1 / 5

Optimizing Cloud Retrievals in Greenland Using IR and VISST Measurements

This analysis focuses on cloud phase and optical depth retrievals in central and southern Greenland using 2-channel infrared (IR) methods. It reveals significant findings, including reduced retrieval numbers and increased occurrences of supercooled water clouds, influenced by varying optical depths (τ). The research indicates that IR values may not always enhance outcomes when VISST is applied and highlights caution regarding pegged VISST values. Key observational challenges are outlined, emphasizing the need for careful interpretation of IR and VISST data for accurate cloud profiling.

nami
Télécharger la présentation

Optimizing Cloud Retrievals in Greenland Using IR and VISST Measurements

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Ed 3 Ed 4 Use IR if: IR 0< τ <6 11 μm T > Tc IR=cloudy OR IR τ>0 IR=cloudy VISST τ=0.05 VISST τ=150 VISST τ < 0 Use IR if: IR 0<τ<6 11 μm T > Tc IR=cloudy

  2. Ed 3 Ed 4 Use IR if: IR 0< τ <6 11 μm T > Tc IR=cloudy OR IR τ>0 IR=cloudy VISST τ=0.05 VISST τ=150 VISST τ < 0 Use IR if: IR 0<τ<6 11 μm T > Tc IR=cloudy

  3. Items of Note: Cloud Phase • Using the 2-channel IR where 0<τ<6 resulted in a decreased number of no retrievals over central/southern Greenland. Most were replaced with ice. • Using the 2-channel IR where 0<τ<6 resulted in an increased number of supercooled water clouds across central/southern Greenland. • Using the 2-channel IR (regardless of value) where VISST is pegged does not lead to significant changes over this domain. There is almost no reduction in no-retrieval areas (both VISST and IR gave no-retrieval).

  4. Items of Note: Optical Depth • Over snow, in this scene, 20% of VISST τ retrievals pegged at 0.05, 10% pegged at 150, and 10% were < 0. • Using the 2-channel IR where 0<τ<6 resulted in increased τ over mostly over western/central Greenland. Note: the new τ, between 1 and 4, still seems low for this area. • Using the 2-channel IR (regardless of value) where VISST is pegged does not lead to significant changes over this domain. Scattered occurrences of higher τ do exist. • Need to exercise caution when using 2-channel IR for pegged VISST values, as IR values may be pegged as well. VISST τ may still provide a better result. Additionally, when the IR method is used, information on particle size is unavailable for larger τ clouds.

More Related