An Overview of the Regional Experiments for Land-atmosphere Exchanges 2012 (REFLEX 2012) Campaign

Abstract

A b s t r a c tThe REFLEX 2012 campaign was initiated as part of a training course on the organization of an airborne campaign to support advancement of the understanding of land-atmosphere interaction processes. This article describes the campaign, its objectives and observations, remote as well as in situ. The observations took place at the experimental Las Tiesas farm in an agricultural area in the south of Spain. During the period of ten days, measurements were made to capture the main processes controlling the local and regional land-atmosphere exchanges. Apart from multi-temporal, multi-directional and multi-spatial space-borne and airborne observations, measurements of the local meteorology, energy fluxes, soil temperature profiles, soil moisture profiles, surface temperature, canopy structure as well as leaf-level measurements were carried out. Additional thermo-dynamical monitoring took place at selected sites. REFLEX 2012 CAMPAIGN 1467After presenting the different types of measurements, some examples are given to illustrate the potential of the observations made.

Modelling the footprint of the land on the atmosphere

“…First the ability of estimating local energy fluxes is presented. In order to ensure both a range of environmental and climatic conditions as well as sufficient ground truth data, four study areas having extensive field observations were selected for evaluating DATTUTDUT output and to compare results with published results using more established and more complex remote sensing-based energy balance models (French et al, 2005b;Timmermans et al, 2015a;Timmermans et al, 2007). The other remote sensing energy balance modelling approaches applied to these data sets are SEBAL as originally formulated in Bastiaanssen et al (1998) and two versions of the TSEB (Norman et al, 1995).…”

“…Data from the REFLEX'12 experiment (Timmermans et al, 2015a) over an agricultural test-site near Barrax, Spain, is used here since the area is characterized by the co-existence of dry and hot bare soil and a variety of well-watered crops.…”

“…The REFLEX'12 campaign was an airborne campaign to support the understanding of land-atmosphere interaction processes (Timmermans et al, 2015a). The experiment was carried out over the Las Tiesas Experimental Farm test site near Barrax in the La-Mancha region in Spain, maintained by the Provincial Technical Agronomical Institute (ITAP).…”

“…The data used in this section is taken from the REFLEX-2012 airborne field campaign organized during July 2012 over a very heterogeneous agricultural test site in the south-east of Spain (Timmermans et al, 2015a). Remote sensing data is taken from the Advanced Hyperspectral Scanner (AHS) flown on the 25 th of July 2012 at 11:28 local time, 09:28 UTC.…”

“…In section 2.4 a discussion of the results of the different evaluations follows, after which the concluding remarks are provided in section 2.5. The validation data for the evaluations come from large scale interdisciplinary experiments conducted in a semi-arid rangeland region -Monsoon 1990 (Kustas et al, 1994a), a winter wheat/grazing-lands siteSouthern Great Plains 1997 (Jackson et al, 1999), a corn and soybean production region -SMEX/SMACEX 2002 , an agricultural test site -REFLEX'12 (Timmermans et al, 2015a) and an irrigated agricultural site within an arid region -Gediz 1998 (Kite & Droogers, 2000).…”