MODIS/Aqua Clouds 5-Min L2 Swath 1km and 5km - NRT

The level-2 MODIS cloud product consists of cloud optical and physical parameters. These parameters are derived using remotely sensed infrared, visible and near infrared solar reflected radiances. MODIS infrared channel radiances are used to derive cloud top temperature, cloud top height, effective emissivity, cloud phase (ice vs. water, opaque vs. non-opaque), and cloud fraction under both daytime and nighttime conditions. MODIS visible radiances are used to derive cloud optical thickness and effective particle radius and cloud shadow effects. Near infrared solar reflected radiance provides additional information in the retrieval of cloud particle phase (ice vs. water, clouds vs. snow). The shortname for this level-2 MODIS cloud product is MYD06_L2. MYD06_L2 consists of parameters at a spatial resolution of either 1- km or 5-km (at nadir). Each MYD06_L2 product file covers a five-minute time interval. This means that for 5-km resolution parameters, the output grid is 270 pixels in width by 406 pixels in length.

C6.1 changes for the cloud optical property retrievals are low-impact, and are limited primarily
to ancillary product usage, the Quality Assurance (QA), and handling of cloud top (CT) properties
fill values; no updates to retrieval science are implemented.

For more information about the MODIS Cloud product, visit the MODIS-Atmosphere site at:

https://modis-atmos.gsfc.nasa.gov/products/cloud

For more details regarding dataset changes read the document at https://modis-atmos.gsfc.nasa.gov/documentation/collection-61

二级 MODIS 云产品包含了云的光学和物理参数。这些参数通过遥感获取的红外、可见光和近红外太阳反射辐射率进行推导。MODIS 红外通道辐射率被用于推导云顶温度、云顶高度、有效发射率、云相（冰与水、不透明与半透明）以及昼夜条件下的云量。MODIS 可见辐射率被用于推导云光学厚度、有效粒子半径和云阴影效应。近红外太阳反射辐射率在云粒子相（冰与水、云与雪）的检索中提供了额外信息。该二级 MODIS 云产品的简称是 MYD06_L2。MYD06_L2 包含了空间分辨率为 1 公里或 5 公里（正下方）的参数。每个 MYD06_L2 产品文件覆盖五分钟的时间间隔。这意味着对于 5 公里分辨率的参数，输出网格的宽度为 270 像素，长度为 406 像素。

C6.1 版本对云光学性质检索的变更影响轻微，主要限于辅助产品使用、质量保证（QA）以及云顶（CT）属性填充值的处理；未实施检索科学的更新。

如需了解更多关于 MODIS 云产品信息，请访问 MODIS-大气网站：

https://modis-atmos.gsfc.nasa.gov/products/cloud

如需了解数据集变更的详细信息，请阅读文档：

https://modis-atmos.gsfc.nasa.gov/documentation/collection-61

搜集汇总

背景与挑战

背景概述

该数据集是MODIS/Aqua卫星的二级云产品，提供5分钟时间间隔、1km和5km空间分辨率的近实时数据，包含云顶温度、高度、光学厚度等多种云光学和物理参数，通过红外、可见光和近红外辐射反演，适用于全天候监测。版本更新C6.1主要优化辅助产品使用和质量保证，未更改反演科学核心。