110 degrees Fahrenheit; Scope of the thermal lows shown in the map; Cause of the high pressure level over Arizona.

Presents weather-related updates in the United States for May-June 2001. Temperature posted by Bozeman, Montana on May 7; Average volume of rain netted by Honolulu, Hawaii on June 5-6; Rainfall record of Baton Rouge, Louisiana.

Focuses on the conversion of forests to croplands to increase air temperature in tropical and semiarid regions. Information on the atmospheric temperature; Climate simulations conducted by Gordon B. Bonan of the National Center for Atmospheric Research in Colorado; Results of the simulation.