By extracting and comparing long-term trend components of coral gray value, sea surface temperature, cloudiness, and net heat flux for the period of 1946-1992, the relationships among them are addressed. There exists ...By extracting and comparing long-term trend components of coral gray value, sea surface temperature, cloudiness, and net heat flux for the period of 1946-1992, the relationships among them are addressed. There exists a prominent regime shift in the cloudiness associated with the corresponding variabilities of sea surface temperature and net heat flux occurred in the mid-1960s, which can be successfully recorded by coral gray value, a climatic proxy. Long-term cloudiness variations in the South China Sea are completely opposite to the equatorial western Pacific in the past five decades, whereas they share a similar trend to that over Asian monsoon prevailing waters. The fact that the coral gray value is highly correlated to cloudiness provides a unique perspective on utilizing this coral to study cloudiness variations in the pre-instrumental period.展开更多
The purpose of this research is to determine the influence of Total Ozone and Aerosols about variability of Ultraviolet Radiation (UV) in the east coast of the Northeastern region of Brazil through measures from multi...The purpose of this research is to determine the influence of Total Ozone and Aerosols about variability of Ultraviolet Radiation (UV) in the east coast of the Northeastern region of Brazil through measures from multispectral sensor GUV (Ground-based Ultraviolet Radiometer). The methodology consisted of descriptive study and cluster analyses using data of UV in channels UVB (305 nm) and UVA (320 nm, 340 nm and 380 nm) and data of UV index, Total Ozone, Aerosol, Global Solar Radiation, Cloudiness and Wind. The results for city of Natal indicated that an annual event occurs in September/October which stabilizes the UV or UV Index when Total Ozone levels reach their annual maximum. This event is influenced by marine Aerosol that is found on mainland at a higher concentration in September due to greater Wind intensity and their southeasterly direction (sea for land). The cluster analysis using the variables above allowed us to detect three different groups: the first group is formed by Natal, Recife and Jo?o Pessoa and so determined that this event occurs in these three cities;the second group is formed by Maceió, Aracaju and Salvador and the third group includes only Fortaleza and had different results.展开更多
基金This research was supported by the National Natural Science Foundation of China under contract Nos 40136010 and 40305009the Guangdong Science Foundation under contract No.04001308.The authors thank the anonymous reviewers for their comments and suggestions.
文摘By extracting and comparing long-term trend components of coral gray value, sea surface temperature, cloudiness, and net heat flux for the period of 1946-1992, the relationships among them are addressed. There exists a prominent regime shift in the cloudiness associated with the corresponding variabilities of sea surface temperature and net heat flux occurred in the mid-1960s, which can be successfully recorded by coral gray value, a climatic proxy. Long-term cloudiness variations in the South China Sea are completely opposite to the equatorial western Pacific in the past five decades, whereas they share a similar trend to that over Asian monsoon prevailing waters. The fact that the coral gray value is highly correlated to cloudiness provides a unique perspective on utilizing this coral to study cloudiness variations in the pre-instrumental period.
文摘The purpose of this research is to determine the influence of Total Ozone and Aerosols about variability of Ultraviolet Radiation (UV) in the east coast of the Northeastern region of Brazil through measures from multispectral sensor GUV (Ground-based Ultraviolet Radiometer). The methodology consisted of descriptive study and cluster analyses using data of UV in channels UVB (305 nm) and UVA (320 nm, 340 nm and 380 nm) and data of UV index, Total Ozone, Aerosol, Global Solar Radiation, Cloudiness and Wind. The results for city of Natal indicated that an annual event occurs in September/October which stabilizes the UV or UV Index when Total Ozone levels reach their annual maximum. This event is influenced by marine Aerosol that is found on mainland at a higher concentration in September due to greater Wind intensity and their southeasterly direction (sea for land). The cluster analysis using the variables above allowed us to detect three different groups: the first group is formed by Natal, Recife and Jo?o Pessoa and so determined that this event occurs in these three cities;the second group is formed by Maceió, Aracaju and Salvador and the third group includes only Fortaleza and had different results.
