scholarly journals Long-term trends in solar radiation and the associated climatic factors over China for 1961-2000

2005 ◽  
Vol 23 (7) ◽  
pp. 2425-2432 ◽  
Author(s):  
F. Liang ◽  
X. A. Xia
Keyword(s):  
Solar Radiation ◽  
Climatic Factors ◽  
Sunshine Duration ◽  
Cloud Amount ◽  
Atmospheric Composition ◽  
Abrupt Decrease ◽  
Radiative Processes ◽  
Aerosol Loading ◽  
Long Term Trends

Abstract. Long-term trends in downwelling solar irradiance and associated climatic factors over China are studied in the paper. Decreasing trends in global and direct radiation are observed over much of China. The largest decrease occurs in South and East China (east of about 100° E and south of about 40° N). The spatial pattern of observed trends in diffuse irradiance is complex and inhomogeneous. An intriguing aspect of trends in global and direct irradiance is the rather abrupt decrease in annual and seasonal mean values from 1978 onward. The decreasing trends in solar radiation in China did not persist into the 1990s. The spatial and temporal patterns of trends in sunshine duration are consistent with that of global and direct irradiance. A decreasing trend in rainy days is observed over much of China, which is in agreement with the secular trend in cloud amount. The fact that trends in cloud amount and solar radiation are quite similar suggests that the cloud amount is not the primary cause for the decrease in solar radiation. Visibility in the eastern part of China has deteriorated heavily as a result of the rapid increase in aerosol loading. The statistical analysis showed that atmospheric transmission under clear conditions decreased rapidly. These facts suggest that the rapid increase in aerosol loading should be one of the principle causes for the decrease in solar radiation. The observed diurnal temperature range decreases remarkably in China, which is closely related to the increase in aerosols. The effects of anthropogenic air pollutants on climate should be further studied and included in the simulation of climate and projection of climate scenario. Keywords. Atmospheric composition and structure (Aerosol and particles; General or miscellaneous) – Meteorology and atmospheric dynamics (Radiative processes)

scholarly journals Compatibility of different measurement techniques. Long-term global solar radiation observations at Izaña Observatory

2016 ◽  
Author(s):  
Rosa Delia García ◽  
Emilio Cuevas ◽  
Omaira Elena García ◽  
Ramon Ramón ◽  
Pedro Miguel Romero-Campos ◽  
...  
Keyword(s):  
Time Series ◽  
Solar Radiation ◽  
Sunshine Duration ◽  
Measurement Techniques ◽  
Temporal Stability ◽  
Global Solar Radiation ◽  
Surface Radiation ◽  
Multifilter Rotating Shadowband Radiometer ◽  
High Consistency

Abstract. A 1-year intercomparison of classical and modern radiation and sunshine duration instruments has been performed at Izaña Atmospheric Observatory (IZO) located in Tenerife (Canary Islands, Spain) starting on July 17, 2014. We compare global solar radiation (GSR) records measured with a CM-21 pyranometer Kipp & Zonen, taken in the framework of the Baseline Surface Radiation Network, with those measured with a Multifilter Rotating Shadowband Radiometer (MFRSR), and a bimetallic pyranometer (PYR), and GSR estimated from sunshine duration performed by a Campbell-Stokes sunshine recorder (CS) and a Kipp & Zonen sunshine duration sensor (CSD). Given the GSR BSRN records are subject of strict quality controls (based on principles of physical limits and comparison with the LibRadtran model), they have been used as reference in the intercomparison study. We obtain an overall root mean square error (RMSE) of ~0.9 MJm2 (4 %) for GSR PYR and GSR MFRSR, 1.9 MJm2 (7 %) and 1.2 MJm2 (5 %) for GSR CS and GSR CSD, respectively. Factors such as temperature, fraction of the clear sky, relative humidity and the solar zenith angle have shown to moderately affect the GSR observations. As application of the methodology developed in this work, we have re-evaluated the GSR time series between 1977 and 1991 obtained with two PYRs at IZO. By comparing with coincident GSR estimates from SD observations, we probe the high consistency of those measurements and their temporal stability. These results demonstrate that 1) the continuous-basis intercomparison of different GSR techniques offers important diagnostics for identifying inconsistencies between GSR data records, and 2) the GSR measurements performed with classical and more simple instruments are consistent with more modern techniques and, thus, valid to recover GSR time series and complete worldwide distributed GSR data. The intercomparison and quality assessment of these different techniques have allowed to obtain a complete and consistent long-term global solar radiation series (1977–2015) at Izaña.

