How thunderstorms are generated in clouds continues to be not totally understood. However John Latham, who has died aged 83, did a lot to clarify the bodily processes of cloud electrification, cloud lightning and precipitation – how water falls from clouds in numerous types. Later he proposed a approach through which clouds might present a vital if momentary function in lowering the impression of worldwide warming.
The analysis he started underneath John (BJ) Mason in 1958 at what’s now Imperial Faculty London targeted on the function of ice crystals in cloud electrification. His laboratory research of thunderstorms concerned the idea of a temperature distinction between graupel – tender hail – and ice crystal surfaces. He and Mason developed the Temperature Gradient Concept and supplied numerical predictions of the mechanism. Like all theories of thunderstorm electrification, it proved controversial.
After acquiring a lectureship in 1961 at Umist, now a part of Manchester College, John constructed a succession of chilly rooms with a purpose to examine thunderstorm electrification.
He and colleagues devised the “who grows quicker” speculation, exploring whether or not underneath sure circumstances throughout ice-particle collisions the particle rising quicker from the vapour turns into positively charged and the opposite negatively charged, resulting in the event of electrical fields that can lead to lightning discharges. This conclusion, subsequently supported by additional information, stays the premise for fashions of electrification to today.
Maybe his biggest contribution got here in 1979, in relation to droplet development and microphysics in heat clouds – these containing water vapour and the droplets condensed from it, quite than ice. A significant downside in cloud physics was to clarify how rain in heat clouds fashioned in an noticed time of about 20 minutes. Not one of the fashions on the time have been in a position to clarify this.
John recommended a novel speculation for the method, which he termed “inhomogeneous mixing”. On this account, discrete blobs of dry air are carried alongside into the clouds, fully evaporating close by droplets, whereas others additional away are unaffected. Decreasing the general focus of drops decreases the competitors for the out there water vapour and permits the biggest drops to develop quicker and rain to develop inside the noticed time.
In 1988, John left Umist for the National Center for Atmospheric Research in Boulder, Colorado.
Two years after arriving there, he addressed the issue of worldwide warming by proposing that marine cloud brightening (MCB) might be quickly used to replicate incoming photo voltaic radiation again. It will obtain this via exploiting what is named the Twomey effect: for a similar quantity of liquid water, a lot of small droplets replicate extra incoming photo voltaic radiation than a smaller variety of bigger ones. He proposed to result in this radiative cooling by utilizing a sea-salt spray of specified measurement, generated from wind-driven ships, and from 2008 onwards revealed the supporting science.
Researchers on the Centre for Climate Repair, Cambridge, and elsewhere are at present engaged on prototypes to check the concept. US companies have helped sponsor the work, and parallel research are being carried out on the College of Washington, Seattle.
As a author, John revealed six collections of poetry, together with All-Clear (1990), Sailor Boy (2006) and From Professor Murasaki’s Notebooks on the Effects of Lightning on the Human Body (2017). The title poem of the final had received second prize in 2006 within the Nationwide Poetry Competitors in Britain. He additionally produced quick fiction, performs for BBC Radio 4 and a surrealistic novel, Ditch-Crawl (2006).
Although involved with analysing pure phenomena all the way down to a molecular degree, John by no means misplaced a way of marvel on the imaginative impact they’ve on us, as within the poem Double-jointed (from the Murasaki assortment):
I’m again now within the Rockies,
a spurting, crackling hearth
sends flame-shadows scudding
spherical stripped-log cabin partitions,
and a light-weight up excessive, exterior, reveals
us snowflakes crazy-dancing into oblivion.
In his later years, whereas residing in that cabin in Gold Hill, close to Boulder, he wrote the poem Nightfall Phrases (from Crossing Over, 2017), as he turned conscious of the onset of dementia: “I’m not afraid of it, not a lot, not but, / however I can really feel it coming, the dawning darkish, / wisps of altostratus that subdue the solar”. In 2018 he returned to his birthplace, Frodsham, in Cheshire.
His father, Jack (William John), was an electrician and ran a store within the village together with his mom, Ruth (nee Barrow). From Helsby highschool John went to Imperial, the place he accomplished his PhD.
At Umist he was awarded a DSc (1968) earlier than being appointed professor, and I knew him as a colleague there from 1985. He gave workshops on the physics of lightning at universities world wide, his work was recognised by the Royal Meteorological Society, and he served as president of the Worldwide Fee on Atmospheric Electrical energy (1975-83). The thought that his work may assist fight world warming saved him working at NCAR so long as he might, and we continued to collaborate on analysis initiatives.
In 1961 John married Ann Bromley, additionally from Frodsham, and so they had 4 youngsters; they divorced amicably in 1992. He was predeceased by two sons, Rob and Mike, and is survived by his youngsters David and Rebecca, seven grandchildren, Samuel, Shane, Jessica, Natasha, Molly, James and Evie, and a great-grandchild, Tamara.