Extreme climate response to marine cloud brightening in the arid Sahara-Sahel-Arabian Peninsula zone

[Andrew Lockley]

Extreme climate response to

marine cloud brightening in the

arid Sahara-Sahel-Arabian

Peninsula zone

Yuanzhuo Zhu

Climate Modeling Laboratory, School of Mathematics, Shandong University,

Jinan, China

Zhihua Zhang

Climate Modeling Laboratory, School of Mathematics, Shandong University,

Jinan, China and MOE Key Laboratory of Environmental Change and Natural

Disaster, Beijing Normal University, China, and

M. James C. Crabbe

Wolfson College, Oxford University, Oxford, UK; Institute of Biomedical and

Environmental Science and Technology, University of Bedfordshire, Luton, UK

and School of Life Sciences, Shanxi University, Taiyuan, China

Abstract

Purpose – Climatic extreme events are predicted to occur more frequently and intensely and will significantly

threat the living of residents in arid and semi-arid regions. Therefore, this study aims to assess climatic extremes’

response to the emerging climate change mitigation strategy using a marine cloud brightening (MCB) scheme.

Design/methodology/approach – Based on Hadley Centre Global Environmental Model version 2-

Earth System model simulations of a MCB scheme, this study used six climatic extreme indices [i.e. the hottest

days (TXx), the coolest nights (TNn), the warm spell duration (WSDI), the cold spell duration (CSDI), the

consecutive dry days (CDD) and wettest consecutive five days (RX5day)] to analyze spatiotemporal evolution

of climate extreme events in the arid Sahara-Sahel-Arabian Peninsula Zone with and without MCB

implementation.

Findings – Compared with a Representative Concentration Pathways 4.5 scenario, from 2030 to 2059,

implementation of MCB is predicted to decrease the mean annual TXx and TNn indices by 0.4–1.7 and 0.3–

2.1°C, respectively, for most of the Sahara-Sahel-Arabian Peninsula zone. It would also shorten the mean

annual WSDI index by 118–183 days and the mean annual CSDI index by only 1–3 days, especially in the

southern Sahara-Sahel-Arabian Peninsula zone. In terms of extreme precipitation, MCB could also decrease

the mean annual CDD index by 5–25 days in the whole Sahara and Sahel belt and increase the mean annual

RX5day index by approximately 10 mm in the east part of the Sahel belt during 2030–2059.

[SALTER Stephen]

Hi All

 

If my decrypting of the Met. Speak encoding is correct this sounds quite encouraging.  The 50% increase in nuclei concentration under clouds is quite a modest dose. Working at latitudes between 30N and 30S at the same spray with the full dispersion width of the accumulation mode of aerosol sizes is so boring.  It would interesting to know what the concentrations were before treatment so that we could calculate the amount spray and the number of spray vessels needed. 

 

If the concentrations were like the ones given by Vallina in doi:10.1029/2006GB002787 and the spray was monodisperse with a liquid diameter of 0.8 microns so as to avoid wasting energy on spraying salt mass very much heavier than Kohler would recommend,  we would need about a hundred vessels spraying  15 kg of water per second. 

 

They will not all be working at full power and not all in the right place at the right time but some of this would be offset by an even more sophisticated planning of vessel movements based on real-time satellite observations and clever climate planners with ginormous quantum computers.  I predict that they would find the temperature gradients across oceans a very useful guide.

 

Stephen

 

Emeritus Professor of Engineering Design

School of Engineering

Mayfield Road  EH9 3 DW

University of Edinburgh

Scotland.

Tel 0131 662 1180

 

From: geoengi...@googlegroups.com <geoengi...@googlegroups.com> On Behalf Of Andrew Lockley
Sent: 09 February 2021 15:27
To: geoengineering <geoengi...@googlegroups.com>
Subject: [geo] Extreme climate response to marine cloud brightening in the arid Sahara-Sahel-Arabian Peninsula zone

 

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