GB/T 21983-2020Warm winter grades (English PDF)

Foreword

This standard was drafted in accordance with the rules given in GB/T 1.1-2009.

This standard replaces GB/T 21983-2008 "Warm Winter Grade". Compared with GB/T 21983-2008, the main technical The technical changes are as follows.

--- Revised the "Scope" chapter (see Chapter 1, Chapter 1 of the 2008 edition);

---Modified the definitions of "warm winter", "single station warm winter threshold", "winter average temperature" and "climate average" (see Chapter 2, 2008 edition 2.1~2.4);

---Added the terms and definitions of "single station", "area", "warm winter index", "effective site" and "effective grid" (see 2.5, 2.6, 2.8~2.10);

--- Added "Warm Winter Classification" (see 3.1);

---Modified the definition method of regional strong warm winter and national strong warm winter (see 3.2.2.2, 3.3.2.2, 3.2.2 and 3.3.2 of the 2008 edition);

---Added requirements for regional warm winter assessment sites (see 3.2.2.3);

--- Added a description of the coverage of the national warm winter index calculation (see 3.2.3.3);

---Added the regulations for selecting the age of the climatic average of the target year (see Appendix A, A.1);

---Added anomaly calculation formula (see Appendix A, A.4);

---Modified the calculation formulas for the grid spacing and effective grid area of latitude and longitude grid division (see Appendix B, B.1, 2008 edition, 3.3.1.1, 3.3.1.2);

---The calculation method of the National Strong Warm Winter Index has been added (see Appendix B, B.6 and B.7).

1 Scope

This standard specifies the determination method and classification of single station, regional and national warm winter.

This standard is applicable to the monitoring, forecasting, evaluation and service of warm winter.

2 Terms and definitions

The following terms and definitions apply to this document.