scholarly journals Time-Varying Biases in U.S. Total Cloud Cover Data

2013 ◽  
Vol 30 (12) ◽  
pp. 2838-2849 ◽  
Author(s):  
Melissa Free ◽  
Bomin Sun
Keyword(s):  
Cloud Cover ◽  
The United States ◽  
Range Data ◽  
Time Varying ◽  
Total Cloud Cover ◽  
Frequency Distributions ◽  
Fractional Cloud ◽  
Trend Assessment ◽  
Weather Stations

Abstract This paper presents evidence of significant discontinuities in U.S. cloud cover data from the Integrated Surface Database (ISD) and its predecessor datasets. While long-term U.S. cloud records have some well-known homogeneity problems related to the introduction of the Automated Surface Observing System (ASOS) in the 1990s, the change to the international standard reporting format [aviation routine weather report (METAR)] in the United States in July 1996 introduces an additional inhomogeneity at many of the stations where humans still make or supplement cloud observations. This change is associated with an upward shift in total cloud of 0.1%–10%, statistically significant at 95 of 172 stations. The shift occurs at both National Weather Service and military weather stations, producing a mean increase in total cloud of 2%–3%. This suggests that the positive trends in U.S. cloud cover reported by other researchers for recent time periods may be exaggerated, a conclusion that is supported by comparisons with precipitation and diurnal temperature range data. Additional discontinuities exist at other times in the frequency distributions of fractional cloud cover at the majority of stations, many of which may be explained by changes in the sources and types of data included in ISD. Some of these result in noticeable changes in monthly-mean total cloud. The current U.S. cloud cover database needs thorough homogeneity testing and adjustment before it can be used with confidence for trend assessment or satellite product validation.

scholarly journals Comparison between Total Cloud Cover in Four Reanalysis Products and Cloud Measured by Visual Observations at U.S. Weather Stations

2016 ◽  
Vol 29 (6) ◽  
pp. 2015-2021 ◽  
Author(s):  
Melissa Free ◽  
Bomin Sun ◽  
Hye Lim Yoo
Keyword(s):  
Cloud Cover ◽  
Large Scale ◽  
Cloud Amount ◽  
Surface Radiation ◽  
Japan Meteorological Agency ◽  
Total Cloud Cover ◽  
Surface Data ◽  
Lower Cloud ◽  
Weather Stations ◽  
Modern Era

Abstract A homogeneity-adjusted dataset of total cloud cover from weather stations in the contiguous United States is compared with cloud cover in four state-of-the-art global reanalysis products: the Climate Forecast System Reanalysis from NCEP, the Modern-Era Retrospective Analysis for Research and Applications from NASA, ERA-Interim from ECMWF, and the Japanese 55-year Reanalysis Project from the Japan Meteorological Agency. The reanalysis products examined in this study generally show much lower cloud amount than visual weather station data, and this underestimation appears to be generally consistent with their overestimation of downward surface shortwave fluxes when compared with surface radiation data from the Surface Radiation Network. Nevertheless, the reanalysis products largely succeed in simulating the main aspects of interannual variability of cloudiness for large-scale means, as measured by correlations of 0.81–0.90 for U.S. mean time series. Trends in the reanalysis datasets for the U.S. mean for 1979–2009, ranging from −0.38% to −1.8% decade−1, are in the same direction as the trend in surface data (−0.50% decade−1), but further effort is needed to understand the discrepancies in their magnitudes.

scholarly journals Variability and trend of diurnal temperature range in China and their relationship to total cloud cover and sunshine duration

2013 ◽  
Vol 31 (5) ◽  
pp. 795-804 ◽  
Author(s):  
X. Xia
Keyword(s):  
Diurnal Temperature Range ◽  
Cloud Cover ◽  
Sunshine Duration ◽  
Radiative Effect ◽  
Total Cloud Cover ◽  
Diurnal Temperature ◽  
Temperature Range ◽  
Clear Sky ◽  
Sky Conditions

Abstract. This study aims to investigate the effect of total cloud cover (TCC) and sunshine duration (SSD) in the variation of diurnal temperature range (DTR) in China during 1954–2009. As expected, the inter-annual variation of DTR was mainly determined by TCC. Analysis of trends of 30-year moving windows of DTR and TCC time series showed that TCC changes could account for that of DTR in some cases. However, TCC decreased during 1954–2009, which did not support DTR reduction across China. DTRs under sky conditions such as clear, cloudy and overcast showed nearly the same decreasing rate that completely accounted for the overall DTR reduction. Nevertheless, correlation between SSD and DTR was weak and not significant under clear sky conditions in which aerosol direct radiative effect should be dominant. Furthermore, 30–60% of DTR reduction was associated with DTR decrease under overcast conditions in south China. This implies that aerosol direct radiative effect appears not to be one of the main factors determining long-term changes in DTR in China.

