Office of Research, UC Riverside
Robert Allen
Full Professor of Climatology
Earth & Planetary Sciences Dep
rjallen@ucr.edu
(951) 827-4870


"Collaborative Research: Observationally-constrained estimates of effective radiative forcing from aerosol radiation interactions".

AWARD NUMBER
007465-002
FUND NUMBER
33148
STATUS
Closed
AWARD TYPE
3-Grant
AWARD EXECUTION DATE
6/8/2015
BEGIN DATE
6/15/2015
END DATE
5/31/2018
AWARD AMOUNT
$325,735

Sponsor Information

SPONSOR AWARD NUMBER
1455682
SPONSOR
NATIONAL SCIENCE FOUNDATION
SPONSOR TYPE
Federal
FUNCTION
Organized Research
PROGRAM NAME

Proposal Information

PROPOSAL NUMBER
15010097
PROPOSAL TYPE
New
ACTIVITY TYPE
Basic Research

PI Information

PI
Allen, Robert
PI TITLE
Other
PI DEPTARTMENT
Earth and Planetary Sciences
PI COLLEGE/SCHOOL
College of Nat & Agr Sciences
CO PIs

Project Information

ABSTRACT

The solar heating of the Earth is affected by aerosols emitted from human activites including agriculture (for instance the burning of crop residue after the harvest), power generation (including both sulfate aerosol which reflects solar radiation and black carbon aerosol that absorbs it), and transportation. The radiative effects of these anthropogenic aerosols are hard to quantify, and their climatic effect is among the largest uncertainties in projections of future climate change. The goal of this project is to develop observationally-based estimates of the radiative forcing due to anthropogenic aerosols using the best available satellite and surface-based datasets. More specifically, the research seeks to produce estimates of the effective radiative forcing from aerosol-radiation interactions (ERFari), which includes both the radiative effects of the aerosols and the changes in radiative forcing due to changes in clouds brought about by aerosol radiative heating. For example, the heating due to absorption of solar radiation by black carbon aerosols (soot) can lead to the "burn off" of clouds, resulting in more sunlight reaching the ground. Data used to determine aerosol amounts, vertical profiles, and radiative parameters comes from several satellite missions ( (MODIS, the CALIPSO/CALIOP lidar, MISR, CERES) and from the ground-based AERONET network. The aerosol amounts and properties are used in combination with a radiative transfer model (MACR) to determine the aerosol radiative forcing. The radiative forcing is then used as an input to global climate models, from which estimates of the further impact of aerosols on cloud radiative forcing are determined. Model-derived estimates of the cloud radiative properties are then compared to further satellite cloud observations. A key assumption of the project is that fine-mode aerosols can be used as a proxy for anthropogenic aerosols, provided that known natural sources of fine-mode aerosol (dust, marine sulfate, sea salt) can be factored out.

The work has broader impacts due to the potential importance of anthropogenic aerosol as a regional and global climate forcing. Work to reduce the large uncertainty in this climate forcing could lead to better projections of future climate change and its impacts on human activities. In addition, the project would support a graduate student and provide a research opportunity for an undergraduate student at an ethnically diverse university. One of the PIs also performs outreach to local K-12 students through a local nonprofit organization.
(Abstract from NSF)