Academic Journal
A meteorological overview of the ORACLES (ObseRvations of Aerosols above CLouds and their intEractionS) campaign over the southeastern Atlantic during 2016–2018: Part 2 – Daily and synoptic characteristics
| العنوان: | A meteorological overview of the ORACLES (ObseRvations of Aerosols above CLouds and their intEractionS) campaign over the southeastern Atlantic during 2016–2018: Part 2 – Daily and synoptic characteristics |
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| المؤلفون: | Ryoo, Ju-Mee, Pfister, Leonhard, Ueyama, Rei, Zuidema, Paquita, Wood, Robert, Chang, Ian, Redemann, Jens |
| المصدر: | eISSN: 1680-7324 |
| سنة النشر: | 2023 |
| المجموعة: | Copernicus Publications: E-Journals |
| الوصف: | Part 1 (Ryoo et al., 2021) provided a climatological overview of the ObsErvation of Aerosols above CLouds and their intEractionS (ORACLES) period and assessed the representativeness of the deployment years. In part 2, more detailed meteorological analyses support the interpretation of the airborne measurements for aerosol transport and its interaction with low clouds over the southeastern (SE) Atlantic Ocean during the September 2016, August 2017, and October 2018 deployments at a daily and synoptic scale. The key meteorological characteristics during the September 2016 deployment are (1) the southern African easterly jet (AEJ-S), centered at around 600 hPa ( ∼4 km), which strengthens throughout the month in concert with a warming continental heat low, with the strongest winds occurring around 23 September. These advect both aerosol and moisture in the free troposphere. (2) Mid-tropospheric black carbon (BC) is entrained at times into the boundary layer, and (3) convection over land is dry south of about 10 ∘ S and moist north of 10 ∘ S. The daily mean low-cloud fraction (low CF) is well correlated with the daily mean high low tropospheric stability (LTS, r =0.44 –0.73 over the flight domain; 0–10 ∘ E, 5–25 ∘ S) and moderately correlated with the daily mean boundary layer height (BLH, r =0.37 –0.52), defined as the altitude of the maximum vertical gradient of moisture. For the August 2017 deployment, the primary meteorological characteristics are that (1) the AEJ-S is at a lower altitude ( ∼3 km; ∼700 hPa) and further north (5–7 ∘ S) than in September 2016 and only becomes established by 20 August, with a separate easterly jet present aloft above 500 hPa ( ∼5.5 km) before that, (2) the mid-tropospheric BC–RH coupling strengthens after the AEJ-S develops, at around 3 km, (3) the daily mean low CF is less closely correlated with the daily mean LTS ( r =0.16 –0.57) and BLH ( r =0.11 –0.25) than in September 2016, and (4) dry convection reaches 700 hPa over the Namibian–Kalahari dryland ( ∼15 –25 ∘ S, ∼18 –24 ∘ E), ... |
| نوع الوثيقة: | text |
| وصف الملف: | application/pdf |
| اللغة: | English |
| Relation: | https://acp.copernicus.org/articles/22/14209/2022/ |
| DOI: | 10.5194/acp-22-14209-2022 |
| الاتاحة: | https://doi.org/10.5194/acp-22-14209-2022 https://acp.copernicus.org/articles/22/14209/2022/ |
| رقم الانضمام: | edsbas.DF2C20E9 |
| قاعدة البيانات: | BASE |
| DOI: | 10.5194/acp-22-14209-2022 |
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