scholarly journals Long‐term change of total cloud cover and its possible reason over South China during 1960–2012

2019 ◽  
Vol 20 (11) ◽  
Author(s):  
Chuanbo Fu ◽  
Li Dan ◽  
Xiaobin Lin ◽  
Fuqiang Yang
Keyword(s):  
South China ◽  
Cloud Cover ◽  
Total Cloud Cover ◽  
Term Change

scholarly journals ONLINE INTEGRATED MODELING ON REGIONAL SCALE IN NORTH-WEST RUSSIA: EVALUATION OF AEROSOLS INFLUENCE ON METEOROLOGICAL PARAMETERS

2018 ◽  
Vol 11 (2) ◽  
pp. 73-83
Author(s):  
Georgy Nerobelov ◽  
Margarita Sedeeva ◽  
Alexander Mahura ◽  
Roman Nuterman ◽  
Suleiman Mostamandi ◽  
...  
Keyword(s):  
Cloud Cover ◽  
Meteorological Parameters ◽  
Regional Scale ◽  
Total Cloud Cover ◽  
North West ◽  
The North ◽  
Aerosol Effect ◽  
Short And Long Term ◽  
Aerosol Effects

In this study the aerosols influence on selected meteorological parameters during two summer 2010 periods is evaluated with focus on the North-West Russia and urban area of St. Petersburg. For that, the seamless fully online-integrated Enviro-HIRLAM model is used. The simulations are realised in short- and long-term modes for selected periods. For evaluation of aerosol influence, in addition to the control/ reference run, the runs with direct, indirect and both combined aerosol effects are performed.It was found that for the North-West Russia region, the direct aerosol effect had increased air temperature (by 1-3˚) and decreased total cloud cover (by 10-20%). The indirect effect decreased temperature (by 0.4-1˚) and increased cloud cover (by 10-20%). The combined effect was the largest territorially; and such effect both decreased temperature and cloud cover (by 1-3˚ and by 6-20%, respectively) as well as increased these (by 0.4-0.6˚ and 1020%).

Trends in U.S. Total Cloud Cover from a Homogeneity-Adjusted Dataset

2014 ◽  
Vol 27 (13) ◽  
pp. 4959-4969 ◽  
Author(s):  
Melissa Free ◽  
Bomin Sun
Keyword(s):  
United States ◽  
Time Series ◽  
Cloud Cover ◽  
Original Data ◽  
The United States ◽  
Adjustment Process ◽  
Total Cloud Cover ◽  
Regional Variability ◽  
The Difference ◽  
The Military

Cloud cover data from ground-based weather observers can be an important source of climate information, but the record of such observations in the United States is disrupted by the introduction of automated observing systems and other artificial shifts that interfere with our ability to assess changes in cloudiness at climate time scales. A new dataset using 54 National Weather Service (NWS) and 101 military stations that continued to make human-augmented cloud observations after the 1990s has been adjusted using statistical changepoint detection and visual scrutiny. The adjustments substantially reduce the trends in U.S. mean total cloud cover while increasing the agreement between the cloud cover time series and those of physically related climate variables. For 1949–2009, the adjusted time series give a trend in U.S. mean total cloud of 0.11% ± 0.22% decade−1 for the military data, 0.55% ± 0.24% decade−1 for the NWS data, and 0.31% ± 0.22% decade−1 for the combined dataset. These trends are less than one-half of those in the original data. For 1976–2004, the original data give a significant increase but the adjusted data show an insignificant trend from −0.17% decade−1 (military stations) to 0.66% decade−1 (NWS stations). Trends have notable regional variability, with the northwest United States showing declining total cloud cover for all time periods examined, while trends for most other regions are positive. Differences between trends in the adjusted datasets from military stations and NWS stations may be rooted in the difference in data source and reflect the uncertainties in the homogeneity adjustment process.

scholarly journals Variations in Cloud Cover and Cloud Types over the Ocean from Surface Observations, 1954–2008

2011 ◽  
Vol 24 (22) ◽  
pp. 5914-5934 ◽  
Author(s):  
Ryan Eastman ◽  
Stephen G. Warren ◽  
Carole J. Hahn
Keyword(s):  
Time Series ◽  
Surface Temperature ◽  
Negative Correlation ◽  
Cloud Cover ◽  
Sea Surface ◽  
Interannual Variations ◽  
Total Cloud Cover ◽  
Marine Stratus ◽  
Long Term Variations

