Details

Autor(en) / Beteiligte

• Räsänen, M.
• Chung, M.
• Katurji, M.
• Pellikka, P.
• Rinne, J.
• Katul, G. G.

Titel

Similarity in Fog and Rainfall Intermittency

Ist Teil von

• Geophysical research letters, 2018-10, Vol.45 (19), p.10,691-10,699

Ort / Verlag

Washington: John Wiley & Sons, Inc

Erscheinungsjahr

2018

Link zum Volltext

Quelle

Wiley Online Library - AutoHoldings Journals

Beschreibungen/Notizen

• Intermittent fog occurrences supply significant amounts of moisture to plants in the form of fog drip onto the soil surface thereby prompting interest in their statistical behavior at multiple timescales. A comparison of rainfall and fog measurements collected at an inland tropical cloud forest in Kenya and a coastal rangeland in Northern California is presented to explore whether fog occurrences have similar intermittency characteristics as rainfall. The results confirm that both rainfall and fog show approximate power law relations for distributions of dry period and event size consistent with predictions from self‐organized criticality. Moreover, the spectral exponents of the on‐off time series of the fog and rainfall exhibited an approximate f−0.8 over a broad range of frequencies f, which is remarkably close to scaling exponents across sites experiencing different rainfall generation mechanisms. These results suggest that fog intermittency shares some properties of critical behavior documented in numerous rainfall studies. Plain Language Summary Beyond rainfall, intermittent fog occurrence provides water subsidy that is needed for sustaining transpiration and photosynthesis in forests. To study the connections between fog formation and rainfall, a comparison of rainfall and fog occurrence statistics is carried out at two sites: a Kenyan inland cloud forest and a coastal forest in Northern California. For durations exceeding 1 day, rainfall and fog event sizes and dry periods appear similar. Due to these similarities, intermittency in fog occurrences may abide by general laws describing critical phenomenon. Key Points The spectrum of on‐off time series of fog and rainfall are similar Rainfall and fog exhibit power laws for distributions of dry period and event size (depth of deposited water) The switching between on and off states is not entirely independent from the amplitude intermittency for fog and rainfall