ICON-NWP simulations of the mid-Holocene West African Monsoon using parameterized and explicit convection and mid-Holocene land surface

The experiment aims to investigate how the representation of convection influences the West African Monsoon during the mid-Holocene.
Atmospheric and SST input data originate from the MPI-ESM Holocene simulations reflecting Holocene condition.
External Parameters (surface condition) were adjusted to reflect mid-Holocene vegetation conditions. We prescribe an idealized, denser vegetation cover based on the simulated desert fraction (1-vegetation fraction) of the transient mid-Holocene MPI-ESM simulations (Dallmeyer et al., 2020).

We use the ICON (ICOsahedral Nonhydrostatic) model framework version 2.5.0 (see Zängl et al. (2014) for more details).

The provided data covers one simulation from June to October (JJASO) for the year 7024 before present (BP) with the year 2000 as the reference year.

The time axes of the NetCDF files reflect the model year which is based on the time axes of the MPI-ESM slo0021a Holocene simulations. The artificial model year 1001 in slo0021a refers to the year 8000 BP. Therefore, the model year 1978 refers to the year 7024 BP.

The experiment compares a 5km horizontal resolution, deep convection resolving simulation with a 40km-horizontal resolution, parameterized convection simulation.

The 40km-domain (DOM01) covers a range from 70.5°W - 99.5°E; 49°S - 59°N
The 5km-domain (DOM04) covers a range from 37°W - 53°E; 0°N - 40°N

The dataset provides daily mean values on the triangular ICON grid.

The datasets provide atmospheric (_atm_ 3D), surface (_sfc_ 2D) and precipitation ( _prec_ 2D) and forcing (extpar_) data and the following variables:
w_so, lhfl_s, shfl_s, runoff_s, runoff_g, rain_con_rate, rain_gsp_rate, geopot, temp, rh, qv, u, v, w, clc

Precipitation and forcing data are combined into 2 data files for DOM01 and DOM04. Surface data are combined into 2 data files for DOM01.
The dataset with the suffix "_constSM_sep_" contains the data for the constant soil moisture simulations. In these simulations we prescribe the same constant soil moisture field, representing 1st September-soil moisture conditions, both for the 40km-P (DOM01) and the 5km-E (DOM04) simulations.

The DS ("Dry Sahara") simulations refer to the simulations where we prescribe present-day land surface cover - the Sahara remains a desert.
The GS ("Green Sahara") simulations represent idealized mid-Holocene conditions where we prescribe a higher vegetation cover that also extend further north. The Sahara reflects more savannah-like vegetation.

本研究旨在探讨对流表征如何影响中全新世的西非季风。大气和海表温度输入数据源自 MPI-ESM 对全新世的模拟，反映全新世的气候条件。外部参数（地表条件）经过调整，以反映中全新世植被条件。本研究基于中全新世 MPI-ESM 模拟的瞬态模拟中沙漠分数（1-植被分数）的理想化、密度更高的植被覆盖层（Dallmeyer 等人，2020年）。

我们使用的是 ICON（等边非静力）模型框架的 2.5.0 版本（详情参见 Zängl 等人，2014年）。

提供的数据涵盖了公元前7024年（BP）6月至10月（JJASO）期间的模拟结果，以2000年为参照年份。NetCDF文件的时间轴反映了模型年份，该年份基于 MPI-ESM slo0021a 全新世模拟的时间轴。slo0021a 中的虚拟模型年份1001对应公元前8000年。因此，模型年份1978对应公元前7024年。

实验对比了5公里水平分辨率的深对流解析模拟和40公里水平分辨率的参数化对流模拟。

40公里域（DOM01）覆盖范围从西经70.5°至东经99.5°；南纬49°至北纬59°。

5公里域（DOM04）覆盖范围从西经37°至东经53°；赤道至北纬40°。

数据集提供了三角形 ICON 格网的每日平均值。

数据集提供了大气（_atm_ 3D）、地表（_sfc_ 2D）和降水（_prec_ 2D）以及强迫（extpar_）数据，以及以下变量：w_so, lhfl_s, shfl_s, runoff_s, runoff_g, rain_con_rate, rain_gsp_rate, geopot, temp, rh, qv, u, v, w, clc。

降水和强迫数据合并为两个数据文件，分别针对 DOM01 和 DOM04。地表数据合并为两个数据文件，针对 DOM01。

以“_constSM_sep_”后缀的数据集包含恒定土壤湿度模拟的数据。在这些模拟中，我们指定相同的恒定土壤湿度场，代表9月1日的土壤湿度条件，既适用于40公里-P（DOM01）模拟，也适用于5公里-E（DOM04）模拟。

DS（“干旱撒哈拉”）模拟指的是我们指定了当今陆地地表覆盖的模拟——撒哈拉仍然是一个沙漠。GS（“绿色撒哈拉”）模拟代表理想化的中全新世条件，其中我们指定了更高的植被覆盖，并向北延伸。撒哈拉反映了更多类似草原的植被。