The effects of desert plantations, such as those used for climate change mitigation, during extreme heat events remain an important yet unresolved question. The Eastern Mediterranean and the Middle East face intensified heat and drought due to climate change, impacting regional weather and local ecosystems. Semi-arid forests, such as the Yatir pine forest on the edge of the Negev Desert, provide a unique lens through which to study land surface-atmosphere interactions, particularly under extreme heat events.
Ongoing studies show that due to high incoming solar radiation and its low albedo, the Yatir Forest net radiation is higher than in any other Eco-regions, balanced by a large sensible heat flux. Thus, the resulting cooler surface suppresses the emission of longwave radiation compared with the surrounding warmer shrubland. This reduction in longwave radiation alters the energy balance of the soil-forest-atmosphere continuum, both below and above the canopy, and influences the forest microclimate. The thermal contrast can also result in the development of secondary circulations within the planetary boundary layer, significantly impacting energy exchange and potentially regional weather.
This research investigates Yatir Forest-atmosphere interactions during extreme heat events. Using in-situ data and ICON numerical weather prediction model simulations, we explore the influence of semi-arid afforestation on boundary layer dynamics and local weather. Our simulations reveal sensible heat flux increases of up to 300 W/m² in forested areas, leading to surface (skin) cooling of 14-15°C but 2°C warming of 2-meter air temperatures in some regions, with altered wind patterns, significantly affecting boundary layer dynamics.
