Saturday, February 4, 2023

Someone tries to debunk GEE McFearSun with the Cloud Masking Effect

 

1
the arctic extent may have gained but not the multiyear ice - the volume of ice keeps going down. The multiyear ice is almost all gone.
Highlighted reply
The Arctic was ice free many times and the feedback is negative. Read "High cloud coverage over melted areas dominates the impact of clouds on the albedo feedback in the Arctic" on Nature.

 @Leynad Jee  thanks - that article is cited 23 times in googlescholar. Process Drivers, Inter-Model Spread, and the Path Forward: A Review of Amplified Arctic Warming: Front. Earth Sci., 09 February 2022 Sec. Interdisciplinary Climate Studies Volume 9 - 2021 "The Arctic surface has warmed more than twice as fast as the global average surface temperature (Figure 1; Lenssen et al., 2019), a phenomenon known as Arctic Amplification (AA).... The cloud phase feedback magnitude is likely biased negative in most contemporary climate models due to excessive cloud ice and too little supercooled liquid under present-day conditions, yielding unrealistically large increases in mixed-phase cloud optical thickness with warming (Tsushima et al., 2006; Klein et al., 2009; Komurcu et al., 2014; McCoy et al., 2016; Tan et al., 2016). This cloud optical depth feedback bias may have broader implications to AA by enhancing the Arctic lapse rate feedback (Tan and Storelvmo 2019). Recent model experiments revealed that while global cloud feedbacks warm the Arctic, the local feedback contributes negligibly to Arctic warming (Middlemas et al., 2020) suggesting a potential remote influence (Section 5e). However, the model exhibits a low mixed-phase supercooled liquid bias and likely an optical depth feedback that is too negative....Several studies indicate that the cloud masking effect reduced the TOA [top of atmosphere] radiative impact of the observed surface albedo decline by ∼50% (Sledd and L’Ecuyer 2019; He et al., 2019; Alkama et al., 2020; Stapf et al., 2020). While not a feedback, the cloud masking effect highlights a mechanism through which present-day cloud properties influence Arctic climate change.....Through this water vapor triple effect, increased LH [latent heat] transport (C4) overcomes the countering effect of reduced DSE [dry static energy] transports due to a weakened equator-to-pole temperature gradient. As a result, remote atmospheric and oceanic processes drive additional surface warming that triggers interactions with local feedbacks (from C1) that cause further warming (C5)."

https://www.frontiersin.org/articles/10.3389/feart.2021.758361/full 

 2022: Thermodynamics of the climate system

 

 

 

No comments:

Post a Comment