Challenges for describing agroecosystems in the land-atmosphere interaction

大気―陸面相互作用を研究する上で大気―陸面結合モデルは重要なツールであり，領域気象解析，流域水文解析，気候変動予測等において欠かすことのできない存在となっている．陸面モデルは，大気―陸面結合モデルの基幹を成すモデルで，大気の境界条件に当たる地表面フラックスを算出する．陸面モデルで多様な地表面を表現するために目的と空間スケールに応じた簡略化が行われるが，農耕地に関しては実態とかけ離れた仮定や表現がなされる場合もある．そこで，大気―陸面相互作用における農耕地の扱いについて理解を深めることを目的に，農耕地で実際に起きていること，およびそれをモデル化する際の課題や注意点を考察した．Land-atmosphere coupled models are widely used for investigating the land-atmosphere interaction in the studies on regional weather and hydrological analyses as well as climate projections. Land surfaces consist of many types of land cover/use and thus the exact parameterization of each type of surfaces is a key for the success of those studies. Cropland occupies substantial area in certain regions, so-called breadbasket. However, in many land surface models, croplands are expressed as a small number of virtual/actual crop species and not precisely parameterized for crop growth and crop/field management. Moreover, the spatial distributions of crop/field management as well as the characteristics of cropland are highly variable depending on farmersʼ circumstance and governmental policy. This paper provides a short review and future direction on those topics towards the improvement of land-atmosphere coupled models