A Climatic Model of Solar Radiation and Temperature Change

1974 ◽  
Vol 4 (1) ◽  
pp. 25-38 ◽  
Author(s):  
Clayton H. Reitan
Keyword(s):  
Solar Radiation ◽  
Energy Budget ◽  
Temperature Data ◽  
Direct Solar Radiation ◽  
Response Ratio ◽  
Radiation Data ◽  
Long Term Trends ◽  
The 1960S ◽  
The Relationship

Mean monthly temperatures for the Northern Hemisphere were determined for the years 1955 through 1968 following the same procedures used by H. C. Willett and J. M. Mitchell, Jr., in their studies of long-term trends. It was found that the downward trend they reported starting in the 1940s continued, though interrupted, into the 1960s.The temperature data when combined with radiation data and other components of the hemispheric energy budget led to the formulation of the response ratio, the relationship between change in incoming solar radiation and change in temperature. When this response ratio was applied to the reported trends in direct solar radiation and to the decrease in direct solar radiation following the eruption of Agung in 1963, a probable cause-effect relationship was suggested.

scholarly journals Using routine meteorological data to derive sky conditions

2003 ◽  
Vol 21 (3) ◽  
pp. 649-654 ◽  
Author(s):  
D. Pagès ◽  
J. Calbó ◽  
J. A. González
Keyword(s):  
Solar Radiation ◽  
Meteorological Data ◽  
Atmospheric Composition ◽  
Likelihood Method ◽  
Total Solar Radiation ◽  
The Public ◽  
Radiative Processes ◽  
Composition And Structure ◽  
Real Time Information ◽  
Sky Conditions

Abstract. Sky condition is a matter of interest for public and weather predictors as part of weather analyses. In this study, we apply a method that uses total solar radiation and other meteorological data recorded by an automatic station for deriving an estimation of the sky condition. The impetus of this work is the intention of the Catalan Meteorological Service (SMC) to provide the public with real-time information about the sky condition. The methodology for deriving sky conditions from meteorological records is based on a supervised classification technique called maximum likelihood method. In this technique we first need to define features which are derived from measured variables. Second, we must decide which sky conditions are intended to be distinguished. Some analyses have led us to use four sky conditions: (a) cloudless or almost cloudless sky, (b) scattered clouds, (c) mostly cloudy – high clouds, (d) overcast – low clouds. An additional case, which may be treated separately, corresponds to precipitation (rain or snow). The main features for estimating sky conditions are, as expected, solar radiation and its temporal variability. The accuracy of this method of guessing sky conditions compared with human observations is around 70% when applied to four sites in Catalonia (NE Iberian Peninsula). The agreement increases if we take into account the uncertainty both in the automatic classifier and in visual observations.Key words. Meteorological and atmospheric dynamics (instruments and techniques; radiative processes) – Atmospheric composition and structure (cloud physics and chemistry)

scholarly journals Internal consistency of the IAGOS ozone and carbon monoxide measurements for the last 25 years

2020 ◽  
Author(s):  
Romain Blot ◽  
Philippe Nedelec ◽  
Damien Boulanger ◽  
Pawel Wolff ◽  
Bastien Sauvage ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Data Base ◽  
Internal Consistency ◽  
Selection Criteria ◽  
Meteorological Data ◽  
Atmospheric Composition ◽  
European Research ◽  
Air Masses ◽  
Long Term Trends

Abstract. The In-service Aircraft for a Global Observing System is a European research infrastructure that equips Airbus A340/330 with a system for monitoring atmospheric composition. The IAGOS instruments have three different configurations: IAGOS-CORE, IAGOS-MOZAIC and IAGOS-CARIBIC. Since 1994, there have been a total of 17 aircraft equipped. In this study, we perform an inter-comparison of about 8000 landing and take-off profiles to compare the O3 and CO measurements performed from these different configurations. The collocated profiles used in the study met various selection criteria. The first was a maximal 1 hour time difference between an ascent or descent by two different aircraft at the same airport and the second was a selection based on the similarity of air masses based on the meteorological data acquired by the aircraft. We provide here an evaluation of the internal consistency of the O3 and CO measurements since 1994. For both O3 and CO, we find no drift in the bias amongst the different instrument units (6 O3 and 6 CO IAGOS-MOZAIC instruments, 9 IAGOS-CORE Package 1 and the 2 instruments used in the IAGOS-CARIBIC aircraft). This results gives us confidence that the entire IAGOS data base can be treated as one continuous program, and is therefore appropriate for studies of long-term trends.

scholarly journals Improving the reliability of cable lines operation in hot climates

2020 ◽  
Vol 216 ◽  
pp. 01151
Author(s):  
Daniyar Bakhtiyarovich Madrakhimov ◽  
Vera Pavlovna Ivanova ◽  
Victoria Vyacheslavovna Tsypkina
Keyword(s):  
Solar Radiation ◽  
Climatic Factors ◽  
Climate Conditions ◽  
Term Operation ◽  
Asian Region ◽  
Hot Climate ◽  
Central Asian ◽  
Cable Lines ◽  
The Impact

