Global monthly diurnal temperature cycle parameters derived from ERA5-Land (2 m air temperature, land areas)

This repository provides a global monthly gridded dataset that parameterises the climatological diurnal cycle of 2 m air temperature over land using ERA5-Land. For each land grid cell and calendar month, a dual-harmonic representation (24 h and 12 h components) is fitted to the multi-year hourly climatology, yielding parameter fields that describe the mean level, amplitude, and timing of the typical diurnal temperature cycle.

Contents
The archive includes monthly parameter fields and accompanying diagnostics, including:
(1) climatological mean temperature (Tmean);
(2) first harmonic amplitude (A1) and second harmonic amplitude (A2);
(3) first harmonic phase parameter (ϕ₁) and second harmonic phase parameter (ϕ₂);
(4) fitting diagnostics (e.g., RMSE and R²);
(5) quality-control flag(s), if provided.

Data coverage and grid
The dataset covers 1990–2024 and is provided on the native ERA5-Land land grid at 0.1° spatial resolution. Coordinates follow the ERA5-Land convention (latitude, longitude), and parameters are provided for land grid cells only.

File format and variables
The data are distributed as a NetCDF file. Variable definitions, units, and missing-value conventions are documented in the NetCDF metadata.

Provenance
ERA5-Land is a third-party reanalysis product distributed under its own terms. This archive contains derived parameter fields and does not redistribute ERA5-Land hourly data.

Access during peer review
The record is publicly visible and citable via DOI, while file access is restricted during peer review. The files will be made publicly available upon publication.