The impact of seasonalities on direct radiative effects and radiative heating rates of absorbing aerosols above clouds

Abstract

The impact of seasonalities on direct radiative effects (DREs) and radiative heating rates (RHRs) of absorbing aerosols above clouds in the southeast Atlantic is examined using radiative transfer calculations. For an aerosol optical thickness of 0.6 located between 0 and 4 km, a cloud optical thickness of 9.0 and a cloud effective radius of 12.8 µm at 0.55 µm located between 1 and 2 km, the diurnally averaged RHR at noon in the aerosol layer increases from ∼6.6 K day−1 in June to ∼8.9 K day−1 in October. In June (October), the RHR in the cloud layer at noon is 1.3 (1.7) K day−1 higher than the case of pristine clouds. However, an elevated aerosol layer (2–4 km) reduces the RHR by ∼0.2 K day−1 in the cloud layer relative to a pristine cloudy case. The DRE at top‐of‐atmosphere (TOA) reaches its peak when the solar zenith angle (SZA) is 54°. The DRE increases (decreases) with SZA for SZA less (greater) than 54°. The primary peak DRE is ∼29.5 W m−2 at 5.0°S 5.0°E, occurring at 0800 UTC. At noon, the DRE at TOA is ∼18.9, ∼20.5 and ∼23.1 W m−2 at 5.0°S, 15.0°S and 25.0°S along 5.0°E, respectively. This study provides data and theoretical understanding to help positioning science flights that target measurements of above‐cloud aerosol radiative effects.

Geochemistry of Pyrite from the Gangcha Gold Deposit, West Qinling Orogen, China: Implications for Ore Genesis

“…This is further supported by Kong et al (2017) who documented that these pyrites have δ 34 S values in the 0.6-1.3 ‰ range (consistent with a magmatic origin). This is further supported by Kong et al (2017) who documented that these pyrites have δ 34 S values in the 0.6-1.3 ‰ range (consistent with a magmatic origin).…”

“…This is further supported by Kong et al (2017) who documented that these pyrites have δ 34 S values in the 0.6-1.3 ‰ range (consistent with a magmatic origin). This is supported by the low oxygen isotope signature of late-stage quartz from the Gangcha gold deposit, which is indicative of isotope exchange between magmatic and meteoritic waters (Kong et al, 2017). This is supported by the low oxygen isotope signature of late-stage quartz from the Gangcha gold deposit, which is indicative of isotope exchange between magmatic and meteoritic waters (Kong et al, 2017).…”

“…In the Gangcha gold deposit, the Co/Ni ratios of py1 are in the 1.58-10.66 range, which indicates that py1 is of a magma-driven hydrothermal origin. This is further supported by Kong et al (2017) who documented that these pyrites have δ 34 S values in the 0.6-1.3 ‰ range (consistent with a magmatic origin). The majority of Co/ Ni ratios for py2, py3 and py4 are in the 0.11-2.2 range with almost half of the ratios <1 (Table 3), which is attributed to boiling of ore fluid and ore fluid mixing with meteoric water.…”

“…Recently, Rb-Sr dating of hydrothermal pyrite from the Gangcha gold deposit yielded an isochron age of 229 to 225 Ma (Kong et al, 2017), which is consistent with metallogenic epoch that persisted in the Xiahe-Hezuo region (ca. Recently, Rb-Sr dating of hydrothermal pyrite from the Gangcha gold deposit yielded an isochron age of 229 to 225 Ma (Kong et al, 2017), which is consistent with metallogenic epoch that persisted in the Xiahe-Hezuo region (ca.…”

“…The majority of Co/ Ni ratios for py2, py3 and py4 are in the 0.11-2.2 range with almost half of the ratios <1 (Table 3), which is attributed to boiling of ore fluid and ore fluid mixing with meteoric water. This is supported by the low oxygen isotope signature of late-stage quartz from the Gangcha gold deposit, which is indicative of isotope exchange between magmatic and meteoritic waters (Kong et al, 2017).…”