GB/T 19721.6-2023The issue of marine forecasts and warnings - Part 6: The issue of sea current forecasts (English PDF)

Foreword

This document was issued on 23 May 2023 by the State Administration for Market Regulation; Standardization Administration of the PRC and takes effect on 1 September 2023.

It is a GB/T standard: recommended rather than compulsory, but it is the text a Chinese reviewer applies when assessing a submission.

It is classified under ICS 07.060, Chinese classification A45.

This document is in accordance with the provisions of GB/T 1.1-2020 "Guidelines for Standardization Work Part 1. Structure and Drafting Rules for Standardization Documents"

drafting.

This document is part 6 of GB/T 19721 "Issuance of Marine Forecasts and Warnings". GB/T 19721 has published the following parts.

--- Part 1. Storm surge warning issued;

--- Part 2. Wave forecast and warning issuance;

--- Part 3. Sea ice forecast and warning issuance;

--- Part 4. Tsunami warning issued;

--- Part 5. Issuance of sea temperature forecast;

--- Part 6. Current forecast release.

Please note that some contents of this document may refer to patents. The issuing agency of this document assumes no responsibility for identifying patents.

This document is proposed by the Ministry of Natural Resources of the People's Republic of China.

This document is under the jurisdiction of the National Marine Standardization Technical Committee (SAC/TC283).

This document was drafted by. National Marine Environment Forecasting Center, North Sea Forecasting and Disaster Reduction Center of Ministry of Natural Resources, East China Sea Forecasting and Disaster Reduction Center of Ministry of Natural Resources

Disaster Center, South China Sea Forecast and Disaster Reduction Center of the Ministry of Natural Resources.

The main drafters of this document. Li Yun, Kuang Xiaodi, Li Jingshi, Wang Zhaoyi, Zhang Miaoyin, Xu Jiangling, Xiao Wenjun, Zhou Shuihua.

Introduction

GB/T 19721 "Issuance of Marine Forecasts and Warnings" aims to guide the issuance of marine forecasts and warnings, establish the forecast and

The principles, contents and technical requirements of alert issuance are proposed to be composed of six parts.

--- Part 1. Storm surge warning issued. The purpose is to stipulate the classification and content requirements of storm surge warnings in coastal areas of our country.

--- Part 2. Wave forecasts and warnings issued. The purpose is to specify the classification and content requirements of wave forecasts and warnings.

--- Part 3. Sea ice forecast and warning issued. The purpose is to define the classification of sea ice forecasts and warnings in the Bohai Sea and the northern part of the Yellow Sea,

content requirements.

--- Part 4. Tsunami warning issued. The purpose is to stipulate the classification and content requirements of tsunami warnings in coastal areas of our country.

--- Part 5. SST forecast release. The purpose is to stipulate the classification and content requirements of SST forecast in my country.

--- Part 6. Current forecast release. The purpose is to stipulate the classification and content requirements of ocean current forecasting in my country.

Ocean current forecasting is one of the basic elements to describe the marine environment.

Production, marine disaster prevention and mitigation, and marine national defense construction are all of great significance. With the development of coastal national economy, coastal provinces, autonomous regions, municipalities directly under the Central Government,

The county (city) ocean forecasting station also successively releases the ocean current forecast for the sea area under its jurisdiction. In order to further improve the protection work of ocean current forecast for marine environment

Therefore, there is an urgent need to formulate unified ocean current forecast release standards to establish the principles of ocean current forecast release and to unify the classification, content and technology of ocean current forecasts.

Require.

This document focuses on the classification of ocean current forecasts, and divides ocean current forecasts into conventional ocean current forecasts, emergency ocean current forecasts, and special ocean current forecasts.

Three aspects, and put forward the relevant forecast content and technical requirements. It can not only guarantee daily maritime activities, but also meet the needs of maritime emergencies.

The release of ocean current forecast products provides a unified framework, which facilitates the standardized production of ocean current forecast products, promotes the effective use of ocean current forecast functions, and makes the ocean current forecast more effective.

Evaluate the risk of marine disasters in our country well and reduce the loss of marine disasters.

Marine Forecasts and Warnings Issued

Part 6. Issuance of Ocean Current Forecast

1 Scope

GB/T 19721.6-2023 is the sixth part of GB/T 19721 and deals with the issuing of ocean current forecasts by marine forecasting agencies. Two clauses carry the substance. The first divides current forecasts into three kinds — the conventional forecast issued on a regular cycle, the emergency forecast, and the special forecast produced for a particular occasion or user — and the second gives the issuing requirements for each of those three in turn. A normative annex holds the table that ties flow direction to degrees. That table is more than housekeeping: a current bulletin is fed straight into the drift and set calculations that operational users make from it, and if one agency states direction in compass points, another gives the bearing the current sets towards, and a third gives the bearing it comes from, the drift track computed from the bulletin points the wrong way at the moment it matters most. Terms follow GB/T 15920-2010 and GB/T 39628-2020. Written for the marine forecasting agencies that issue the bulletins and for the maritime safety, offshore and environmental response users who act on them.

This document specifies the classification of ocean current forecasts and the requirements for issuing forecasts.

This document is suitable for use by marine forecasting agencies when conducting ocean current forecasting services.

2 Normative references

The contents of the following documents constitute the essential provisions of this document through normative references in the text. Among them, dated references

For documents, only the version corresponding to the date is applicable to this document; for undated reference documents, the latest version (including all amendments) is applicable to

this document.

GB/T 15920-2010 Oceanographic Terminology Physical Oceanography

GB/T 39628-2020 Marine Forecast Terminology

3 Terms and Definitions

The following terms and definitions defined in GB/T 15920-2010 and GB/T 39628-2020 apply to this document.

3.1

ocean current

Macro flow of sea water.

Note. Ocean currents are characterized by velocity and direction.

[Source. GB/T 15920-2010, 2.3.1]

3.2

flow to currentdirection

The direction the sea is going.

Note. The unit of flow direction is degree (°), true north is zero, and measured clockwise.

[Source. GB/T 15920-2010, 2.3.2]

3.3

flow ratecurrentspeed

The distance traveled by seawater in unit time.

[Source. GB/T 15920-2010, 2.3.3, modified]

3.4

ocean current forecast

A marine forecast issued for a specific area and timeliness, including information on the flow of seawater, its direction, and velocity.

[Source. GB/T 39628-2020, 4.1.4]

3.5

surface current surface current

The upper boundary is the average current with a certain thickness on the free sea surface.