Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: UHI in Fortaleza and trends on screen-level air temperature and
  precipitation   There is a consensus that Urban Heat Island phenomenon - UHI occurs in every
large city. This effect is characterized by higher air temperatures in cities
than in the neighboring countryside at night. However, to date, there has been
no systematic study on the Fortaleza case, the Brazil's 5th largest city. By
the comparison between screen-level air temperature measured by two automatic
weather stations, one located in the city and the other in the neighboring
region, this work shows the occurrence of the UHI in Fortaleza, even during the
rainy season. In an attempt to find some effect of the UHI on precipitation
(and vice-versa), historical series of air temperature and precipitation were
analyzed from 1966 to 2020. Besides the considerable increase in air
temperature over the years, a slight downward trend was observed in UHI and
even more in accumulated precipitation between the hours of 15:00 and 21:00
(local time). However, one believes that these trends may be related to climate
change at large scale rather than an urban scale.

23
The categories of this paper are: solv-int
22
The categories of this paper are: chao-dyn
24
The categories of this paper are: dg-ga
14
The categories of this paper are: math-ph
2
The categories of this paper are: math
6
The categories of this paper are: astro-ph
21
The categories of this paper are: adap-org
0
The categories of this paper are: hep-ph
11
The categories of this paper are: hep-lat
10
The categories of this paper are: q-bio
28
The categories of this paper are: alg-geom
18
The categories of this paper are: econ
37
The categories of this paper are: supr-con
9
The categories of this paper are: nlin
25
The categories of this paper are: patt-sol
29
The categories of this paper are: funct-an