Abstract Synoptic weather observations from ships throughout the World Ocean have been analyzed to produce a climatology of total cloud cover and the amounts of nine cloud types. About 54 million observations contributed to the climatology, which now covers 55 years from 1954 to 2008. In this work, interannual variations of seasonal cloud amounts are analyzed in 10° grid boxes. Long-term variations O(5–10 yr), coherent across multiple latitude bands, remain present in the updated cloud data. A comparison to coincident data on islands indicates that the coherent variations are probably spurious. An exact cause for this behavior remains elusive. The globally coherent variations are removed from the gridbox time series using a Butterworth filter before further analysis. Before removing the spurious variation, the global average time series of total cloud cover over the ocean shows low-amplitude, long-term variations O(2%) over the 55-yr span. High-frequency, year-to-year variation is seen O(1%–2%). Among the cloud types, the most widespread and consistent relationship is found for the extensive marine stratus and stratocumulus clouds (MSC) over the eastern parts of the subtropical oceans. Substantiating and expanding upon previous work, strong negative correlation is found between MSC and sea surface temperature (SST) in the eastern North Pacific, eastern South Pacific, eastern South Atlantic, eastern North Atlantic, and the Indian Ocean west of Australia. By contrast, a positive correlation between cloud cover and SST is seen in the central Pacific. High clouds show a consistent low-magnitude positive correlation with SST over the equatorial ocean. In regions of persistent MSC, time series show decreasing MSC amount. This decrease could be due to further spurious variation within the data. However, the decrease combined with observed increases in SST and the negative correlation between marine stratus and sea surface temperature suggests a positive cloud feedback to the warming sea surface. The observed decrease of MSC has been partly but not completely offset by increasing cumuliform clouds in these regions; a similar decrease in stratiform and increase in cumuliform clouds had previously been seen over land. Interannual variations of cloud cover in the tropics show strong correlation with an ENSO index.

Speech-Language Pathology in the Peace Corps: Necessity and Sustainability

2012 ◽  
Vol 2 (1) ◽  
pp. 11-18
Author(s):  
Melissa A. Pierce
Keyword(s):  
United States ◽  
Special Education ◽  
Peace Corps ◽  
People With Disabilities ◽  
Communication Disorders ◽  
The United States ◽  
Speech Language Pathology ◽  
Speech Language Pathologists ◽  
Language Pathology

In countries other than the United States, the study and practice of speech-language pathology is little known or nonexistent. Recognition of professionals in the field is minimal. Speech-language pathologists in countries where speech-language pathology is a widely recognized and respected profession often seek to share their expertise in places where little support is available for individuals with communication disorders. The Peace Corps offers a unique, long-term volunteer opportunity to people with a variety of backgrounds, including speech-language pathologists. Though Peace Corps programs do not specifically focus on speech-language pathology, many are easily adapted to the profession because they support populations of people with disabilities. This article describes how the needs of local children with communication disorders are readily addressed by a Special Education Peace Corps volunteer.

Multidisciplinary Evidence to Treat Bilingual Individuals with Aphasia

2008 ◽  
Vol 15 (3) ◽  
pp. 66-72 ◽  
Author(s):  
José G. Centeno
Keyword(s):  
Stroke Rehabilitation ◽  
Culturally Diverse ◽  
Treatment Strategies ◽  
The United States ◽  
Intervention Strategies ◽  
Steady Increase ◽  
Clinical Procedures ◽  
Bilingual Speakers ◽  
Aphasic Clients

Abstract The steady increase in linguistic and cultural diversity in the country, including the number of bilingual speakers, has been predicted to continue. Minorities are expected to be the majority by 2042. Strokes, the third leading cause of death and the leading cause of long-term disability in the U.S., are quite prevalent in racial and ethnic minorities, so population estimates underscore the imperative need to develop valid clinical procedures to serve the predicted increase in linguistically and culturally diverse bilingual adults with aphasia in post-stroke rehabilitation. Bilingualism is a complex phenomenon that interconnects culture, cognition, and language; thus, as aphasia is a social phenomenon, treatment of bilingual aphasic persons would benefit from conceptual frameworks that exploit the culture-cognition-language interaction in ways that maximize both linguistic and communicative improvement leading to social re-adaptation. This paper discusses a multidisciplinary evidence-based approach to develop ecologically-valid treatment strategies for bilingual aphasic individuals. Content aims to spark practitioners' interest to explore conceptually broad intervention strategies beyond strictly linguistic domains that would facilitate linguistic gains, communicative interactions, and social functioning. This paper largely emphasizes Spanish-English individuals in the United States. Practitioners, however, are advised to adapt the proposed principles to the unique backgrounds of other bilingual aphasic clients.

Sign in / Sign up

Export Citation Format

Share Document