Scheduled Downtime
On Friday 21 April 2023 @ 5pm MT, this website will be down for maintenance and expected to return online the morning of 24 April 2023 at the latest

Daytime temperatures in Clay in Soil texture


New member
I am currently studying the heat island of Bangkok, Thailand as part of a Southeast Asian urban climate research.

This study uses WRF versions 4.2.2 and 4.3.3.
Also, Noah LSM and Single layer UCM are used.

I have run simulations on many cases, but the simulations do not reproduce the daytime and surface temperatures correctly.
In particular, daytime temperatures cause a high-temperature bias in clayey soils.

As an example, I share the following figures:
(a) Soil category (top layer) as simulated by WRF
(b) Surface temperature at 11:00 local time on June 19, 2022 (Himawari 8 satellite observation)
(c) Surface temperature at the same time simulated by WRF (Inside the black line indicates the urban area)

These symptoms appear only during the day and are not seen at night.

These results occur even if the initial condition and physical scheme are changed.
Also, when Clay was changed to Loam for testing purposes, the high temperature in the upper left corner of the area disappeared.

This high-temperature bias in clayey soils occurs mainly in the Southeast Asian region, including Manila, Philippines, Kuala Lumpur, Malaysia, and Ho Chi Minh City, Vietnam.

Please let us know if you have any remedies to improve this high-temperature bias.

Best regards,


  • Figure_1.jpg
    744.4 KB · Views: 13
Thank you for your many responses.
Upon investigation, we found that this was due to the low resolution of soil conditions.

Thank you so much.