|
 Aiguo Dai
answers a few questions about this month's
new hot paper in the field of Geosciences.
The author has also
sent along images of their work.
From
•>>November 2006
Field:
Geosciences
Article Title: A global dataset of Palmer Drought Severity Index for 1870-2002: Relationship with soil moisture and effects of surface warming
Authors: Dai,
AG;Trenberth, KE;Qian, TT
Journal: J HYDROMETEOROL
Volume: 5
Issue: 6
Page: 1117-1130
Year: DEC 2004
* Natl Ctr Atmospher Res, POB 3000, Boulder, CO 80307 USA.
* Natl Ctr Atmospher Res, Boulder, CO 80307 USA.
|
 Why
do you think your paper is highly cited?
I think the reason is that it provides a useful global drought
data set, and, more importantly, it also addresses a popular and
important question for the first time: how has the recent global
warming affected surface moisture conditions and droughts?
Does
it describe a new discovery, methodology, or synthesis of knowledge?
Yes, it represents a first study to address the effect of global
warming on drought, using observed climate data.
Could
you summarize the significance of your paper in layman’s terms?
The paper shows that global drought areas have more than doubled
since the 1970s due to precipitation changes associated with the
1982/83 El Niño and enhanced evaporation caused by the recent rapid
warming over northern mid- and high-latitudes.
How
did you become involved in this research, and were there obstacles
along the way?
We have been doing research related to climate change and global
warming, and in particular, the changes in the global water cycle.
This study is just one of our many papers on this general subject.
Are
there any social or political implications for your research?
Droughts are among the most damaging natural disasters each year.
Large increases in drought areas have huge impacts on our society
and the environment.
Aiguo Dai, Scientist
Climate & Global Dynamics Division
National Center for Atmospheric Research
Boulder, CO, USA
|
|
A Closer Look...
|
 |
Below
are images sent in by Aiguo Dai which correspond with the featured
paper, or current research. |
|
Figure
1:
 |
|
Figure
1: Maps of linear trends of PDSI (change per 50 years, calculated with both precipitation and temperature changes) during (top) 1900-1949 and (middle) 1950-2002. The bottom panel shows the trends of PDSI calculated without temperature changes. Red (blue) areas indicate drying (wetting).
|
|
| |
|
| |
|
Figure 2:
 |
|
Figure
2: Smoothed time series of the percentage of the total land areas within 60oS-75oN that were in very dry (PDSI < -3.0, red lines), very wet (PDSI > +3.0, green lines), and very dry or wet (thickest black lines) conditions from 1950 to 2002. The solid lines are based on the PDSI calculated with both precipitation and temperature changes while the dashed lines are without temperature changes (i.e., due to precipitation alone). |
|
| |
|
| |
|
Figure 3:
 |
|
Figure
2: Smoothed time series of percentage areas in very dry (PDSI < -3.0, red line), very wet (PDSI > +3.0, blue line), and the sum of the two (black line) over the regions where data are sufficient during the plotted periods. Note that the very wet area is plotted using the downward scale on the right-side ordinate (0-80% except for the Sahel and S. Africa) and the dry and total areas are on the left-side ordinate. |
|
| |
|
ESI Special Topics,
November 2006
Citing URL - http://www.esi-topics.com/nhp/2006/november-06-AiguoDai.html
|
|
