The short lifetime of aerosol particles in the atmosphere means that they tend to be found concentrated in regions close to where they were formed. As they only last for days to weeks in the atmosphere, they don’t travel too far as the Earth’s winds aren’t able to fully mix the air over such a short period. This short lifetime should also mean that any changes in the emissions of ...[Read More]
Aerosol particles typically have short life spans in the atmosphere (days to weeks) but they can travel far and wide in that time. They can be lifted up to new horizons, higher and higher in the atmosphere. This is important for their impact on our climate, for example, at least 20% of the uncertainty in the climate impact of black carbon aerosol is due to differences in its vertical distribution. ...[Read More]
In order to understand past climate change and to better project future changes, we need to understand how humans disturbed the radiative balance of our planet. Aerosols are one component of this disruption. The final report from the Intergovernmental Panel on Climate Change (IPCC) physical science basis concluded that aerosols dominate the uncertainty in the total anthropogenic radiative forcing. ...[Read More]
There is a new commentary piece in Nature Geoscience by Gavin Schmidt and colleagues on ‘Reconciling warming trends’. The paper investigates several potential causes for the discrepancy between climate model projections and the recent ‘slowdown’ in global surface temperatures, which is nicely illustrated on Ed Hawkins’ Climate Lab Book blog. One of the aspects the pap ...[Read More]
Aerosols dominate the uncertainty in the total anthropogenic radiative forcing. A complete understanding of past and future climate change requires a thorough assessment of aerosol-cloud-radiation interactions. This is one of the conclusions about aerosols and their impact on our climate from the the final report from the Intergovernmental Panel on Climate Change (IPCC) on the physical science bas ...[Read More]
Now that the 2013 AGU Fall Meeting has ended, I thought I would roundup what I’ve been involved with over the week for both this blog and the Barometer Podcast, which I was recording each day with Sam Illingworth. Links to each piece are available below. Many thanks to all who have read and shared these over the past week. Recording the podcast at conferences is becoming a trend as we’ ...[Read More]
My second day at the AGU 2013 Fall Meeting revolved around more short-lived climate forcers, which I wrote about yesterday and also a broader session on the results from the recent IPCC Working Group 1 report. The latter was an opportunity for the community to quiz some of the lead authors of the report on a variety of issues including observations of the climate system, aerosol and clouds (yippee ...[Read More]
My first day at AGU 2013 revolved around sessions on short-live climate forcers, which are components in the atmosphere that have short lifetimes (compared to carbon dioxide for example) and generally warm the atmosphere. Reduction of these compounds, such as methane and black carbon, has been mooted as a way to reduce global mean temperatures in coming decades. This is summarised in the figure be ...[Read More]
One of the most fundamental aspects of aerosols that we are continually striving to understand is how they are actually born. One pathway that aerosol particles can take is a process known as “nucleation“. This nucleation process is where new particles are formed by gaseous molecules getting together and deciding that they’ve had enough of the gas-phase and would prefer to be tin ...[Read More]