A230-0005
Modeling and Observation of Processes that Impact the Far-Infrared in Mid-Latitude, High-Altitude Complex Terrain

Wednesday, 16 December 2020
Poster
Daniel Feldman1, Helen E Brindley2, P Jonathan Gero3, Matthew Worden4, Nicola Falco1, Baptiste Dafflon1, P. James Dennedy-Frank1, Haruko M Wainwright1 and Tristan L'Ecuyer5, (1)Lawrence Berkeley National Laboratory, Berkeley, CA, United States, (2)Imperial College London, Physics, London, SW7, United Kingdom, (3)University of Wisconsin Madison, Space Science and Engineering Center, Madison, WI, United States, (4)Lawrence Berkeley National Laboratory, Climate Sciences, Berkeley, CA, United States, (5)University of Wisconsin, Department of Atmospheric and Oceanic Sciences, Madison, WI, United States
Abstract:
Earth System Models persistently exhibit cold biases and underestimate elevation-dependent warming in mid-latitude high-altitude complex terrain, such as over the Tibetan Plateau, the Rocky Mountains, and the Andes, relative to observations. The list of suspected sources of these biases include errors in modeled thermal radiative environment, but it has, to date, proven difficult to reduce uncertainties in the satellite retrievals of temperature, humidity, and emissivity enough to identify the model structural errors that impact processes affecting thermal radiation.

We therefore explore how novel far-infrared observations from satellites (PREFIRE and FORUM) can improve these retrievals. We find that in complex terrain, the role of three-dimensional radiative effects from topography cannot be neglected. From ECOSTRESS 70-meter surface temperature observations, we show that up to 50% of the downwelling longwave radiation and up to 3 K brightness temperature equivalent in FORUM and PREFIRE radiances is the result of heterogeneous terrain emission. Sub-kilometer information on topographic effects, snow cover and surface temperature is necessary for far-infrared retrievals of emissivity and temperature and humidity profiles. With this information, these retrievals may enable downwelling longwave radiation estimates that provide meaningful observational constraints on the surface thermal environment.

These results indicate the importance of the joint analysis of surface and satellite data, and shows that field campaign data will provide key guidance for complex terrain retrievals. If there is overlap between the upcoming Surface Atmosphere Integrated Field Laboratory (SAIL) campaign over the Rocky Mountains in Colorado and the PREFIRE mission, opportunities for surface and TOA analysis of the thermal radiative environment, including the role of processes that impact the far-infrared, will be possible.

<< Previous Abstract | Next Abstract >>