Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Spatiotemporal continuous estimates of daily 1-km PM2.5 from 2000 to
  present under the Tracking Air Pollution in China (TAP) framework   High spatial resolution PM2.5 data products covering a long time period are
urgently needed to support population exposure assessment and refined air
quality management. In this study, we provided complete-coverage PM2.5
predictions with a 1-km spatial resolution from 2000 to the present under the
Tracking Air Pollution in China (TAP) framework. To support model fitting at a
high spatial resolution, we collected PM2.5 measurements from both national and
local monitoring stations that better described the PM2.5 distributions at the
local scale. To correctly reflect the temporal variations in land cover
characteristics that significantly affected the local variations in PM2.5
levels, we constructed continuous annual geoinformation datasets, including the
annual road distribution maps and ensemble gridded population distribution maps
in China from 2000 to 2021. We also examined various model structures and
predictor combinations to balance the computational cost and model performance.
The final model fused 0.1-degree TAP PM2.5 predictions, multi-angle
implementation of atmospheric correction (MAIAC) aerosol optical depth
retrievals and land use parameters with a random forest model. The land use
parameters correctly reflected the infrastructure development and population
migration in China. Our annual model had an out-of-bag R2 ranging between 0.80
and 0.84, and our hindcast model had a by-year cross-validation R2 of 0.76. The
high-resolution daily and annual pollution maps successfully revealed the
local-scale spatial variations in PM2.5 distributions that could not be
characterized by the previous 0.1-degree resolution PM2.5 data. This
open-access 1-km resolution PM2.5 data product with complete coverage could
benefit environmental studies and policy-making.

19
The categories of this paper are: eess
32
The categories of this paper are: atom-ph
12
The categories of this paper are: nucl-th
8
The categories of this paper are: hep-ex
0
The categories of this paper are: hep-ph
28
The categories of this paper are: alg-geom
22
The categories of this paper are: chao-dyn
2
The categories of this paper are: math
33
The categories of this paper are: plasm-ph
24
The categories of this paper are: dg-ga
16
The categories of this paper are: stat
9
The categories of this paper are: nlin
5
The categories of this paper are: gr-qc
1
The categories of this paper are: cs
13
The categories of this paper are: quant-ph
36
The categories of this paper are: cmp-lg