Reliability of cable lines in hot climate is determined by the climatic characteristics of cables and wires, which include: long-term and short-term heat resistance, cold resistance, moisture resistance, resistance to cyclic exposure to temperatures and solar radiation, ozone resistance, etc. This article considers the main impacts of environmental factors: high temperatures, solar radiation, which, as practice shows, lead to irreversible deterioration of the electrical and mechanical properties of cable products. The result of climatic impacts in the Central Asian region, in hot climate conditions, is the aging of both insulation and protective coverings, which leads to irreversible change in the mechanical and electrical properties of the used polymers due to the loss of elasticity of the extruded material and its subsequent cracking, turning into cracks. The assessment of the possibility of long-term operation of the used polymer was carried out according to the polyethylene oxidation period, which determines the time of natural preservation of various types of cables during the period of their operation. The research was carried out on samples of cables stored under a canopy in wooden boxes, protected from sunlight and precipitation, by measuring criterion parameters with strict compliance with the established norms. Thus, the proposed solution for increasing the reliability of cable lines consists of debugging the technological process of applying insulation and sheathing, in which the extrusion of the polymer mass is carried out by technique that minimizes the ingress of contamination. Review of the results showed that extrusion line improvement would provide possibility of increasing reliability in the operation of cable products under the impact of climatic factors of the Central Asian region due to the reduced aging of insulation.

scholarly journals Merging ground-based sunshine duration observations with satellite cloud and aerosol retrievals to produce high-resolution long-term surface solar radiation over China

2021 ◽  
Vol 13 (3) ◽  
pp. 907-922
Author(s):  
Fei Feng ◽  
Kaicun Wang
Keyword(s):  
Standard Deviation ◽  
High Resolution ◽  
Solar Radiation ◽  
Spatial Resolution ◽  
Sunshine Duration ◽  
Ordinary Least Squares ◽  
Cloud Fraction ◽  
Surface Solar Radiation ◽  
The Impact

Abstract. Although great progress has been made in estimating surface solar radiation (Rs) from meteorological observations, satellite retrieval, and reanalysis, getting best-estimated long-term variations in Rs are sorely needed for climate studies. It has been shown that Rs data derived from sunshine duration (SunDu) can provide reliable long-term variability, but such data are available at sparsely distributed weather stations. Here, we merge SunDu-derived Rs with satellite-derived cloud fraction and aerosol optical depth (AOD) to generate high-spatial-resolution (0.1∘) Rs over China from 2000 to 2017. The geographically weighted regression (GWR) and ordinary least-squares regression (OLS) merging methods are compared, and GWR is found to perform better. Based on the SunDu-derived Rs from 97 meteorological observation stations, which are co-located with those that direct Rs measurement sites, the GWR incorporated with satellite cloud fraction and AOD data produces monthly Rs with R2=0.97 and standard deviation =11.14 W m−2, while GWR driven by only cloud fraction produces similar results with R2=0.97 and standard deviation =11.41 W m−2. This similarity is because SunDu-derived Rs has included the impact of aerosols. This finding can help to build long-term Rs variations based on cloud data, such as Advanced Very High Resolution Radiometer (AVHRR) cloud retrievals, especially before 2000, when satellite AOD retrievals are not unavailable. The merged Rs product at a spatial resolution of 0.1∘ in this study can be downloaded at https://doi.org/10.1594/PANGAEA.921847 (Feng and Wang, 2020).

scholarly journals Vertical Differences in the Long-Term Trends and Breakpoints of NDVI and Climate Factors in Taiwan

2021 ◽  
Vol 13 (22) ◽  
pp. 4707
Author(s):  
Hui Ping Tsai ◽  
Geng-Gui Wang ◽  
Zhong-Han Zhuang
Keyword(s):  
Climate Change ◽  
Minimum Temperature ◽  
Vegetation Index ◽  
Climatic Factors ◽  
Maximum Temperature ◽  
Climatic Data ◽  
Positive Effects ◽  
Central Regions ◽  
Long Term Trends

This study explored the long-term trends and breakpoints of vegetation, rainfall, and temperature in Taiwan from overall and regional perspectives in terms of vertical differences from 1982 to 2012. With time-series Advanced Very-High-Resolution Radiometer (AVHRR) normalized difference vegetation index (NDVI) data and Taiwan Climate Change Estimate and Information Platform (TCCIP) gridded monthly climatic data, their vertical dynamics were investigated by employing the Breaks for Additive Seasonal and Trend (BFAST) algorithm, Pearson’s correlation analysis, and the Durbin–Watson test. The vertical differences in NDVI values presented three breakpoints and a consistent trend from positive (1982 to 1989) to negative at varied rates, and then gradually increased after 2000. In addition, a positive rainfall trend was discovered. Average and maximum temperature had similar increasing trends, while minimum temperature showed variations, especially at higher altitudes. In terms of regional variations, the vegetation growth was stable in the north but worse in the central region. Higher elevations revealed larger variations in the NDVI and temperature datasets. NDVI, along with average and minimum temperature, showed their largest changes earlier in higher altitude areas. Specifically, the increasing minimum temperature direction was more prominent in the mid-to-high-altitude areas in the eastern and central regions. Seasonal variations were observed for each region. The difference between the dry and wet seasons is becoming larger, with the smallest difference in the northern region and the largest difference in the southern region. Taiwan’s NDVI and climatic factors have a significant negative correlation (p < 0.05), but the maximum and minimum temperatures have significant positive effects at low altitudes below 500 m. The northern and central regions reveal similar responses, while the south and east display different feedbacks. The results illuminate climate change evidence from assessment of the long-term dynamics of vegetation and climatic factors, providing valuable references for establishing correspondent climate-adaptive strategies in Taiwan.

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